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Ishu K, Prabhakar NS, Singh KN. A regioselective synthesis of β-difluoromethoxy vinyl sulfones via O-difluoromethylation of β-ketosulfones using sodium chlorodifluoroacetate. Org Biomol Chem 2023; 21:6588-6594. [PMID: 37528684 DOI: 10.1039/d3ob01142a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/03/2023]
Abstract
A practical synthesis of new β-difluoromethoxy vinyl sulfones has been explored by O-difluoromethylation of β-ketosulfones using the inexpensive and easily workable sodium chlorodifluoroacetate as a difluorocarbene precursor. The strategy is convenient and regioselective, and features an adequate substrate scope and functional group tolerance.
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Affiliation(s)
- Km Ishu
- Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi-221005, India.
| | - Neha Sharma Prabhakar
- Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi-221005, India.
| | - Krishna Nand Singh
- Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi-221005, India.
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2
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Loison A, Toulgoat F, Billard T, Hanquet G, Panossian A, Leroux FR. Recent synthetic methods towards the –OCHF2 moiety. Tetrahedron 2021. [DOI: 10.1016/j.tet.2021.132458] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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3
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Yang RY, Wang H, Xu B. Base promoted gem-difluoroolefination of alkyl triflones. Chem Commun (Camb) 2021; 57:4831-4834. [PMID: 33861249 DOI: 10.1039/d1cc01132d] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
A new synthesis of gem-difluoroalkenes from readily available alkyl triflones and difluorocarbene precursors such as TMSCF2Br has been reported. The reaction, regardless of electronic effect, gives gem-difluoroalkenes in good to excellent yields. The mechanism may involve deprotonation of triflones, nucleophilic addition, and the elimination of SO2CF3.
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Affiliation(s)
- Ren-Yin Yang
- College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620, P. R. China.
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Okamura T, Koyamada K, Kanazawa J, Miyamoto K, Iwabuchi Y, Uchiyama M, Kanoh N. Synthetic Access to gem-Difluoropropargyl Vinyl Ethers and Their Application to Propargyl Claisen Rearrangement. J Org Chem 2021; 86:1911-1924. [PMID: 33284629 DOI: 10.1021/acs.joc.0c01777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
With the increasing importance of fluorine to medicinal chemistry and other areas, methods to access various fluorinated compounds are needed. Herein, we report the synthesis of difluoropropargyl vinyl ethers from ketones and aldehydes using difluoropropargyl bromide dicobalt complexes. We applied difluoropropargyl vinyl ethers to the synthesis of difluorodienone or difluoroallene under thermal conditions and trifluoro-pyran under acid-catalyzed conditions.
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Affiliation(s)
- Toshitaka Okamura
- School of Pharmacy and Pharmaceutical Sciences, and Institute of Medicinal Chemistry, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan
| | - Kenta Koyamada
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Junichiro Kanazawa
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Kazunori Miyamoto
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Yoshiharu Iwabuchi
- Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3 Aza-Aoba, Aramaki, Aoba-ku, Sendai 980-8578, Japan
| | - Masanobu Uchiyama
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan, Cluster of Pioneering Research (CPR), Advanced Elements Chemistry Laboratory, RIKEN, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan, and Research Initiative for Supra-Materials (RISM), Shinshu University, 3-15-1 Tokida, Ueda, Nagano 386-8567, Japan
| | - Naoki Kanoh
- School of Pharmacy and Pharmaceutical Sciences, and Institute of Medicinal Chemistry, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan
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Difluoromethylation of alcohols with TMSCF2Br in water: A new insight into the generation and reactions of difluorocarbene in a two-phase system. Tetrahedron 2020. [DOI: 10.1016/j.tet.2020.131676] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Lin JH, Xiao JC. Fluorinated Ylides/Carbenes and Related Intermediates from Phosphonium/Sulfonium Salts. Acc Chem Res 2020; 53:1498-1510. [PMID: 32786338 DOI: 10.1021/acs.accounts.0c00244] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Owing to the special effects of the fluorine element, including high electronegativity and small atomic radius, the incorporation of a fluorinated group into organic molecules may modify their physical, chemical, and biological properties. Fluorine-containing compounds have found widespread application in a variety of areas, and thus, the development of efficient reagents and methods for the incorporation of fluorinated groups has become a subject of significant interest.Described in this Account are our recent discoveries in the chemistry of fluorinated ylides/carbenes and related intermediates generated from phosphonium/sulfonium salts. Initially, we obtained the (triphenylphosphonio) difluoroacetate, Ph3P+CF2CO2- (PDFA), which was proposed as a reactive intermediate but had never been successfully synthesized. PDFA, shelf-stable and easy to prepare, is not only a mild ylide (Ph3P+CF2-) reagent, but also an efficient difluorocarbene source. It can directly generate difluorocarbene, via the first generation of ylide Ph3P+CF2-, simply under warming conditions without the need for any additive. Interestingly, difluorocarbene chemistry was then discovered by using PDFA as a reagent. Difluorocarbene can be oxidized to CF2═O, can react with elemental sulfur to afford CF2═S, and can be trapped by NaNH2 or NH3 to give CN-. The development of these processes into synthetic tools allowed us to achieve various reactions, including the challenging 18F-trifluoromethylthiolation and cyanodifluoromethylation. It was found that a substituent on the cation of a phosphonium salt can be directly transferred as a nucleophile despite the cation's high electrophilicity. This transfer process is like an "umpolung" of the cation, which may provide more opportunities for the synthetic utilities of phosphonium salts. The investigation of this transfer process led us to find that iodophosphonium salts, active intermediates which can be easily generated, may efficiently promote deoxygenative functionalizations of aldehydes and alcohols. Dehydroxylative substitution of alcohols by this protocol permits the use of unprotected amines with higher pKa values as nucleophiles, which is an attractive feature compared with the Mitsunobu reaction. On the basis of the ylide-to-carbene process (Ph3P+CF2- → :CF2), we further developed sulfonium salts as precursors of fluorinated ylides and fluorinated methyl carbenes. In particular, the studies on difluoromethylcarbene, remaining largely unexplored, may deserve more attention. The discoveries may find utility in the synthesis of biologically active fluorine-containing molecules.
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Affiliation(s)
- Jin-Hong Lin
- Key Laboratory of Organofluorine Chemistry, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China
| | - Ji-Chang Xiao
- Key Laboratory of Organofluorine Chemistry, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China
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Tang L, Yang Z, Jiao J, Cui Y, Zou G, Zhou Q, Zhou Y, Rao W, Ma X. Chemoselective Mono- and Difluorination of 1,3-Dicarbonyl Compounds. J Org Chem 2019; 84:10449-10458. [PMID: 31335142 DOI: 10.1021/acs.joc.9b01808] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
By altering the amount of Selectfluor, the highly selective mono- and difluorination of 1,3-dicarbonyl compounds has been achieved, affording a variety of 2-fluoro- and 2,2-difluoro-1,3-dicarbonyl compounds in good to excellent yields. The reaction can be readily performed in aqueous media without any catalyst and base, which features practical and convenient fluorination. Importantly, a gram-scale reaction, transformation of 2-fluoro-1,3-diphenylpropane-1,3-dione to 4-fluoro-1,3,5-triphenyl-1H-pyrazole, and chlorination and bromination of 1,3-dicarbonyl compounds are realized to further exhibit its synthetic utility.
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Affiliation(s)
- Lin Tang
- Henan Key Laboratory of Utilization of Non-metallic Mineral in the Sourth of Henan , Xinyang 464000 , P. R. China
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Liu GK, Li X, Qin WB, Lin WF, Lin LT, Chen JY, Liu JJ. Selective O-difluoromethylation of 1,3-diones using S-(difluoromethyl) sulfonium salt. CHINESE CHEM LETT 2019. [DOI: 10.1016/j.cclet.2019.03.036] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Xie Q, Zhu Z, Li L, Ni C, Hu J. A General Protocol for C−H Difluoromethylation of Carbon Acids with TMSCF
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Br. Angew Chem Int Ed Engl 2019; 58:6405-6410. [DOI: 10.1002/anie.201900763] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2019] [Indexed: 11/11/2022]
Affiliation(s)
- Qiqiang Xie
- Key Laboratory of Organofluorine ChemistryCenter for Excellence in Molecular SynthesisShanghai Institute of Organic ChemistryUniversity of Chinese Academy of SciencesChinese Academy of Sciences 345 Ling-Ling Road Shanghai 200032 China
| | - Ziyue Zhu
- Key Laboratory of Organofluorine ChemistryCenter for Excellence in Molecular SynthesisShanghai Institute of Organic ChemistryUniversity of Chinese Academy of SciencesChinese Academy of Sciences 345 Ling-Ling Road Shanghai 200032 China
| | - Lingchun Li
- Key Laboratory of Organofluorine ChemistryCenter for Excellence in Molecular SynthesisShanghai Institute of Organic ChemistryUniversity of Chinese Academy of SciencesChinese Academy of Sciences 345 Ling-Ling Road Shanghai 200032 China
| | - Chuanfa Ni
- Key Laboratory of Organofluorine ChemistryCenter for Excellence in Molecular SynthesisShanghai Institute of Organic ChemistryUniversity of Chinese Academy of SciencesChinese Academy of Sciences 345 Ling-Ling Road Shanghai 200032 China
| | - Jinbo Hu
- Key Laboratory of Organofluorine ChemistryCenter for Excellence in Molecular SynthesisShanghai Institute of Organic ChemistryUniversity of Chinese Academy of SciencesChinese Academy of Sciences 345 Ling-Ling Road Shanghai 200032 China
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10
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A General Protocol for C−H Difluoromethylation of Carbon Acids with TMSCF
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Br. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201900763] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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11
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Wang J, Tokunaga E, Shibata N. Highly C-selective difluoromethylation of β-ketoesters by using TMSCF2Br/lithium hydroxide/N,N,N-trimethylhexadecan-1-ammonium bromide. Chem Commun (Camb) 2018; 54:8881-8884. [DOI: 10.1039/c8cc05135f] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The first highly C-selective difluoromethylation of β-ketoesters was achieved by combining TMSCF2Br/LiOH/(CH3(CH2)15(CH3)3NBr).
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Affiliation(s)
- Jiandong Wang
- Department of Nanopharmaceutical Sciences
- Nagoya Institute of Technology
- Gokiso
- Showa-ku
- Japan
| | - Etsuko Tokunaga
- Department of Nanopharmaceutical Sciences
- Nagoya Institute of Technology
- Gokiso
- Showa-ku
- Japan
| | - Norio Shibata
- Department of Nanopharmaceutical Sciences
- Nagoya Institute of Technology
- Gokiso
- Showa-ku
- Japan
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Zhao CL, Yang J, Han ZZ, Zhang CP. Structure-dependent selective O - or C -trifluoroethylation of 1,3-dicarbonyls by mesityl(2,2,2-trifluoroethyl)iodonium triflate. J Fluor Chem 2017. [DOI: 10.1016/j.jfluchem.2017.09.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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