101
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Abstract
Domino reactions involving nickel-catalyzed additions of (hetero)arylboronic acids to alkynes, followed by cyclization of the alkenylnickel intermediates onto tethered acyclic ketones to give chiral tertiary-alcohol-containing products in high enantioselectivities, are described. The reversible E/Z isomerization of the alkenylnickel intermediates enables overall anti-arylmetallative cyclization to occur. The ring system of the products are substructures of certain diarylindolizidine alkaloids.
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Affiliation(s)
- Harley Green
- The GlaxoSmithKline Carbon Neutral Laboratories for, Sustainable ChemistryUniversity of NottinghamJubilee Campus, Triumph RoadNottinghamNG7 2TUUK
- School of ChemistryUniversity of NottinghamUniversity ParkNottinghamNG7 2RDUK
| | - Stephen P. Argent
- School of ChemistryUniversity of NottinghamUniversity ParkNottinghamNG7 2RDUK
| | - Hon Wai Lam
- The GlaxoSmithKline Carbon Neutral Laboratories for, Sustainable ChemistryUniversity of NottinghamJubilee Campus, Triumph RoadNottinghamNG7 2TUUK
- School of ChemistryUniversity of NottinghamUniversity ParkNottinghamNG7 2RDUK
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102
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Woof CR, Durand DJ, Fey N, Richards E, Webster RL. Iron Catalyzed Double Bond Isomerization: Evidence for an Fe I /Fe III Catalytic Cycle. Chemistry 2021; 27:5972-5977. [PMID: 33492679 PMCID: PMC8048803 DOI: 10.1002/chem.202004980] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 01/19/2021] [Indexed: 12/21/2022]
Abstract
Iron-catalyzed isomerization of alkenes is reported using an iron(II) β-diketiminate pre-catalyst. The reaction proceeds with a catalytic amount of a hydride source, such as pinacol borane (HBpin) or ammonia borane (H3 N⋅BH3 ). Reactivity with both allyl arenes and aliphatic alkenes has been studied. The catalytic mechanism was investigated by a variety of means, including deuteration studies, Density Functional Theory (DFT) and Electron Paramagnetic Resonance (EPR) spectroscopy. The data obtained support a pre-catalyst activation step that gives access to an η2 -coordinated alkene FeI complex, followed by oxidative addition of the alkene to give an FeIII intermediate, which then undergoes reductive elimination to allow release of the isomerization product.
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Affiliation(s)
- Callum R. Woof
- School of ChemistryUniversity of BathClaverton DownBathBA2 7AYUK
| | - Derek J. Durand
- School of ChemistryUniversity of BristolCantock's CloseBristolBS8 1TSUK
| | - Natalie Fey
- School of ChemistryUniversity of BristolCantock's CloseBristolBS8 1TSUK
| | - Emma Richards
- School of ChemistryCardiff UniversityMain Building, Park PlaceCardiffCF10 3ATUK
| | - Ruth L. Webster
- School of ChemistryUniversity of BathClaverton DownBathBA2 7AYUK
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103
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Zanakhov TO, Galenko EE, Kryukova MA, Novikov MS, Khlebnikov AA. Isomerization of 5-(2 H-Azirin-2-yl)oxazoles: An Atom-Economic Approach to 4 H-Pyrrolo[2,3- d]oxazoles. Molecules 2021; 26:molecules26071881. [PMID: 33810476 PMCID: PMC8036974 DOI: 10.3390/molecules26071881] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Revised: 03/19/2021] [Accepted: 03/23/2021] [Indexed: 11/16/2022] Open
Abstract
An atom economical method for the preparation of variously substituted 4H-pyrrolo[2,3-d]oxazoles was developed on the basis of thermal isomerization of 5-(2H-azirin-2-yl)oxazoles. The latter were prepared by Rh2(oct)4 catalyzed reaction of 2-(3-aryl/heteroaryl)-2-diazoacetyl-2H-azirines with a set of substituted acetonitriles, benzonitriles, acrylonitrile and fumaronitrile. According to DFT calculations the transformation of 5-(2H-azirin-2-yl)oxazole to 4H-pyrrolo[2,3-d]oxazole occurs through the nitrenoid-like transition state to give a 3aH-pyrrolo[2,3-d]oxazole intermediate, followed by 1,5-H-shift.
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104
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Honda M, Murakami K, Osawa Y, Kawashima Y, Hirasawa K, Kuroda I. Z-Isomers of Astaxanthin Exhibit Greater Bioavailability and Tissue Accumulation Efficiency than the All- E-Isomer. J Agric Food Chem 2021; 69:3489-3495. [PMID: 33689342 DOI: 10.1021/acs.jafc.1c00087] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The purpose of the present study was to clarify the differences in the bioavailability and tissue accumulation efficiency between (all-E)- and (Z)-astaxanthin. Astaxanthin with a high proportion of the Z-isomer (especially rich in the 9Z- and 13Z-isomers) was prepared from (all-E)-astaxanthin by thermal treatment and solid-liquid separation. The all-E-isomer- or Z-isomer-rich diet was fed to male rats for 2 weeks. After the feeding period, blood and tissue samples were collected, and their astaxanthin levels were evaluated. The Z-isomer-rich astaxanthin diet resulted in higher levels of astaxanthin in blood and many tissues (in particular, skin, lung, prostate, and eye) compared to the all-E-isomer-rich diet. Moreover, the Z-isomer-rich diet enhanced the level of the 13Z-isomer in blood and tissues rather than that of the 9Z-isomer. These results strongly supported that astaxanthin Z-isomers have greater bioavailability and tissue accumulation efficiency than the all-E-isomer. Moreover, (13Z)-astaxanthin would have higher bioavailability and tissue accumulation than the other isomers.
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Affiliation(s)
- Masaki Honda
- Department of Chemistry, Faculty of Science & Technology, Meijo University, Shiogamaguchi, Tempaku-ku, Nagoya 468-8502, Japan
| | - Kazuya Murakami
- Department of Chemistry, Faculty of Science & Technology, Meijo University, Shiogamaguchi, Tempaku-ku, Nagoya 468-8502, Japan
- Department of Materials Process Engineering, Nagoya University, Nagoya, Aichi 464-8603, Japan
| | - Yukiko Osawa
- Biotechnology R&D Group, ENEOS Corporation, Chidoricho, Naka-ku, Yokohama 231-0815, Japan
| | - Yuki Kawashima
- Biotechnology R&D Group, ENEOS Corporation, Chidoricho, Naka-ku, Yokohama 231-0815, Japan
| | - Kazuaki Hirasawa
- Biotechnology R&D Group, ENEOS Corporation, Chidoricho, Naka-ku, Yokohama 231-0815, Japan
| | - Ikuo Kuroda
- Biotechnology R&D Group, ENEOS Corporation, Chidoricho, Naka-ku, Yokohama 231-0815, Japan
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105
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Mukherjee S, Perez KA, Lago LC, Klatt S, McLean CA, Birchall IE, Barnham KJ, Masters CL, Roberts BR. Quantification of N-terminal amyloid-β isoforms reveals isomers are the most abundant form of the amyloid-β peptide in sporadic Alzheimer's disease. Brain Commun 2021; 3:fcab028. [PMID: 33928245 PMCID: PMC8062259 DOI: 10.1093/braincomms/fcab028] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 01/09/2021] [Accepted: 01/15/2021] [Indexed: 12/30/2022] Open
Abstract
Plaques that characterize Alzheimer’s disease accumulate over 20 years as a result of decreased clearance of amyloid-β peptides. Such long-lived peptides are subjected to multiple post-translational modifications, in particular isomerization. Using liquid chromatography ion mobility separations mass spectrometry, we characterized the most common isomerized amyloid-β peptides present in the temporal cortex of sporadic Alzheimer’s disease brains. Quantitative assessment of amyloid-β N-terminus revealed that > 80% of aspartates (Asp-1 and Asp-7) in the N-terminus was isomerized, making isomerization the most dominant post-translational modification of amyloid-β in Alzheimer’s disease brain. Total amyloid-β1–15 was ∼85% isomerized at Asp-1 and/or Asp-7 residues, with only 15% unmodified amyloid-β1–15 left in Alzheimer’s disease. While amyloid-β4–15 the next most abundant N-terminus found in Alzheimer’s disease brain, was only ∼50% isomerized at Asp-7 in Alzheimer’s disease. Further investigations into different biochemically defined amyloid-β-pools indicated a distinct pattern of accumulation of extensively isomerized amyloid-β in the insoluble fibrillar plaque and membrane-associated pools, while the extent of isomerization was lower in peripheral membrane/vesicular and soluble pools. This pattern correlated with the accumulation of aggregation-prone amyloid-β42 in Alzheimer’s disease brains. Isomerization significantly alters the structure of the amyloid-β peptide, which not only has implications for its degradation, but also for oligomer assembly, and the binding of therapeutic antibodies that directly target the N-terminus, where these modifications are located.
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Affiliation(s)
- Soumya Mukherjee
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Keyla A Perez
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Larissa C Lago
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Stephan Klatt
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Catriona A McLean
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, VIC 3010, Australia.,Department of Anatomical Pathology, Alfred Hospital, Prahran, VIC 3004, Australia
| | - Ian E Birchall
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Kevin J Barnham
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Colin L Masters
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Blaine R Roberts
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, VIC 3010, Australia.,Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA.,Department of Neurology, Emory University School of Medicine, Atlanta, GA 30322, USA
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106
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Xie F, Seifert NA, Hazrah AS, Jäger W, Xu Y. Conformational Landscape, Chirality Recognition and Chiral Analyses: Rotational Spectroscopy of Tetrahydro-2-Furoic Acid⋅⋅⋅Propylene Oxide Conformers. Chemphyschem 2021; 22:455-460. [PMID: 33453085 DOI: 10.1002/cphc.202000995] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 12/31/2020] [Indexed: 11/05/2022]
Abstract
A chiral adduct formed between a chiral carboxylic acid, tetrahydro-2-furoic acid (THFA), and a chiral ester, propylene oxide (PO), was investigated using rotational spectroscopy and DFT calculations. Isolated THFA exists dominantly as three different conformers: I, II, and III in a jet, with I and II taking on the trans-COOH configuration and III having the cis-COOH configuration. We utilized CREST, a conformational ensemble space exploration tool, to identify the possible conformations of the binary adduct, THFA⋅⋅⋅PO. Subsequent DFT geometry optimizations predicted about two hundred homochiral and heterochiral binary structures with 28 low energy structures within an energy window of 15 kJ mol-1 . A rich broadband rotational spectrum was obtained with a mixture of trace amounts of THFA+PO in neon in a supersonic jet expansion. Six THFA⋅⋅⋅PO conformers were identified experimentally. Kinetically favored binary products which contain trans-COOH I dominate among the observed conformers, while thermodynamically more stable adducts were also detected. Detailed analyses of the structures of the observed conformers show interesting chirality-controlled structural preferences. Such non-covalently bound chiral contact pairs are the foundation of chiral-tag rotational spectroscopy, an exciting new analytical application of rotational spectroscopy for determination of enantiomeric excess. Enantiomeric excess analyses were performed and the results are discussed.
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Affiliation(s)
- Fan Xie
- Department of Chemistry, University of Alberta Edmonton, Alberta, T6G 2G2, Canada
| | - Nathan A Seifert
- Current address: Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, IL 60439, USA
| | - Arsh S Hazrah
- Department of Chemistry, University of Alberta Edmonton, Alberta, T6G 2G2, Canada
| | - Wolfgang Jäger
- Department of Chemistry, University of Alberta Edmonton, Alberta, T6G 2G2, Canada
| | - Yunjie Xu
- Department of Chemistry, University of Alberta Edmonton, Alberta, T6G 2G2, Canada
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107
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Furfari SK, Tegner BE, Burnage AL, Doyle LR, Bukvic AJ, Macgregor SA, Weller AS. Selectivity of Rh⋅⋅⋅H-C Binding in a σ-Alkane Complex Controlled by the Secondary Microenvironment in the Solid State. Chemistry 2021; 27:3177-3183. [PMID: 33112000 PMCID: PMC7898853 DOI: 10.1002/chem.202004585] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 10/27/2020] [Indexed: 12/13/2022]
Abstract
Single-crystal to single-crystal solid-state molecular organometallic (SMOM) techniques are used for the synthesis and structural characterization of the σ-alkane complex [Rh(tBu2 PCH2 CH2 CH2 PtBu2 )(η2 ,η2 -C7 H12 )][BArF 4 ] (ArF =3,5-(CF3 )2 C6 H3 ), in which the alkane (norbornane) binds through two exo-C-H⋅⋅⋅Rh interactions. In contrast, the bis-cyclohexyl phosphine analogue shows endo-alkane binding. A comparison of the two systems, supported by periodic DFT calculations, NCI plots and Hirshfeld surface analyses, traces this different regioselectivity to subtle changes in the local microenvironment surrounding the alkane ligand. A tertiary periodic structure supporting a secondary microenvironment that controls binding at the metal site has parallels with enzymes. The new σ-alkane complex is also a catalyst for solid/gas 1-butene isomerization, and catalyst resting states are identified for this.
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Affiliation(s)
| | - Bengt E. Tegner
- Institute of Chemical SciencesHeriot-Watt UniversityEdinburghEH14 4ASUK
| | - Arron L. Burnage
- Institute of Chemical SciencesHeriot-Watt UniversityEdinburghEH14 4ASUK
| | | | - Alexander J. Bukvic
- Department of ChemistryUniversity of YorkYorkYO10 5DDUK
- Department of ChemistryUniversity of OxfordMansfield RoadOxfordOX1 3TAUK
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108
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Zhou X, Mao B, Zhang Z. Synthesis of 2-Oxazolines from Ring Opening Isomerization of 3-Amido-2-Phenyl Azetidines. Molecules 2021; 26:molecules26040857. [PMID: 33562033 PMCID: PMC7914936 DOI: 10.3390/molecules26040857] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Revised: 02/02/2021] [Accepted: 02/03/2021] [Indexed: 12/28/2022] Open
Abstract
Chiral 2-oxazolines are valuable building blocks and famous ligands for asymmetric catalysis. The most common synthesis involves the reaction of an amino alcohol with a carboxylic acid. In this paper, an efficient synthesis of 2-oxazolines has been achieved via the stereospecific isomerization of 3-amido-2-phenyl azetidines. The reactions were studied in the presence of both Brønsted and Lewis acids, and Cu(OTf)2 was found to be the most effective.
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109
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Tong F, Kitagawa D, Bushnak I, Al-Kaysi RO, Bardeen CJ. Light-Powered Autonomous Flagella-Like Motion of Molecular Crystal Microwires. Angew Chem Int Ed Engl 2021; 60:2414-2423. [PMID: 33185017 DOI: 10.1002/anie.202012417] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 11/09/2020] [Indexed: 12/17/2022]
Abstract
The ability to exhibit life-like oscillatory motion fueled by light represents a new capability for stimuli-responsive materials. Although this capability has been demonstrated in soft materials like polymers, it has never been observed in molecular crystals, which are not generally regarded as dynamic objects. In this work, it is shown that molecular crystalline microwires composed of (Z)-2-(3-(anthracen-9-yl)allylidene)malononitrile ((Z)-DVAM) can be continuously actuated when exposed to a combination of ultraviolet and visible light. The photo-induced motion mimics the oscillatory behavior of biological flagella and enables propagation of microwires across a surface and through liquids, with translational speeds up to 7 μm s-1 . This is the first example of molecular crystals that show complex oscillatory behavior under continuous irradiation. A model that relates the rotation of the transition dipole moment between reversible E→Z photoisomerization to the microscopic torque can qualitatively reproduce how the rotational frequency depends on light intensity and polarization.
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Affiliation(s)
- Fei Tong
- Department of Chemistry, University of California, Riverside, 501 Big Springs Road, Riverside, CA, 92521, USA.,Current Address: Key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and Molecular Engineering, Feringa Nobel Prize Scientist Joint Research Center, Frontiers Science Center for Materiobiology and Dynamic Chemistry, Institute of Fine Chemicals, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai, 200237, China
| | - Daichi Kitagawa
- Department of Applied Chemistry, Graduate School of Engineering, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka, 558-8585, Japan
| | - Ibraheem Bushnak
- College of Science and Health Professions, King Saud bin Abdulaziz University for Health Sciences, and, King Abdullah International Medical Research Center, (Nanomedicine), Ministry of National Guard Health Affairs, Riyadh, 11426, Kingdom of Saudi Arabia
| | - Rabih O Al-Kaysi
- College of Science and Health Professions, King Saud bin Abdulaziz University for Health Sciences, and, King Abdullah International Medical Research Center, (Nanomedicine), Ministry of National Guard Health Affairs, Riyadh, 11426, Kingdom of Saudi Arabia
| | - Christopher J Bardeen
- Department of Chemistry, University of California, Riverside, 501 Big Springs Road, Riverside, CA, 92521, USA
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110
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Ohno K, Kishimoto N, Iwamoto T, Satoh H, Watanabe H. High performance global exploration of isomers and isomerization channels on quantum chemical potential energy surface of H 5 C 2 NO 2. J Comput Chem 2021; 42:192-204. [PMID: 33146910 DOI: 10.1002/jcc.26446] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Revised: 10/14/2020] [Accepted: 10/16/2020] [Indexed: 11/07/2022]
Abstract
High performance global exploration of isomers and isomerization channels on the quantum chemical potential energy surface (PES) is performed for H5 C2 NO2 by using the scaled hypersphere search-anharmonic downward distortion following (SHS-ADDF) method. A multi-node operation, NeoGRRM, has achieved high performance exploration calculations for the large system by submitting SHS-ADDF sub-jobs into many cores in parallel and unifying the results of sub-jobs into the total lists of the main-job. Global exploration of equilibrium (EQ) and transition-state structures at the level of B3LYP/6-31G(d) gave 3210 EQs and 23278 TSs. Nine compounds were found in the low energy regions of 0-100 kJ/mol; the lowest energy compound is N-methylcarbamic acid, the second is methyl carbamate, and the third is glycine (the most fundamental amino acid). Interconversion pathways between the conformers of each of the low energy compounds were surveyed. Isomerization channels around glycine were explored in detail. The lowest energy barriers around some of the EQs turned to be negative after zero-point energy corrections. This indicates that those structures cannot exist as independent structures because they spontaneously collapse into more stable structures. The global PES search showed various interesting dissociating channels which indicate synthon reaction pathways in the reverse directions.
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Affiliation(s)
- Koichi Ohno
- Institute for Quantum Chemical Exploration, Tokyo, Japan.,Department of Chemistry, Graduate School of Science, Tohoku University, Sendai, Japan
| | - Naoki Kishimoto
- Department of Chemistry, Graduate School of Science, Tohoku University, Sendai, Japan
| | - Takeaki Iwamoto
- Department of Chemistry, Graduate School of Science, Tohoku University, Sendai, Japan
| | - Hiroko Satoh
- Institute for Quantum Chemical Exploration, Tokyo, Japan.,Department of Chemistry, University of Zurich, Zurich, Switzerland.,Research Organization of Information and Systems (ROIS), Tokyo, Japan
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111
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Jornet-Mollá V, Giménez-Saiz C, Yufit DS, Howard JAK, Romero FM. A Reversible Hydrogen-Bond Isomerization Triggered by an Abrupt Spin Crossover near Room Temperature. Chemistry 2021; 27:740-750. [PMID: 32812653 DOI: 10.1002/chem.202003654] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Indexed: 11/10/2022]
Abstract
The spin crossover salt [Fe(bpp)2 ](isonicNO)2 ⋅ 2.4 H2 O (1⋅2.4 H2 O) (bpp=2,6-bis(pyrazol-3-yl)pyridine; isonicNO=isonicotinate N-oxide anion) exhibits a very abrupt spin crossover at T1/2 =274.4 K. This triggers a supramolecular linkage (H-bond) isomerization that responds reversibly towards light irradiation or temperature change. Isotopic effects in the thermomagnetic behavior reveal the importance of hydrogen bonds in defining the magnetic state. Further, the title compound can be reversibly dehydrated to afford 1, a material that also exhibits spin crossover coupled to H-bond isomerization, leading to strong kinetic effects in the thermomagnetic properties.
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Affiliation(s)
- Verónica Jornet-Mollá
- Instituto de Ciencia Molecular, Universitat de València, P. O. Box 22085, 46071, Valencia, Spain
| | - Carlos Giménez-Saiz
- Instituto de Ciencia Molecular, Universitat de València, P. O. Box 22085, 46071, Valencia, Spain
| | - Dmitry S Yufit
- Department of Chemistry, Durham University, Durham, DH1 3LE, UK
| | | | - Francisco M Romero
- Instituto de Ciencia Molecular, Universitat de València, P. O. Box 22085, 46071, Valencia, Spain
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112
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Pounder A, Ho A, Macleod M, Tam W. Chemistry of Unsymmetrical C1-Substituted Oxabenzonorbornadienes. Curr Org Synth 2021; 18:446-474. [PMID: 33402089 DOI: 10.2174/1570179417666210105121115] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 11/23/2020] [Accepted: 11/30/2020] [Indexed: 11/22/2022]
Abstract
Oxabenzonorbornadiene (OBD) is a useful synthetic intermediate, which can be readily activated by transition metal complexes with great face selectivity due to its dual-faced nature and intrinsic angle strain on the alkene. To date, the understanding of transition-metal catalyzed reactions of OBD itself has burgeoned; however, this has not been the case for unsymmetrical OBDs. Throughout the development of these reactions, the nature of C1-substituent has proven to have a profound effect on both the reactivity and selectivity of the outcome of the reaction. Upon substitution, different modes of reactivity arise, contributing to the possibility of multiple stereo-, regio-, and in extreme cases, constitutional isomers, which can provide unique means of constructing a variety of synthetically useful cyclic frameworks. To maximize selectivity, an understanding of bridgehead substituent effects is crucial. To that end, this review outlines hitherto reported examples of bridgehead substituent effects on the chemistry of unsymmetrical C1-substituted OBDs.
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Affiliation(s)
- Austin Pounder
- Guelph-Waterloo Center for Graduate Work in Chemistry and Biochemistry, Department of Chemistry, University of Guelph, Guelph, Ontario, N1G 2W1, Canada
| | - Angel Ho
- Guelph-Waterloo Center for Graduate Work in Chemistry and Biochemistry, Department of Chemistry, University of Guelph, Guelph, Ontario, N1G 2W1, Canada
| | - Matthew Macleod
- Guelph-Waterloo Center for Graduate Work in Chemistry and Biochemistry, Department of Chemistry, University of Guelph, Guelph, Ontario, N1G 2W1, Canada
| | - William Tam
- Guelph-Waterloo Center for Graduate Work in Chemistry and Biochemistry, Department of Chemistry, University of Guelph, Guelph, Ontario, N1G 2W1, Canada
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113
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Shahbazali E, Billaud EMF, Fard AS, Meuldijk J, Bormans G, Noel T, Hessel V. Photo isomerization of cis-cyclooctene to trans-cyclooctene: Integration of a micro-flow reactor and separation by specific adsorption. AIChE J 2021; 67:e17067. [PMID: 33380744 PMCID: PMC7757390 DOI: 10.1002/aic.17067] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Revised: 08/19/2020] [Accepted: 09/16/2020] [Indexed: 12/11/2022]
Abstract
Liquid-phase adsorption has hardly been established in micro-flow, although this constitutes an industrially vital method for product separation. A micro-flow UV-photo isomerization process converts cis-cyclooctene partly into trans-cyclooctene, leaving an isomeric mixture. Trans-cyclooctene adsorption and thus separation was achieved in a fixed-bed micro-flow reactor, packed with AgNO3/SiO2 powder, while the cis-isomer stays in the flow. The closed-loop recycling-flow has been presented as systemic approach to enrich the trans-cyclooctene from its cis-isomer. In-flow adsorption in recycling-mode has hardly been reported so that a full theoretical study has been conducted. This insight is used to evaluate three process design options to reach an optimum yield of trans-cyclooctene. These differ firstly in the variation of the individual residence times in the reactor and separator, the additional process option of refreshing the adsorption column under use, and the periodicity of the recycle flow.
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Affiliation(s)
- Elnaz Shahbazali
- Department of Chemical Engineering and Chemistry, Micro Flow Chemistry and Process TechnologyEindhoven University of TechnologyEindhovenThe Netherlands
| | - Emilie M. F. Billaud
- Laboratory for Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological SciencesKU LeuvenLeuvenBelgium
| | - Arash Sarhangi Fard
- Materials Technology InstituteEindhoven University of TechnologyEindhovenThe Netherlands
| | - Jan Meuldijk
- Department of Chemical Engineering and Chemistry, Micro Flow Chemistry and Process TechnologyEindhoven University of TechnologyEindhovenThe Netherlands
| | - Guy Bormans
- Laboratory for Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological SciencesKU LeuvenLeuvenBelgium
| | - Timothy Noel
- Department of Chemical Engineering and Chemistry, Micro Flow Chemistry and Process TechnologyEindhoven University of TechnologyEindhovenThe Netherlands
| | - Volker Hessel
- Department of Chemical Engineering and Chemistry, Micro Flow Chemistry and Process TechnologyEindhoven University of TechnologyEindhovenThe Netherlands
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114
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Liu J, Gong H, Zhu S. Nickel-Catalyzed, Regio- and Enantioselective Benzylic Alkenylation of Olefins with Alkenyl Bromide. Angew Chem Int Ed Engl 2020; 60:4060-4064. [PMID: 33171012 DOI: 10.1002/anie.202012614] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 11/01/2020] [Indexed: 12/20/2022]
Abstract
A NiH-catalyzed migratory hydroalkenylation reaction of olefins with alkenyl bromides has been developed, affording benzylic alkenylation products with high yields and excellent chemoselectivity. The mild conditions of the reaction preclude olefinic products from undergoing further isomerization or subsequent alkenylation. Catalytic enantioselective hydroalkenylation of styrenes was achieved by using a chiral bisoxazoline ligand.
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Affiliation(s)
- Jiandong Liu
- School of Materials Science and Engineering, Center for Supramolecular Chemistry and Catalysis, Department of Chemistry, Shanghai University, Shanghai, 200444, China
| | - Hegui Gong
- School of Materials Science and Engineering, Center for Supramolecular Chemistry and Catalysis, Department of Chemistry, Shanghai University, Shanghai, 200444, China
| | - Shaolin Zhu
- State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, China
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115
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Yu B, Perfetto A, Allievi L, Dhambri S, Rager MN, Selkti M, Ciofini I, Lannou MI, Sorin G. Silver(I) Oxide-/DBU-Promoted Synthesis of Dihydrofuran Units through Allenyl Silver Formation. Chemistry 2020; 26:17455-17461. [PMID: 32978998 DOI: 10.1002/chem.202002696] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 09/17/2020] [Indexed: 11/08/2022]
Abstract
A formal [3+2] cyclization mediated by silver(I) oxide and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) is described herein. Through a broad variety of carbonyl compounds, this system can promote cyclization reactions with high yield (up to 85 %) and diastereoselectivity (up to 95:5) for a straightforward access to complex and congested dihydrofuran derivatives in one step under mild conditions. Based on DFT studies, the proposed mechanism would involve an allenyl silver intermediate.
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Affiliation(s)
- Bao Yu
- Faculté des Sciences Pharmaceutiques et Biologiques, Unité CNRS UMR 8038 CiTCoM, Université de Paris Descartes, 4 avenue de l'Observatoire, 75270, Paris Cedex 06, France
| | - Anna Perfetto
- Chimie ParisTech, PSL University, Unité CNRS FRE 2027, Institute of Chemistry for Life and Health Science (i-CLeHS), 11, rue Pierre et Marie Curie, 75005, Paris, France
| | - Luca Allievi
- Faculté des Sciences Pharmaceutiques et Biologiques, Unité CNRS UMR 8038 CiTCoM, Université de Paris Descartes, 4 avenue de l'Observatoire, 75270, Paris Cedex 06, France
| | - Sabrina Dhambri
- Faculté des Sciences Pharmaceutiques et Biologiques, Unité CNRS UMR 8038 CiTCoM, Université de Paris Descartes, 4 avenue de l'Observatoire, 75270, Paris Cedex 06, France
| | - Marie-Noelle Rager
- Chimie ParisTech, PSL University, Unité CNRS FRE 2027, Institute of Chemistry for Life and Health Science (i-CLeHS), 11, rue Pierre et Marie Curie, 75005, Paris, France
| | - Mohamed Selkti
- Faculté des Sciences Pharmaceutiques et Biologiques, Unité CNRS UMR 8038 CiTCoM, Université de Paris Descartes, 4 avenue de l'Observatoire, 75270, Paris Cedex 06, France
| | - Ilaria Ciofini
- Chimie ParisTech, PSL University, Unité CNRS FRE 2027, Institute of Chemistry for Life and Health Science (i-CLeHS), 11, rue Pierre et Marie Curie, 75005, Paris, France
| | - Marie-Isabelle Lannou
- Faculté des Sciences Pharmaceutiques et Biologiques, Unité CNRS UMR 8038 CiTCoM, Université de Paris Descartes, 4 avenue de l'Observatoire, 75270, Paris Cedex 06, France
| | - Geoffroy Sorin
- Faculté des Sciences Pharmaceutiques et Biologiques, Unité CNRS UMR 8038 CiTCoM, Université de Paris Descartes, 4 avenue de l'Observatoire, 75270, Paris Cedex 06, France
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116
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Zhai DD, Xie SJ, Xia Y, Fang HY, Shi ZJ. Silylamido supported dinitrogen heterobimetallic complexes: syntheses and their catalytic ability. Natl Sci Rev 2020; 8:nwaa290. [PMID: 34987834 PMCID: PMC8694672 DOI: 10.1093/nsr/nwaa290] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 11/25/2020] [Accepted: 11/25/2020] [Indexed: 11/13/2022] Open
Abstract
Molybdenum dinitrogen complexes supported by monodentate arylsilylamido ligand, [Ar(Me3Si)N]3MoN2Mg(THF)2[N(SiMe3)Ar] (5) and [Ar(Me3Si)N]3MoN2SiMe3 (6) (Ar = 3,5-Me2C6H3) were synthesized and structurally characterized, and proved to be effective catalysts for the disproportionation of cyclohexadienes and isomerization of terminal alkenes. The 1H NMR spectrum suggested that the bridging nitrogen ligand remains intact during the catalytic reaction, indicating possible catalytic ability of the Mo-N=N motif.
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Affiliation(s)
- Dan-Dan Zhai
- Department of Chemistry, Fudan University, Shanghai 200433, China
| | - Si-Jun Xie
- Department of Chemistry, Fudan University, Shanghai 200433, China
| | - Yi Xia
- Department of Chemistry, Fudan University, Shanghai 200433, China
| | - Hua-Yi Fang
- Department of Chemistry, Fudan University, Shanghai 200433, China
| | - Zhang-Jie Shi
- Department of Chemistry, Fudan University, Shanghai 200433, China
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117
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Li M, Sanz‐Marco A, Martinez‐Erro S, García‐Vázquez V, Mai BK, Fernández‐Gallardo J, Himo F, Martín‐Matute B. Unraveling the Mechanism of the Ir III -Catalyzed Regiospecific Synthesis of α-Chlorocarbonyl Compounds from Allylic Alcohols. Chemistry 2020; 26:14978-14986. [PMID: 32757212 PMCID: PMC7756427 DOI: 10.1002/chem.202002845] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 07/19/2020] [Indexed: 01/02/2023]
Abstract
We have used experimental studies and DFT calculations to investigate the IrIII -catalyzed isomerization of allylic alcohols into carbonyl compounds, and the regiospecific isomerization-chlorination of allylic alcohols into α-chlorinated carbonyl compounds. The mechanism involves a hydride elimination followed by a migratory insertion step that may take place at Cβ but also at Cα with a small energy-barrier difference of 1.8 kcal mol-1 . After a protonation step, calculations show that the final tautomerization can take place both at the Ir center and outside the catalytic cycle. For the isomerization-chlorination reaction, calculations show that the chlorination step takes place outside the cycle with an energy barrier much lower than that for the tautomerization to yield the saturated ketone. All the energies in the proposed mechanism are plausible, and the cycle accounts for the experimental observations.
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Affiliation(s)
- Man Li
- Department of Organic ChemistryStockholm University10691StockholmSweden
| | - Amparo Sanz‐Marco
- Department of Organic ChemistryStockholm University10691StockholmSweden
| | | | | | - Binh Khanh Mai
- Department of Organic ChemistryStockholm University10691StockholmSweden
| | | | - Fahmi Himo
- Department of Organic ChemistryStockholm University10691StockholmSweden
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118
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Sullivan M, Naumkin FY. Highly Polar Insertion Complexes with Focused IR Spectra and Internal Field-Inhibited Isomerization. Chempluschem 2020; 85:2438-2445. [PMID: 33155771 DOI: 10.1002/cplu.202000626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 10/20/2020] [Indexed: 11/08/2022]
Abstract
Complexes of a polar molecule (benzene trioxide) and alkali halide diatoms are predicted to form stable conformers through not only a common attachment, but also trapping the molecule between the counterions. Two possible low- and no-barrier routes of formation of such an insertion complex are identified, and stability and other properties of this and other conformers are analyzed, including polarity and charge distribution. Calculated IR spectra indicate a bright feature specific for the insertion complex, facilitating its reliable experimental detection. Isomerization of the ion-pair-trapped molecule shows a nonobvious inhibition effect (through an increased potential energy barrier) compared to the free molecule due to the reduction of its polarity in the isomerization. Formation of a flatter isomer, trioxonine, is clearly "reported" by a sharp alteration of the IR spectrum, distinguishable also from its variation for the nonreactive relaxation of the insertion complex into an attached one.
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Affiliation(s)
- Mason Sullivan
- Faculty of Science, Ontario Tech University/UOIT, Oshawa, ON, L1G 0C5, Canada
| | - Fedor Y Naumkin
- Faculty of Science, Ontario Tech University/UOIT, Oshawa, ON, L1G 0C5, Canada
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119
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Abstract
The synthesis of a new type of chiral and dynamic nonplanar aromatics containing a combination of fused perylene-based coronenes and helicenes is reported. Either one or two helicene moieties were fused to the bay regions of an extended perylene core. The target compounds contain either identical or two different helicene building blocks. The combination with two helicene units leads to six different isomers, including two pairs of enantiomers and two meso forms. The experimental determination of the isomerization barriers the corresponding double [5]-helicenes revealed activation energies of Ea =24.81 and 25.38 kcal mol-1 , which is slightly above the barrier of the parent [5]-helicene. Resolution of all possible regio- and stereoisomers allowed for the systematic investigation of the chiroptical properties. They revealed remarkable dissymmetry factors Igabs I of up to 1.2×10-2 , which mirror the synergy between the strong absorbing perylenes and the inherent chirality of helicenes.
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Affiliation(s)
- Corinna Weiss
- Department of Chemistry and PharmacyFriedrich-Alexander University Erlangen-NürnbergNikolaus-Fiebiger-Straße 1091058ErlangenGermany
| | - Dmitry I. Sharapa
- Institute of Catalysis Research and TechnologyKarlsruhe Institute of TechnologyHermann-von-Helmholtz-Platz 176344Eggenstein-LeopoldshafenGermany
| | - Andreas Hirsch
- Department of Chemistry and PharmacyFriedrich-Alexander University Erlangen-NürnbergNikolaus-Fiebiger-Straße 1091058ErlangenGermany
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120
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Abstract
The total synthesis of cryptotrione (1) was enabled by substrate-controlled diastereoselective construction of the bicyclo[3.1.0]hexene framework through platinum-catalyzed enyne cycloisomerization and Lewis acid induced polyene cyclization to construct the abietane-type tricyclic diterpene skeleton. The stereogenic tertiary carbon center in the side chain was installed in a diastereodivergent manner by conjugate addition reactions.
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Affiliation(s)
- Mao-Yun Lyu
- Department of Chemistry, State Key Laboratory of Synthetic Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China
| | - Zhuliang Zhong
- Department of Chemistry, State Key Laboratory of Synthetic Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China
| | - Vanessa Kar-Yan Lo
- State Key Laboratory of Synthetic Chemistry and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China
| | - Henry N C Wong
- School of Science and Engineering, The Chinese, University of Hong Kong (Shenzhen), Longgang District, Shenzhen, China.,Department of Chemistry, State Key Laboratory of Synthetic Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China
| | - Xiao-Shui Peng
- School of Science and Engineering, The Chinese, University of Hong Kong (Shenzhen), Longgang District, Shenzhen, China.,Department of Chemistry, State Key Laboratory of Synthetic Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China
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121
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Feng Y, Hua X, Shen Q, Matthews M, Zhang Y, Fisher AJ, Lyu X, Yang R. Insight into the potential factors influencing the catalytic direction in cellobiose 2-epimerase by crystallization and mutagenesis. Acta Crystallogr D Struct Biol 2020; 76:1104-1113. [PMID: 33135681 DOI: 10.1107/s205979832001222x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 09/03/2020] [Indexed: 11/10/2022]
Abstract
Cellobiose 2-epimerase (CE) is commonly recognized as an epimerase as most CEs mainly exhibit an epimerization activity towards disaccharides. In recent years, several CEs have been found to possess bifunctional epimerization and isomerization activities. They can convert lactose into lactulose, a high-value disaccharide that is widely used in the food and pharmaceutical industries. However, the factors that determine the catalytic direction in CEs are still not clear. In this study, the crystal structures of three newly discovered CEs, CsCE (a bifunctional CE from Caldicellulosiruptor saccharolyticus), StCE (a bifunctional CE from Spirochaeta thermophila DSM 6578) and BtCE (a monofunctional CE from Bacillus thermoamylovorans B4166), were determined at 1.54, 2.05 and 1.80 Å resolution, respectively, in order to search for structural clues to their monofunctional/bifunctional properties. A comparative analysis of the hydrogen-bond networks in the active pockets of diverse CEs, YihS and mannose isomerase suggested that the histidine corresponding to His188 in CsCE is uniquely required to catalyse isomerization. By alignment of the apo and ligand-bound structures of diverse CEs, it was found that bifunctional CEs tend to have more flexible loops and a larger entrance around the active site, and that the flexible loop 148-181 in CsCE displays obvious conformational changes during ligand binding. It was speculated that the reconstructed molecular interactions of the flexible loop during ligand binding helped to motivate the ligands to stretch in a manner beneficial for isomerization. Further site-directed mutagenesis analysis of the flexible loop in CsCE indicated that the residue composition of the flexible loop did not greatly impact epimerization but affects isomerization. In particular, V177D and I178D mutants showed a 50% and 80% increase in isomerization activity over the wild type. This study provides new information about the structural characteristics involved in the catalytic properties of CEs, which can be used to guide future molecular modifications.
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Affiliation(s)
- Yinghui Feng
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, People's Republic of China
| | - Xiao Hua
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, People's Republic of China
| | - Qiuyun Shen
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, People's Republic of China
| | - Melissa Matthews
- Department of Molecular and Cellular Biology, University of California Davis, Davis, CA 95616, USA
| | - Yuzhu Zhang
- Western Regional Research Center, Agricultural Research Service, United States Department of Agriculture, Albany, CA 94710, USA
| | - Andrew J Fisher
- Department of Molecular and Cellular Biology, University of California Davis, Davis, CA 95616, USA
| | - Xiaomei Lyu
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, People's Republic of China
| | - Ruijin Yang
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, People's Republic of China
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122
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Köttner L, Schildhauer M, Wiedbrauk S, Mayer P, Dube H. Oxidized Hemithioindigo Photoswitches-Influence of Oxidation State on (Photo)physical and Photochemical Properties. Chemistry 2020; 26:10712-10718. [PMID: 32485011 PMCID: PMC7496871 DOI: 10.1002/chem.202002176] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Revised: 05/28/2020] [Indexed: 11/05/2022]
Abstract
The photophysical and photochemical properties of sulfoxide and sulfone derivatives of hemithioindigo photoswitches are scrutinized and compared to the unoxidized parent chromophores. Oxidation results in significantly blue-shifted absorptions and mostly reduction of photochromism while thermal stabilities of individual isomers remain largely unaltered. Effective photoswitching takes place at shorter wavelengths compared to parent hemithioindigos and high isomeric yields can be obtained reversibly in the respective photostationary states. Reversible solid-state photoswitching is observed for a twisted sulfone derivative accompanied by visible color changes. These results establish oxidized hemithioindigo photoswitches as promising and versatile tools for robust light-control of molecular behavior for a wide range of applications.
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Affiliation(s)
- Laura Köttner
- Department of Chemistry and Center for Integrated Protein Science CIPSMLudwig-Maximilians-Universität MünchenButenandtstr. 5–1381377München
| | - Monika Schildhauer
- Department of Chemistry and Center for Integrated Protein Science CIPSMLudwig-Maximilians-Universität MünchenButenandtstr. 5–1381377München
| | - Sandra Wiedbrauk
- Department of Chemistry and Center for Integrated Protein Science CIPSMLudwig-Maximilians-Universität MünchenButenandtstr. 5–1381377München
| | - Peter Mayer
- Department of Chemistry and Center for Integrated Protein Science CIPSMLudwig-Maximilians-Universität MünchenButenandtstr. 5–1381377München
| | - Henry Dube
- Department of Chemistry and Center for Integrated Protein Science CIPSMLudwig-Maximilians-Universität MünchenButenandtstr. 5–1381377München
- Department of Chemistry and PharmacyFriedrich-Alexander-Universität Erlangen-NürnbergNikolaus-Fiebiger-Str. 1091058Erlangen
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123
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Ando D, Fujisawa T. Metabolism of esfenvalerate in tomato plants ( Solanum lycopersicum). J Pestic Sci 2020; 45:138-146. [PMID: 32913416 PMCID: PMC7453297 DOI: 10.1584/jpestics.d20-022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Accepted: 06/10/2020] [Indexed: 06/11/2023]
Abstract
The metabolic fate of esfenvalerate (1), 14C-labeled at the chlorophenyl or phenoxyphenyl ring, in tomato plants was investigated by spraying it three times at 15 g/ha. The overall metabolic trend of 1 was similar in foliage and fruit. The applied 1 gradually penetrated into the foliage/fruit, and approximately 30% of the total radioactive residue (TRR) distributed within the plant. The applied radioactivity remained mostly intact on the plant surface, while its degradation proceeded via ester cleavage to produce two corresponding acids derived from the chlorophenyl and phenoxyphenyl moieties, followed by saccharide conjugation at the inner tissues (each <5%TRR). While 1 retained its optical configuration (2S,αS) on the plant surface and in the fruit, a very slight isomerization at the α-cyanobenzyl carbon occurred to form a (2S,αR) isomer in the foliage (≤1%TRR). The isomerization at another asymmetric carbon C2 in the isovaleric acid moiety did not proceed on/in the plant for 1 or its metabolite.
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Affiliation(s)
- Daisuke Ando
- Environmental Health Science Laboratory, Sumitomo Chemical Co., Ltd., 4–2–1 Takarazuka, Hyogo 665–8555, Japan
| | - Takuo Fujisawa
- Environmental Health Science Laboratory, Sumitomo Chemical Co., Ltd., 4–2–1 Takarazuka, Hyogo 665–8555, Japan
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124
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Khattib D, Ishan M, Karmakar S, Kostrhunova H, Brabec V, Gibson D. Oxidation of cis-Diamminediacetato Pt II with Hydrogen Peroxide Can Give Rise to Two Isomeric Pt IV Products. Chemistry 2020; 26:9475-9480. [PMID: 32428256 DOI: 10.1002/chem.202001472] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 05/08/2020] [Indexed: 11/12/2022]
Abstract
The oxidation of cis-[Pt(NH3 )2 (OAc)2 ] with H2 O2 yields a mixture of two isomers: ctc-[Pt(NH3 )2 (OH)2 (OAc)2 ] and ctc-[Pt(NH3 )2 (OH)(OAc)(OH)(OAc)]. Following modification with 4-phenylbutyric (PhB) anhydride, two isomers were separated and characterized; the symmetric ctc-[Pt(NH3 )2 (PhB)2 (OAc)2 ] (1) and the nonsymmetric ctc-[Pt(NH3 )2 (PhB)(OAc)(PhB)(OAc)] (2). They differ in their log P values and despite having similar cellular uptake and similar DNA platination levels, the symmetric ctc-[Pt(NH3 )2 (OH)2 (OAc)2 ] is more than 4-fold more potent than the nonsymmetric isomer in a panel of 4 cancer cell lines.
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Affiliation(s)
- D Khattib
- Institute for Drug Research, School of Pharmacy, The Hebrew University of Jerusalem, Jerusalem, 9112102, Israel
| | - M Ishan
- Institute for Drug Research, School of Pharmacy, The Hebrew University of Jerusalem, Jerusalem, 9112102, Israel
| | - S Karmakar
- Institute for Drug Research, School of Pharmacy, The Hebrew University of Jerusalem, Jerusalem, 9112102, Israel
| | - H Kostrhunova
- Institute of Biophysics, Czech Academy of Sciences, Kralovopolska 135, 61265, Brno, Czech Republic
| | - V Brabec
- Institute of Biophysics, Czech Academy of Sciences, Kralovopolska 135, 61265, Brno, Czech Republic
| | - D Gibson
- Institute for Drug Research, School of Pharmacy, The Hebrew University of Jerusalem, Jerusalem, 9112102, Israel
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125
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Matos JLM, Green SA, Chun Y, Dang VQ, Dushin RG, Richardson P, Chen JS, Piotrowski DW, Paegel BM, Shenvi RA. Cyclo isomerization of Olefins in Water. Angew Chem Int Ed Engl 2020; 59:12998-13003. [PMID: 32285542 DOI: 10.1002/anie.202003948] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Indexed: 11/11/2022]
Abstract
Preparative reactions that occur efficiently under dilute, buffered, aqueous conditions in the presence of biomolecules find application in ligation, peptide synthesis, and polynucleotide synthesis and sequencing. However, the identification of functional groups or reagents that are mutually reactive with one another, but unreactive with biopolymers and water, is challenging. Shown here are cobalt catalysts that react with alkenes under dilute, aqueous, buffered conditions and promote efficient cycloisomerization and formal Friedel-Crafts reactions. The constraining conditions of bioorthogonal chemistry are beneficial for reaction efficiency as superior conversion at low catalyst concentration is obtained and competent rates in dilute conditions are maintained. Efficiency at high dilution in the presence of buffer and nucleobases suggests that these reaction conditions may find broad application.
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Affiliation(s)
- Jeishla L M Matos
- Department of Chemistry, Scripps Research, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Samantha A Green
- Department of Chemistry, Scripps Research, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Yuge Chun
- Department of Chemistry, Scripps Research, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Vuong Q Dang
- Department of Pharmaceutical Sciences, University of California Irvine, 101 Theory, Suite 100, Irvine, CA, 92617, USA
| | - Russell G Dushin
- Pfizer Medicinal Chemistry, Eastern Point Road, Groton, CT, 06340, USA
| | - Paul Richardson
- Pfizer Medicinal Chemistry, 10578 Science Center Drive, San Diego, CA, 92121, USA
| | - Jason S Chen
- Automated Synthesis Facility, Scripps Research, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | | | - Brian M Paegel
- Department of Pharmaceutical Sciences, University of California Irvine, 101 Theory, Suite 100, Irvine, CA, 92617, USA.,Departments of Chemistry & Biomedical Engineering, University of California Irvine, 101 Theory, Suite 100, Irvine, CA, 92617, USA
| | - Ryan A Shenvi
- Department of Chemistry, Scripps Research, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
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126
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Grab HA, Kirsch VC, Sieber SA, Bach T. Total Synthesis of the Cyclic Depsipeptide Vioprolide D via its (Z)-Diastereoisomer. Angew Chem Int Ed Engl 2020; 59:12357-12361. [PMID: 32126146 PMCID: PMC7383572 DOI: 10.1002/anie.202002328] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Indexed: 12/15/2022]
Abstract
The first total synthesis of vioprolide D was accomplished in an overall yield of 2.0 % starting from methyl (2S)-3-benzyloxy-2-hydroxypropanoate (16 steps in the longest linear sequence). The cyclic depsipeptide was assembled from two building blocks of similar size and complexity in a modular, highly convergent approach. Peptide bond formation at the C-terminal dehydrobutyrine amino acid of the northern fragment was possible via its (Z)-diastereoisomer. After macrolactamization and formation of the thiazoline ring, the (Z)-double bond of the dehydrobutyrine unit was isomerized to the (E)-double bond of the natural product. The cytotoxicity of vioprolide D is significantly higher than that of its (Z)-diastereoisomer.
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Affiliation(s)
- Hanusch A. Grab
- Department ChemieTechnische Universität MünchenLichtenbergstrasse 485747GarchingGermany
| | - Volker C. Kirsch
- Department ChemieTechnische Universität MünchenLichtenbergstrasse 485747GarchingGermany
| | - Stephan A. Sieber
- Department ChemieTechnische Universität MünchenLichtenbergstrasse 485747GarchingGermany
| | - Thorsten Bach
- Department ChemieTechnische Universität MünchenLichtenbergstrasse 485747GarchingGermany
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127
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Tieu P, Nguyen V, Shon YS. Proximity Effects of Methyl Group on Ligand Steric Interactions and Colloidal Stability of Palladium Nanoparticles. Front Chem 2020; 8:599. [PMID: 32754577 PMCID: PMC7381309 DOI: 10.3389/fchem.2020.00599] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 06/09/2020] [Indexed: 12/05/2022] Open
Abstract
Metal nanoparticle catalysts functionalized with small, well-defined organic ligands are important because such systems can provide a spatial control in the catalyst-substrate interactions. This article describes the synthesis, stability, and catalytic property evaluations of four different Pd nanoparticles capped with constitutional isomers of pentanethiolate ligands that have either a straight chain or an alkyl chain with one methyl group at different locations (α, β, or γ from the surface-bound sulfur). The structure and composition analyses of Pd nanoparticles confirm that they have similar average core sizes and organic ligand contents. The presence of methyl group at α position is found to lower the capping ability of short ligands and thus make Pd nanoparticles to lose their colloidal stability during the catalytic reactions. The overall activity and selectivity for hydrogenation and isomerization of pentene and allylbenzene derivatives are investigated for each combination of ligand and substrate. Catalysis results indicate that steric interactions between the ligands on the metal catalyst surface and the alkene substrates are a factor in controlling the activity of Pd nanoparticles. In particular, Pd nanoparticles capped with pentanethiolate isomer having a methyl group at α position exhibit poor and inconsistent catalytic activity due to its low colloidal stability. The presence of a methyl group at β position mildly interferes the adsorption of alkene group on the nanoparticle surface resulting in lower conversion yields. Interestingly, a methyl group at γ position only has a minimal effect on the catalytic property of Pd nanoparticles exhibiting similar catalysis results with Pd nanoparticles capped with straight chain pentanethiolate ligands. This indicates the proximity of steric group at the reactive site controls the nanoparticle activity for surface oriented reactions, such as hydrogenation and isomerization of alkenes in addition to their colloidal stability.
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Affiliation(s)
- Peter Tieu
- Department of Chemistry and Biochemistry, California State University, Long Beach, CA, United States
| | - Vincent Nguyen
- Keck Energy and Materials Research Program, California State University, Long Beach, CA, United States
| | - Young-Seok Shon
- Department of Chemistry and Biochemistry, California State University, Long Beach, CA, United States
- Keck Energy and Materials Research Program, California State University, Long Beach, CA, United States
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128
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Guo K, Zhang Z, Li A, Li Y, Huang J, Yang Z. Photoredox-Catalyzed Isomerization of Highly Substituted Allylic Alcohols by C-H Bond Activation. Angew Chem Int Ed Engl 2020; 59:11660-11668. [PMID: 32281730 DOI: 10.1002/anie.202000743] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Indexed: 12/15/2022]
Abstract
Photoredox-catalyzed isomerization of γ-carbonyl-substituted allylic alcohols to their corresponding carbonyl compounds was achieved for the first time by C-H bond activation. This catalytic redox-neutral process resulted in the synthesis of 1,4-dicarbonyl compounds. Notably, allylic alcohols bearing tetrasubstituted olefins can also be transformed into their corresponding carbonyl compounds. Density functional theory calculations show that the carbonyl group at the γ-position of allylic alcohols are beneficial to the formation of their corresponding allylic alcohol radicals with high vertical electron affinity, which contributes to the completion of the photoredox catalytic cycle.
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Affiliation(s)
- Kai Guo
- State Key Laboratory of Chemical Oncogenomics and Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, 518055, P. R. China
| | - Zhongchao Zhang
- State Key Laboratory of Chemical Oncogenomics and Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, 518055, P. R. China
| | - Anding Li
- State Key Laboratory of Chemical Oncogenomics and Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, 518055, P. R. China
| | - Yuanhe Li
- Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education and Beijing National Laboratory for Molecular Science (BNLMS), Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, P. R. China
| | - Jun Huang
- State Key Laboratory of Chemical Oncogenomics and Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, 518055, P. R. China
| | - Zhen Yang
- State Key Laboratory of Chemical Oncogenomics and Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, 518055, P. R. China
- Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education and Beijing National Laboratory for Molecular Science (BNLMS), Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, P. R. China
- Shenzhen Bay laboratory, Shenzhen, 518055, P. R. China
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129
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Abstract
Disulfides are versatile catalysts. They can be photocatalysts, hydrogen atom transfer (HAT) catalysts, cocatalysts, or initiators in photocatalytic reactions. Under photoirradiation, organic disulfides can be easily cleaved into free thiyl radicals (RS•) and can reversibly add to unsaturated multiple bonds to catalyze a variety of functionalization reactions under mild conditions. In photoredox catalysis reactions, an excellent electron transfer ability and excellent radical properties also made these thiyl radicals powerful HAT catalysts. They have increasingly been proven useful in various types of organic photoreactions, such as cyclizations, anti-Markovnikov additions, aromatic olefin carbonylations, isomerizations, etc. They are a class of green, economic, mild, and chemoselective radical catalysts that deserve more attention. The present review highlights the recent progress in the field of disulfide-catalyzed and -cocatalyzed photocatalytic reactions for different reaction types.
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Affiliation(s)
- Yeersen Patehebieke
- School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, China
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130
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Fu J, Zhang X, Liang W, Lei Q, Sun B, He W, Deng G. Direct Gas-Phase Oxidation of Propylene to Acetone in the Presence of H 2 and O 2 over Au/TS-1 Catalyst. Curr Org Synth 2020; 17:685-690. [PMID: 32538729 DOI: 10.2174/1570179417666200615154837] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Revised: 05/21/2020] [Accepted: 05/21/2020] [Indexed: 11/22/2022]
Abstract
A novel process for the preparation of acetone is reported by gas-phase oxidation of propylene in the presence of H2 and O2 with Au supported TS-1 catalyst (Au/TS-1). By elevating the reaction temperature to 280°C, Au/TS-1 catalyzes 11.6% propylene generating acetone with 70.6% selectivity, and 8.2% acetone in onepass yield. Acetone is originated from propylene oxide isomerization, which is mainly attributed to the surface of the Lewis base and high reaction temperature. Furthermore, small Au nanoparticle size promotes the reaction.
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Affiliation(s)
- Jinsong Fu
- Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu, Sichuan 610041, China,University of Chinese Academy of Sciences, Beijing 100049, China,College of Chemistry and Materials Science, Sichuan Normal University. Chengdu 610068, China
| | - Xiaoming Zhang
- Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu, Sichuan 610041, China
| | - Wuyang Liang
- Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu, Sichuan 610041, China,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qian Lei
- Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu, Sichuan 610041, China
| | - Bing Sun
- Sinopec Research Institute of Safety Engineering, Qingdao 266000, China
| | - Wujun He
- Xi’an University of Technology, Xi’an 710048, China
| | - Guowei Deng
- College of Chemistry and Life Science, Sichuan Provincial Key Laboratory for Structural Optimization and Application of Functional Molecules, Chengdu Normal University, Chengdu 611130, China
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131
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Schön F, Greb L, Kaifer E, Himmel HJ. Desymmetrization of Dicationic Diboranes by Isomerization Catalyzed by a Nucleophile. Angew Chem Int Ed Engl 2020; 59:9127-9133. [PMID: 32181953 PMCID: PMC7317786 DOI: 10.1002/anie.202001640] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 03/16/2020] [Indexed: 11/11/2022]
Abstract
Cationic monoboranes exhibit a rich chemistry. By constrast, only a few cationic diboranes are known, that all are symmetrically substituted. In this work, the first unsymmetrically substituted dicationic diboranes, featuring sp2 -sp2 -hybridized boron atoms, are reported. The compounds are formed by intramolecular rearrangement from preceding isomeric symmetrically substituted dicationic diboranes, a process that is catalyzed by nucleophiles. From the temperature-dependence of the isomerization rate, activation parameters for this unprecedented rearrangement are derived. The difference in fluoride ion affinity between the two boron atoms and the bonding situation in these unique unsymmetrical dicationic diboranes are evaluated.
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Affiliation(s)
- Florian Schön
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Lutz Greb
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Elisabeth Kaifer
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Hans-Jörg Himmel
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
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132
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Casella P, Iovine A, Mehariya S, Marino T, Musmarra D, Molino A. Smart Method for Carotenoids Characterization in Haematococcus pluvialis red phase and Evaluation of Astaxanthin Thermal Stability. Antioxidants (Basel) 2020; 9:antiox9050422. [PMID: 32414186 PMCID: PMC7278830 DOI: 10.3390/antiox9050422] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 04/30/2020] [Accepted: 05/01/2020] [Indexed: 02/07/2023] Open
Abstract
Haematococcus pluvialis microalgae is a promising source of astaxanthin, an excellent antioxidant carotenoid. H. pluvialis, as well as other species, could find more extensive applications as healthy food for a variegated carotenoids composition in addition to astaxanthin. Official method has not currently been used for this purpose. The objective of this work was to propose a method to characterize carotenoids in H. pluvialis after the comparison between spectrophotometric and liquid chromatography analysis. In addition, in order to improve the use of astaxanthin in the food industry, thermal stability was investigated. In this context, the effect of temperature at 40-80 °C, over a 16 h storage period was tested on astaxanthin produced by H. pluvialis. A further test was carried out at room temperature (20 °C) for seven days. A decrease in the astaxanthin concentration was observed at all tested temperatures with a decrease >50% of all-trans isomer at 80 °C after 16 h and an increase of 9-cis and 13-cis isomers. In conclusion, the obtained results showed the importance of evaluating the degradation effect of temperature on astaxanthin used as a food additive for a future greater enhancement of this bioproduct in the food field.
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Affiliation(s)
- Patrizia Casella
- ENEA, Italian National Agency for New Technologies, Energy and Sustainable Economic Development, Department of Sustainability—CR Portici. P. Enrico Fermi, 1, 80055 Portici (NA), Italy; (P.C.); (A.I.); (S.M.)
| | - Angela Iovine
- ENEA, Italian National Agency for New Technologies, Energy and Sustainable Economic Development, Department of Sustainability—CR Portici. P. Enrico Fermi, 1, 80055 Portici (NA), Italy; (P.C.); (A.I.); (S.M.)
- Department of Engineering, University of Campania “Luigi Vanvitelli”, Real Casa dell’Annunziata, Via Roma 29, 81031 Aversa (CE), Italy; (T.M.); (D.M.)
| | - Sanjeet Mehariya
- ENEA, Italian National Agency for New Technologies, Energy and Sustainable Economic Development, Department of Sustainability—CR Portici. P. Enrico Fermi, 1, 80055 Portici (NA), Italy; (P.C.); (A.I.); (S.M.)
- Department of Engineering, University of Campania “Luigi Vanvitelli”, Real Casa dell’Annunziata, Via Roma 29, 81031 Aversa (CE), Italy; (T.M.); (D.M.)
| | - Tiziana Marino
- Department of Engineering, University of Campania “Luigi Vanvitelli”, Real Casa dell’Annunziata, Via Roma 29, 81031 Aversa (CE), Italy; (T.M.); (D.M.)
| | - Dino Musmarra
- Department of Engineering, University of Campania “Luigi Vanvitelli”, Real Casa dell’Annunziata, Via Roma 29, 81031 Aversa (CE), Italy; (T.M.); (D.M.)
| | - Antonio Molino
- ENEA, Italian National Agency for New Technologies, Energy and Sustainable Economic Development, Department of Sustainability—CR Portici. P. Enrico Fermi, 1, 80055 Portici (NA), Italy; (P.C.); (A.I.); (S.M.)
- Correspondence: ; Tel.: +39-081-772-3276
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133
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Bagi P, Herbay R, Péczka N, Mucsi Z, Timári I, Keglevich AG. Preparation of 2-phospholene oxides by the isomerization of 3-phospholene oxides. Beilstein J Org Chem 2020; 16:818-832. [PMID: 32395185 PMCID: PMC7189000 DOI: 10.3762/bjoc.16.75] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 03/31/2020] [Indexed: 12/19/2022] Open
Abstract
A series of 1-substituted-3-methyl-2-phospholene oxides was prepared from the corresponding 3-phospholene oxides by double bond rearrangement. The 2-phospholene oxides could be obtained by heating the 3-phospholene oxides in methanesulfonic acid, or via the formation of cyclic chlorophosphonium salts. Whereas mixtures of the 2- and 3-phospholene oxides formed, when the isomerization of 3-phospholene oxides was attempted under thermal conditions, or in the presence of a base. The mechanisms of the various double bond migration pathways were elucidated by quantum chemical calculations.
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Affiliation(s)
- Péter Bagi
- Department of Organic Chemistry and Technology, Budapest University of Technology and Economics, Műegyetem rkp. 3., H-1111 Budapest, Hungary
| | - Réka Herbay
- Department of Organic Chemistry and Technology, Budapest University of Technology and Economics, Műegyetem rkp. 3., H-1111 Budapest, Hungary
| | - Nikolett Péczka
- Department of Organic Chemistry and Technology, Budapest University of Technology and Economics, Műegyetem rkp. 3., H-1111 Budapest, Hungary
| | | | - István Timári
- Department of Inorganic and Analytical Chemistry, University of Debrecen, H-4032 Debrecen, Hungary
| | - And György Keglevich
- Department of Organic Chemistry and Technology, Budapest University of Technology and Economics, Műegyetem rkp. 3., H-1111 Budapest, Hungary
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134
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Cabré A, Rafael S, Sciortino G, Ujaque G, Verdaguer X, Lledós A, Riera A. Catalytic Regioselective Isomerization of 2,2-Disubstituted Oxetanes to Homoallylic Alcohols. Angew Chem Int Ed Engl 2020; 59:7521-7527. [PMID: 31981390 DOI: 10.1002/anie.201915772] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 01/24/2020] [Indexed: 12/27/2022]
Abstract
The selective isomerization of strained heterocyclic compounds is an important tool in organic synthesis. An unprecedented regioselective isomerization of 2,2-disubstituted oxetanes into homoallylic alcohols is described. The use of tris(pentafluorophenyl)borane (B(C6 F5 )3 ), a commercially available Lewis acid was key to obtaining good yields and selectivities since other Lewis acids afforded mixtures of isomers and substantial polymerization. The reaction took place under exceptionally mild reaction conditions and very low catalyst loading (0.5 mol %). DFT calculations disclose the mechanistic features of the isomerization and account for the high selectivity displayed by the B(C6 F5 )3 catalyst. The synthetic applicability of the new reaction is demonstrated by the preparation of γ-chiral alcohols using iridium-catalyzed asymmetric hydrogenation.
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Affiliation(s)
- Albert Cabré
- Institute of Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac 10, 08028, Barcelona, Spain.,Departament de Química Inorgànica i Orgànica, Secció Orgànica, Universitat de Barcelona, Martí i Franquès 1, 08028, Barcelona, Spain
| | - Sergi Rafael
- Departament de Química Inorgànica i Orgànica, Secció Orgànica, Universitat de Barcelona, Martí i Franquès 1, 08028, Barcelona, Spain
| | - Giuseppe Sciortino
- Departament de Química, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, 08193, Barcelona, Spain.,Dipartimento di Chimica e Farmacia, Università di Sassari, Via Vienna 2, 07100, Sassari, Italy
| | - Gregori Ujaque
- Departament de Química, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, 08193, Barcelona, Spain
| | - Xavier Verdaguer
- Institute of Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac 10, 08028, Barcelona, Spain.,Departament de Química Inorgànica i Orgànica, Secció Orgànica, Universitat de Barcelona, Martí i Franquès 1, 08028, Barcelona, Spain
| | - Agustí Lledós
- Departament de Química, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, 08193, Barcelona, Spain
| | - Antoni Riera
- Institute of Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac 10, 08028, Barcelona, Spain.,Departament de Química Inorgànica i Orgànica, Secció Orgànica, Universitat de Barcelona, Martí i Franquès 1, 08028, Barcelona, Spain
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135
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Cohn GM, Liefwalker DF, Langer EM, Sears RC. PIN1 Provides Dynamic Control of MYC in Response to Extrinsic Signals. Front Cell Dev Biol 2020; 8:224. [PMID: 32300594 PMCID: PMC7142217 DOI: 10.3389/fcell.2020.00224] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 03/16/2020] [Indexed: 01/05/2023] Open
Abstract
PIN1 is a phosphorylation-directed member of the peptidyl-prolyl cis/trans isomerase (PPIase) family that facilitates conformational changes in phosphorylated targets such as c-MYC (MYC). Following signaling events that mediate phosphorylation of MYC at Serine 62, PIN1 establishes structurally distinct pools of MYC through its trans-cis and cis-trans isomerization activity at Proline 63. Through these isomerization steps, PIN1 functionally regulates MYC's stability, the molecular timing of its DNA binding and transcriptional activity, and its subnuclear localization. Recently, our group showed that Serine 62 phosphorylated MYC can associate with the inner basket of the nuclear pore (NP) in a PIN1-dependent manner. The poised euchromatin at the NP basket enables rapid cellular response to environmental signals and cell stress, and PIN1-mediated trafficking of MYC calibrates this response. In this perspective, we describe the molecular aspects of PIN1 target recognition and PIN1's function in the context of its temporal and spatial regulation of MYC.
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Affiliation(s)
- Gabriel M Cohn
- Department of Molecular and Medical Genetics, School of Medicine, Oregon Health and Science University, Portland, OR, United States
| | - Daniel F Liefwalker
- Department of Molecular and Medical Genetics, School of Medicine, Oregon Health and Science University, Portland, OR, United States
| | - Ellen M Langer
- Department of Molecular and Medical Genetics, School of Medicine, Oregon Health and Science University, Portland, OR, United States.,Knight Cancer Institute, Oregon Health and Science University, Portland, OR, United States
| | - Rosalie C Sears
- Department of Molecular and Medical Genetics, School of Medicine, Oregon Health and Science University, Portland, OR, United States.,Knight Cancer Institute, Oregon Health and Science University, Portland, OR, United States.,Brenden-Colson Center for Pancreatic Care, Oregon Health and Science University, Portland, OR, United States
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136
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Takata T, Ha S, Koide T, Fujii N. Site-specific rapid deamidation and isomerization in human lens αA-crystallin in vitro. Protein Sci 2020; 29:955-965. [PMID: 31930615 PMCID: PMC7096717 DOI: 10.1002/pro.3821] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 12/27/2019] [Accepted: 12/27/2019] [Indexed: 12/16/2022]
Abstract
Recent studies have suggested that the isomerization/racemization of aspartate residues in proteins increases in aged tissues. One such residue is Asp151 in lens-specific αA-crystallin. Although many isomerization/racemization sites have been reported in various proteins, the factors that lead to those modifications in proteins in vivo remain obscure. Therefore, an in vitro system is needed to assess the mechanisms of modifications of Asp under various conditions. Deamidation of Asn to Asp in proteins occurs more rapidly than isomerization/racemization of Asp, although the reaction passes through the same intermediate in both pathways. Here, therefore, we replaced Asp151 in human lens αA-crystallin with Asn by using site-directed mutagenesis. The recombinant protein was expressed in Escherichia coli and used to investigate the deamidation/isomerization/racemization of Asn151 after incubation at 50°C for various durations and under different pH. After incubation, the mutant αA-crystallin was subjected to enzymatic digestion followed by liquid chromatography-MS/MS to evaluate the ratio of modifications in Asn151-containing peptides. The Asp151Asn αA-crystallin mutant showed rapid deamidation to Asp with the formation of specific Asp isomers. In particular, deamidation increased greatly under basic conditions. By contrast, subunit-subunit interactions between αA-crystallin and αB-crystallin had little effect on the modification of Asn151. Our findings suggest that the Asp151Asn αA-crystallin mutant represents a good in vitro model protein to assess deamidation, isomerization, and the racemization intermediates. Furthermore, our in vitro results show a different trend from in vivo data, implying the presence of specific factors that induce racemization from L-Asp to D-Asp residues in vivo.
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Affiliation(s)
- Takumi Takata
- Kyoto University Institute for Integrated Radiation and Nuclear ScienceOsakaJapan
| | - Seongmin Ha
- Department of ChemistryGraduate School of Science, Kyoto UniversityKyotoJapan
| | | | - Noriko Fujii
- Kyoto University Institute for Integrated Radiation and Nuclear ScienceOsakaJapan
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137
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Uhl E, Mayer P, Dube H. Active and Unidirectional Acceleration of Biaryl Rotation by a Molecular Motor. Angew Chem Int Ed Engl 2020; 59:5730-5737. [PMID: 31943681 PMCID: PMC7154650 DOI: 10.1002/anie.201913798] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 12/09/2019] [Indexed: 12/11/2022]
Abstract
Light-driven molecular motors possess immense potential as central driving units for future nanotechnology. Integration into larger molecular setups and transduction of their mechanical motions represents the current frontier of research. Herein we report on an integrated molecular machine setup allowing the transmission of potential energy from a motor unit onto a remote receiving entity. The setup consists of a motor unit connected covalently to a distant and sterically encumbered biaryl receiver. By action of the motor unit, single-bond rotation of the receiver is strongly accelerated and forced to proceed unidirectionally. The transmitted potential energy is directly measured as the extent to which energy degeneration is lifted in the thermal atropisomerization of this biaryl. Energy degeneracy is reduced by more than 1.5 kcal mol-1 , and rate accelerations of several orders of magnitude in terms of the rate constants are achieved.
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Affiliation(s)
- Edgar Uhl
- Ludwig-Maximilians-Universität MünchenDepartment of Chemistry and Center for Integrated Protein Science CIPSMButenandtstr. 5–1381377MünchenGermany
| | - Peter Mayer
- Ludwig-Maximilians-Universität MünchenDepartment of Chemistry and Center for Integrated Protein Science CIPSMButenandtstr. 5–1381377MünchenGermany
| | - Henry Dube
- Ludwig-Maximilians-Universität MünchenDepartment of Chemistry and Center for Integrated Protein Science CIPSMButenandtstr. 5–1381377MünchenGermany
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138
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He Y, Liu C, Yu L, Zhu S. Ligand-Enabled Nickel-Catalyzed Redox-Relay Migratory Hydroarylation of Alkenes with Arylborons. Angew Chem Int Ed Engl 2020; 59:9186-9191. [PMID: 32141689 DOI: 10.1002/anie.202001742] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 03/04/2020] [Indexed: 12/31/2022]
Abstract
A redox-relay migratory hydroarylation of isomeric mixtures of olefins with arylboronic acids catalyzed by nickel complexes bearing diamine ligands is described. A range of structurally diverse 1,1-diarylalkanes, including those containing a 1,1-diarylated quaternary carbon, were obtained in excellent yields and with high regioselectivity. Preliminary experimental evidence supports the proposed non-dissociated chainwalking of aryl-nickel(II)-hydride species along the alkyl chain of alkenes before selective reductive elimination at a benzylic position. A catalyst loading as low as 0.5 mol % proved to be sufficient in large-scale synthesis while retaining high reactivity, highlighting the practical value of this transformation.
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Affiliation(s)
- Yuli He
- State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, China
| | - Chuang Liu
- School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou, 225002, China
| | - Lei Yu
- School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou, 225002, China
| | - Shaolin Zhu
- State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, China
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139
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Johnson SR, Rikli HG. Aspartic Acid Isomerization Characterized by High Definition Mass Spectrometry Significantly Alters the Bioactivity of a Novel Toxin from Poecilotheria. Toxins (Basel) 2020; 12:E207. [PMID: 32218140 DOI: 10.3390/toxins12040207] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 03/20/2020] [Accepted: 03/23/2020] [Indexed: 11/25/2022] Open
Abstract
Research in toxinology has created a pharmacological paradox. With an estimated 220,000 venomous animals worldwide, the study of peptidyl toxins provides a vast number of effector molecules. However, due to the complexity of the protein-protein interactions, there are fewer than ten venom-derived molecules on the market. Structural characterization and identification of post-translational modifications are essential to develop biological lead structures into pharmaceuticals. Utilizing advancements in mass spectrometry, we have created a high definition approach that fuses conventional high-resolution MS-MS with ion mobility spectrometry (HDMSE) to elucidate these primary structure characteristics. We investigated venom from ten species of “tiger” spider (Genus: Poecilotheria) and discovered they contain isobaric conformers originating from non-enzymatic Asp isomerization. One conformer pair conserved in five of ten species examined, denominated PcaTX-1a and PcaTX-1b, was found to be a 36-residue peptide with a cysteine knot, an amidated C-terminus, and isoAsp33Asp substitution. Although the isomerization of Asp has been implicated in many pathologies, this is the first characterization of Asp isomerization in a toxin and demonstrates the isomerized product’s diminished physiological effects. This study establishes the value of a HDMSE approach to toxin screening and characterization.
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140
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Hu X, Chen LF. Pinning Down the Transcription: A Role for Peptidyl-Prolyl cis-trans Isomerase Pin1 in Gene Expression. Front Cell Dev Biol 2020; 8:179. [PMID: 32266261 PMCID: PMC7100383 DOI: 10.3389/fcell.2020.00179] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Accepted: 03/04/2020] [Indexed: 12/14/2022] Open
Abstract
Pin1 is a peptidyl-prolyl cis-trans isomerase that specifically binds to a phosphorylated serine or threonine residue preceding a proline (pSer/Thr-Pro) motif and catalyzes the cis-trans isomerization of proline imidic peptide bond, resulting in conformational change of its substrates. Pin1 regulates many biological processes and is also involved in the development of human diseases, like cancer and neurological diseases. Many Pin1 substrates are transcription factors and transcription regulators, including RNA polymerase II (RNAPII) and factors associated with transcription initiation, elongation, termination and post-transcription mRNA decay. By changing the stability, subcellular localization, protein-protein or protein-DNA/RNA interactions of these transcription related proteins, Pin1 modulates the transcription of many genes related to cell proliferation, differentiation, apoptosis and immune response. Here, we will discuss how Pin regulates the properties of these transcription relevant factors for effective gene expression and how Pin1-mediated transcription contributes to the diverse pathophysiological functions of Pin1.
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Affiliation(s)
- Xiangming Hu
- Fujian Key Laboratory for Translational Research in Cancer and Neurodegenerative Diseases, Institute for Translational Medicine, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China
| | - Lin-Feng Chen
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL, United States.,Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, United States
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141
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Zhang X, Xu X, Yao X, Wang R, Tang H, Ju X, Li L. Exploring Multifunctional Residues of Ribose-5-phosphate Isomerase B from Ochrobactrum sp. CSL1 Enhancing Isomerization of d-Allose. J Agric Food Chem 2020; 68:3539-3547. [PMID: 32100533 DOI: 10.1021/acs.jafc.9b07855] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Ribose-5-phosphate isomerase B is of great importance for biocatalysis and biosynthesis, but the multifunctional residues in active sites hinder the research efforts. This study employed rational design strategies to locate the key residues of RpiB from Ochrobactrum sp. CSL1 (OsRpiB). A single-mutant S9T of a noncontact residue showed 80% activity improvement toward d-allose. A double-mutant S98H/S134H further increased the activity to 3.6-fold. The mutations were analyzed by kinetics and molecular dynamics analyses, indicating that S9T might enhance the substrate binding and catalysis by inducing a steric effect, and S98H/S134H could strengthen both ring opening and binding of d-allose. Though S98H/S134H showed low temperature stability, its potential was explored by isomerizing d-allose to d-psicose with higher conversion and in less reaction time. The findings of this study were beneficial for illustrating the complex functions of key residues in RpiBs and applying OsRpiB in preparing rare sugars.
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Affiliation(s)
- Xiaofeng Zhang
- School of Chemistry, Biology, and Material Engineering, Suzhou University of Science and Technology, Suzhou 215009, P.R. China
| | - Xinqi Xu
- Fujian Key Laboratory of Marine Enzyme Engineering, Fuzhou University, Fujian 350116, P.R. China
| | - Xuemei Yao
- School of Chemistry, Biology, and Material Engineering, Suzhou University of Science and Technology, Suzhou 215009, P.R. China
| | - Rong Wang
- School of Chemistry, Biology, and Material Engineering, Suzhou University of Science and Technology, Suzhou 215009, P.R. China
| | - Hengtao Tang
- School of Chemistry, Biology, and Material Engineering, Suzhou University of Science and Technology, Suzhou 215009, P.R. China
| | - Xin Ju
- School of Chemistry, Biology, and Material Engineering, Suzhou University of Science and Technology, Suzhou 215009, P.R. China
| | - Liangzhi Li
- School of Chemistry, Biology, and Material Engineering, Suzhou University of Science and Technology, Suzhou 215009, P.R. China
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142
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Heymann T, Schmitz LM, Lange J, Glomb MA. Influence of β-Carotene and Lycopene on Oxidation of Ethyl Linoleate in One- and Disperse-Phased Model Systems. J Agric Food Chem 2020; 68:2747-2756. [PMID: 32028770 DOI: 10.1021/acs.jafc.9b07862] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The induction period (IP) of ethyl linoleate stressed at 60 °C was monitored via the formation of hydroperoxides. The addition of lycopene (1% w/w) increased the IP from 7.0 to 10.0 h to prove the strong antioxidative potential in contrast to β-carotene with pro-oxidative effects (IP: 6.0 h), both showing strong scavenging activity under fast degradation. When peroxidation was induced by singlet oxygen, both carotenoids effectively inhibited the formation of hydroperoxides, with quenching activity only observed at low singlet oxygen concentrations, while scavenging still dominated. Thus, carotenoids did not interact with the introduced singlet oxygen but rather with the radical intermediates of fat oxidation. These experiments were then transferred to lecithin-based micelles more related to biological systems, where singlet oxygen was generated in the outer aqueous phase. Lycopene and β-carotene delayed or inhibited lipid peroxidation depending on concentration. In this setup, β-carotene showed exclusively quenching activity, while lycopene was additionally degraded to about 70%.
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Affiliation(s)
- Thomas Heymann
- Institute of Chemistry-Food Chemistry, Martin-Luther-University Halle-Wittenberg, Kurt-Mothes-Straße 2, D-06120 Halle/Saale, Germany
| | - Lea M Schmitz
- Institute of Chemistry-Food Chemistry, Martin-Luther-University Halle-Wittenberg, Kurt-Mothes-Straße 2, D-06120 Halle/Saale, Germany
| | - Josefine Lange
- Institute of Chemistry-Food Chemistry, Martin-Luther-University Halle-Wittenberg, Kurt-Mothes-Straße 2, D-06120 Halle/Saale, Germany
| | - Marcus A Glomb
- Institute of Chemistry-Food Chemistry, Martin-Luther-University Halle-Wittenberg, Kurt-Mothes-Straße 2, D-06120 Halle/Saale, Germany
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143
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Li H, Chen H, Zhou Y, Huang J, Yi J, Zhao H, Wang W, Jing L. Selective Synthesis of Z-Cinnamyl Ethers and Cinnamyl Alcohols through Visible Light-Promoted Photocatalytic E to Z Isomerization. Chem Asian J 2020; 15:555-559. [PMID: 31901002 DOI: 10.1002/asia.201901778] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Indexed: 12/19/2022]
Abstract
A photocatalytic E to Z isomerization of alkenes using an iridium photosensitizer under mild reaction conditions is disclosed. This method provides scalable and efficient access to Z-cinnamyl ether and allylic alcohol derivatives in high yields with excellent stereoselectivity. Importantly, this method also provides a powerful strategy for the selective synthesis of Z-magnolol and honokiol derivatives possessing potential biological activity.
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Affiliation(s)
- Hengchao Li
- Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province/College of Chemistry & Chemical Engineering, China West Normal University, No. 1 Shi Da Road, Nanchong, 637009, China
| | - Hang Chen
- Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province/College of Chemistry & Chemical Engineering, China West Normal University, No. 1 Shi Da Road, Nanchong, 637009, China
| | - Yang Zhou
- Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province/College of Chemistry & Chemical Engineering, China West Normal University, No. 1 Shi Da Road, Nanchong, 637009, China
| | - Jin Huang
- Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province/College of Chemistry & Chemical Engineering, China West Normal University, No. 1 Shi Da Road, Nanchong, 637009, China
| | - Jundan Yi
- Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province/College of Chemistry & Chemical Engineering, China West Normal University, No. 1 Shi Da Road, Nanchong, 637009, China
| | - Hongcai Zhao
- Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province/College of Chemistry & Chemical Engineering, China West Normal University, No. 1 Shi Da Road, Nanchong, 637009, China
| | - Wei Wang
- Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province/College of Chemistry & Chemical Engineering, China West Normal University, No. 1 Shi Da Road, Nanchong, 637009, China
| | - Linhai Jing
- Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province/College of Chemistry & Chemical Engineering, China West Normal University, No. 1 Shi Da Road, Nanchong, 637009, China
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144
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Zhuo KF, Yu SH, Gong TJ, Fu Y. Regioselective β-Arylation of α-Angelica Lactone through Isomerization/Addition under Mild Conditions. ChemSusChem 2020; 13:693-697. [PMID: 31821717 DOI: 10.1002/cssc.201902761] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Indexed: 06/10/2023]
Abstract
The conversion of biomass-based platform molecules into various high-value chemicals greatly promotes the utilization of renewable biomass resources. Herein, an example of Rh-catalyzed β-arylation of levulinic-acid-derived α-angelica lactone was reported, providing the γ-lactone-structure products with high regioselectivity. Both arylboronic and alkenylboronic acids could be applied in this transformation. This reaction tolerated a variety of synthetically important functional groups. Moreover, the obtained γ-lactone products could be readily converted to high-value products such as 1,4-diols and γ-methoxy-carboxylates.
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Affiliation(s)
- Kai-Feng Zhuo
- Hefei National Laboratory for Physical Sciences at the Microscale, CAS Key Laboratory of Urban Pollutant Conversion, Anhui Province Key Laboratory of Biomass Clean Energy, iChEM, University of Science and Technology of China, Hefei, 230026, P.R. China
| | - Shang-Hai Yu
- Hefei National Laboratory for Physical Sciences at the Microscale, CAS Key Laboratory of Urban Pollutant Conversion, Anhui Province Key Laboratory of Biomass Clean Energy, iChEM, University of Science and Technology of China, Hefei, 230026, P.R. China
| | - Tian-Jun Gong
- Hefei National Laboratory for Physical Sciences at the Microscale, CAS Key Laboratory of Urban Pollutant Conversion, Anhui Province Key Laboratory of Biomass Clean Energy, iChEM, University of Science and Technology of China, Hefei, 230026, P.R. China
| | - Yao Fu
- Hefei National Laboratory for Physical Sciences at the Microscale, CAS Key Laboratory of Urban Pollutant Conversion, Anhui Province Key Laboratory of Biomass Clean Energy, iChEM, University of Science and Technology of China, Hefei, 230026, P.R. China
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145
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Naumkin FY, Wales DJ. Counterion-Trapped-Molecules: From High Polarity and Enriched IR Spectra to Induced Isomerization. Chemphyschem 2020; 21:348-355. [PMID: 31944545 DOI: 10.1002/cphc.201901112] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 12/12/2019] [Indexed: 12/25/2022]
Abstract
We report extensive computational studies of some novel intermolecular systems and their properties. Recombination of alkali-halide counterions separated by a noncovalently trapped hydrocarbon molecule is prevented by significant potential energy barriers, resulting in unusual metastable insertion complexes. These systems are extremely polar, while the inserted molecule is strongly counter-polarized, leading to significant cooperative nonadditivity effects. The compression and electric field produced by the counterions favours isomerization of the trapped molecule via a significant reduction of the barriers to bond rearrangement, in a field-induced mechanochemical process. The predicted IR intensity spectra clearly reflect (1) formation of the insertion complex, rather than simple attachment of alkali halide, and (2) isomerization of the trapped molecule, thus allowing experimental access to these events.
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Affiliation(s)
- Fedor Y Naumkin
- On sabbatical leave from Faculty of Science, UOIT, /Ontario Tech University, Oshawa, L1G 0C5, Canada
| | - David J Wales
- Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW, United Kingdom
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146
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Li X, Zhang L, Wang S, Wu Y. Recent Advances in Aqueous-Phase Catalytic Conversions of Biomass Platform Chemicals Over Heterogeneous Catalysts. Front Chem 2020; 7:948. [PMID: 32117861 PMCID: PMC7018683 DOI: 10.3389/fchem.2019.00948] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 12/31/2019] [Indexed: 11/26/2022] Open
Abstract
A series of biomass-derived platform molecules, such as glucose, furans, levulinic acid, 5-hydroxymethylfurfural, and acetic acids, can be converted into a variety of value-added chemicals through catalytic transformations that include dehydration, hydrogenation, oxidation, isomerization, reforming, ketonization, and aldol condensation over heterogeneous catalysts. Aqueous-phase processing is an important issue and a great challenge for the heterogeneous catalytic conversion of biobased chemicals due to the high water content of the biomass and the formation of water during the transformation process. In this paper, heterogeneous catalysts that are applicable to the aqueous-phase conversion process of biomass platform chemicals, including noble metal catalysts, non-noble metal catalysts, bimetallic catalysts, metal oxides, and zeolite, are introduced, and a comprehensive evaluation of the catalyst performance, including the catalytic activity, stability, and regeneration performance of different kinds of heterogeneous catalysts, are made. Besides, we highlighted the effect of water on heterogeneous catalysts and the deactivation mechanism in the aqueous phase. Beyond this, several catalytic mechanisms of aqueous-phase conversion over heterogeneous catalysts are summarized in order to help understand the reaction process on the surface of catalysts in the aqueous phase, so as to design targeted catalysts. At last, a prospect of biobased chemicals and fuels is forecasted.
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Affiliation(s)
- Xiaoxian Li
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing, China
| | - Lilong Zhang
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing, China
| | - Shanshan Wang
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing, China
| | - Yulong Wu
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing, China.,Laboratory of Advanced Reactor Engineering and Safety of Ministry of Education, Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing, China
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147
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Liu J, Li X, Cai R, Ren Z, Zhang A, Deng F, Chen D. Simultaneous Study of Anti-Ferroptosis and Antioxidant Mechanisms of Butein and ( S)-Butin. Molecules 2020; 25:E674. [PMID: 32033283 PMCID: PMC7036861 DOI: 10.3390/molecules25030674] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 02/04/2020] [Accepted: 02/04/2020] [Indexed: 12/14/2022] Open
Abstract
To elucidate the mechanism of anti-ferroptosis and examine structural optimization in natural phenolics, cellular and chemical assays were performed with 2'-hydroxy chalcone butein and dihydroflavone (S)-butin. C11-BODIPY staining and flow cytometric assays suggest that butein more effectively inhibits ferroptosis in erastin-treated bone marrow-derived mesenchymal stem cells than (S)-butin. Butein also exhibited higher antioxidant percentages than (S)-butin in five antioxidant assays: linoleic acid emulsion assay, Fe3+-reducing antioxidant power assay, Cu2+-reducing antioxidant power assay, 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide radical (PTIO•)-trapping assay, and α,α-diphenyl-β-picrylhydrazyl radical (DPPH•)-trapping assay. Their reaction products with DPPH• were further analyzed using ultra-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UPLC-ESI-Q-TOF-MS). Butein and (S)-butin produced a butein 5,5-dimer (m/z 542, 271, 253, 225, 135, and 91) and a (S)-butin 5',5'-dimer (m/z 542, 389, 269, 253, and 151), respectively. Interestingly, butein forms a cross dimer with (S)-butin (m/z 542, 523, 433, 419, 415, 406, and 375). Therefore, we conclude that butein and (S)-butin exert anti-ferroptotic action via an antioxidant pathway (especially the hydrogen atom transfer pathway). Following this pathway, butein and (S)-butin yield both self-dimers and cross dimers. Butein displays superior antioxidant or anti-ferroptosis action to (S)-butin. This can be attributed the decrease in π-π conjugation in butein due to saturation of its α,β-double bond and loss of its 2'-hydroxy group upon biocatalytical isomerization.
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Affiliation(s)
- Jie Liu
- School of Basic Medical Science, Guangzhou University of Chinese Medicine, Guangzhou 510006, China;
- The Research Center of Basic Integrative Medicine, Guangzhou University of Chinese Medicine, Guangzhou 510006, China
| | - Xican Li
- School of Chinese Herbal Medicine, Guangzhou University of Chinese Medicine, Waihuan East Road No. 232, Guangzhou Higher Education Mega Center, Guangzhou 510006, China; (R.C.); (Z.R.); (A.Z.); (F.D.)
| | - Rongxin Cai
- School of Chinese Herbal Medicine, Guangzhou University of Chinese Medicine, Waihuan East Road No. 232, Guangzhou Higher Education Mega Center, Guangzhou 510006, China; (R.C.); (Z.R.); (A.Z.); (F.D.)
| | - Ziwei Ren
- School of Chinese Herbal Medicine, Guangzhou University of Chinese Medicine, Waihuan East Road No. 232, Guangzhou Higher Education Mega Center, Guangzhou 510006, China; (R.C.); (Z.R.); (A.Z.); (F.D.)
| | - Aizhen Zhang
- School of Chinese Herbal Medicine, Guangzhou University of Chinese Medicine, Waihuan East Road No. 232, Guangzhou Higher Education Mega Center, Guangzhou 510006, China; (R.C.); (Z.R.); (A.Z.); (F.D.)
| | - Fangdan Deng
- School of Chinese Herbal Medicine, Guangzhou University of Chinese Medicine, Waihuan East Road No. 232, Guangzhou Higher Education Mega Center, Guangzhou 510006, China; (R.C.); (Z.R.); (A.Z.); (F.D.)
| | - Dongfeng Chen
- School of Basic Medical Science, Guangzhou University of Chinese Medicine, Guangzhou 510006, China;
- The Research Center of Basic Integrative Medicine, Guangzhou University of Chinese Medicine, Guangzhou 510006, China
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148
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Schlatzer T, Schröder H, Trobe M, Lembacher‐Fadum C, Stangl S, Schlögl C, Weber H, Breinbauer R. Pd/BIPHEPHOS is an Efficient Catalyst for the Pd-Catalyzed S-Allylation of Thiols with High n-Selectivity. Adv Synth Catal 2020; 362:331-336. [PMID: 32063821 PMCID: PMC7004212 DOI: 10.1002/adsc.201901250] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 10/22/2019] [Indexed: 11/06/2022]
Abstract
The Pd-catalyzed S-allylation of thiols with stable allylcarbonate and allylacetate reagents offers several advantages over established reactions for the formation of thioethers. We could demonstrate that Pd/BIPHEPHOS is a catalyst system which allows the transition metal-catalyzed S-allylation of thiols with excellent n-regioselectivity. Mechanistic studies showed that this reaction is reversible under the applied reaction conditions. The excellent functional group tolerance of this transformation was demonstrated with a broad variety of thiol nucleophiles (18 examples) and allyl substrates (9 examples), and could even be applied for the late-stage diversification of cephalosporins, which might find application in the synthesis of new antibiotics.
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Affiliation(s)
- Thomas Schlatzer
- Institute of Organic ChemistryGraz University of TechnologyStremayrgasse 9A-8010GrazAustria
| | - Hilmar Schröder
- Institute of Organic ChemistryGraz University of TechnologyStremayrgasse 9A-8010GrazAustria
| | - Melanie Trobe
- Institute of Organic ChemistryGraz University of TechnologyStremayrgasse 9A-8010GrazAustria
| | | | - Simon Stangl
- Institute of Organic ChemistryGraz University of TechnologyStremayrgasse 9A-8010GrazAustria
| | - Christoph Schlögl
- Institute of Organic ChemistryGraz University of TechnologyStremayrgasse 9A-8010GrazAustria
| | - Hansjörg Weber
- Institute of Organic ChemistryGraz University of TechnologyStremayrgasse 9A-8010GrazAustria
| | - Rolf Breinbauer
- Institute of Organic ChemistryGraz University of TechnologyStremayrgasse 9A-8010GrazAustria
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149
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Abstract
Octaphosphane {cyclo-(P4 tBu3 )}2 (1) undergoes an unexpected isomerization reaction to the constitutional isomer 2,2',2'',2''',3,3'-hexa-tert-butyl-bicyclo[3.3.0]octaphosphane (2) in the presence of Lewis acidic metal salts. The mechanism of this reaction is discussed and elucidated with DFT calculations. The results underline the fascinating similarity between phosphorus-rich and isolobal carbon compounds. The new bicyclic octaphosphane 2 shows a dynamic behavior in solution and reacts with [AuCl(tht)] (tht=tetrahydrothiophene) to give a mono- ([AuCl(2-κP3 )], 3) and a dinuclear complex ([(AuCl)2 (2-κP3 ,κP3' )], 4). With cis-[PdCl2 (cod)] (cod=1,5-cyclooctadiene), the chelate complex ([PdCl2 (2-κ2 P2 ,P2' )], 5) with a different coordination mode of the ligand was obtained.
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Affiliation(s)
- Toni Grell
- Faculty of Chemistry and Mineralogy, Institute of Inorganic Chemistry, Leipzig University, Johannisallee 29, 04103, Leipzig, Germany
| | - Evamarie Hey-Hawkins
- Faculty of Chemistry and Mineralogy, Institute of Inorganic Chemistry, Leipzig University, Johannisallee 29, 04103, Leipzig, Germany
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150
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Cheng Q, Zhang Y, Luan T, Wang Z, Tang R, Xing P, Hao A. Hydrogels Self-Assembled from an Azobenzene Building Block: Stability toward UV Irradiation in the Gel and Thin-Film States. Chempluschem 2020; 84:328-332. [PMID: 31939216 DOI: 10.1002/cplu.201900042] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2019] [Revised: 02/27/2019] [Indexed: 10/27/2022]
Abstract
Azobenzene and its derivatives are widely used as photoresponsive units for the fabrication of photoresponsive smart materials. In this work, two azobenzene derivatives were designed and investigated as hydrogelators, namely N-4-azodiphenyl-maleimic acid (ADPMA) and N-4-azodiphenyl-succinic acid (ADPSA) bearing azobenzene and carboxylic acid segments. In the process of deprotonation/protonation of the carboxylic acids by pH variation, the self-assembly of these two gelators was triggered. ADPMA could transform from solution to hydrogel while the solution of ADPSA formed a precipitate under the same conditions. The solution-gel/precipitate transformation can be repeated by changing the pH. In contrast to the conventional responsiveness to UV-light irradiation for azobenzene-based gels, the ADPMA hydrogel shows typical trans-cis isomerization of the azobenzene unit in solution, yet the hydrogel demonstrates remarkable stability to UV light irradiation in both the bulk gel and thin film states.
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Affiliation(s)
- Qiuhong Cheng
- Key Laboratory of Colloid and Interface Chemistry of Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, P. R. China
| | - Yimeng Zhang
- Key Laboratory of Colloid and Interface Chemistry of Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, P. R. China
| | - Tianxiang Luan
- Key Laboratory of Colloid and Interface Chemistry of Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, P. R. China
| | - Zhuoer Wang
- Key Laboratory of Colloid and Interface Chemistry of Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, P. R. China
| | - Ruipeng Tang
- Key Laboratory of Colloid and Interface Chemistry of Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, P. R. China
| | - Pengyao Xing
- Key Laboratory of Colloid and Interface Chemistry of Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, P. R. China
| | - Aiyou Hao
- Key Laboratory of Colloid and Interface Chemistry of Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, P. R. China
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