1
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Hazra S, Panda S. Stereoselective Synthesis of Silylated Vinylboronates by a Boron-Wittig Reaction and Their Application to Tetrasubstituted Olefins. Chemistry 2023:e202303056. [PMID: 37991686 DOI: 10.1002/chem.202303056] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Revised: 11/20/2023] [Accepted: 11/21/2023] [Indexed: 11/23/2023]
Abstract
The highly stereoselective synthesis of a series of tetrasubstituted mono- as well as disilylated vinylboronates is reported by using the boron-Wittig approach. The condensation between acylsilanes and gem-diborylalkanes gave the desired tetrasubstituted olefins in good to excellent yield and high stereoselectivity. Also, a series of trisubstituted silylated vinyl MIDA-boronates was synthesized by using the boron-Wittig reaction followed by a transesterification reaction. This methodology allows direct incorporation of B(pin) and TMS groups in the anti-position of the olefin in a highly stereoselective manner. Further, sequential Suzuki coupling reaction with the silylated vinyl boronic esters generated all-carbon tetrasubstituted alkenes, which have been applied in the total synthesis of the anticancer drug Tamoxifen and aggregation-induced luminogen agent TPE-TF17.
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Affiliation(s)
- Subrata Hazra
- Indian Institute of Technology Kharagpur, 721302, Kharagpur, West Bengal, India
| | - Santanu Panda
- Indian Institute of Technology Kharagpur, 721302, Kharagpur, West Bengal, India
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2
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Abstract
A metal-free one-pot process for the gem-difluoroolefination of amides is described. The reaction is based on interaction of generated in situ α-chloroiminium salts with difluorinated phosphorus ylide formed from difluorocarbene and triphenylphosphine. The olefination involves nucleophile-assisted dephosphorylation and proceeds within one hour at low temperature. The gem-difluoroenamines were used in further transformations leading to a variety of fluoroalkylated amines.
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Affiliation(s)
- Alexey L Trifonov
- N. D. Zelinsky Institute of Organic Chemistry, 119991, Moscow, Leninsky prosp. 47, Russian Federation
| | - Alexander D Dilman
- N. D. Zelinsky Institute of Organic Chemistry, 119991, Moscow, Leninsky prosp. 47, Russian Federation
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3
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Volchkov I, Powell BV, Zatolochnaya OV, Leung JC, Pennino S, Wu L, Gonnella NC, Bhaskararao B, Kozlowski MC, Reeves JT. Practical Synthesis of Terminal Vinyl Fluorides. J Org Chem 2023; 88:10881-10904. [PMID: 37441763 PMCID: PMC10530197 DOI: 10.1021/acs.joc.3c00917] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/15/2023]
Abstract
The synthesis of di- and trisubstituted vinyl fluorides with high isomeric purity remains a challenge for organic synthesis. While many methods exist to access these compounds, the separation of the desired isomer from the minor isomer and/or starting materials often is difficult. Herein, we report a practical method to access di- and trisubstituted vinyl fluorides via a selective Horner-Wadsworth-Emmons olefination/hydrolysis, which provides crystalline 2-fluoroacrylic acids in high (>98%) E-isomeric purity. A subsequent silver-catalyzed stereoretentive decarboxylation provides the title substances with high isomeric purity and without the need for tedious chromatography to remove the minor isomer. The process was amenable to a variety of aldehydes and ketones and provided a diverse array of di- and trisubstituted vinyl fluorides. The sequence was applied to the synthesis of antibacterial and anti-inflammatory compounds.
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Affiliation(s)
- Ivan Volchkov
- Departments of Chemical Development and Material and Analytical Sciences, Boehringer Ingelheim Pharmaceuticals, Inc., Ridgefield, Connecticut 06877, United States
| | - Brent V. Powell
- Departments of Chemical Development and Material and Analytical Sciences, Boehringer Ingelheim Pharmaceuticals, Inc., Ridgefield, Connecticut 06877, United States
| | - Olga V. Zatolochnaya
- Departments of Chemical Development and Material and Analytical Sciences, Boehringer Ingelheim Pharmaceuticals, Inc., Ridgefield, Connecticut 06877, United States
| | - Joyce C. Leung
- Departments of Chemical Development and Material and Analytical Sciences, Boehringer Ingelheim Pharmaceuticals, Inc., Ridgefield, Connecticut 06877, United States
| | - Scott Pennino
- Departments of Chemical Development and Material and Analytical Sciences, Boehringer Ingelheim Pharmaceuticals, Inc., Ridgefield, Connecticut 06877, United States
| | - Lifen Wu
- Departments of Chemical Development and Material and Analytical Sciences, Boehringer Ingelheim Pharmaceuticals, Inc., Ridgefield, Connecticut 06877, United States
| | - Nina C. Gonnella
- Departments of Chemical Development and Material and Analytical Sciences, Boehringer Ingelheim Pharmaceuticals, Inc., Ridgefield, Connecticut 06877, United States
| | - Bangaru Bhaskararao
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104, United States
| | - Marisa C. Kozlowski
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104, United States
| | - Jonathan T. Reeves
- Departments of Chemical Development and Material and Analytical Sciences, Boehringer Ingelheim Pharmaceuticals, Inc., Ridgefield, Connecticut 06877, United States
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4
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Shigeno M, Kajima A, Toyama E, Korenaga T, Yamakoshi H, Nozawa-Kumada K, Kondo Y. LiHMDS-Mediated Deprotonative Coupling of Toluenes with Ketones. Chemistry 2023; 29:e202203549. [PMID: 36479733 DOI: 10.1002/chem.202203549] [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: 11/15/2022] [Revised: 12/05/2022] [Accepted: 12/06/2022] [Indexed: 12/12/2022]
Abstract
We demonstrate that lithium hexamethyldisilazide (LiHMDS) acts as an effective base for deprotonative coupling reactions of toluenes with ketones to afford stilbenes. Various functionalities (halogen, OCF3 , amide, Me, aryl, alkenyl, alkynyl, SMe, and SPh) are allowed on the toluenes. Notably, this system proved successful with low-reactive toluenes bearing a large pKa value compared to that of the conjugate acid of LiHMDS (hexamethyldisilazane, 25.8, THF), as demonstrated by 4-phenyltoluene (38.57, THF) and toluene itself (∼43, DMSO).
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Affiliation(s)
- Masanori Shigeno
- Department of Biophysical Chemistry Graduate School of Pharmaceutical Science, Tohoku University, 6-3 Aoba, Sendai, 980-8578, Japan.,JST, PRESTO, Kawaguchi, Saitama, 332-0012, Japan
| | - Akihisa Kajima
- Department of Biophysical Chemistry Graduate School of Pharmaceutical Science, Tohoku University, 6-3 Aoba, Sendai, 980-8578, Japan
| | - Eito Toyama
- Department of Biophysical Chemistry Graduate School of Pharmaceutical Science, Tohoku University, 6-3 Aoba, Sendai, 980-8578, Japan
| | - Toshinobu Korenaga
- Department of Chemistry and Biological Sciences Faculty of Science and Engineering, Iwate University Ueda, Morioka, 020-8551, Japan.,Soft-Path Science and Engineering Research Center (SPERC), Iwate University, Ueda, Morioka, 020-8551, Japan
| | - Hiroyuki Yamakoshi
- Central Analytical Center, Graduate School of Pharmaceutical Science, Tohoku University, 6-3 Aoba, Sendai, 980-8578, Japan
| | - Kanako Nozawa-Kumada
- Department of Biophysical Chemistry Graduate School of Pharmaceutical Science, Tohoku University, 6-3 Aoba, Sendai, 980-8578, Japan
| | - Yoshinori Kondo
- Department of Biophysical Chemistry Graduate School of Pharmaceutical Science, Tohoku University, 6-3 Aoba, Sendai, 980-8578, Japan
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5
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Bognar S, van Gemmeren M. A Modular Olefination of Aldehydes with Thiols as Coupling Partners. Chemistry 2023; 29:e202203512. [PMID: 36455150 DOI: 10.1002/chem.202203512] [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: 11/11/2022] [Revised: 11/30/2022] [Accepted: 12/01/2022] [Indexed: 12/03/2022]
Abstract
Olefins range amongst the most important motifs in organic chemistry. Hence, the development of novel olefin syntheses has remained a constant field of research in synthetic chemistry to date. Herein, we report the development of a modular olefination that converts aldehydes into olefins with thiols as reaction partners. The simple, transition metal-free protocol proceeds via an unsymmetrical bissulfone intermediate which is converted into the respective alkene in a Ramberg-Bäcklund-type process. Differently substituted olefins can be synthesized from readily available starting materials in typically good yields and stereoselectivities using basic laboratory chemicals exclusively. Complementary reaction conditions differing in the choice of solvent favor the E/Z-products respectively under kinetic control rendering this protocol an interesting economical addition to the family of olefin syntheses.
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Affiliation(s)
- Sabine Bognar
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstraße 36, 48149, Münster, Germany
| | - Manuel van Gemmeren
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstraße 36, 48149, Münster, Germany.,Otto-Diels-Institut für Organische Chemie, Christian-Albrechts-Universität zu Kiel, Otto-Hahn-Platz 4, 24118, Kiel, Germany
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6
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Fritsch S, Aldemir N, Balszuweit J, Bojaryn K, Voskuhl J, Hirschhäuser C. Total Synthesis of Resveratrone and iso-Resveratrone. Chemistry 2022; 11:e202200098. [PMID: 35770975 PMCID: PMC9278093 DOI: 10.1002/open.202200098] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 05/30/2022] [Indexed: 12/03/2022]
Abstract
The first total synthesis of resveratrone and iso‐resveratrone based on an epoxide olefination approach is described. The pivotal reaction proceeds by insertion of the lithiated epoxide into a boronic ester and subsequent syn‐elimination. Resveratrone has been described to have remarkable photophysical properties, including two‐photon absorption. Therefore, an azide derivative has been prepared to allow for use as a biological label.
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Affiliation(s)
- Stefan Fritsch
- Organic Chemistry and Center for Nanointegration Duisburg-Essen (CeNIDE), University of Duisburg-Essen, Universitätsstr. 5-7, 45117, Essen, Germany
| | - Nazli Aldemir
- Organic Chemistry and Center for Nanointegration Duisburg-Essen (CeNIDE), University of Duisburg-Essen, Universitätsstr. 5-7, 45117, Essen, Germany
| | - Jan Balszuweit
- Organic Chemistry and Center for Nanointegration Duisburg-Essen (CeNIDE), University of Duisburg-Essen, Universitätsstr. 5-7, 45117, Essen, Germany
| | - Kevin Bojaryn
- Organic Chemistry and Center for Nanointegration Duisburg-Essen (CeNIDE), University of Duisburg-Essen, Universitätsstr. 5-7, 45117, Essen, Germany
| | - Jens Voskuhl
- Organic Chemistry and Center for Nanointegration Duisburg-Essen (CeNIDE), University of Duisburg-Essen, Universitätsstr. 5-7, 45117, Essen, Germany
| | - Christoph Hirschhäuser
- Organic Chemistry and Center for Nanointegration Duisburg-Essen (CeNIDE), University of Duisburg-Essen, Universitätsstr. 5-7, 45117, Essen, Germany
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7
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Tian X, Karl TA, Reiter S, Yakubov S, de Vivie‐Riedle R, König B, Barham JP. Electro-mediated PhotoRedox Catalysis for Selective C(sp 3 )-O Cleavages of Phosphinated Alcohols to Carbanions. Angew Chem Int Ed Engl 2021; 60:20817-20825. [PMID: 34165861 PMCID: PMC8518744 DOI: 10.1002/anie.202105895] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [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: 04/30/2021] [Revised: 06/21/2021] [Indexed: 12/13/2022]
Abstract
We report a novel example of electro-mediated photoredox catalysis (e-PRC) in the reductive cleavage of C(sp3 )-O bonds of phosphinated alcohols to alkyl carbanions. As well as deoxygenations, olefinations are reported which are E-selective and can be made Z-selective in a tandem reduction/photosensitization process where both steps are photoelectrochemically promoted. Spectroscopy, computation, and catalyst structural variations reveal that our new naphthalene monoimide-type catalyst allows for an intimate dispersive precomplexation of its radical anion form with the phosphinate substrate, facilitating a reactivity-determining C(sp3 )-O cleavage. Surprisingly and in contrast to previously reported photoexcited radical anion chemistries, our conditions tolerate aryl chlorides/bromides and do not give rise to Birch-type reductions.
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Affiliation(s)
- Xianhai Tian
- Institute of Organic ChemistryUniversity of RegensburgUniversitätsstr. 3193053RegensburgGermany
| | - Tobias A. Karl
- Institute of Organic ChemistryUniversity of RegensburgUniversitätsstr. 3193053RegensburgGermany
| | | | - Shahboz Yakubov
- Institute of Organic ChemistryUniversity of RegensburgUniversitätsstr. 3193053RegensburgGermany
| | | | - Burkhard König
- Institute of Organic ChemistryUniversity of RegensburgUniversitätsstr. 3193053RegensburgGermany
| | - Joshua P. Barham
- Institute of Organic ChemistryUniversity of RegensburgUniversitätsstr. 3193053RegensburgGermany
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8
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Trzmiel S, Langmann J, Werner D, Maichle-Mössmer C, Scherer W, Anwander R. Beyond Takai's Olefination Reagent: Persistent Dehalogenation Emerges in a Chromium(III)-μ 3 -Methylidyne Complex. Angew Chem Int Ed Engl 2021; 60:20049-20054. [PMID: 34213805 PMCID: PMC8456800 DOI: 10.1002/anie.202106608] [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: 05/17/2021] [Revised: 07/01/2021] [Indexed: 11/05/2022]
Abstract
Reaction of CHI3 with six equivalents of CrCl2 in THF at low temperatures affords [Cr3 Cl3 (μ2 -Cl)3 (μ3 -CH)(thf)6 ] as the first isolable high-yield CrIII μ3 -methylidyne complex. Substitution of the terminal chlorido ligands via salt metathesis with alkali-metal cyclopentadienides generates isostructural half-sandwich chromium(III)-μ3 -methylidynes [CpR 3 Cr3 (μ2 -Cl)3 (μ3 -CH)] (CpR =C5 H5 , C5 Me5 , C5 H4 SiMe3 ). Side and decomposition products of the Cl/CpR exchange reactions were identified and structurally characterized for [Cr4 (μ2 -Cl)4 (μ2 -I)2 (μ4 -O)(thf)4 ] and [(η5 -C5 H4 SiMe3 )CrCl(μ2 -Cl)2 Li(thf)2 ]. The Cl/CpR exchange drastically changed the ambient-temperature effective magnetic moment μeff from 9.30/9.11 μB (solution/solid) to 3.63/4.32 μB (CpR =C5 Me5 ). Reactions of [Cr3 Cl3 (μ2 -Cl)3 (μ3 -CH)(thf)6 ] with aldehydes and ketones produce intricate mixtures of species through oxy/methylidyne exchange, which were partially identified as radical recombination products through GC/MS analysis and 1 H NMR spectroscopy.
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Affiliation(s)
- Simon Trzmiel
- Institut für Anorganische Chemie, Eberhard-Karls-Universität Tübingen, Auf der Morgenstelle 18, 72076, Tübingen, Germany
| | - Jan Langmann
- Institut für Physik, Universität Augsburg, Universitätsstr. 1, 86159, Augsburg, Germany
| | - Daniel Werner
- Institut für Anorganische Chemie, Eberhard-Karls-Universität Tübingen, Auf der Morgenstelle 18, 72076, Tübingen, Germany
| | - Cäcilia Maichle-Mössmer
- Institut für Anorganische Chemie, Eberhard-Karls-Universität Tübingen, Auf der Morgenstelle 18, 72076, Tübingen, Germany
| | - Wolfgang Scherer
- Institut für Physik, Universität Augsburg, Universitätsstr. 1, 86159, Augsburg, Germany
| | - Reiner Anwander
- Institut für Anorganische Chemie, Eberhard-Karls-Universität Tübingen, Auf der Morgenstelle 18, 72076, Tübingen, Germany
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9
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Faltracco M, van de Vrande KNA, Dijkstra M, Saya JM, Hamlin TA, Ruijter E. Palladium-Catalyzed Cascade to Benzoxepins by Using Vinyl-Substituted Donor-Acceptor Cyclopropanes. Angew Chem Int Ed Engl 2021; 60:14410-14414. [PMID: 33822456 PMCID: PMC8251625 DOI: 10.1002/anie.202102862] [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] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Indexed: 12/18/2022]
Abstract
A palladium-catalyzed intermolecular cascade (4+3) cyclocondensation of salicylaldehydes and vinylcyclopropanes is reported. A key feature of the reaction is the use of a phosphonate group as an acceptor moiety on the cyclopropane, exploiting its propensity to undergo olefination with aldehydes. Subsequent O-allylation enabled the formation of a range of substituted benzoxepinsWith a novel chiral ligand, the products were obtained in generally good yield and with reasonable enantioselectivity.
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Affiliation(s)
- Matteo Faltracco
- Department of Chemistry and Pharmaceutical SciencesAmsterdam Institute of Molecular and Life Sciences (AIMMS)Vrije Universiteit AmsterdamDe Boelelaan 11081081 HZAmsterdamThe Netherlands
| | - Koen N. A. van de Vrande
- Department of Chemistry and Pharmaceutical SciencesAmsterdam Institute of Molecular and Life Sciences (AIMMS)Vrije Universiteit AmsterdamDe Boelelaan 11081081 HZAmsterdamThe Netherlands
| | - Martijn Dijkstra
- Department of Chemistry and Pharmaceutical SciencesAmsterdam Institute of Molecular and Life Sciences (AIMMS)Vrije Universiteit AmsterdamDe Boelelaan 11081081 HZAmsterdamThe Netherlands
| | - Jordy M. Saya
- Aachen-Maastricht Institute for Biobased Materials (AMIBM)Maastricht UniversityUrmonderbaan 226167 RDGeleenThe Netherlands
| | - Trevor A. Hamlin
- Department of Theoretical ChemistryAmsterdam Institute of Molecular and Life Sciences (AIMMS)Amsterdam Center for Multiscale Modeling (ACMM)Vrije Universiteit AmsterdamDe Boelelaan 10831081 HVAmsterdamThe Netherlands
| | - Eelco Ruijter
- Department of Chemistry and Pharmaceutical SciencesAmsterdam Institute of Molecular and Life Sciences (AIMMS)Vrije Universiteit AmsterdamDe Boelelaan 11081081 HZAmsterdamThe Netherlands
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10
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Ansari T, Jasinski JB, Leahy DK, Handa S. Metal-Micelle Cooperativity: Phosphine Ligand-Free Ultrasmall Palladium(II) Nanoparticles for Oxidative Mizoroki-Heck-type Couplings in Water at Room Temperature. JACS Au 2021; 1:308-315. [PMID: 34467295 PMCID: PMC8395633 DOI: 10.1021/jacsau.0c00087] [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] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Indexed: 05/08/2023]
Abstract
The amphiphile PS-750-M generates stable, phosphine ligand-free, and catalytically active ultrasmall Pd(II) nanoparticles (NPs) from Pd(OAc)2, preventing their precipitation, polymerization, and oxidation state changes. PS-750-M directly interacts with Pd(II) NP surfaces, as confirmed by high-resolution mass spectrometry and IR spectroscopy, resulting in their high stability. The Pd cations in NPs are most likely held together by hydroxides and acetate ions. The NPs were characterized by HRTEM, revealing their morphology and particle size distribution, and by HRMS and IR, providing evidence for NP-amphiphile interaction. The NP catalytic activity was examined in the context of oxidative Mizoroki-Heck-type couplings in water at room temperature. Hot filtration, hot extraction, and three-phase tests indicate heterogeneous catalysis occurring at the micellar interface rather than homogeneous catalysis occurring in the solution. NMR studies indicate that the catalytic activity stems from metal cation-π interactions of the styrene along with transmetalation by the arylboronic acid, followed by insertion and β-H elimination to furnish the coupled product along with the reoxidation of Pd by benzoquinone to complete the catalytic cycle. This method is very mild and sustainable, both in terms of NP synthesis and subsequent catalysis, and shows broad substrate scope while circumventing the need for organic solvents for this important class of couplings.
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Affiliation(s)
- Tharique
N. Ansari
- Department
of Chemistry, University of Louisville, Louisville, Kentucky 40292, United States
| | - Jacek B. Jasinski
- Conn
Center for Renewable Energy Research, University
of Louisville, Louisville, Kentucky 40292, United States
| | - David K. Leahy
- Process
Chemistry Development, Takeda Pharmaceuticals
International, Cambridge, Massachusetts 02139, United States
| | - Sachin Handa
- Department
of Chemistry, University of Louisville, Louisville, Kentucky 40292, United States
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11
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Ascherl JDR, Neiß C, Vogel A, Graf J, Rominger F, Oeser T, Hampel F, Görling A, Kivala M. Phosphorus-Containing Dibenzonaphthanthrenes: Electronic Fine Tuning of Polycyclic Aromatic Hydrocarbons through Organophosphorus Chemistry. Chemistry 2020; 26:13157-13162. [PMID: 32558004 PMCID: PMC7693108 DOI: 10.1002/chem.202002872] [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] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Indexed: 02/03/2023]
Abstract
A concise synthetic route towards a new family of phosphorus-containing polycyclic aromatic hydrocarbons starting from the versatile acridophosphine has been established. The structural and optoelectronic properties of these compounds were efficiently modulated through derivatization of the phosphorus center. X-ray crystallographic analysis, UV/Vis spectroscopic, and electrochemical studies supported by DFT calculations identified the considerable potential of these scaffolds for the development of organophosphorus functional materials with tailored properties upon further functionalization.
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Affiliation(s)
- Johannes D. R. Ascherl
- Institute of Organic ChemistryRuprecht-Karls-Universität HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
- Centre for Advanced MaterialsRuprecht-Karls-Universität HeidelbergIm Neuenheimer Feld 22569120HeidelbergGermany
| | - Christian Neiß
- Department of Chemistry and PharmacyChair of Theoretical ChemistryFriedrich-Alexander-Universität Erlangen-NürnbergEgerlandstrasse 391058ErlangenGermany
| | - Alexander Vogel
- Institute of Organic ChemistryRuprecht-Karls-Universität HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
- Centre for Advanced MaterialsRuprecht-Karls-Universität HeidelbergIm Neuenheimer Feld 22569120HeidelbergGermany
| | - Jürgen Graf
- Institute of Organic ChemistryRuprecht-Karls-Universität HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
| | - Frank Rominger
- Institute of Organic ChemistryRuprecht-Karls-Universität HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
| | - Thomas Oeser
- Institute of Organic ChemistryRuprecht-Karls-Universität HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
| | - Frank Hampel
- Department of Chemistry and PharmacyChair of Organic ChemistryUniversity of Erlangen-NürnbergNikolaus-Fiebiger-Str. 1091058ErlangenGermany
| | - Andreas Görling
- Department of Chemistry and PharmacyChair of Theoretical ChemistryFriedrich-Alexander-Universität Erlangen-NürnbergEgerlandstrasse 391058ErlangenGermany
| | - Milan Kivala
- Institute of Organic ChemistryRuprecht-Karls-Universität HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
- Centre for Advanced MaterialsRuprecht-Karls-Universität HeidelbergIm Neuenheimer Feld 22569120HeidelbergGermany
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12
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Abstract
Metal-catalyzed chelation-assisted C-H olefinations have emerged as powerful tools for the construction of functionalized alkenes. Herein, we describe the rhoda-electrocatalyzed C-H activation/alkenylation of arenes. The olefinations of challenging electron-poor benzamides were thus accomplished in a fully dehydrogenative fashion under electrochemical conditions, avoiding stoichiometric chemical oxidants, and with H2 as the only byproduct. This versatile alkenylation reaction also features broad substrate scope and used electricity as a green oxidant.
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Affiliation(s)
- Yan Zhang
- Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammannstrasse 2, 37077, Göttingen, Germany.,Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Zhejiang Normal University, 321004, Jinhua, China
| | - Julia Struwe
- Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammannstrasse 2, 37077, Göttingen, Germany
| | - Lutz Ackermann
- Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammannstrasse 2, 37077, Göttingen, Germany
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13
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Abstract
The regioselective functionalization of heteroarenes is a highly attractive synthetic target due to the prevalence of multiply substituted heteroarenes in nature and bioactive compounds. Some substitution patterns remain challenging: While highly efficient methods for the C2-selective olefination of 3-substituted five-membered heteroarenes have been reported, analogous methods to access the 5-olefinated products have remained limited by poor regioselectivities and/or the requirement to use an excess of the valuable heteroarene starting material. Herein we report a sterically controlled C-H olefination using heteroarenes as the limiting reagent. The method enables the highly C5-selective olefination of a wide range of heteroarenes and is shown to be useful in the context of late-stage functionalization.
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Affiliation(s)
- Hao Chen
- Max Planck Institute for Chemical Energy ConversionStiftstraße 34–3645470Mülheim an der RuhrGermany
| | - Mirxan Farizyan
- Max Planck Institute for Chemical Energy ConversionStiftstraße 34–3645470Mülheim an der RuhrGermany
| | - Francesca Ghiringhelli
- Organisch-Chemisches InstitutWestfälische Wilhelms-Universität MünsterCorrensstraße 4048149MünsterGermany
| | - Manuel van Gemmeren
- Max Planck Institute for Chemical Energy ConversionStiftstraße 34–3645470Mülheim an der RuhrGermany
- Organisch-Chemisches InstitutWestfälische Wilhelms-Universität MünsterCorrensstraße 4048149MünsterGermany
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14
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Baumann AN, Music A, Dechent J, Müller N, Jagau TC, Didier D. Electro- Olefination-A Catalyst Free Stereoconvergent Strategy for the Functionalization of Alkenes. Chemistry 2020; 26:8382-8387. [PMID: 32203624 PMCID: PMC7383514 DOI: 10.1002/chem.202001394] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [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: 03/20/2020] [Indexed: 01/09/2023]
Abstract
Conventional methods carrying out C(sp2 )-C(sp2 ) bond formations are typically mediated by transition-metal-based catalysts. Herein, we conceptualize a complementary avenue to access such bonds by exploiting the potential of electrochemistry in combination with organoboron chemistry. We demonstrate a transition metal catalyst-free electrocoupling between (hetero)aryls and alkenes through readily available alkenyl-tri(hetero)aryl borate salts (ATBs) in a stereoconvergent fashion. This unprecedented transformation was investigated theoretically and experimentally and led to a library of functionalized alkenes. The concept was then carried further and applied to the synthesis of the natural product pinosylvin and the derivatization of the steroidal dehydroepiandrosterone (DHEA) scaffold.
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Affiliation(s)
- Andreas N Baumann
- Department of Chemistry and Pharmacy, Ludwig-Maximilians-University Munich, Butenandtstraße 5-13, Haus F, 81377, Munich, Germany
| | - Arif Music
- Department of Chemistry and Pharmacy, Ludwig-Maximilians-University Munich, Butenandtstraße 5-13, Haus F, 81377, Munich, Germany
| | - Jonas Dechent
- Department of Chemistry and Pharmacy, Ludwig-Maximilians-University Munich, Butenandtstraße 5-13, Haus F, 81377, Munich, Germany
| | - Nicolas Müller
- Department of Chemistry and Pharmacy, Ludwig-Maximilians-University Munich, Butenandtstraße 5-13, Haus F, 81377, Munich, Germany
| | - Thomas C Jagau
- Department of Chemistry and Pharmacy, Ludwig-Maximilians-University Munich, Butenandtstraße 5-13, Haus F, 81377, Munich, Germany
| | - Dorian Didier
- Department of Chemistry and Pharmacy, Ludwig-Maximilians-University Munich, Butenandtstraße 5-13, Haus F, 81377, Munich, Germany
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15
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Yoshimura R, Tanaka K. Rhodium-Catalyzed ortho- Olefination of Sterically Demanding Benzamides: Application to the Asymmetric Synthesis of Axially Chiral Benzamides. Chemistry 2020; 26:4969-4973. [PMID: 32073186 DOI: 10.1002/chem.202000797] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [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: 02/14/2020] [Indexed: 12/18/2022]
Abstract
It has been established that an unsubstituted cyclopentadienyl rhodium(III) (CpRhIII ) complex is a highly active catalyst for the aerobic oxidative ortho C-H bond olefination of sterically demanding ortho-substituted benzamides with alkenes. This catalysis was successfully applied to the diastereoselective synthesis of axially chiral N,N-dialkylbenzamides. The combination of the ruthenium(II)-catalyzed enantioselective hydrogenation and the CpRhIII -catalyzed diastereoselective ortho C-H bond olefination enabled the asymmetric synthesis of axially chiral N,N-dialkylbenzamide derivatives with high ee values.
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Affiliation(s)
- Ryo Yoshimura
- Department of Chemical Science and Engineering, Tokyo Institute of Technology, O-okayama, Meguro-ku, Tokyo, 152-8550, Japan
| | - Ken Tanaka
- Department of Chemical Science and Engineering, Tokyo Institute of Technology, O-okayama, Meguro-ku, Tokyo, 152-8550, Japan
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16
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Huang G, Solano CM, Su Y, Ezzat N, Matsui S, Huang L, Chakrabarti D, Yuan Y. Microwave-assisted, rapid synthesis of 2-vinylquinolines and evaluation of their antimalarial activity. Tetrahedron Lett 2019; 60:1736-1740. [PMID: 31802783 PMCID: PMC6892474 DOI: 10.1016/j.tetlet.2019.05.054] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
A rapid and efficient synthesis of 2-vinylquinolines via trifluoromethanesulfonamidemediated olefination of 2-methylquinoline and aldehyde under microwave irradiation is reported. Biological evaluation of these scaffolds demonstrates that 2-vinylquinolines 3x - 3z possess excellent antimalarial activities against chloroquine-resistant Dd2 strain of Plasmodium falciparum (IC50 < 100 nM).
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Affiliation(s)
- Guang Huang
- Department of Chemistry, University of Central Florida, Orlando, FL, USA
| | - Claribel Murillo Solano
- Division of Molecular Microbiology, Burnett School of Biomedical Sciences, University of Central Florida, Orlando, FL, USA
| | - Yuxin Su
- Academy of Military Medical Science, Beijing, China
- Chinese PLA Center for Disease Control and Prevention, Beijing, China
| | - Nameer Ezzat
- Department of Chemistry, University of Central Florida, Orlando, FL, USA
| | - Shino Matsui
- Department of Chemistry, University of Central Florida, Orlando, FL, USA
| | - Liuyu Huang
- Chinese PLA Center for Disease Control and Prevention, Beijing, China
| | - Debopam Chakrabarti
- Division of Molecular Microbiology, Burnett School of Biomedical Sciences, University of Central Florida, Orlando, FL, USA
| | - Yu Yuan
- Department of Chemistry, University of Central Florida, Orlando, FL, USA
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17
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Lee DC, Kensy VK, Maroon CR, Long BK, Boydston AJ. The Intrinsic Mechanochemical Reactivity of Vinyl-Addition Polynorbornene. Angew Chem Int Ed Engl 2019; 58:5639-5642. [PMID: 30753753 DOI: 10.1002/anie.201900467] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [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: 01/14/2019] [Indexed: 11/08/2022]
Abstract
Herein we report the discovery of the intrinsic mechanochemical reactivity of vinyl-addition polynorbornene (VA-PNB), which has strained bicyclic ring repeat units along the polymer backbone. VA-PNBs with three different side chains were found to undergo ring-opening olefination upon sonication in dilute solutions. The sonicated polymers exhibited spectroscopic signatures consistent with conversion of the bicyclic norbornane repeat units into the ring-open isomer typical of polynorbornene made by ring-opening metathesis polymerization (ROMP-PNB). Thermal analysis and evaluation of chain-scission kinetics suggest that sonication of VA-PNB results in chain segments containing a statistical mixture of vinyl-added and ROMP-type repeat units.
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Affiliation(s)
- Daniel C Lee
- Molecular Engineering and Sciences, University of Washington, 3946 W Stevens Way NE, Seattle, WA, 98105, USA
| | - Victoria K Kensy
- Department of Chemistry, University of Washington, Box 351700, Seattle, WA, 98195-1700, USA
| | - Christopher R Maroon
- Department of Chemistry, University of Tennessee, 320 Buehler Hall, Knoxville, TN, 37996-1600, USA
| | - Brian K Long
- Department of Chemistry, University of Tennessee, 320 Buehler Hall, Knoxville, TN, 37996-1600, USA
| | - Andrew J Boydston
- Department of Chemistry, University of Washington, Box 351700, Seattle, WA, 98195-1700, USA.,Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI, 53706, USA
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18
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19
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Abstract
Efficient access to medicinally significant natural products is an essential basis for the development of pharmaceuticals. The limited availability of marine natural products impedes broad biological evaluation. Despite several elegant syntheses of (-)-lasonolide A having been reported, a practical synthesis of this potent anticancer polyketide remains elusive. Based on the application of borane as a traceless protecting group and the development of an unprecedented bissulfone reagent for Julia olefination, (-)-lasonolide A was assembled in an enantioconvergent manner through the application of stereoselective hydroboration, allylation, and oxidation. This concise route may provide a realistic solution for accessing derivatives and analogues.
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Affiliation(s)
- Lin Yang
- Key Laboratory of Synthetic Chemistry of Natural Substances, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, P. R. China.,University of Chinese of Academy of Sciences, 19A Yuquan Road, Beijing, 100049, P. R. China
| | - Zuming Lin
- Key Laboratory of Synthetic Chemistry of Natural Substances, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, P. R. China.,University of Chinese of Academy of Sciences, 19A Yuquan Road, Beijing, 100049, P. R. China
| | - Shunjie Shao
- Key Laboratory of Synthetic Chemistry of Natural Substances, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, P. R. China.,University of Chinese of Academy of Sciences, 19A Yuquan Road, Beijing, 100049, P. R. China
| | - Qian Zhao
- Jiangsu Key Laboratory of Chiral Drug Development, Jiangsu Aosaikang Parmaceutical CO., LTD., Nanjing, 211112, P. R. China
| | - Ran Hong
- Key Laboratory of Synthetic Chemistry of Natural Substances, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, P. R. China.,University of Chinese of Academy of Sciences, 19A Yuquan Road, Beijing, 100049, P. R. China
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20
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Simões MMQ, Gonzaga DTG, Cardoso MFC, Forezi LDSM, Gomes ATPC, da Silva FC, Ferreira VF, Neves MGPMS, Cavaleiro JAS. Carbene Transfer Reactions Catalysed by Dyes of the Metalloporphyrin Group. Molecules 2018; 23:E792. [PMID: 29596367 DOI: 10.3390/molecules23040792] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [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: 02/27/2018] [Revised: 03/26/2018] [Accepted: 03/27/2018] [Indexed: 01/29/2023] Open
Abstract
Carbene transfer reactions are very important transformations in organic synthesis, allowing the generation of structurally challenging products by catalysed cyclopropanation, cyclopropenation, carbene C-H, N-H, O-H, S-H, and Si-H insertion, and olefination of carbonyl compounds. In particular, chiral and achiral metalloporphyrins have been successfully explored as biomimetic catalysts for these carbene transfer reactions under both homogeneous and heterogeneous conditions. In this work the use of synthetic metalloporphyrins (MPorph, M = Fe, Ru, Os, Co, Rh, Ir, Sn) as homogeneous or heterogeneous catalysts for carbene transfer reactions in the last years is reviewed, almost exclusively focused on the literature since the year 2010, except when reference to older publications was deemed to be crucial.
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21
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Abstract
A single and simple ortho-sulfonyl benzonitrile template was developed to achieve remote C-H olefination of six different classes of N-heterocycles. We demonstrate that, by varying precatalysts and conditions, the same template can be applied to the remote C-H activation of six structurally distinct heterocyclic scaffolds, and the site-selectivity can be predicted based on distance and geometry. Furthermore, this new development shows that template-directed remote C-H activation is possible through macrocyclopalladation processes with smaller ring sizes.
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Affiliation(s)
- Guoqiang Yang
- Department of Chemistry, The Scripps Research Institute (TSRI), 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Dajian Zhu
- Department of Chemistry, The Scripps Research Institute (TSRI), 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Peng Wang
- Department of Chemistry, The Scripps Research Institute (TSRI), 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Ri-Yuan Tang
- Department of Chemistry, The Scripps Research Institute (TSRI), 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Jin-Quan Yu
- Department of Chemistry, The Scripps Research Institute (TSRI), 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
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22
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Chen H, Wedi P, Meyer T, Tavakoli G, van Gemmeren M. Dual Ligand-Enabled Nondirected C-H Olefination of Arenes. Angew Chem Int Ed Engl 2018; 57:2497-2501. [PMID: 29316127 DOI: 10.1002/anie.201712235] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [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: 11/29/2017] [Indexed: 01/13/2023]
Abstract
The application of the Pd-catalyzed oxidative C-H olefination of arenes, also known as the Fujiwara-Moritani reaction, has traditionally been limited by the requirement for directing groups on the substrate or the need to use the arene in large excess, typically as a (co)solvent. Herein the development of a catalytic system is described that, through the combined action of two complementary ligands, makes it possible to use directing-group-free arenes as limiting reagents for the first time. The reactions proceed under a combination of both steric and electronic control and enable the application of this powerful reaction to valuable arenes, which cannot be utilized in excess.
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Affiliation(s)
- Hao Chen
- Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34-36, 45470, Mülheim an der Ruhr, Germany
| | - Philipp Wedi
- Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34-36, 45470, Mülheim an der Ruhr, Germany
| | - Tim Meyer
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstrasse 40, 48149, Münster, Germany
| | - Ghazal Tavakoli
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstrasse 40, 48149, Münster, Germany
| | - Manuel van Gemmeren
- Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34-36, 45470, Mülheim an der Ruhr, Germany.,Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstrasse 40, 48149, Münster, Germany
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23
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Ortega MJ, Pantoja JJ, de Los Reyes C, Zubía E. 5-Alkylresorcinol Derivatives from the Bryozoan Schizomavella mamillata: Isolation, Synthesis, and Antioxidant Activity. Mar Drugs 2017; 15:E344. [PMID: 29099074 DOI: 10.3390/md15110344] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [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: 10/11/2017] [Revised: 10/24/2017] [Accepted: 10/30/2017] [Indexed: 12/18/2022] Open
Abstract
The chemical study of the bryozoan Schizomavella mamillata has led to the isolation of six new 5-alkylresorcinol derivatives, schizols A–F (1–6), whose structures were established by spectrocospic means. Schizol A (1) exhibits a (E)-6-phenylnon-5-enyl moiety linked to the C-5 of a resorcinol ring, while in schizol B (2) the substituent at C-5 contains an unusual 1,2-dihydrocyclobutabenzene moiety. Schizols C (3) and D (4) have been characterized as the 1-sulfate derivatives of 1 and 2, respectively, and schizols E (5) and F (6) are the corresponding 1,3-disulfates. Schizol A (1) has been synthetized from 3,5-dimethoxybenzaldehyde through a sequence involving a Wittig reaction for the construction of the C-1′,C-2′ bond and a Julia–Kocienski olefination for the synthesis of the C-5′,C-6′ double bond. In the ABTS (2,2′-azinobis(3-ethylbenzothiazoline-6-sulphonic acid)) antioxidant assay, the natural compounds schizol A (1) and schizol B (2) showed higher radical scavenging activity than the Trolox standard.
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24
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Qiu Y, Posevins D, Bäckvall JE. Selective Palladium-Catalyzed Allenic C-H Bond Oxidation for the Synthesis of [3]Dendralenes. Angew Chem Int Ed Engl 2017; 56:13112-13116. [PMID: 28799682 DOI: 10.1002/anie.201706211] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [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: 06/19/2017] [Indexed: 12/13/2022]
Abstract
A highly selective palladium-catalyzed allenic C-H bond oxidation was developed, and it provides a novel and straightforward synthesis of [3]dendralene derivatives. A variety of [3]dendralenes with diverse substitution patterns are accessible with good efficiency and high stereoselectivity. The reaction tolerates a broad substrate scope containing various functional groups on the allene moiety, including ketone, aldehyde, ester, and phenyl groups. Also, a wide range of olefins with both electron-donating and electron-withdrawing aryls, acrylate, sulfone, and phosphonate groups are tolerated.
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Affiliation(s)
- Youai Qiu
- Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, 10691, Stockholm, Sweden
| | - Daniels Posevins
- Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, 10691, Stockholm, Sweden
| | - Jan-E Bäckvall
- Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, 10691, Stockholm, Sweden
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25
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Naksomboon K, Valderas C, Gómez-Martínez M, Álvarez-Casao Y, Fernández-Ibáñez MÁ. S,O-Ligand-Promoted Palladium-Catalyzed C-H Functionalization Reactions of Nondirected Arenes. ACS Catal 2017; 7:6342-6346. [PMID: 28966841 PMCID: PMC5617328 DOI: 10.1021/acscatal.7b02356] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [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: 07/17/2017] [Revised: 08/17/2017] [Indexed: 01/06/2023]
Abstract
Pd(II)-catalyzed C-H functionalization of nondirected arenes has been realized using an inexpensive and easily accessible type of bidentate S,O-ligand. The catalytic system shows high efficiency in the C-H olefination reaction of electron-rich and electron-poor arenes. This methodology is operationally simple, scalable, and can be used in late-stage functionalization of complex molecules. The broad applicability of this catalyst has been showcased in other transformations such as Pd(II)-catalyzed C-H acetoxylation and allylation reactions.
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Affiliation(s)
- Kananat Naksomboon
- Van’t Hoff Institute
for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Carolina Valderas
- Van’t Hoff Institute
for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Melania Gómez-Martínez
- Van’t Hoff Institute
for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Yolanda Álvarez-Casao
- Van’t Hoff Institute
for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - M. Ángeles Fernández-Ibáñez
- Van’t Hoff Institute
for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
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26
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Liao FM, Cao ZY, Yu JS, Zhou J. Highly Stereoselective Gold-Catalyzed Coupling of Diazo Reagents and Fluorinated Enol Silyl Ethers to Tetrasubstituted Alkenes. Angew Chem Int Ed Engl 2017; 56:2459-2463. [PMID: 28097773 DOI: 10.1002/anie.201611625] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [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: 11/29/2016] [Revised: 12/22/2016] [Indexed: 02/03/2023]
Abstract
We report a highly stereoselective synthesis of all-carbon or fluorinated tetrasubstituted alkenes from diazo reagents and fluorinated enol silyl ethers, using C-F bond as a synthetic handle. Cationic AuI catalysis plays a key role in this reaction. Remarkable fluorine effects on the reactivity and selectivity was also observed.
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Affiliation(s)
- Fu-Min Liao
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, East China Normal University, 3663N Zhongshan Road, Shanghai, 200062, China
| | - Zhong-Yan Cao
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, East China Normal University, 3663N Zhongshan Road, Shanghai, 200062, China
| | - Jin-Sheng Yu
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, East China Normal University, 3663N Zhongshan Road, Shanghai, 200062, China
| | - Jian Zhou
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, East China Normal University, 3663N Zhongshan Road, Shanghai, 200062, China.,State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Shanghai, 200032, China
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27
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Silveira-Dorta G, Álvarez-Méndez SJ, Martín VS, Padrón JM. One-pot synthesis of enantiomerically pure N-protected allylic amines from N-protected α-amino esters. Beilstein J Org Chem 2016; 12:957-62. [PMID: 27340486 PMCID: PMC4902051 DOI: 10.3762/bjoc.12.94] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [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: 02/20/2016] [Accepted: 04/25/2016] [Indexed: 12/11/2022] Open
Abstract
An improved protocol for the synthesis of enantiomerically pure allylic amines is reported. N-Protected α-amino esters derived from natural amino acids were submitted to a one-pot tandem reduction–olefination process. The sequential reduction with DIBAL-H at −78 °C and subsequent in situ addition of organophosphorus reagents yielded the corresponding allylic amines without the need to isolate the intermediate aldehyde. This circumvents the problem of instability of the aldehydes. The method tolerates well both Wittig and Horner–Wadsworth–Emmons organophosphorus reagents. A better Z-(dia)stereoselectivity was observed when compared to the previous one-pot method. The (dia)stereoselectivity of the process was affected neither by the reaction solvent nor by the amount of DIBAL-H employed. The method is compatible with the presence of free hydroxy groups as shown with serine and threonine derivatives.
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Affiliation(s)
- Gastón Silveira-Dorta
- Instituto Universitario de Bio-Orgánica "Antonio González" (IUBO-AG), Centro de Investigaciones Biomédicas de Canarias (CIBICAN), Universidad de La Laguna. C/ Astrofísico Francisco Sánchez 2, 38206, La Laguna, Spain
| | - Sergio J Álvarez-Méndez
- Instituto Universitario de Bio-Orgánica "Antonio González" (IUBO-AG), Centro de Investigaciones Biomédicas de Canarias (CIBICAN), Universidad de La Laguna. C/ Astrofísico Francisco Sánchez 2, 38206, La Laguna, Spain
| | - Víctor S Martín
- Instituto Universitario de Bio-Orgánica "Antonio González" (IUBO-AG), Centro de Investigaciones Biomédicas de Canarias (CIBICAN), Universidad de La Laguna. C/ Astrofísico Francisco Sánchez 2, 38206, La Laguna, Spain
| | - José M Padrón
- Instituto Universitario de Bio-Orgánica "Antonio González" (IUBO-AG), Centro de Investigaciones Biomédicas de Canarias (CIBICAN), Universidad de La Laguna. C/ Astrofísico Francisco Sánchez 2, 38206, La Laguna, Spain
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28
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Nishikata T, Abela AR, Huang S, Lipshutz BH. Cationic Pd(II)-catalyzed C-H activation/cross-coupling reactions at room temperature: synthetic and mechanistic studies. Beilstein J Org Chem 2016; 12:1040-64. [PMID: 27340491 PMCID: PMC4902085 DOI: 10.3762/bjoc.12.99] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [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: 01/18/2016] [Accepted: 04/28/2016] [Indexed: 11/23/2022] Open
Abstract
Cationic palladium(II) complexes have been found to be highly reactive towards aromatic C-H activation of arylureas at room temperature. A commercially available catalyst [Pd(MeCN)4](BF4)2 or a nitrile-free cationic palladium(II) complex generated in situ from the reaction of Pd(OAc)2 and HBF4, effectively catalyzes C-H activation/cross-coupling reactions between aryl iodides, arylboronic acids and acrylates under milder conditions than those previously reported. The nature of the directing group was found to be critical for achieving room temperature conditions, with the urea moiety the most effective in promoting facile coupling reactions at an ortho C-H position. This methodology has been utilized in a streamlined and efficient synthesis of boscalid, an agent produced on the kiloton scale annually and used to control a range of plant pathogens in broadacre and horticultural crops. Mechanistic investigations led to a proposed catalytic cycle involving three steps: (1) C-H activation to generate a cationic palladacycle; (2) reaction of the cationic palladacycle with an aryl iodide, arylboronic acid or acrylate, and (3) regeneration of the active cationic palladium catalyst. The reaction between a cationic palladium(II) complex and arylurea allowed the formation and isolation of the corresponding palladacycle intermediate, characterized by X-ray analysis. Roles of various additives in the stepwise process have also been studied.
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Affiliation(s)
- Takashi Nishikata
- Department of Chemistry & Biochemistry, University of California, Santa Barbara, CA 93106, USA
| | - Alexander R Abela
- Department of Chemistry & Biochemistry, University of California, Santa Barbara, CA 93106, USA
| | - Shenlin Huang
- Department of Chemistry & Biochemistry, University of California, Santa Barbara, CA 93106, USA
| | - Bruce H Lipshutz
- Department of Chemistry & Biochemistry, University of California, Santa Barbara, CA 93106, USA
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29
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Abstract
A Pd-catalyzed/N-heterocycle-directed C(sp(3) )-H olefination has been developed. The monoprotected amino acid ligand (MPAA) is found to significantly promote Pd-catalyzed C(sp(3) )-H olefination for the first time. Cu(OAc)2 instead of Ag(+) salts are used as the terminal oxidant. This reaction provides a useful method for the synthesis of alkylated pyrazoles.
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Affiliation(s)
- Weibo Yang
- Department of Chemistry, The Scripps Research Institute (TSRI), 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Shengqing Ye
- Department of Chemistry, The Scripps Research Institute (TSRI), 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Yvonne Schmidt
- Medicinal Chemistry, Vertex Pharmaceuticals, 11010 Torreyana Rd., San Diego, CA, 92121, USA
| | - Dean Stamos
- Medicinal Chemistry, Vertex Pharmaceuticals, 11010 Torreyana Rd., San Diego, CA, 92121, USA
| | - Jin-Quan Yu
- Department of Chemistry, The Scripps Research Institute (TSRI), 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA.
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30
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Schirmer ML, Adomeit S, Spannenberg A, Werner T. Novel Base-Free Catalytic Wittig Reaction for the Synthesis of Highly Functionalized Alkenes. Chemistry 2016; 22:2458-65. [PMID: 26762186 DOI: 10.1002/chem.201503744] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [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: 09/17/2015] [Indexed: 11/06/2022]
Abstract
A highly efficient catalyst system for base-free catalytic Wittig reactions has been developed and optimized. Initially, several potential (pre)catalysts as well as different silanes as reducing agents were screened. A system based on a readily available phosphine oxide as precatalyst and trimethoxy silane as reducing agent proved to be optimal. The effect of various Brønsted acidic additives was studied. Subsequently, the reaction conditions were optimized and standard reaction conditions were determined. Under these conditions the scope of this new protocol was evaluated. Nine activated olefins and 33 aldehydes were converted into 42 highly functionalized alkenes. Notably, aromatic, aliphatic as well as heteroaromatic aldehydes could be converted, giving the desired products in isolated yields up to 99 % and with good to excellent E/Z selectivities. These results underline the remarkable efficiency of this protocol considering the complexity of the reaction mixture and the four reaction steps that proceed in parallel in one pot.
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Affiliation(s)
- Marie-Luis Schirmer
- Leibniz-Institut für Katalyse e.V. an der, Universität Rostock, Albert-Einstein-Str. 29a, 18059, Rostock, Germany
| | - Sven Adomeit
- Leibniz-Institut für Katalyse e.V. an der, Universität Rostock, Albert-Einstein-Str. 29a, 18059, Rostock, Germany
| | - Anke Spannenberg
- Leibniz-Institut für Katalyse e.V. an der, Universität Rostock, Albert-Einstein-Str. 29a, 18059, Rostock, Germany
| | - Thomas Werner
- Leibniz-Institut für Katalyse e.V. an der, Universität Rostock, Albert-Einstein-Str. 29a, 18059, Rostock, Germany.
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31
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Zhu D, Liu P, Lu W, Wang H, Luo B, Hu Y, Huang P, Wen S. Relayed Regioselective Alkynylation/ Olefination of Unsymmetrical Cyclic Diaryliodonium Species Catalyzed by Cu and Pd: Affording Fluorescent Cytotoxic Benzoxazoles. Chemistry 2015; 21:18915-20. [PMID: 26516085 DOI: 10.1002/chem.201503791] [Citation(s) in RCA: 18] [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: 09/21/2015] [Indexed: 11/10/2022]
Abstract
Although cyclic diaryliodonium species have the potential to act as valuable synthons for cascade transformations, they still remain largely unexplored. The regioselectivity associated with unsymmetrical cyclic diaryliodonium species has previously been known to pose a challenge. A regioselective relayed alkynylation and olefination of unsymmetrical cyclic diaryliodonium species has been achieved by installation of a directing amido group. These relayed transformations were delayed until an oxazole ring had formed, delivering a series of unique fluorescent benzoxazoles. Moreover, some of these synthetic benzoxazoles showed apparent inhibitory activity against malignant cancer cells. Further confocal visualization revealed that benzoxazoles targeted cell nuclei. These findings might provide a novel structural scaffold to develop desirable anticancer agents.
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Affiliation(s)
- Daqian Zhu
- Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University 651 Dongfeng East Road, Guangzhou 510060 (China).,School of Pharmaceutical Sciences, Sun Yat-sen University, 132 Waihuan East Road, Guangzhou 510006 (China)
| | - Panpan Liu
- Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University 651 Dongfeng East Road, Guangzhou 510060 (China)
| | - Wenhua Lu
- Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University 651 Dongfeng East Road, Guangzhou 510060 (China)
| | - Haiwen Wang
- School of Pharmaceutical Sciences, Sun Yat-sen University, 132 Waihuan East Road, Guangzhou 510006 (China)
| | - Bingling Luo
- Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University 651 Dongfeng East Road, Guangzhou 510060 (China).,School of Pharmaceutical Sciences, Sun Yat-sen University, 132 Waihuan East Road, Guangzhou 510006 (China)
| | - Yumin Hu
- Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University 651 Dongfeng East Road, Guangzhou 510060 (China)
| | - Peng Huang
- Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University 651 Dongfeng East Road, Guangzhou 510060 (China).
| | - Shijun Wen
- Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University 651 Dongfeng East Road, Guangzhou 510060 (China). .,School of Pharmaceutical Sciences, Sun Yat-sen University, 132 Waihuan East Road, Guangzhou 510006 (China).
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32
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Liu Y, Virgil SC, Grubbs RH, Stoltz BM. Palladium-Catalyzed Decarbonylative Dehydration for the Synthesis of α-Vinyl Carbonyl Compounds and Total Synthesis of (-)-Aspewentins A, B, and C. Angew Chem Int Ed Engl 2015; 54:11800-3. [PMID: 26230413 DOI: 10.1002/anie.201505161] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [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: 06/06/2015] [Indexed: 11/12/2022]
Abstract
The direct α-vinylation of carbonyl compounds to form a quaternary stereocenter is a challenging transformation. It was discovered that δ-oxocarboxylic acids can serve as masked vinyl compounds and be unveiled by palladium-catalyzed decarbonylative dehydration. The carboxylic acids are readily available through enantioselective acrylate addition or asymmetric allylic alkylation. A variety of α-vinyl quaternary carbonyl compounds are obtained in good yields, and an application in the first enantioselective total synthesis of (-)-aspewentins A, B, and C is demonstrated.
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Affiliation(s)
- Yiyang Liu
- The Warren and Katharine Schlinger Laboratory for Chemistry and Chemical Engineering, Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, MC 101-20, Pasadena, CA 91125 (USA)
| | - Scott C Virgil
- The Warren and Katharine Schlinger Laboratory for Chemistry and Chemical Engineering, Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, MC 101-20, Pasadena, CA 91125 (USA)
| | - Robert H Grubbs
- The Warren and Katharine Schlinger Laboratory for Chemistry and Chemical Engineering, Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, MC 101-20, Pasadena, CA 91125 (USA).
| | - Brian M Stoltz
- The Warren and Katharine Schlinger Laboratory for Chemistry and Chemical Engineering, Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, MC 101-20, Pasadena, CA 91125 (USA).
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33
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Vogel CV, Pietraszkiewicz H, Sabry OM, Gerwick WH, Valeriote FA, Vanderwal CD. Enantioselective divergent syntheses of several polyhalogenated Plocamium monoterpenes and evaluation of their selectivity for solid tumors. Angew Chem Int Ed Engl 2014; 53:12205-9. [PMID: 25220828 PMCID: PMC4219742 DOI: 10.1002/anie.201407726] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Revised: 08/20/2014] [Indexed: 11/10/2022]
Abstract
The family of polyhalogenated monoterpenes from Plocamium counts over a hundred known members. Using glyceraldehyde acetonide as a chiral-pool precursor, an enantioselective and divergent strategy was developed that provides a blueprint for the synthesis of many of the small yet complex acyclic members of this family. The broad applicability of this approach is demonstrated with the short, eight-step synthesis of four natural products and three analogues. These syntheses are the first of any members of the acyclic polyhalogenated Plocamium monoterpenes and permitted the evaluation of their selectivity against a range of tumor cell lines.
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Affiliation(s)
- Carl V. Vogel
- 1102 Natural Sciences II, Department of Chemistry, University of California, Irvine, Irvine, CA 92697 USA
| | - Halina Pietraszkiewicz
- Division of Hematology and Oncology, Department of Internal Medicine, Henry Ford Hospital, Detroit, MI 48202 USA
| | - Omar M. Sabry
- College of Pharmacy, Oregon State University, Corvallis, OR 97331 USA
| | - William H. Gerwick
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA 92093 USA
| | - Frederick A. Valeriote
- Division of Hematology and Oncology, Department of Internal Medicine, Henry Ford Hospital, Detroit, MI 48202 USA
| | - Christopher D. Vanderwal
- 1102 Natural Sciences II, Department of Chemistry, University of California, Irvine, Irvine, CA 92697 USA
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Coyle EE, Doonan BJ, Holohan AJ, Walsh KA, Lavigne F, Krenske EH, O'Brien CJ. Catalytic wittig reactions of semi- and nonstabilized ylides enabled by ylide tuning. Angew Chem Int Ed Engl 2014; 53:12907-11. [PMID: 25250907 DOI: 10.1002/anie.201406103] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [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: 06/11/2014] [Indexed: 11/09/2022]
Abstract
The first examples of catalytic Wittig reactions with semistabilized and nonstabilized ylides are reported. These reactions were enabled by utilization of a masked base, sodium tert-butyl carbonate, and/or ylide tuning. The acidity of the ylide-forming proton was tuned by varying the electron density at the phosphorus center in the precatalyst, thus facilitating the use of relatively mild bases. Steric modification of the precatalyst structure resulted in significant enhancement of E selectivity up to >95:5, E/Z.
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Affiliation(s)
- Emma E Coyle
- National Centre for Sensor Research (NCSR), Dublin City University, Glasnevin, Dublin 9 (Ireland)
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35
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Focken T, Hanessian S. Application of cyclic phosphonamide reagents in the total synthesis of natural products and biologically active molecules. Beilstein J Org Chem 2014; 10:1848-77. [PMID: 25246946 PMCID: PMC4168934 DOI: 10.3762/bjoc.10.195] [Citation(s) in RCA: 10] [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: 04/10/2014] [Accepted: 06/26/2014] [Indexed: 12/12/2022] Open
Abstract
A review of the synthesis of natural products and bioactive compounds adopting phosphonamide anion technology is presented highlighting the utility of phosphonamide reagents in stereocontrolled bond-forming reactions. Methodologies utilizing phosphonamide anions in asymmetric alkylations, Michael additions, olefinations, and cyclopropanations will be summarized, as well as an overview of the synthesis of the employed phosphonamide reagents.
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Affiliation(s)
- Thilo Focken
- Xenon Pharmaceuticals Inc., 3650 Gilmore Way, Burnaby, BC V5G 4W8, Canada
| | - Stephen Hanessian
- Department of Chemistry, Université de Montréal, C.P. 6128, Succursale Centre-Ville, Montréal, QC H3C 3J7, Canada
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Chowdhury AD, Weding N, Julis J, Franke R, Jackstell R, Beller M. Towards a practical development of light-driven acceptorless alkane dehydrogenation. Angew Chem Int Ed Engl 2014; 53:6477-81. [PMID: 24829085 DOI: 10.1002/anie.201402287] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [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: 02/11/2014] [Revised: 03/28/2014] [Indexed: 11/07/2022]
Abstract
The efficient catalytic dehydrogenation of alkanes to olefins is one of the most investigated reactions in organic synthesis. In the coming years, an increased supply of shorter-chain alkanes from natural and shale gas will offer new opportunities for inexpensive carbon feedstock through such dehydrogenation processes. Existing methods for alkane dehydrogenation using heterogeneous catalysts require harsh reaction conditions and have a lack of selectivity, whereas homogeneous catalysis methods result in significant waste generation. A strong need exists for atom-efficient alkane dehydrogenations on a useful scale. Herein, we have developed improved acceptorless catalytic systems under optimal light transmittance conditions using trans-[Rh(PMe3)2(CO)Cl] as the catalyst with different additives. Unprecedented catalyst turnover numbers are obtained for the dehydrogenation of cyclic and linear (from C4) alkanes and liquid organic hydrogen carriers. These reactions proceed with unique conversion, thereby providing a basis for practical alkane dehydrogenations.
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Affiliation(s)
- Abhishek Dutta Chowdhury
- Leibniz-Institut für Katalyse an der Universität Rostock, Albert-Einstein-Strasse 29a, 18059 Rostock (Germany)
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37
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Yu YY, Georg GI. Biomimetic Aerobic C-H Olefination of Cyclic Enaminones at Room Temperature: Development toward the Synthesis of 1,3,5-Trisubstituted Benzenes. Adv Synth Catal 2014; 356:1359-1369. [PMID: 25071423 DOI: 10.1002/adsc.201300904] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
A green and mild protocol for the dehydrogenative olefination of cyclic enaminones was devised via palladium catalysis at room temperature using oxygen as the terminal oxidant. The synthetic utility of the olefinated cyclic enaminones afforded a series of unique 1,3,5-trisubstituted benzenes via an unanticipated Diels-Alder tandem reaction. The broad substrate scope and good yields achieved with this new protocol provide an alternative pathway for arene functionalization.
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Affiliation(s)
- Yi-Yun Yu
- Department of Chemistry, Department of Medicinal Chemistry and the Institute for Therapeutics Discovery and Development, University of Minnesota, Twin Cities, 717 Delaware St SE, Minneapolis, Minnesota, USA
| | - Gunda I Georg
- Department of Chemistry, Department of Medicinal Chemistry and the Institute for Therapeutics Discovery and Development, University of Minnesota, Twin Cities, 717 Delaware St SE, Minneapolis, Minnesota, USA
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38
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O'Brien CJ, Nixon ZS, Holohan AJ, Kunkel SR, Tellez JL, Doonan BJ, Coyle EE, Lavigne F, Kang LJ, Przeworski KC. Part I: the development of the catalytic Wittig reaction. Chemistry 2013; 19:15281-9. [PMID: 24115040 DOI: 10.1002/chem.201301444] [Citation(s) in RCA: 77] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Indexed: 11/12/2022]
Abstract
We have developed the first catalytic (in phosphane) Wittig reaction (CWR). The utilization of an organosilane was pivotal for success as it allowed for the chemoselective reduction of a phosphane oxide. Protocol optimization evaluated the phosphane oxide precatalyst structure, loading, organosilane, temperature, solvent, and base. These studies demonstrated that to maintain viable catalytic performance it was necessary to employ cyclic phosphane oxide precatalysts of type 1. Initial substrate studies utilized sodium carbonate as a base, and further experimentation identified N,N-diisopropylethylamine (DIPEA) as a soluble alternative. The use of DIPEA improved the ease of use, broadened the substrate scope, and decreased the precatalyst loading. The optimized protocols were compatible with alkyl, aryl, and heterocyclic (furyl, indolyl, pyridyl, pyrrolyl, and thienyl) aldehydes to produce both di- and trisubstituted olefins in moderate-to-high yields (60-96%) by using a precatalyst loading of 4-10 mol%. Kinetic E/Z selectivity was generally 66:34; complete E selectivity for disubstituted α,β-unsaturated products was achieved through a phosphane-mediated isomerization event. The CWR was applied to the synthesis of 54, a known precursor to the anti-Alzheimer drug donepezil hydrochloride, on a multigram scale (12.2 g, 74% yield). In addition, to our knowledge, the described CWR is the only transition-/heavy-metal-free catalytic olefination process, excluding proton-catalyzed elimination reactions.
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Affiliation(s)
- Christopher J O'Brien
- School of Chemical Sciences, Dublin City University, Glasnevin, Dublin 9 (Ireland) http://webpages.dcu.ie/∼obrienc/OBrien_Group/Home.html.
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Colombel S, Van Hijfte N, Poisson T, Leclerc E, Pannecoucke X. Addition of electrophilic radicals to 2-benzyloxyglycals: synthesis and functionalization of fluorinated α-C-glycosides and derivatives. Chemistry 2013; 19:12778-87. [PMID: 23955898 DOI: 10.1002/chem.201302070] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [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: 05/30/2013] [Indexed: 01/13/2023]
Abstract
A new method for the synthesis of fluorinated α-C-glycosides is described. The reactions between highly electrophilic radicals (fluorinated or unfluorinated) and a 2-benzyloxyglucal or galactal provide 2-keto-D-arabino- or 2-keto-D-lyxo-hexopyranosides through an addition/fragmentation process. Sodium borohydride mediated or Meerwein-Ponndorf-Verley (MPV) reduction of these compounds provides α-C-glycosides that feature appropriate anchoring groups for further synthetic elaboration. The presence of CF2 CO2 iPr or CF2 Br groups at the pseudo-anomeric position allows efficient reduction/olefination or Br/Li-exchange/nucleophilic-addition sequences. These transformations open the way for the synthesis of fluorinated C-glycosidic analogues of glycoconjugates.
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Affiliation(s)
- Sophie Colombel
- Normandie Université, COBRA, UMR 6014 et FR 3038, Université Rouen, INSA Rouen, CNRS, 1 rue Tesnière, 76821 Mont Saint-Aignan Cedex (France)
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40
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Li G, Leow D, Wan L, Yu JQ. Ether-directed ortho-C-H olefination with a palladium(II)/monoprotected amino acid catalyst. Angew Chem Int Ed Engl 2013; 52:1245-7. [PMID: 23239120 PMCID: PMC3786684 DOI: 10.1002/anie.201207770] [Citation(s) in RCA: 132] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2012] [Revised: 11/27/2012] [Indexed: 11/09/2022]
Abstract
Weak coordination is powerful! A PdII-catalyzed olefination of ortho -C–H bonds of arenes directed by weakly coordinating ethers is developed using mono-protected amino acid (MPAA) ligands. This finding provides a method for chemically modifying ethers, which are abundant in natural products and drug molecules.
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Affiliation(s)
- Gang Li
- Department of Chemistry The Scripps Research Institute (TSRI) 10550 North Torrey Pines Road, La Jolla, CA 92037 (USA)
| | - Dasheng Leow
- Department of Chemistry The Scripps Research Institute (TSRI) 10550 North Torrey Pines Road, La Jolla, CA 92037 (USA)
| | | | - Jin-Quan Yu
- Department of Chemistry The Scripps Research Institute (TSRI) 10550 North Torrey Pines Road, La Jolla, CA 92037 (USA)
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41
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Abstract
Heterocyclic compounds are ubiquitous in natural products, pharmaceuticals, and agrochemicals. Therefore, the design of novel protocols to construct heterocycles more efficiently is a major area of focus in the organic chemistry. In the past several years, cyclization reactions based upon palladium-catalyzed C-H activation have received substantial attention due to their capacity for expediting heterocycle synthesis. This review discusses strategies for heterocycle synthesis via palladium-catalyzed C-H bond activation and highlights recent examples from the literature.
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Affiliation(s)
- Tian-Sheng Mei
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Rd., La Jolla, CA 92037 (USA), Fax: (+1) 858-784-2409
| | - Lei Kou
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Rd., La Jolla, CA 92037 (USA), Fax: (+1) 858-784-2409
| | - Sandy Ma
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Rd., La Jolla, CA 92037 (USA), Fax: (+1) 858-784-2409
| | - Keary M. Engle
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Rd., La Jolla, CA 92037 (USA), Fax: (+1) 858-784-2409
| | - Jin-Quan Yu
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Rd., La Jolla, CA 92037 (USA), Fax: (+1) 858-784-2409
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42
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Abstract
Complementary catalytic systems have been developed in which the reactivity/selectivity balance in Pd(II)-catalyzed ortho -C–H olefination can be modulated through ligand control. This allows for sequential C–H functionalization for the rapid preparation of 1,2,3-trisubstituted arenes. Additionally, a rare example of iterative C–H activation, in which a newly installed functional group directs subsequent C–H activation has been demonstrated.
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Affiliation(s)
- Keary M. Engle
- Department of Chemistry, The Scripps Research Institute (TSRI), 10550 N. Torrey Pines Road, La Jolla, CA 92037 (USA)
| | - Dong-Hui Wang
- Department of Chemistry, The Scripps Research Institute (TSRI), 10550 N. Torrey Pines Road, La Jolla, CA 92037 (USA)
| | - Jin-Quan Yu
- Department of Chemistry, The Scripps Research Institute (TSRI), 10550 N. Torrey Pines Road, La Jolla, CA 92037 (USA)
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Abstract
Mild and efficient synthesis of phenyl (alpha-fluoro)vinyl sulfones via condensation of aldehydes and a ketone with a novel benzothiazolyl based bis-sulfone reagent is reported and this proceeds with moderate to good Z-stereoselectivity.
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Affiliation(s)
| | | | - Barbara Zajc
- Department of Chemistry, The City College and The City University of New York, 160 Convent Avenue, New York, NY 10031, USA
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