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Zhang Z, Wang Y, Chen X, Song X, Tu Z, Chen Y, Zhang Z, Ding K. Characterization of an aromatic trifluoromethyl ketone as a new warhead for covalently reversible kinase inhibitor design. Bioorg Med Chem 2021; 50:116457. [PMID: 34670167 DOI: 10.1016/j.bmc.2021.116457] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Revised: 09/17/2021] [Accepted: 09/29/2021] [Indexed: 12/28/2022]
Abstract
An aromatic trifluoromethyl ketone moiety was characterized as a new warhead for covalently reversible kinase inhibitor design to target the non-catalytic cysteine residue. Potent and selective covalently reversible inhibitors of FGFR4 kinase were successfully designed and synthesized by utilizing this new warhead. The binding mode of a representative inhibitor was fully characterized by using multiple technologies including MALDI-TOF mass spectrometry, dialysis assay and X-ray crystallographic studies etc. This functional group was also successfully applied to discovery of a new JAK3 inhibitor, suggesting its potential application in designing other kinase inhibitors.
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Affiliation(s)
- Zhen Zhang
- International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development, Ministry of Education (MOE) of PR China, College of Pharmacy, Jinan University, 601 Huangpu Avenue West, Guangzhou 510632, China
| | - Yongjin Wang
- International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development, Ministry of Education (MOE) of PR China, College of Pharmacy, Jinan University, 601 Huangpu Avenue West, Guangzhou 510632, China
| | - Xiaojuan Chen
- Department of Oncology, NHC Key Laboratory of Cancer Proteomics, Laboratory of Structural Biology, National Clinical Research Center for Geriatric Disorder, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Xiaojuan Song
- Drug Discovery Pipeline & Guangdong Provincial Key Laboratory of Biocomputing, Guangzhou Institutes of Biomedicine and Health, Guangzhou 510530, China
| | - Zhengchao Tu
- International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development, Ministry of Education (MOE) of PR China, College of Pharmacy, Jinan University, 601 Huangpu Avenue West, Guangzhou 510632, China; Drug Discovery Pipeline & Guangdong Provincial Key Laboratory of Biocomputing, Guangzhou Institutes of Biomedicine and Health, Guangzhou 510530, China
| | - Yongheng Chen
- Department of Oncology, NHC Key Laboratory of Cancer Proteomics, Laboratory of Structural Biology, National Clinical Research Center for Geriatric Disorder, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Zhimin Zhang
- International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development, Ministry of Education (MOE) of PR China, College of Pharmacy, Jinan University, 601 Huangpu Avenue West, Guangzhou 510632, China
| | - Ke Ding
- International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development, Ministry of Education (MOE) of PR China, College of Pharmacy, Jinan University, 601 Huangpu Avenue West, Guangzhou 510632, China; The First Affiliated Hospital, Jinan University, 601 Huangpu Avenue West, Guangzhou 510632, China.
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2
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Han ZZ, Dong T, Ming XX, Kuang F, Zhang CP. Synthesis and Biological Evaluation of CF 3 Se-Substituted α-Amino Acid Derivatives. ChemMedChem 2021; 16:3177-3180. [PMID: 34268896 DOI: 10.1002/cmdc.202100451] [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] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 07/14/2021] [Indexed: 11/07/2022]
Abstract
Several CF3 Se-substituted α-amino acid derivatives, such as (R)-2-amino-3-((trifluoromethyl)selanyl)propanoates (5 a/6 a), (S)-2-amino-4-((trifluoromethyl)selanyl)butanoates (5 b/6 b), (2R,3R)-2-amino-3-((trifluoromethyl)selanyl)butanoates (5 c/6 c), (R)-2-((S)-2-amino-3-phenylpropanamido)-3-((trifluoromethyl)selanyl)propanoates (11 a/12 a), and (R)-2-(2-aminoacetamido)-3-((trifluoromethyl)selanyl)propanoates (11 b/12 b), were readily synthesized from natural amino acids and [Me4 N][SeCF3 ]. The primary in vitro cytotoxicity assays revealed that compounds 6 a, 11 a and 12 a were more effective cell growth inhibitors than the other tested CF3 Se-substituted derivatives towards MCF-7, HCT116, and SK-OV-3 cells, with their IC50 values being less than 10 μM for MCF-7 and HCT116 cells. This study indicated the potentials of CF3 Se moiety as a pharmaceutically relevant group in the design and synthesis of novel biologically active molecules.
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Affiliation(s)
- Zhou-Zhou Han
- School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, 205 Luoshi Road, Wuhan, 430070, China
| | - Tao Dong
- School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, 205 Luoshi Road, Wuhan, 430070, China
| | - Xiao-Xia Ming
- School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, 205 Luoshi Road, Wuhan, 430070, China
| | - Fu Kuang
- Department of phase I clinical trial center, the Second Affiliated Hospital of Chongqing Medical University, Chongqing, 40010, China
| | - Cheng-Pan Zhang
- School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, 205 Luoshi Road, Wuhan, 430070, China
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3
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Ariawan AD, Mansour F, Richardson N, Bhadbhade M, Ho J, Hunter L. The Effect of Vicinal Difluorination on the Conformation and Potency of Histone Deacetylase Inhibitors. Molecules 2021; 26:molecules26133974. [PMID: 34209791 PMCID: PMC8271401 DOI: 10.3390/molecules26133974] [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] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 06/24/2021] [Accepted: 06/24/2021] [Indexed: 11/17/2022] Open
Abstract
Histone deacetylase enzymes (HDACs) are potential targets for the treatment of cancer and other diseases, but it is challenging to design isoform-selective agents. In this work, we created new analogs of two established but non-selective HDAC inhibitors. We decorated the central linker chains of the molecules with specifically positioned fluorine atoms in order to control the molecular conformations. The fluorinated analogs were screened against a panel of 11 HDAC isoforms, and minor differences in isoform selectivity patterns were observed.
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Affiliation(s)
- A Daryl Ariawan
- School of Chemistry, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Flora Mansour
- School of Chemistry, UNSW Sydney, Sydney, NSW 2052, Australia
| | | | - Mohan Bhadbhade
- Mark Wainwright Analytical Centre, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Junming Ho
- School of Chemistry, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Luke Hunter
- School of Chemistry, UNSW Sydney, Sydney, NSW 2052, Australia
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4
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Yang H, Zhang R, Li Z, Maienfisch P, Xu X. Design, synthesis and nematicidal activitives of trifluorobutene amide derivatives against Meloidogyne incognita. Bioorg Med Chem Lett 2021; 40:127917. [PMID: 33705904 DOI: 10.1016/j.bmcl.2021.127917] [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] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 02/22/2021] [Accepted: 02/24/2021] [Indexed: 11/19/2022]
Abstract
Plant parasitic nematodes have always been a pressing problem in the field of plant protection. Well-established chemical nematicides, especially organophosphorus and carbamates are the most used products for nematode control worldwide. Due to long-term overuse, they have developed serious resistance and new innovative solutions are urgently required. In this study, thirty-one novel trifluorobutene amide derivatives were designed and synthesized, and their nematicidal activities were determined. Three different synthetic methods have been developed for the final amidation reaction enabling the successfully syntheses of the target compounds independently from the nucleophilicities of the substrate amino group. Most target compounds showed good nematicidal activity in our in vitro test. Among all the compounds, compounds A8 and A23 exhibited excellent nematicidal activity against Meloidogyne incognita, their LC50 values are 2.02 mg L-1 and 0.76 mg L-1, respectively. In particular, compound A23 has found to be almost as active as the commercial nematicide fluensulfone. Furthermore, most compounds gave full control (100% inhibition) of M. incognita at 40 mg L-1 in the in vivo tests in sandy soil, the best compounds were further investigated for in vivo activity in matrix soil. Among the compound tested, compound A8 showed excellent in vivo nematicidal activity. At a concentration of 5 mg L-1 still 56% inhibition was observed. The results of our study indicate that compound A8 possesses excellent in vitro and in vivo nematicidal activity, and can be considered as promising lead molecule for further modification.
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Affiliation(s)
- Haiping Yang
- Shanghai Key Laboratory of Chemical Biology, School of Pharmacy, East China University of Science and Technology, Shanghai 200237, China
| | - Ruifeng Zhang
- Shanghai Key Laboratory of Chemical Biology, School of Pharmacy, East China University of Science and Technology, Shanghai 200237, China
| | - Zhong Li
- Shanghai Key Laboratory of Chemical Biology, School of Pharmacy, East China University of Science and Technology, Shanghai 200237, China
| | - Peter Maienfisch
- Shanghai Key Laboratory of Chemical Biology, School of Pharmacy, East China University of Science and Technology, Shanghai 200237, China; CreInSol MCB, CH-4118 Rodersdorf, Switzerland.
| | - Xiaoyong Xu
- Shanghai Key Laboratory of Chemical Biology, School of Pharmacy, East China University of Science and Technology, Shanghai 200237, China.
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Lai TH, Schröder S, Toussaint M, Dukić-Stefanović S, Kranz M, Ludwig FA, Fischer S, Steinbach J, Deuther-Conrad W, Brust P, Moldovan RP. Development of 18F-Labeled Radiotracers for PET Imaging of the Adenosine A 2A Receptor: Synthesis, Radiolabeling and Preliminary Biological Evaluation. Int J Mol Sci 2021; 22:ijms22052285. [PMID: 33669003 PMCID: PMC7956753 DOI: 10.3390/ijms22052285] [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] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 02/21/2021] [Accepted: 02/22/2021] [Indexed: 12/19/2022] Open
Abstract
The adenosine A2A receptor (A2AR) represents a potential therapeutic target for neurodegenerative diseases. Aiming at the development of a positron emission tomography (PET) radiotracer to monitor changes of receptor density and/or occupancy during the A2AR-tailored therapy, we designed a library of fluorinated analogs based on a recently published lead compound (PPY). Among those, the highly affine 4-fluorobenzyl derivate (PPY1; Ki(hA2AR) = 5.3 nM) and the 2-fluorobenzyl derivate (PPY2; Ki(hA2AR) = 2.1 nM) were chosen for 18F-labeling via an alcohol-enhanced copper-mediated procedure starting from the corresponding boronic acid pinacol ester precursors. Investigations of the metabolic stability of [18F]PPY1 and [18F]PPY2 in CD-1 mice by radio-HPLC analysis revealed parent fractions of more than 76% of total activity in the brain. Specific binding of [18F]PPY2 on mice brain slices was demonstrated by in vitro autoradiography. In vivo PET/magnetic resonance imaging (MRI) studies in CD-1 mice revealed a reasonable high initial brain uptake for both radiotracers, followed by a fast clearance.
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Affiliation(s)
- Thu Hang Lai
- Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Department of Neuroradiopharmaceuticals, Institute of Radiopharmaceutical Cancer Research, Research Site Leipzig, 04318 Leipzig, Germany; (M.T.); (S.D.-S.); (M.K.); (F.-A.L.); (S.F.); (J.S.); (W.D.-C.); (P.B.)
- Department of Research and Development, ROTOP Pharmaka Ltd., Dresden 01328, Germany;
- Correspondence: (T.H.L.); (R.-P.M.); Tel.: +49-341-234-179-4635 (T.H.L.); +49-341-234-179-4634 (R.-P.M.)
| | - Susann Schröder
- Department of Research and Development, ROTOP Pharmaka Ltd., Dresden 01328, Germany;
| | - Magali Toussaint
- Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Department of Neuroradiopharmaceuticals, Institute of Radiopharmaceutical Cancer Research, Research Site Leipzig, 04318 Leipzig, Germany; (M.T.); (S.D.-S.); (M.K.); (F.-A.L.); (S.F.); (J.S.); (W.D.-C.); (P.B.)
| | - Sladjana Dukić-Stefanović
- Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Department of Neuroradiopharmaceuticals, Institute of Radiopharmaceutical Cancer Research, Research Site Leipzig, 04318 Leipzig, Germany; (M.T.); (S.D.-S.); (M.K.); (F.-A.L.); (S.F.); (J.S.); (W.D.-C.); (P.B.)
| | - Mathias Kranz
- Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Department of Neuroradiopharmaceuticals, Institute of Radiopharmaceutical Cancer Research, Research Site Leipzig, 04318 Leipzig, Germany; (M.T.); (S.D.-S.); (M.K.); (F.-A.L.); (S.F.); (J.S.); (W.D.-C.); (P.B.)
- PET Imaging Center, University Hospital of North Norway (UNN), 9009 Tromsø, Norway
- Nuclear Medicine and Radiation Biology Research Group, The Arctic University of Norway, 9009 Tromsø, Norway
| | - Friedrich-Alexander Ludwig
- Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Department of Neuroradiopharmaceuticals, Institute of Radiopharmaceutical Cancer Research, Research Site Leipzig, 04318 Leipzig, Germany; (M.T.); (S.D.-S.); (M.K.); (F.-A.L.); (S.F.); (J.S.); (W.D.-C.); (P.B.)
| | - Steffen Fischer
- Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Department of Neuroradiopharmaceuticals, Institute of Radiopharmaceutical Cancer Research, Research Site Leipzig, 04318 Leipzig, Germany; (M.T.); (S.D.-S.); (M.K.); (F.-A.L.); (S.F.); (J.S.); (W.D.-C.); (P.B.)
| | - Jörg Steinbach
- Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Department of Neuroradiopharmaceuticals, Institute of Radiopharmaceutical Cancer Research, Research Site Leipzig, 04318 Leipzig, Germany; (M.T.); (S.D.-S.); (M.K.); (F.-A.L.); (S.F.); (J.S.); (W.D.-C.); (P.B.)
- Department of Research and Development, ROTOP Pharmaka Ltd., Dresden 01328, Germany;
| | - Winnie Deuther-Conrad
- Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Department of Neuroradiopharmaceuticals, Institute of Radiopharmaceutical Cancer Research, Research Site Leipzig, 04318 Leipzig, Germany; (M.T.); (S.D.-S.); (M.K.); (F.-A.L.); (S.F.); (J.S.); (W.D.-C.); (P.B.)
| | - Peter Brust
- Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Department of Neuroradiopharmaceuticals, Institute of Radiopharmaceutical Cancer Research, Research Site Leipzig, 04318 Leipzig, Germany; (M.T.); (S.D.-S.); (M.K.); (F.-A.L.); (S.F.); (J.S.); (W.D.-C.); (P.B.)
| | - Rareş-Petru Moldovan
- Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Department of Neuroradiopharmaceuticals, Institute of Radiopharmaceutical Cancer Research, Research Site Leipzig, 04318 Leipzig, Germany; (M.T.); (S.D.-S.); (M.K.); (F.-A.L.); (S.F.); (J.S.); (W.D.-C.); (P.B.)
- Correspondence: (T.H.L.); (R.-P.M.); Tel.: +49-341-234-179-4635 (T.H.L.); +49-341-234-179-4634 (R.-P.M.)
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6
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Li MY, Gao YH, Zhang JH, Mi L, Zhu XX, Wang F, Zhou XP, Yan YJ, Chen ZL. Synthesis and evaluation of novel fluorinated hematoporphyrin ether derivatives for photodynamic therapy. Bioorg Chem 2021; 107:104528. [PMID: 33357982 DOI: 10.1016/j.bioorg.2020.104528] [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] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 11/20/2020] [Accepted: 12/01/2020] [Indexed: 12/13/2022]
Abstract
A photosensitizer with high phototoxicity, suitable amphipathy and low dark toxicity could play a pivotal role in photodynamic therapy (PDT). In this study, a facile and versatile approach was adopted to synthesize a series of novel fluorinated hematoporphyrin ether derivatives (I1-I5 and II1-II4), and the photodynamic activities of these compounds were studied. Compared to hematoporphyrin monomethyl ether (HMME), all PSs showed preferable photodynamic activity against A549 lung tumor cells. The longest visible absorption wavelength of these compounds was approximately 622 nm. Among them, II3 revealed the highest singlet oxygen yield (0.0957 min-1), the strongest phototoxicity (IC50 = 1.24 μM), the lowest dark toxicity in vitro, and exhibited excellent anti-tumor effects in vivo. So compound II3 could act as new drug candidate for photodynamic therapy.
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Affiliation(s)
- Man-Yi Li
- Department of Pharmaceutical Science & Technology, College of Chemistry and Biology, Donghua University, Shanghai 201620, China
| | - Ying-Hua Gao
- Department of Pharmaceutical Science & Technology, College of Chemistry and Biology, Donghua University, Shanghai 201620, China
| | - Jia-Hui Zhang
- Department of Pharmaceutical Science & Technology, College of Chemistry and Biology, Donghua University, Shanghai 201620, China
| | - Le Mi
- Department of Pharmaceutical Science & Technology, College of Chemistry and Biology, Donghua University, Shanghai 201620, China
| | - Xue-Xue Zhu
- Department of Pharmaceutical Science & Technology, College of Chemistry and Biology, Donghua University, Shanghai 201620, China
| | - Feng Wang
- Department of Pharmaceutical Science & Technology, College of Chemistry and Biology, Donghua University, Shanghai 201620, China
| | - Xing-Ping Zhou
- Department of Pharmaceutical Science & Technology, College of Chemistry and Biology, Donghua University, Shanghai 201620, China
| | - Yi-Jia Yan
- Shanghai Xianhui Pharmaceutical Co., Ltd., Shanghai 200433, China.
| | - Zhi-Long Chen
- Department of Pharmaceutical Science & Technology, College of Chemistry and Biology, Donghua University, Shanghai 201620, China.
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7
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Lee JW, Lim S, Maienshein DN, Liu P, Ngai MY. Redox-Neutral TEMPO Catalysis: Direct Radical (Hetero)Aryl C-H Di- and Trifluoromethoxylation. Angew Chem Int Ed Engl 2020; 59:21475-21480. [PMID: 32830430 PMCID: PMC7720849 DOI: 10.1002/anie.202009490] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [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: 07/09/2020] [Revised: 08/12/2020] [Indexed: 12/15/2022]
Abstract
Applications of TEMPO. catalysis for the development of redox-neutral transformations are rare. Reported here is the first TEMPO. -catalyzed, redox-neutral C-H di- and trifluoromethoxylation of (hetero)arenes. The reaction exhibits a broad substrate scope, has high functional-group tolerance, and can be employed for the late-stage functionalization of complex druglike molecules. Kinetic measurements, isolation and resubjection of catalytic intermediates, UV/Vis studies, and DFT calculations support the proposed oxidative TEMPO. /TEMPO+ redox catalytic cycle. Mechanistic studies also suggest that Li2 CO3 plays an important role in preventing catalyst deactivation. These findings will provide new insights into the design and development of novel reactions through redox-neutral TEMPO. catalysis.
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Affiliation(s)
- Johnny W Lee
- Department of Chemistry and Institute of Chemical Biology and Drug Discovery, State University of New York, Stony Brook, NY, 11794, USA
| | - Sanghyun Lim
- Department of Chemistry and Institute of Chemical Biology and Drug Discovery, State University of New York, Stony Brook, NY, 11794, USA
| | - Daniel N Maienshein
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - Peng Liu
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - Ming-Yu Ngai
- Department of Chemistry and Institute of Chemical Biology and Drug Discovery, State University of New York, Stony Brook, NY, 11794, USA
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8
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Bekker RBW, Fjellaksel R, Hjornevik T, Nuruddin S, Rafique W, Hansen JH, Sundset R, Haraldsen IH, Riss PJ. Discovery of a Lead Brain-Penetrating Gonadotropin-Releasing Hormone Receptor Antagonist with Saturable Binding in Brain. ChemMedChem 2020; 15:1624-1628. [PMID: 32677155 PMCID: PMC7540054 DOI: 10.1002/cmdc.202000256] [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] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 07/12/2020] [Indexed: 11/30/2022]
Abstract
We report the synthesis, radiosynthesis and biological characterisation of two gonadotropin-releasing hormone receptor (GnRH-R) antagonists with nanomolar binding affinity. A small library of GnRH-R antagonists was synthesised in 20-67 % overall yield with the aim of identifying a high-affinity antagonist capable of crossing the blood-brain barrier. Binding affinity to rat GnRH-R was determined by autoradiography in competitive-binding studies against [125 I]buserelin, and inhibition constants were calculated by using the Cheng-Prusoff equation. The radioligands were obtained in 46-79 % radiochemical yield and >95 % purity and with a molar activity of 19-38 MBq/nmol by direct nucleophilic radiofluorination. Positron emission tomography imaging in rat under baseline conditions in comparison to pretreatment with a receptor-saturating dose of GnRH antagonist revealed saturable uptake (0.1 %ID/mL) into the brain.
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Affiliation(s)
| | - Richard Fjellaksel
- Department of Clinical MedicineUiT The Arctic University of NorwayHansine Hansens veg 189019TromsøNorway
- PET Imaging CenterUniversity Hospital of North NorwaySykehusvegen 389019TromsøNorway
- Department of ChemistryUiT – The Arctic University of NorwayHansine Hansens veg 189019TromsøNorway
| | - Trine Hjornevik
- Department of Diagnostic PhysicsOslo University HospitalSognsvannsveien 200372OsloNorway
| | - Syed Nuruddin
- Norwegian Medical Cyclotron AS, RikshospitaletSognsvannsveien 20OsloNorway
| | - Waqas Rafique
- Department of ChemistryUniversity of OsloSem Sælands vei, 260371OsloNorway
| | - Jørn H. Hansen
- Department of ChemistryUiT – The Arctic University of NorwayHansine Hansens veg 189019TromsøNorway
| | - Rune Sundset
- Department of Clinical MedicineUiT The Arctic University of NorwayHansine Hansens veg 189019TromsøNorway
- PET Imaging CenterUniversity Hospital of North NorwaySykehusvegen 389019TromsøNorway
| | - Ira H. Haraldsen
- Clinical NeurosciencesOslo University Hospital-UllevalKirkeveien 166, post code?OsloNorway
| | - Patrick J. Riss
- Department of ChemistryUniversity of OsloSem Sælands vei, 260371OsloNorway
- Norwegian Medical Cyclotron AS, RikshospitaletSognsvannsveien 20OsloNorway
- Clinical NeurosciencesOslo University Hospital-UllevalKirkeveien 166, post code?OsloNorway
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9
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Pikun NV, Sobolev A, Plotniece A, Rucins M, Vigante B, Petrova M, Muhamadejev R, Pajuste K, Shermolovich YG. Synthesis of Fluorinated 3,6-Dihydropyridines and 2-(Fluoromethyl)pyridines by Electrophilic Fluorination of 1,2-Dihydropyridines with Selectfluor ®. Molecules 2020; 25:E3143. [PMID: 32660085 PMCID: PMC7397266 DOI: 10.3390/molecules25143143] [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] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 07/08/2020] [Accepted: 07/08/2020] [Indexed: 12/02/2022] Open
Abstract
New fluorinated 3,6-dihydropyridines were obtained by the electrophilic fluorination of 1,2-dihydropyridines with Selectfluor®. These 3-fluoro-3,6-dihydropyridines were easily converted to corresponding pyridines by the elimination of hydrogen fluoride under mild conditions. A new approach to the synthesis of methyl 2-(fluoromethyl)-5-nitro-6-arylnicotinates by the fluorination of 3-fluoro-2-methyl-5-nitro-3,6-dihydropyridines or 1,2-dihydropyridines with Selectfluor® has been developed.
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Affiliation(s)
- Nadiia V. Pikun
- Latvian Institute of Organic Synthesis, Aizkraukles Str. 21, LV-1006 Riga, Latvia; (A.S.); (A.P.); (M.R.); (B.V.); (M.P.); (R.M.); (K.P.)
| | - Arkadij Sobolev
- Latvian Institute of Organic Synthesis, Aizkraukles Str. 21, LV-1006 Riga, Latvia; (A.S.); (A.P.); (M.R.); (B.V.); (M.P.); (R.M.); (K.P.)
| | - Aiva Plotniece
- Latvian Institute of Organic Synthesis, Aizkraukles Str. 21, LV-1006 Riga, Latvia; (A.S.); (A.P.); (M.R.); (B.V.); (M.P.); (R.M.); (K.P.)
| | - Martins Rucins
- Latvian Institute of Organic Synthesis, Aizkraukles Str. 21, LV-1006 Riga, Latvia; (A.S.); (A.P.); (M.R.); (B.V.); (M.P.); (R.M.); (K.P.)
| | - Brigita Vigante
- Latvian Institute of Organic Synthesis, Aizkraukles Str. 21, LV-1006 Riga, Latvia; (A.S.); (A.P.); (M.R.); (B.V.); (M.P.); (R.M.); (K.P.)
| | - Marina Petrova
- Latvian Institute of Organic Synthesis, Aizkraukles Str. 21, LV-1006 Riga, Latvia; (A.S.); (A.P.); (M.R.); (B.V.); (M.P.); (R.M.); (K.P.)
| | - Ruslan Muhamadejev
- Latvian Institute of Organic Synthesis, Aizkraukles Str. 21, LV-1006 Riga, Latvia; (A.S.); (A.P.); (M.R.); (B.V.); (M.P.); (R.M.); (K.P.)
| | - Karlis Pajuste
- Latvian Institute of Organic Synthesis, Aizkraukles Str. 21, LV-1006 Riga, Latvia; (A.S.); (A.P.); (M.R.); (B.V.); (M.P.); (R.M.); (K.P.)
| | - Yuriy G. Shermolovich
- Institute of Organic Chemistry NAS of Ukraine, Murmanska Str. 5, 02660 Kyiv, Ukraine;
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10
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Miller E, Kim S, Gibson K, Derrick JS, Toste FD. Regio- and Enantioselective Bromocyclization of Difluoroalkenes as a Strategy to Access Tetrasubstituted Difluoromethylene-Containing Stereocenters. J Am Chem Soc 2020; 142:8946-8952. [PMID: 32352775 PMCID: PMC7508160 DOI: 10.1021/jacs.0c02331] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Difluoromethylene-containing compounds have attracted substantial research interest over the past decades for their ability to mimic biological functions of traditional functional groups while providing a wide variety of pharmacological benefits bestowed by the C-F bond. We report a novel strategy to access RCF2Br-containing heterocycles by regio- and enantioselective bromocyclization of difluoroalkenes enabled by chiral anion phase-transfer catalysis. The utility of this methodology was highlighted through a synthesis of an analogue of efavirenz, a drug used for treating HIV. Additionally, the synthetic versatility of the CF2Br intermediates was showcased through functionalization to a variety of enantioenriched α,α-difluoromethylene-containing products.
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Affiliation(s)
- Edward Miller
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Suhong Kim
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Katarina Gibson
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Jeffrey S Derrick
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - F Dean Toste
- Department of Chemistry, University of California, Berkeley, California 94720, United States
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11
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Han J, Takeda R, Liu X, Konno H, Abe H, Hiramatsu T, Moriwaki H, Soloshonok VA. Preparative Method for Asymmetric Synthesis of ( S)-2-Amino-4,4,4-trifluorobutanoic Acid. Molecules 2019; 24:E4521. [PMID: 31835583 PMCID: PMC6943542 DOI: 10.3390/molecules24244521] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [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: 10/29/2019] [Revised: 12/06/2019] [Accepted: 12/09/2019] [Indexed: 11/30/2022] Open
Abstract
Enantiomerically pure derivatives of 2-amino-4,4,4-trifluorobutanoic acid are in great demand as bioisostere of leucine moiety in the drug design. Here, we disclose a method specifically developed for large-scale (>150 g) preparation of the target (S)-N-Fmoc-2-amino-4,4,4-trifluorobutanoic acid. The method employs a recyclable chiral auxiliary to form the corresponding Ni(II) complex with glycine Schiff base, which is alkylated with CF3-CH2-I under basic conditions. The resultant alkylated Ni(II) complex is disassembled to reclaim the chiral auxiliary and 2-amino-4,4,4-trifluorobutanoic acid, which is in situ converted to the N-Fmoc derivative. The whole procedure was reproduced several times for consecutive preparation of over 300 g of the target (S)-N-Fmoc-2-amino-4,4,4-trifluorobutanoic acid.
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Affiliation(s)
- Jianlin Han
- College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, Jiangsu, China; (J.H.); (X.L.)
| | - Ryosuke Takeda
- Hamari Chemicals Ltd., 1-4-29 Kunijima, Higashi-Yodogawa-ku, Osaka 533-0024, Japan; (R.T.); (T.H.)
| | - Xinyi Liu
- College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, Jiangsu, China; (J.H.); (X.L.)
| | - Hiroyuki Konno
- Department of Biochemical Engineering, Graduate School of Science and Engineering, Yamagata University, Yonezawa, Yamagata 992‑8510, Japan;
| | - Hidenori Abe
- Hamari Chemicals Ltd., 1-4-29 Kunijima, Higashi-Yodogawa-ku, Osaka 533-0024, Japan; (R.T.); (T.H.)
| | - Takahiro Hiramatsu
- Hamari Chemicals Ltd., 1-4-29 Kunijima, Higashi-Yodogawa-ku, Osaka 533-0024, Japan; (R.T.); (T.H.)
| | - Hiroki Moriwaki
- Hamari Chemicals Ltd., 1-4-29 Kunijima, Higashi-Yodogawa-ku, Osaka 533-0024, Japan; (R.T.); (T.H.)
| | - Vadim A. Soloshonok
- Department of Organic Chemistry I, Faculty of Chemistry, University of the Basque Country UPV/EHU, Paseo Manuel Lardizábal 3, 20018 San Sebastián, Spain
- IKERBASQUE, Basque Foundation for Science, María Díaz de Haro 3, Plaza Bizkaia, 48013 Bilbao, Spain
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12
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L Calandrino R, J McAuliffe K, E Dolmage L, R Trivedi E. Synthesis of the C 3 and C 1 Constitutional Isomers of Trifluorosubphthalocyanine and Their Fluorescence within MDA-MB-231 Breast Tumor Cells. Molecules 2019; 24:E3832. [PMID: 31652970 PMCID: PMC6864546 DOI: 10.3390/molecules24213832] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [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: 09/30/2019] [Revised: 10/15/2019] [Accepted: 10/16/2019] [Indexed: 11/24/2022] Open
Abstract
Metal tetrapyrrole macrocycles such as porphyrins and chlorins are ubiquitous in nature. Synthetic analogs, including phthalocyanines, have found applications in medicine, particularly as photosensitizers for photodynamic therapy and as fluorescent imaging probes. Tripyrrolic macrocycles, called subphthalocyanines (SPcs) with a smaller boron atom at their core, have similar potential as optical agents. We have recently reported a series of mixed fluorinated SPcs with varying aromaticity, showing that electronic absorption and emission are synthetically tunable across the far visible region, and that the inclusion of 4-12 peripheral fluorine atoms results in strong fluorescence within MDA-MB-231 breast tumor cells. Further probing this system, we report herein the synthesis and characterization of boron trifluorosubphthalocyanine chloride (F3SPc). The constitutional isomers F3SPc(C3) and F3SPc(C1) are readily separable by chromatography, and their identity and purity have been confirmed by 1H NMR, 19F NMR, HR APCI-MS, and HPLC. Unsurprisingly, these structurally similar F3SPcs have identical electronic absorption (λmax = 557 nm; tetrahydrofuran (THF)) and emission (λem = 574 nm; Φf = 0.27-0.28; THF). Strong fluorescence from MDA-MB-231 breast tumor cells was observed following treatment with F3SPc(C3) and F3SPc(C1) (50 µM F3SPc, 15 min), further highlighting the importance of even a limited number of peripheral fluorine atoms for this type of application.
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Affiliation(s)
| | | | - Lauren E Dolmage
- Department of Chemistry, Oakland University, Rochester, MI 48309, USA.
| | - Evan R Trivedi
- Department of Chemistry, Oakland University, Rochester, MI 48309, USA.
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13
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Abstract
We have examined the insertion of carbenes carrying leaving groups into the [nido-B11H13]2- dianion to form the [closo-1-CB11H12]- anion. The best procedure uses CF3SiMe3 and LiCl as the source of CF2. It is simple, convenient and scalable and proceeds with 70-90% yield. Density functional calculations have been used to develop a mechanistic proposal that accounts for the different behavior of CF2, requiring only one equivalent of base for successful conversion of Na[nido-B11H14]- to [closo-1-CB11H12]-, and CCl2 and CBr2, which require more.
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Affiliation(s)
- Jacek Pecyna
- Department of Chemistry, University of Colorado, Boulder, CO 80309-0215, USA.
| | - Igor Rončević
- Institute of Organic Chemistry and Biochemistry Academy of Sciences of the Czech Republic, Flemingovo nám. 2, 16610 Prague 6, Czech Republic.
| | - Josef Michl
- Department of Chemistry, University of Colorado, Boulder, CO 80309-0215, USA.
- Institute of Organic Chemistry and Biochemistry Academy of Sciences of the Czech Republic, Flemingovo nám. 2, 16610 Prague 6, Czech Republic.
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14
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Khatri HR, Han C, Luong E, Pan X, Adam AT, Alshammari MD, Shao Y, Colby DA. Controlling the Cleavage of Carbon-Carbon Bonds To Generate α,α-Difluorobenzyl Carbanions for the Construction of Difluoromethylbenzenes. J Org Chem 2019; 84:11665-11675. [PMID: 31449418 PMCID: PMC8262649 DOI: 10.1021/acs.joc.9b01595] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Controlling the cleavage of carbon-carbon bonds during a chemical reaction is a substantial challenge; however, synthetic methods that accomplish this objective produce valuable and often unexplored reactivity. We have designed a mild process to generate α,α-difluorobenzyl carbanions in the presence of potassium carbonate by exploiting the cleavage of C-C bonds during the release of trifluoroacetate. The initiating reagent is potassium carbonate, which represents an improvement over existing protocols that require a strong base. Fragmentation studies across substituted arenes and heteroarenes were conducted along with computational analyses to elucidate reactivity trends. Furthermore, the mildly generated α,α-difluorobenzyl carbanions from electron-deficient aromatics and heteroaromatic rings can react with aldehydes to create derivatives of difluoromethylbenzenes, which are valuable synthetic targets.
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Affiliation(s)
- Hari R. Khatri
- Department of BioMolecular Sciences, University of Mississippi, University, Mississippi 38677, United States
| | - Changho Han
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana 47907, United States
| | - Erica Luong
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma 73019, United States
| | - Xiaoliang Pan
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma 73019, United States
| | - Amna T. Adam
- Department of BioMolecular Sciences, University of Mississippi, University, Mississippi 38677, United States
| | - Maali D. Alshammari
- Department of BioMolecular Sciences, University of Mississippi, University, Mississippi 38677, United States
| | - Yihan Shao
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma 73019, United States
| | - David A. Colby
- Department of BioMolecular Sciences, University of Mississippi, University, Mississippi 38677, United States
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15
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Zhou B, Haj MK, Jacobsen EN, Houk KN, Xue XS. Mechanism and Origins of Chemo- and Stereoselectivities of Aryl Iodide-Catalyzed Asymmetric Difluorinations of β-Substituted Styrenes. J Am Chem Soc 2018; 140:15206-15218. [PMID: 30350956 PMCID: PMC6261351 DOI: 10.1021/jacs.8b05935] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The mechanism of the aryl iodide-catalyzed asymmetric migratory geminal difluorination of β-substituted styrenes ( Banik et al. Science 2016, 353, 51 ) has been explored with density functional theory computations. The computed mechanism consists of (a) activation of iodoarene difluoride (ArIF2), (b) enantiodetermining 1,2-fluoroiodination, (c) bridging phenonium ion formation via SN2 reductive displacement, and (d) regioselective fluoride addition. According to the computational model, the ArIF2 intermediate is stabilized through halogen-π interactions between the electron-deficient iodine(III) center and the benzylic substituents at the catalyst stereogenic centers. Interactions with the catalyst ester carbonyl groups (I(III)+···O) are not observed in the unactivated complex, but do occur upon activation of ArIF2 through hydrogen-bonding interactions with external Brønsted acid (HF). The 1,2-fluoroiodination occurs via alkene complexation to the electrophilic, cationic I(III) center followed by C-F bond formation anti to the forming C-I bond. The bound olefin and the C-I bond of catalyst adopt a spiro arrangement in the favored transition structures but a nearly periplanar arrangement in the disfavored transition structures. Multiple attractive non-covalent interactions, including slipped π···π stacking, C-H···O, and C-H···π interactions, are found to underlie the high asymmetric induction. The chemoselectivity for 1,1-difluorination versus 1,2-difluorination is controlled mainly by (1) the steric effect of the substituent on the olefinic double bond and (2) the nucleophilicity of the carbonyl oxygen of substrate.
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Affiliation(s)
- Biying Zhou
- State Key Laboratory of Elemento-Organic Chemistry, College of Chemistry , Nankai University , Tianjin 300071 , China
| | - Moriana K Haj
- Department of Chemistry and Chemical Biology , Harvard University , Cambridge , Massachusetts 02138 , United States
| | - Eric N Jacobsen
- Department of Chemistry and Chemical Biology , Harvard University , Cambridge , Massachusetts 02138 , United States
| | - K N Houk
- Department of Chemistry and Biochemistry , University of California , Los Angeles , California 90095 , United States
| | - Xiao-Song Xue
- State Key Laboratory of Elemento-Organic Chemistry, College of Chemistry , Nankai University , Tianjin 300071 , China
- Department of Chemistry and Biochemistry , University of California , Los Angeles , California 90095 , United States
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16
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Abstract
The intermolecular C-H trifluoromethoxylation of arenes remains a long-standing and unsolved problem in organic synthesis. Herein, we report the first catalytic protocol employing a novel trifluoromethoxylating reagent and redox-active catalysts for the direct (hetero)aryl C-H trifluoromethoxylation. Our approach is operationally simple, proceeds at room temperature, uses easy-to-handle reagents, requires only 0.03 mol % of redox-active catalysts, does not need specialized reaction apparatus, and tolerates a wide variety of functional groups and complex structures such as sugars and natural product derivatives. Importantly, both ground-state and photoexcited redox-active catalysts are effective. Detailed computational and experimental studies suggest a unique reaction pathway where photoexcitation of the trifluoromethoxylating reagent releases the OCF3 radical that is trapped by (hetero)arenes. The resulting cyclohexadienyl radicals are oxidized by redox-active catalysts and deprotonated to form the desired products of trifluoromethoxylation.
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Affiliation(s)
- Weijia Zheng
- Department of Chemistry, and Institute of Chemical Biology and Drug Discovery, Stony Brook University, Stony Brook, NY, 11794, USA
| | | | - Johnny W Lee
- Department of Chemistry, and Institute of Chemical Biology and Drug Discovery, Stony Brook University, Stony Brook, NY, 11794, USA
| | - Peng Liu
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - Ming-Yu Ngai
- Department of Chemistry, and Institute of Chemical Biology and Drug Discovery, Stony Brook University, Stony Brook, NY, 11794, USA
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17
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Imiołek M, Karunanithy G, Ng WL, Baldwin AJ, Gouverneur V, Davis BG. Selective Radical Trifluoromethylation of Native Residues in Proteins. J Am Chem Soc 2018; 140:1568-1571. [PMID: 29301396 PMCID: PMC5806083 DOI: 10.1021/jacs.7b10230] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Indexed: 12/20/2022]
Abstract
The incorporation of fluorine can not only significantly facilitate the study of proteins but also potentially modulate their function. Though some biosynthetic methods allow global residue-replacement, post-translational fluorine incorporation would constitute a fast and efficient alternative. Here, we reveal a mild method for direct protein radical trifluoromethylation at native residues as a strategy for symmetric-multifluorine incorporation on mg scales with high recoveries. High selectivity toward tryptophan residues enhanced the utility of this direct trifluoromethylation technique allowing ready study of fluorinated protein constructs using 19F-NMR.
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Affiliation(s)
- Mateusz Imiołek
- Chemistry Research Laboratory,
Department of Chemistry, University of Oxford, Mansfield Road, Oxford OX1 3TA, United
Kingdom
| | - Gogulan Karunanithy
- Chemistry Research Laboratory,
Department of Chemistry, University of Oxford, Mansfield Road, Oxford OX1 3TA, United
Kingdom
| | - Wai-Lung Ng
- Chemistry Research Laboratory,
Department of Chemistry, University of Oxford, Mansfield Road, Oxford OX1 3TA, United
Kingdom
| | - Andrew J. Baldwin
- Chemistry Research Laboratory,
Department of Chemistry, University of Oxford, Mansfield Road, Oxford OX1 3TA, United
Kingdom
| | - Véronique Gouverneur
- Chemistry Research Laboratory,
Department of Chemistry, University of Oxford, Mansfield Road, Oxford OX1 3TA, United
Kingdom
| | - Benjamin G. Davis
- Chemistry Research Laboratory,
Department of Chemistry, University of Oxford, Mansfield Road, Oxford OX1 3TA, United
Kingdom
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18
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Verhoog S, Kee CW, Wang Y, Khotavivattana T, Wilson TC, Kersemans V, Smart S, Tredwell M, Davis BG, Gouverneur V. 18F-Trifluoromethylation of Unmodified Peptides with 5- 18F-(Trifluoromethyl)dibenzothiophenium Trifluoromethanesulfonate. J Am Chem Soc 2018; 140:1572-1575. [PMID: 29301394 DOI: 10.1021/jacs.7b10227] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The 18F-labeling of 5-(trifluoromethyl)-dibenzothiophenium trifluoromethanesulfonate, commonly referred to as the Umemoto reagent, has been accomplished applying a halogen exchange 18F-fluorination with 18F-fluoride, followed by oxidative cyclization with Oxone and trifluoromethanesulfonic anhydride. This new 18F-reagent allows for the direct chemoselective 18F-labeling of unmodified peptides at the thiol cysteine residue.
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Affiliation(s)
- Stefan Verhoog
- Chemistry Research Laboratory, University of Oxford , 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Choon Wee Kee
- Chemistry Research Laboratory, University of Oxford , 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Yanlan Wang
- Chemistry Research Laboratory, University of Oxford , 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Tanatorn Khotavivattana
- Chemistry Research Laboratory, University of Oxford , 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Thomas C Wilson
- Chemistry Research Laboratory, University of Oxford , 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Veerle Kersemans
- Oxford Institute for Radiation Oncology, University of Oxford , Roosevelt Drive, Oxford OX3 7DQ, United Kingdom
| | - Sean Smart
- Oxford Institute for Radiation Oncology, University of Oxford , Roosevelt Drive, Oxford OX3 7DQ, United Kingdom
| | - Matthew Tredwell
- Chemistry Research Laboratory, University of Oxford , 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Benjamin G Davis
- Chemistry Research Laboratory, University of Oxford , 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Véronique Gouverneur
- Chemistry Research Laboratory, University of Oxford , 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
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19
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Abstract
A highly diastereoselective organocatalytic method that produces 3-fluoro-3'-hydroxy-3,3'-bisoxindoles and the corresponding 3-fluoro-3'-amino derivatives having two adjacent chirality centers from fluorooxindoles and isatins in high yields is described. The reaction occurs in protic solvents at room temperature, it can be upscaled without compromising yield and stereoselectivity, and chromatographic product purification is not required.
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Affiliation(s)
- Max Moskowitz
- Department of Chemistry, Georgetown University , 37th and O Streets, Washington, DC 20057, United States
| | - Kaluvu Balaraman
- Department of Chemistry, Georgetown University , 37th and O Streets, Washington, DC 20057, United States
| | - Christian Wolf
- Department of Chemistry, Georgetown University , 37th and O Streets, Washington, DC 20057, United States
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20
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Abstract
The photocatalytic C-F functionalization of highly fluorinated arenes is a powerful method for accessing functionalized multifluorinated arenes. The decisive step in the determining regioselectivity in fluorine functionalization is fluoride fragmentation from the radical anion of the multifluorinated arene. To date, the availability of regioisomers has been dictated by the innate electronics of the fluorinated arene, limiting the synthetic utility of the chemistry. This study investigates the remarkable ability of a strategically located hydrogen bond to transcend the normal regioselectivity of the C-F functionalization event. A significant rate acceleration is additionally observed for hydrodefluorination of fluorines that can undergo intramolecular hydrogen bonds that form 5-8-membered cycles with moderately acidic N-H's. The hydrogen bond is expected to facilitate the fragmentation not only by bending the C-F bond of the radical anion out of planarity but also by increasing the exothermicity of the fluoride extrusion step through protonation of the naked fluoride. Finally, the synthetic utility of the method is demonstrated in an expedited synthesis of the trifluorinated α-phenyl acetic acid derivative required for the commercial synthesis of Januvia, an antidiabetic drug. This represents the first synthesis of a commercially important multifluorinated arene via a defluorination strategy and is significantly shorter than the current strategy.
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Affiliation(s)
- Mohammad B. Khaled
- Department of Chemistry, Oklahoma State University, Stillwater, OK 74078
| | | | - Jimmie D. Weaver
- Department of Chemistry, Oklahoma State University, Stillwater, OK 74078
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21
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Commare B, Schmitt E, Aribi F, Panossian A, Vors JP, Pazenok S, Leroux FR. Fluoroalkyl Amino Reagents (FARs): A General Approach towards the Synthesis of Heterocyclic Compounds Bearing Emergent Fluorinated Substituents. Molecules 2017; 22:molecules22060977. [PMID: 28604633 PMCID: PMC6152730 DOI: 10.3390/molecules22060977] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [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: 05/20/2017] [Revised: 06/06/2017] [Accepted: 06/07/2017] [Indexed: 01/05/2023] Open
Abstract
Fluorinated heterocycles are important building blocks in pharmaceutical, agrochemical and material sciences. Therefore, organofluorine chemistry has witnessed high interest in the development of efficient methods for the introduction of emergent fluorinated substituents (EFS) onto heterocycles. In this context, fluoroalkyl amino reagents (FARs)—a class of chemicals that was slightly forgotten over the last decades—has emerged again recently and proved to be a powerful tool for the introduction of various fluorinated groups onto (hetero)aromatic derivatives.
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Affiliation(s)
- Bruno Commare
- University of Strasbourg, CNRS, LCM UMR 7509, 67000 Strasbourg, France.
| | - Etienne Schmitt
- University of Strasbourg, CNRS, LCM UMR 7509, 67000 Strasbourg, France.
| | - Fallia Aribi
- University of Strasbourg, CNRS, LCM UMR 7509, 67000 Strasbourg, France.
| | - Armen Panossian
- University of Strasbourg, CNRS, LCM UMR 7509, 67000 Strasbourg, France.
| | - Jean-Pierre Vors
- Bayer S.A.S., 14 Impasse Pierre Baizet, BP 99163, 69263 Lyon CEDEX 09, France.
| | - Sergiy Pazenok
- Bayer AG, Alfred-Nobel-Strasse 50, 40789 Monheim, Germany.
| | - Frédéric R Leroux
- University of Strasbourg, CNRS, LCM UMR 7509, 67000 Strasbourg, France.
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22
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Meirer K, Glatzel D, Kretschmer S, Wittmann SK, Hartmann M, Blöcher R, Angioni C, Geisslinger G, Steinhilber D, Hofmann B, Fürst R, Proschak E. Design, Synthesis and Cellular Characterization of a Dual Inhibitor of 5-Lipoxygenase and Soluble Epoxide Hydrolase. Molecules 2016; 22:molecules22010045. [PMID: 28036068 PMCID: PMC6155600 DOI: 10.3390/molecules22010045] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [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: 11/07/2016] [Revised: 12/15/2016] [Accepted: 12/23/2016] [Indexed: 01/13/2023] Open
Abstract
The arachidonic acid cascade is a key player in inflammation, and numerous well-established drugs interfere with this pathway. Previous studies have suggested that simultaneous inhibition of 5-lipoxygenase (5-LO) and soluble epoxide hydrolase (sEH) results in synergistic anti-inflammatory effects. In this study, a novel prototype of a dual 5-LO/sEH inhibitor KM55 was rationally designed and synthesized. KM55 was evaluated in enzyme activity assays with recombinant enzymes. Furthermore, activity of KM55 in human whole blood and endothelial cells was investigated. KM55 potently inhibited both enzymes in vitro and attenuated the formation of leukotrienes in human whole blood. KM55 was also tested in a cell function-based assay. The compound significantly inhibited the LPS-induced adhesion of leukocytes to endothelial cells by blocking leukocyte activation.
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Affiliation(s)
- Karin Meirer
- Institute of Pharmaceutical Chemistry, Goethe-University of Frankfurt, Max-von-Laue Str. 9, D-60438 Frankfurt am Main, Germany.
| | - Daniel Glatzel
- Institute of Pharmaceutical Biology, Goethe-University of Frankfurt, Max-von-Laue Str. 9, D-60438 Frankfurt am Main, Germany.
| | - Simon Kretschmer
- Institute of Pharmaceutical Chemistry, Goethe-University of Frankfurt, Max-von-Laue Str. 9, D-60438 Frankfurt am Main, Germany.
| | - Sandra K Wittmann
- Institute of Pharmaceutical Chemistry, Goethe-University of Frankfurt, Max-von-Laue Str. 9, D-60438 Frankfurt am Main, Germany.
| | - Markus Hartmann
- Institute of Pharmaceutical Chemistry, Goethe-University of Frankfurt, Max-von-Laue Str. 9, D-60438 Frankfurt am Main, Germany.
| | - René Blöcher
- Institute of Pharmaceutical Chemistry, Goethe-University of Frankfurt, Max-von-Laue Str. 9, D-60438 Frankfurt am Main, Germany.
| | - Carlo Angioni
- Institute of Clinical Pharmacology, Goethe-University of Frankfurt, Theodor-Stern-Kai 7, D-60590 Frankfurt am Main, Germany.
| | - Gerd Geisslinger
- Institute of Clinical Pharmacology, Goethe-University of Frankfurt, Theodor-Stern-Kai 7, D-60590 Frankfurt am Main, Germany.
| | - Dieter Steinhilber
- Institute of Pharmaceutical Chemistry, Goethe-University of Frankfurt, Max-von-Laue Str. 9, D-60438 Frankfurt am Main, Germany.
| | - Bettina Hofmann
- Institute of Pharmaceutical Chemistry, Goethe-University of Frankfurt, Max-von-Laue Str. 9, D-60438 Frankfurt am Main, Germany.
| | - Robert Fürst
- Institute of Pharmaceutical Biology, Goethe-University of Frankfurt, Max-von-Laue Str. 9, D-60438 Frankfurt am Main, Germany.
| | - Ewgenij Proschak
- Institute of Pharmaceutical Chemistry, Goethe-University of Frankfurt, Max-von-Laue Str. 9, D-60438 Frankfurt am Main, Germany.
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23
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Abstract
Fluoro-substituted flavones and 2-styrykhromones, related to natural and synthetic flavonoids previously described, were prepared, characterized and tested for anti-rhinovirus activity. Structural elucidation of the new compounds was performed by IR, NMR spectra and X-ray crystal structure analysis for 6-fluoro-3-hydroxy-2-styrylchromone. The antiviral potency was evaluated by a plaque reduction assay in HeLa cell cultures infected with rhinoviruses 1B and 14, selected as representative serotypes for viral groups B and A of human rhinoviruses, respectively. In comparison with results previously obtained, the introduction of the fluorine atom seems to exert a positive influence on the activity against serotype 14 while counteracting the effect against serotype 1B.
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Affiliation(s)
- Cinzia Conti
- Dipartimento di Scienze di Sanitá Pubblica, Sezione di Microbiologia, Universitá La Sapienza di Roma, Roma, Italy
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24
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Padala AK, Wani A, Vishwakarma RA, Kumar A, Bharate SB. Functional induction of P-glycoprotein efflux pump by phenyl benzenesulfonamides: Synthesis and biological evaluation of T0901317 analogs. Eur J Med Chem 2016; 122:744-755. [PMID: 27497733 DOI: 10.1016/j.ejmech.2016.07.005] [Citation(s) in RCA: 4] [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: 03/09/2016] [Revised: 06/17/2016] [Accepted: 07/05/2016] [Indexed: 10/21/2022]
Abstract
N-(2,2,2-Trifluoroethyl)-N-[4-[2,2,2-trifluoro-1-hydroxy-1-(trifluoromethyl)ethyl]phenyl]-benzenesulfonamide (T0901317, 6) is a potent activator of pregnane-X-receptor (PXR), which is a nuclear receptor controlling P-gp expression. Herein, we aimed to investigate P-gp induction activity of T0901317 and establish its structure-activity relationship. T0901317 along with a series of N-triazolyl-methylene-linked benzenesulfonamides were synthesized and screened for P-gp induction activity using a rhodamine-123 based efflux assay in the P-gp overexpressing human adenocarcinoma LS-180 cells, wherein several compounds showed potent P-gp induction activity at 5 μM. Treatment with benzene sulphonamides led to the decrease in intracellular accumulation of a fluorescent P-gp substrate rhodamine-123 up to 48% (control 100%). In the western-blot studies, T0901317 (6) and its triazole linked analog 26e at 5 μM displayed induction of P-gp expression in LS180 cells. These compounds were non-toxic in LS-180 and human neuroblastoma SH-SY5Y cells (IC50 > 50 μM). The compound 26e showed significant P-gp induction even at 0.3 μM, indicating an excellent therapeutic window. These results clearly indicate promise of this class of compounds as potential agents to enhance amyloid-β clearance in Alzheimers patients.
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Affiliation(s)
- Anil K Padala
- Medicinal Chemistry Division, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, India; Academy of Scientific & Innovative Research (AcSIR), CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, India
| | - Abubakar Wani
- Cancer Pharmacology Division, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, India
| | - Ram A Vishwakarma
- Medicinal Chemistry Division, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, India; Academy of Scientific & Innovative Research (AcSIR), CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, India
| | - Ajay Kumar
- Cancer Pharmacology Division, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, India.
| | - Sandip B Bharate
- Medicinal Chemistry Division, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, India; Academy of Scientific & Innovative Research (AcSIR), CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, India.
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25
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Abstract
A method for the trifluoromethylation of arylsilanes is reported. The reaction proceeds with [(phen)CuCF3 ] as the CF3 source under mild, oxidative conditions with high functional-group compatibility. This transformation complements prior trifluoromethylation of arenes in several ways. Most important, this method converts arylsilanes formed by the silylation of aryl C-H bonds to trifluoromethylarenes, thereby allowing the conversion of arenes to trifluoromethylarenes. The unique capabilities of the reported method are demonstrated by the conversion of a C-H bond into a C-CF3 bond in active pharmaceutical ingredients which do not undergo this overall transformation by alternative functionalization processes, including a combination of borylation and trifluoromethylation.
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Affiliation(s)
- Johannes Morstein
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Haiyun Hou
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Chen Cheng
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - John F Hartwig
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, 94720, USA.
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26
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Feng P, Ngai MY. Protocol for the Synthesis of Ortho-trifluoromethoxylated Aniline Derivatives. J Vis Exp 2016:e53789. [PMID: 26862864 PMCID: PMC4781656 DOI: 10.3791/53789] [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] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Molecules bearing trifluoromethoxy (OCF3) group often show desired pharmacological and biological properties. However, facile synthesis of trifluoromethoxylated aromatic compounds remains a formidable challenge in organic synthesis. Conventional approaches often suffer from poor substrate scope, or require use of highly toxic, difficult-to-handle, and/or thermally labile reagents. Herein, we report a user-friendly protocol for the synthesis of methyl 4-acetamido-3-(trifluoromethoxy)benzoate using 1-trifluoromethyl-1,2-benziodoxol-3(1H)-one (Togni reagent II). Treating methyl 4-(N-hydroxyacetamido)benzoate (1a) with Togni reagent II in the presence of a catalytic amount of cesium carbonate (Cs2CO3) in chloroform at RT afforded methyl 4-(N-(trifluoromethoxy)acetamido)benzoate (2a). This intermediate was then converted to the final product methyl 4-acetamido-3-(trifluoromethoxy)benzoate (3a) in nitromethane at 120 °C. This procedure is general and can be applied to the synthesis of a broad spectrum of ortho-trifluoromethoxylated aniline derivatives, which could serve as useful synthetic building blocks for the discovery and development of new pharmaceuticals, agrochemicals, and functional materials.
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Affiliation(s)
- Pengju Feng
- Department of Chemistry, State University of New York at Stony Brook; Institute of Chemical Biology and Drug Discovery, State University of New York at Stony Brook
| | - Ming-Yu Ngai
- Department of Chemistry, State University of New York at Stony Brook; Institute of Chemical Biology and Drug Discovery, State University of New York at Stony Brook;
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27
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Abstract
Novel and general copper-catalyzed cyclopropanol ring opening cross-coupling reactions with difluoroalkyl bromides, perfluoroalkyl iodides, monofluoroalkyl bromides, and 2-bromo-2-alkylesters to synthesize various β-(fluoro)alkylated ketones are reported. The reactions feature mild conditions and excellent functional group compatibility and can be scaled up to gram scale. Preliminary mechanistic studies suggest the involvement of radical intermediates. The difluoroalkyl-alkyl cross-coupling products can also be readily converted to more valuable and diverse gem-difluoro-containing compounds by taking advantage of the carbonyl group resulting from cyclopropanol ring opening.
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Affiliation(s)
- Zhishi Ye
- Department of Chemistry and Center for Cancer Research, Purdue University , 560 Oval Drive, West Lafayette, Indiana 47907, United States
| | - Kristen E Gettys
- Department of Chemistry and Center for Cancer Research, Purdue University , 560 Oval Drive, West Lafayette, Indiana 47907, United States
| | - Xingyu Shen
- Department of Chemistry and Center for Cancer Research, Purdue University , 560 Oval Drive, West Lafayette, Indiana 47907, United States
| | - Mingji Dai
- Department of Chemistry and Center for Cancer Research, Purdue University , 560 Oval Drive, West Lafayette, Indiana 47907, United States
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28
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Yasui N, Mayne CG, Katzenellenbogen JA. Preparation of o-Fluorophenols from Nonaromatic Precursors: Mechanistic Considerations for Adaptation to Fluorine-18 Radiolabeling. Org Lett 2015; 17:5540-3. [PMID: 26536250 PMCID: PMC4795842 DOI: 10.1021/acs.orglett.5b02640] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The preparation of fluorine-18 labeled o-fluorophenols at high specific activity is challenging and requires use of [(18)F]fluoride ion as the radioisotope source. As a novel, alternative approach, we found that treatment of α-diazocyclohexenones with Selectfluor and Et3N·3HF followed by HF elimination and tautomerization afforded o-fluorophenols regioselectively and rapidly. To adapt this chemistry to (18)F radiolabeling, using bromine electrophiles in place of Selectfluor gave the o-fluorophenol via an α-bromo-α-fluoroketone intermediate in lower but still reasonable yields.
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Affiliation(s)
- Norio Yasui
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, IL 61801
| | - Christopher G. Mayne
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, 405 North Mathews Avenue, Urbana, IL 61801
| | - John A. Katzenellenbogen
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, IL 61801
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29
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Lee JH, Hinchet R, Kim TY, Ryu H, Seung W, Yoon HJ, Kim SW. Control of Skin Potential by Triboelectrification with Ferroelectric Polymers. Adv Mater 2015; 27:5553-5558. [PMID: 26292202 DOI: 10.1002/adma.201502463] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Revised: 07/10/2015] [Indexed: 06/04/2023]
Abstract
Negatively polarized ferroelectric polymer β-P(VDF-TrFE) shows higher positive triboelectric properties than skin, which could lead to new medical applications. Kelvin force microscope measurements and triboelectric nanogenerator characterizations are performed to demonstrate this new property. In addition, how many negative charges are exchanged by contact electrification between the negatively polarized β-P(VDF-TrFE) and the skin is estimated.
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Affiliation(s)
- Ju-Hyuck Lee
- SKKU Advanced Institute of Nanotechnology (SAINT), Center for Human Interface Nanotechnology (HINT), Sungkyunkwan University (SKKU), Suwon, 440-746, Republic of Korea
| | - Ronan Hinchet
- School of Advanced Materials Science and Engineering, Sungkyunkwan University (SKKU), Suwon, 440-746, Republic of Korea
| | - Tae Yun Kim
- SKKU Advanced Institute of Nanotechnology (SAINT), Center for Human Interface Nanotechnology (HINT), Sungkyunkwan University (SKKU), Suwon, 440-746, Republic of Korea
| | - Hanjun Ryu
- School of Advanced Materials Science and Engineering, Sungkyunkwan University (SKKU), Suwon, 440-746, Republic of Korea
| | - Wanchul Seung
- School of Advanced Materials Science and Engineering, Sungkyunkwan University (SKKU), Suwon, 440-746, Republic of Korea
| | - Hong-Joon Yoon
- School of Advanced Materials Science and Engineering, Sungkyunkwan University (SKKU), Suwon, 440-746, Republic of Korea
| | - Sang-Woo Kim
- SKKU Advanced Institute of Nanotechnology (SAINT), Center for Human Interface Nanotechnology (HINT), Sungkyunkwan University (SKKU), Suwon, 440-746, Republic of Korea
- School of Advanced Materials Science and Engineering, Sungkyunkwan University (SKKU), Suwon, 440-746, Republic of Korea
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30
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Du XW, Stanley LM. Tandem Alkyne Hydroacylation and Oxo-Michael Addition: Diastereoselective Synthesis of 2,3-Disubstituted Chroman-4-ones and Fluorinated Derivatives. Org Lett 2015; 17:3276-9. [PMID: 26098453 PMCID: PMC4874191 DOI: 10.1021/acs.orglett.5b01447] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Tandem reactions involving Rh-catalyzed intermolecular hydroacylations of alkynes with salicylaldehydes followed by intramolecular oxo-Michael additions are described for the diastereoselective synthesis of 2,3-disubstituted chroman-4-ones. The tandem hydroacylation/oxo-Michael additions occur to form 2,3-disubstituted chroman-4-ones in high yields from a range of 1,2-disubstituted acetylenes and substituted salicylaldehyes. The resulting 2,3-disubstituted chroman-4-ones are readily fluorinated to form trans-3-fluoro-2,3-disubstituted chroman-4-ones in high yields with excellent diastereoselectivity.
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Affiliation(s)
- Xiang-Wei Du
- Department of Chemistry, Iowa State University, 1605 Gilman Hall, Ames, IA 50014 (USA)
| | - Levi M. Stanley
- Department of Chemistry, Iowa State University, 1605 Gilman Hall, Ames, IA 50014 (USA)
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31
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Abstract
A Rh(III)-catalyzed C-H functionalization approach was developed for the preparation of multisubstituted 3-fluoropyridines from α-fluoro-α,β-unsaturated oximes and alkynes. Oximes substituted with aryl, heteroaryl, and alkyl β-substituents were effective coupling partners, as were symmetrical and unsymmetrical alkynes with aryl and alkyl substituents. The first examples of coupling α,β-unsaturated oximes with terminal alkynes was also demonstrated and proceeded with uniformly high regioselectivity to provide single 3-fluoropyridine regioisomers. Reactions were also conveniently set up in air on the benchtop.
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Affiliation(s)
- Shuming Chen
- Department of Chemistry, Yale University, New Haven, Connecticut, 06520, United States, and Division of Chemical Sciences, Lawrence Berkeley National Laboratory, and Department of Chemistry, University of California—Berkeley, Berkeley, California 94720, United States
| | - Robert G. Bergman
- Department of Chemistry, Yale University, New Haven, Connecticut, 06520, United States, and Division of Chemical Sciences, Lawrence Berkeley National Laboratory, and Department of Chemistry, University of California—Berkeley, Berkeley, California 94720, United States
| | - Jonathan A. Ellman
- Department of Chemistry, Yale University, New Haven, Connecticut, 06520, United States, and Division of Chemical Sciences, Lawrence Berkeley National Laboratory, and Department of Chemistry, University of California—Berkeley, Berkeley, California 94720, United States
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32
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Rotsch D, Brossard T, Bihmidine S, Ying W, Gaddam V, Harmata M, Robertson JD, Swyers M, Jurisson SS, Braun DM. Radiosynthesis of 6'-Deoxy-6'[18F]Fluorosucrose via Automated Synthesis and Its Utility to Study In Vivo Sucrose Transport in Maize (Zea mays) Leaves. PLoS One 2015; 10:e0128989. [PMID: 26024520 PMCID: PMC4449027 DOI: 10.1371/journal.pone.0128989] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2015] [Accepted: 05/01/2015] [Indexed: 01/08/2023] Open
Abstract
Sugars produced from photosynthesis in leaves are transported through the phloem tissues within veins and delivered to non-photosynthetic organs, such as roots, stems, flowers, and seeds, to support their growth and/or storage of carbohydrates. However, because the phloem is located internally within the veins, it is difficult to access and to study the dynamics of sugar transport. Radioactive tracers have been extensively used to study vascular transport in plants and have provided great insights into transport dynamics. To better study sucrose partitioning in vivo, a novel radioactive analog of sucrose was synthesized through a completely chemical synthesis route by substituting fluorine-18 (half-life 110 min) at the 6' position to generate 6'-deoxy-6'[(18)F]fluorosucrose ((18)FS). This radiotracer was then used to compare sucrose transport between wild-type maize plants and mutant plants lacking the Sucrose transporter1 (Sut1) gene, which has been shown to function in sucrose phloem loading. Our results demonstrate that (18)FS is transported in vivo, with the wild-type plants showing a greater rate of transport down the leaf blade than the sut1 mutant plants. A similar transport pattern was also observed for universally labeled [U-(14)C]sucrose ([U-(14)C]suc). Our findings support the proposed sucrose phloem loading function of the Sut1 gene in maize, and additionally demonstrate that the (18)FS analog is a valuable, new tool that offers imaging advantages over [U-(14)C]suc for studying phloem transport in plants.
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Affiliation(s)
- David Rotsch
- Department of Chemistry, University of Missouri, Columbia, Missouri, United States of America
| | - Tom Brossard
- Department of Chemistry, University of Missouri, Columbia, Missouri, United States of America
| | - Saadia Bihmidine
- Division of Biological Sciences, Interdisciplinary Plant Group and the Missouri Maize Center, University of Missouri, Columbia, Missouri, United States of America
| | - Weijiang Ying
- Department of Chemistry, University of Missouri, Columbia, Missouri, United States of America
| | - Vikram Gaddam
- Department of Chemistry, University of Missouri, Columbia, Missouri, United States of America
| | - Michael Harmata
- Department of Chemistry, University of Missouri, Columbia, Missouri, United States of America
| | - J. David Robertson
- Department of Chemistry, University of Missouri, Columbia, Missouri, United States of America
- University of Missouri Research Reactor, University of Missouri, Columbia, Missouri, United States of America
| | - Michael Swyers
- Division of Biological Sciences, Interdisciplinary Plant Group and the Missouri Maize Center, University of Missouri, Columbia, Missouri, United States of America
| | - Silvia S. Jurisson
- Department of Chemistry, University of Missouri, Columbia, Missouri, United States of America
| | - David M. Braun
- Division of Biological Sciences, Interdisciplinary Plant Group and the Missouri Maize Center, University of Missouri, Columbia, Missouri, United States of America
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33
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Abstract
The direct conversion of aliphatic carboxylic acids to the corresponding alkyl fluorides has been achieved via visible light-promoted photoredox catalysis. This operationally simple, redox-neutral fluorination method is amenable to a wide variety of carboxylic acids. Photon-induced oxidation of carboxylates leads to the formation of carboxyl radicals, which upon rapid CO2-extrusion and F(•) transfer from a fluorinating reagent yield the desired fluoroalkanes with high efficiency. Experimental evidence indicates that an oxidative quenching pathway is operable in this broadly applicable fluorination protocol.
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Affiliation(s)
| | | | - David W. C. MacMillan
- Merck Center for Catalysis at Princeton University, Princeton, New Jersey 08544, United States
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34
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Sam B, Luong T, Krische MJ. Ruthenium-catalyzed C-C coupling of fluorinated alcohols with allenes: dehydrogenation at the energetic limit of β-hydride elimination. Angew Chem Int Ed Engl 2015; 54:5465-9. [PMID: 25757459 PMCID: PMC4405479 DOI: 10.1002/anie.201500238] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [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: 01/12/2015] [Indexed: 11/05/2022]
Abstract
Ruthenium(II) complexes catalyze the CC coupling of 1,1-disubstituted allenes and fluorinated alcohols to form homoallylic alcohols bearing all-carbon quaternary centers with good to complete levels of diastereoselectivity. Whereas fluorinated alcohols are relatively abundant and tractable, the corresponding aldehydes are often not commercially available because of their instability.
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Affiliation(s)
- Brannon Sam
- University of Texas at Austin, Department of Chemistry, 105 E 24th St. (A5300), Austin, TX 78712-1167 (USA)
| | - Tom Luong
- University of Texas at Austin, Department of Chemistry, 105 E 24th St. (A5300), Austin, TX 78712-1167 (USA)
| | - Michael J. Krische
- University of Texas at Austin, Department of Chemistry, 105 E 24th St. (A5300), Austin, TX 78712-1167 (USA)
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35
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Kostryukova TS, Ivanovskaya NP, Zatonsky GV, Osin NS, Vasilev NV. [Markers for Immunofluorescence Analysis Based on Europium Complex with Fluorinated β-Diketones Carbazole Series]. Bioorg Khim 2015; 41:212-7. [PMID: 26165128 DOI: 10.1134/s1068162015010094] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
In order to develop new markers for immunofluorescence time-resolved luminescence analysis tetraketodiester carbazole series was obtained. Compound contains methoxycarbonyl reactive groups, separated from the 1,3-dicarbonyl chelating fragment by difluoromethylene spacers (CF2)4. Complexes of this compound with the ions Eu3+ are stable in aqueous solution and possess a long-living intensive luminescence with the main peaks: emission--in the area of 615 nm and excitation--in the 380-390 nm, that distinguishes them from most used analogues. Conjugate of streptavidin to compound was obtained and its fluorescent spectral characteristics allow to use it as a universal reagent for various schemes of biological microanalysis.
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36
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Abstract
A highly π-facial selective and regioselective fluorination of chiral enamides is described. The reaction involves an enantioselective fluorination exclusively at the electron-rich enamide olefin with N-F reagents such as Selectfluor and N-fluoro-benzenesulfonimide [NFSI] accompanied by trapping of the β-fluoro-iminium cationic intermediate with water. The resulting N,O-hemiacetal could be oxidized using Dess-Martin periodinane, leading to an asymmetric sequence for syntheses of chiral α-fluoro-imides and optically enriched α-fluoro-ketones.
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Affiliation(s)
- Yan-Shuang Xu
- School of Pharmaceutical Science and Technology, Key Laboratory for Modern Drug Delivery and High-Efficiency, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin University, Tianjin, 300072 P. R. China
| | - Yu Tang
- School of Pharmaceutical Science and Technology, Key Laboratory for Modern Drug Delivery and High-Efficiency, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin University, Tianjin, 300072 P. R. China
| | - He-Jing Feng
- School of Pharmaceutical Science and Technology, Key Laboratory for Modern Drug Delivery and High-Efficiency, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin University, Tianjin, 300072 P. R. China
| | - Ji-Tian Liu
- School of Pharmaceutical Science and Technology, Key Laboratory for Modern Drug Delivery and High-Efficiency, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin University, Tianjin, 300072 P. R. China
| | - Richard P. Hsung
- Division of Pharmaceutical Sciences, School of Pharmacy, and Department of Chemistry, University of Wisconsin, Madison, WI 53705 USA
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37
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Abstract
A two-step Ir-catalyzed borylation/Pd-catalyzed dehalogenation sequence allows for the net synthesis of fluoroarenes where the boronic ester is ortho to fluorine. Key elements of this approach include the use of a halogen para to the fluorine to block meta Ir-catalyzed borylation and the chemoselective Pd-catalyzed dehalogenation by KF activated polymethylhydrosiloxane (PMHS).
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Affiliation(s)
- Chathurika
R. K. Jayasundara
- Department
of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan 48824, United States
| | - Jason M. Unold
- Department
of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan 48824, United States
| | - Jossian Oppenheimer
- The
Dow Chemical Company, Process Chemistry
& Development, Core R&D, Midland, Michigan 48674, United States
| | - Milton R. Smith
- Department
of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan 48824, United States
| | - Robert E. Maleczka
- Department
of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan 48824, United States
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38
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Emer E, Twilton J, Tredwell M, Calderwood S, Collier TL, Liégault B, Taillefer M, Gouverneur V. Diversity-oriented approach to CF3CHF-, CF3CFBr-, CF3CF2-, (CF3)2CH-, and CF3(SCF3)CH-substituted arenes from 1-(diazo-2,2,2-trifluoroethyl)arenes. Org Lett 2014; 16:6004-7. [PMID: 25379614 DOI: 10.1021/ol5030184] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Arenes substituted with perfluoroalkyl groups are attractive targets for drug and agrochemical development. Exploiting the carbenic character of donor/acceptor diazo compounds, a diversity-oriented synthesis of perfluoroalkylated arenes, for late stage fluorofunctionalization, is described. The reaction of 1-(diazo-2,2,2-trifluoroethyl)arenes with HF, F/Br, F2, CF3H, and CF3SH sources give direct access to a variety of perfluoroalkyl-substituted arenes presenting with incremental fluorine content. The value of this approach is also demonstrated for radiochemistry and positron emission tomography with the [(18)F]-labeling of CF3CHF-, CF3CBrF-, and CF3CF2-arenes from [(18)F]fluoride.
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Affiliation(s)
- Enrico Emer
- Chemistry Research Laboratory, University of Oxford , 12 Mansfield Road, OX1 3TA Oxford, U.K
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39
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Ilchenko NO, Tasch BOA, Szabó KJ. Mild silver-mediated geminal difluorination of styrenes using an air- and moisture-stable fluoroiodane reagent. Angew Chem Int Ed Engl 2014; 53:12897-901. [PMID: 25335468 PMCID: PMC4501311 DOI: 10.1002/anie.201408812] [Citation(s) in RCA: 133] [Impact Index Per Article: 13.3] [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: 09/04/2014] [Revised: 10/02/2014] [Indexed: 11/06/2022]
Abstract
An air- and moisture-stable fluoroiodane in the presence of AgBF4 is suitable for selective geminal difluorination of styrenes under mild reaction conditions. One of the CF bonds is formed by transfer of electrophilic fluorine from the hypervalent iodine reagent, while the other one arises from the tetrafluoroborate counterion of silver. Deuterium-isotope-labelling experiments and rearrangement of methyl styrene substrates suggest that the reaction proceeds through a phenonium ion intermediate.
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40
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Okoromoba O, Han J, Hammond GB, Xu B. Designer HF-based fluorination reagent: highly regioselective synthesis of fluoroalkenes and gem-difluoromethylene compounds from alkynes. J Am Chem Soc 2014; 136:14381-4. [PMID: 25260170 PMCID: PMC4210154 DOI: 10.1021/ja508369z] [Citation(s) in RCA: 141] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Indexed: 01/19/2023]
Abstract
Hydrogen fluoride (HF) and selected nonbasic and weakly coordinating (toward cationic metal) hydrogen-bond acceptors (e.g., DMPU) can form stable complexes through hydrogen bonding. The DMPU/HF complex is a new nucleophilic fluorination reagent that has high acidity and is compatible with cationic metal catalysts. The gold-catalyzed mono- and dihydrofluorination of alkynes using the DMPU/HF complex yields synthetically important fluoroalkenes and gem-difluoromethlylene compounds regioselectively.
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Affiliation(s)
- Otome
E. Okoromoba
- Department of Chemistry, University of
Louisville, Louisville, Kentucky 40292, United
States
| | - Junbin Han
- Department of Chemistry, University of
Louisville, Louisville, Kentucky 40292, United
States
| | - Gerald B. Hammond
- Department of Chemistry, University of
Louisville, Louisville, Kentucky 40292, United
States
| | - Bo Xu
- Department of Chemistry, University of
Louisville, Louisville, Kentucky 40292, United
States
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41
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Abstract
"Fluoro" refers to both fluorescent and fluorinated compounds. Despite the shared prefix, there are very few fluorescent molecules that are soluble in perfluorinated solvents. This paucity is surprising, given that optical microscopy is a ubiquitous technique throughout the physical sciences and the orthogonality of fluorous materials is a commonly exploited strategy in synthetic chemistry, materials science, and chemical biology. We have addressed this shortage by synthesizing a panel of "fluorofluorophores," fluorescent molecules containing high weight percent fluorine with optical properties spanning the visible spectrum. We demonstrate the utility of these fluorofluorophores by preparing fluorescent perfluorocarbon nanoemulsions.
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Affiliation(s)
- Ellen
M. Sletten
- Massachusetts Institute
of Technology, Cambridge, Massachusetts 02139, United States
| | - Timothy M. Swager
- Massachusetts Institute
of Technology, Cambridge, Massachusetts 02139, United States
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42
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Sahu S, Quesne M, Davies CG, Dürr M, Ivanović-Burmazović I, Siegler MA, Jameson GNL, de Visser SP, Goldberg DP. Direct observation of a nonheme iron(IV)-oxo complex that mediates aromatic C-F hydroxylation. J Am Chem Soc 2014; 136:13542-5. [PMID: 25246108 PMCID: PMC4183621 DOI: 10.1021/ja507346t] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2014] [Indexed: 11/29/2022]
Abstract
The synthesis of a pentadentate ligand with strategically designed fluorinated arene groups in the second coordination sphere of a nonheme iron center is reported. The oxidatively resistant fluorine substituents allow for the trapping and characterization of an Fe(IV)(O) complex at -20 °C. Upon warming of the Fe(IV)(O) complex, an unprecedented arene C-F hydroxylation reaction occurs. Computational studies support the finding that substrate orientation is a critical factor in the observed reactivity. This work not only gives rare direct evidence for the participation of an Fe(IV)(O) species in arene hydroxylation but also provides the first example of a high-valent iron-oxo complex that mediates aromatic C-F hydroxylation.
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Affiliation(s)
- Sumit Sahu
- Department
of Chemistry, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
| | - Matthew
G. Quesne
- Manchester
Institute of Biotechnology and School of Chemical Engineering and
Analytical Science, The University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
| | - Casey G. Davies
- Department
of Chemistry & MacDiarmid Institute for Advanced Materials and
Nanotechnology, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand
| | - Maximilian Dürr
- Department
of Chemistry and Pharmacy, University of
Erlangen-Nürnberg, 91058 Erlangen, Germany
| | | | - Maxime A. Siegler
- Department
of Chemistry, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
| | - Guy N. L. Jameson
- Department
of Chemistry & MacDiarmid Institute for Advanced Materials and
Nanotechnology, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand
| | - Sam P. de Visser
- Manchester
Institute of Biotechnology and School of Chemical Engineering and
Analytical Science, The University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
| | - David P. Goldberg
- Department
of Chemistry, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
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43
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Sert Y, Doğan H, Navarrete A, Somanathan R, Aguirre G, Çırak Ç. Experimental FT-IR, Laser-Raman and DFT spectroscopic analysis of 2,3,4,5,6-Pentafluoro-trans-cinnamic acid. Spectrochim Acta A Mol Biomol Spectrosc 2014; 128:119-126. [PMID: 24662760 DOI: 10.1016/j.saa.2014.02.122] [Citation(s) in RCA: 7] [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] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Revised: 02/04/2014] [Accepted: 02/19/2014] [Indexed: 06/03/2023]
Abstract
In this study, the experimental and theoretical vibrational frequencies of a newly synthesized 2,3,4,5,6-Pentafluoro-trans-cinnamic acid have been investigated. The experimental FT-IR (4000-400 cm(-1)) and Laser-Raman spectra (4000-100 cm(-1)) of the molecule in solid phase have been recorded. The theoretical vibrational frequencies and optimized geometric parameters (bond lengths and bond angles) have been calculated by using density functional theory (DFT/B3LYP: Becke, 3-parameter, Lee-Yang-Parr) and DFT/M06-2X (the highly parameterized, empirical exchange correlation function) quantum chemical methods with 6-311++G(d,p) basis set by Gaussian 09W software, for the first time. The assignments of the vibrational frequencies have been done by potential energy distribution (PED) analysis by using VEDA 4 software. The theoretical optimized geometric parameters and vibrational frequencies have been found to be in good agreement with the corresponding experimental data, and with the results in the literature. In addition, the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) energies and the other related molecular energy values have been calculated and depicted.
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Affiliation(s)
- Yusuf Sert
- Department of Physics, Faculty of Art & Sciences, Bozok University, Yozgat 66100, Turkey; Sorgun Vocational School, Bozok University, Yozgat 66100, Turkey.
| | - Hatice Doğan
- Department of Physics, Faculty of Art & Sciences, Bozok University, Yozgat 66100, Turkey
| | - Angélica Navarrete
- Centro de Graduados e Investigación del Instituto Tecnológico de Tijuana, Apdo. Postal 1166, 22500 Tijuana, B.C., Mexico
| | - Ratnasamy Somanathan
- Centro de Graduados e Investigación del Instituto Tecnológico de Tijuana, Apdo. Postal 1166, 22500 Tijuana, B.C., Mexico
| | - Gerardo Aguirre
- Centro de Graduados e Investigación del Instituto Tecnológico de Tijuana, Apdo. Postal 1166, 22500 Tijuana, B.C., Mexico
| | - Çağrı Çırak
- Department of Physics, Faculty of Art & Sciences, Erzincan University, Erzincan 24100, Turkey
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44
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Abstract
A practical, rapid, and highly regioselective Cu-catalyzed radiofluorination of (mesityl)(aryl)iodonium salts is described. This protocol utilizes [(18)F]KF to access (18)F-labeled electron-rich, -neutral, and -deficient aryl fluorides under a single set of mild conditions. This methodology is applied to the synthesis of protected versions of two important radiotracers: 4-[(18)F]fluorophenylalanine and 6-[(18)F]fluoroDOPA.
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Affiliation(s)
- Naoko Ichiishi
- Department
of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Allen
F. Brooks
- Department
of Radiology, University of Michigan Medical
School, 1301 Catherine, Ann Arbor, Michigan 48109, United States
| | - Joseph J. Topczewski
- Department
of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Melissa E. Rodnick
- Department
of Radiology, University of Michigan Medical
School, 1301 Catherine, Ann Arbor, Michigan 48109, United States
| | - Melanie S. Sanford
- Department
of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Peter J. H. Scott
- Department
of Radiology, University of Michigan Medical
School, 1301 Catherine, Ann Arbor, Michigan 48109, United States
- Interdepartmental
Program in Medicinal Chemistry, University
of Michigan, 428 Church
Street, Ann Arbor, Michigan 48109, United States
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45
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Abbas A, Hussain S, Hafeez N, Hasan A, Naseer MM. Synthesis and spectral characterization of new 1,3,5-triaryl-2-pyrazolines highlighting effect of alkyloxy chain length on fluorescence. Spectrochim Acta A Mol Biomol Spectrosc 2014; 127:32-40. [PMID: 24632153 DOI: 10.1016/j.saa.2014.02.025] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2013] [Revised: 01/28/2014] [Accepted: 02/09/2014] [Indexed: 06/03/2023]
Abstract
A series of new 1,3,5-triaryl-2-pyrazolines (1b-12b) having one to twelve carbon alkyloxy side chains were synthesized and characterized on the basis of their spectral (IR, (1)H &(13)C NMR and GC-MS) and microanalytical data. The UV-Vis and emission spectroscopy was used to study the effect of alkyloxy chain length on absorption and fluorescence properties of 1b-12b. All the compounds showed fluorescence in the blue region of the visible spectrum. Interestingly, the alkyloxy chain length strongly affects the emission intensity of 1,3,5-triaryl-2-pyrazoline framework without causing any major blue- or red-shift in the emission wavelength (λmax(em)). The absorption and emission maxima (λmax(abs) &λmax(em)) for compounds (1b-12b) were observed in the range of 337-364nm and 454-464nm, respectively. Furthermore, the effect of fluorine substituent on aryl ring present at 3-position of pyrazoline moiety on fluorescence properties is also discussed.
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Affiliation(s)
- Asghar Abbas
- Department of Chemistry, Quaid-i-Azam University, Islamabad 45320, Pakistan.
| | - Safdar Hussain
- Department of Forensic Medicine & Toxicology, National University of Sciences and Technology, Islamabad 44000, Pakistan
| | - Noureen Hafeez
- Department of Forensic Medicine & Toxicology, RIHS, Bahria University, Islamabad, Pakistan
| | - Aurangzeb Hasan
- Department of Chemistry, Quaid-i-Azam University, Islamabad 45320, Pakistan
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46
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Abstract
The stereoselective synthesis of trisubstituted 2-trifluoromethyl pyrrolidines by asymmetric Michael addition/hydrogenative cyclization is described. The direct organocatalytic addition of 1,1,1-trifluoromethylketones to nitroolefins proceeds under mild reaction conditions and low catalyst loadings to provide Michael adducts in high yield with excellent diastereo- and enantioselectivity. Catalytic hydrogenation of the Michael adducts stereoselectively generates 2-trifluoromethylated pyrrolidines bearing three contiguous stereocenters. A stereospecific route to epimeric 2-trifluoromethyl pyrrolidines from a common intermediate is described.
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Affiliation(s)
- Michael
T. Corbett
- Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Qihai Xu
- Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Jeffrey S. Johnson
- Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
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47
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Liu L, Jalili N, Baergen A, Ng S, Bailey J, Derda R, Klassen JS. Fluorine bonding enhances the energetics of protein-lipid binding in the gas phase. J Am Soc Mass Spectrom 2014; 25:751-757. [PMID: 24658801 DOI: 10.1007/s13361-014-0837-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Revised: 01/13/2014] [Accepted: 01/15/2014] [Indexed: 06/03/2023]
Abstract
This paper reports on the first experimental study of the energies of noncovalent fluorine bonding in a protein-ligand complex in the absence of solvent. Arrhenius parameters were measured for the dissociation of gaseous deprotonated ions of complexes of bovine β-lactoglobulin (Lg), a model lipid-binding protein, and four fluorinated analogs of stearic acid (SA), which contained (X =) 13, 15, 17, or 21 fluorine atoms. In all cases, the activation energies (E(a)) measured for the loss of neutral XF-SA from the (Lg + XF-SA)⁷⁻ ions are larger than for SA. From the kinetic data, the average contribution of each > CF₂ group to E(a) was found to be ~1.1 kcal mol⁻¹, which is larger than the ~0.8 kcal mol⁻¹ value reported for > CH₂ groups. Based on these results, it is proposed that fluorocarbon–protein interactions are inherently stronger (enthalpically) than the corresponding hydrocarbon interactions.
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48
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Abstract
The development of new approaches to the construction of fluorine-containing target molecules is important for a variety of scientific disciplines, including medicinal chemistry. In this Article, we describe a method for the catalytic enantioselective synthesis of tertiary alkyl fluorides through Negishi reactions of racemic α-halo-α-fluoroketones, which represents the first catalytic asymmetric cross-coupling that employs geminal dihalides as electrophiles. Thus, selective reaction of a C-Br (or C-Cl) bond in the presence of a C-F bond can be achieved with the aid of a nickel/bis(oxazoline) catalyst. The products of the stereoconvergent cross-couplings, enantioenriched tertiary α-fluoroketones, can be converted into an array of interesting organofluorine compounds.
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Affiliation(s)
- Yufan Liang
- Division
of Chemistry and Chemical Engineering, California
Institute of Technology, Pasadena, California 91125, United States
- Department
of Chemistry, Massachusetts Institute of
Technology, Cambridge, Massachusetts 02139, United States
| | - Gregory C. Fu
- Division
of Chemistry and Chemical Engineering, California
Institute of Technology, Pasadena, California 91125, United States
- Department
of Chemistry, Massachusetts Institute of
Technology, Cambridge, Massachusetts 02139, United States
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49
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Yang X, Phipps R, Toste FD. Asymmetric fluorination of α-branched cyclohexanones enabled by a combination of chiral anion phase-transfer catalysis and enamine catalysis using protected amino acids. J Am Chem Soc 2014; 136:5225-8. [PMID: 24684209 PMCID: PMC4119784 DOI: 10.1021/ja500882x] [Citation(s) in RCA: 123] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2014] [Indexed: 12/18/2022]
Abstract
We report a study involving the successful merger of two separate chiral catalytic cycles: a chiral anion phase-transfer catalysis cycle to activate Selectfluor and an enamine activation cycle, using a protected amino acid as organocatalyst. We have demonstrated the viability of this approach with the direct asymmetric fluorination of α-substituted cyclohexanones to generate quaternary fluorine-containing stereocenters. With these two chiral catalytic cycles operating together in a matched sense, high enantioselectivites can be achieved, and we envisage that this dual catalysis method has the potential to be more broadly applicable, given the breadth of enamine catalysis. It also represents a rare example of chiral enamine catalysis operating successfully on α-branched ketones, substrates commonly inert to this activation mode.
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Affiliation(s)
| | | | - F. Dean Toste
- Department of Chemistry, University
of California, Berkeley, California 94720, United States
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50
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Abstract
The attachment of perfluoroalkyl groups onto organic compounds has been a major synthetic goal over the past several decades. Previously, our group reported phenanthroline-ligated perfluoroalkyl copper reagents, (phen)CuRF, which react with aryl iodides and aryl boronates to form the corresponding benzotrifluorides. Herein the perfluoroalkylation of a series of heteroaryl bromides with (phen)CuCF3 and (phen)CuCF2CF3 is reported. The mild reaction conditions allow the process to tolerate many common functional groups. Perfluoroethylation with (phen)CuCF2CF3 occurs in somewhat higher yields than trifluoromethylation with (phen)CuCF3, creating a method to generate fluoroalkyl heteroarenes that are less accessible from trifluoroacetic acid derivatives.
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Affiliation(s)
- Michael
G. Mormino
- University of California, Department of Chemistry, Berkeley, California 94720, United States
| | - Patrick S. Fier
- University of California, Department of Chemistry, Berkeley, California 94720, United States
| | - John F. Hartwig
- University of California, Department of Chemistry, Berkeley, California 94720, United States
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