28321-07-5Relevant academic research and scientific papers
Fluoride-Triggered Synthesis of 1-Aryl-2,2-difluoroalkenes via Desilylative Defluorination of (1-Aryl)-2,2,2-trifluoroethyl-silanes
Carreras, Virginie,Ollevier, Thierry
, p. 13160 - 13168 (2021/09/18)
An efficient route for the synthesis of 1-aryl-2,2-difluoroalkenes via 1,2-desilylative defluorination is disclosed. Only a catalytic amount of fluoride source is required to initiate the desilylation and afford gem-difluoroalkenes in very good to quantitative yields, using mild reaction conditions in dimethyl carbonate as a green solvent. This reaction uses (1-aryl)-2,2,2-trifluoroethyl-silanes, which are easily prepared via the insertion reaction of trifluoroethyl diazo alkanes into the Si-H bond of tertiary organosilanes. (1-Aryl)-perfluoroalkyl-silanes cleanly afford the corresponding (Z)-1-benzylideneperfluoroalkanes, which upon hydrodefluorination furnish the (E)-β(perfluoroalkyl)styrene derivatives with excellent yield and complete stereoselectivity. A one-pot system involving sequential insertion and desilylative-defluorination is also suitable for this transformation. This method demonstrates the usefulness of organosilanes toward the preparation of fluorinated alkenes as synthetically useful targets.
Dehalogenative Cross-Coupling of gem-Difluoroalkenes with Alkyl Halides via a Silyl Radical-Mediated Process
Tian, Hao,Yang, Shaoxiang,Wang, Xiaochen,Xu, Wentao,Liu, Yuxiu,Li, Yongqiang,Wang, Qingmin
supporting information, p. 12772 - 12782 (2021/09/13)
Herein, we describe a convenient general protocol for monofluoroalkenylation reactions of alkyl bromides involving cooperative visible-light photoredox catalysis and halogen abstraction. Mechanistic experiments showed that the products were generated by selective cross-coupling of aliphatic radicals with fluoroalkenyl radicals. Silyl radical-mediated halogen abstraction enabled the protocol to be used for the monofluoroalkenylation of a broad range of alkyl and heteroaryl halides. The protocol could be carried out on a gram scale and was applied to cholesterol, indicating its utility for late-stage monofluoroalkenylation reactions.
Design and Synthesis of TY-Phos and Application in Palladium-Catalyzed Enantioselective Fluoroarylation of gem-Difluoroalkenes
Li, Zhiming,Lin, Tao-Yan,Liu, Yu,Pan, Zhangjin,Tu, Youshao,Wu, Hai-Hong,Zhang, Junliang,Zhu, Shuai
supporting information, p. 22957 - 22962 (2020/10/19)
The first example of highly enantioselective fluoroarylation of gem-difluoroalkenes with aryl halides is presented by using a new chiral sulfinamide phosphine (Sadphos) type ligand TY-Phos. N-Me-TY-Phos can be easily synthesized on a gram scale from readily available starting materials in three steps. Salient features of this work including readily available starting materials, good yields, high enantioselectivities as well as broad substrate scope make this approach very practical and attractive. Notably, the asymmetric synthesis of an analogue of a biologically active molecule is also reported.
Metal-Free Access to (E/Z)-α-Fluorovinyl Phosphorus Compounds from gem-Difluorostyrenes
Peng, Yingyuan,Zhang, Xiaofei,Qi, Xueyu,He, Qian,Zhang, Bin,Hao, Jian,Yang, Chunhao
, p. 1170 - 1177 (2019/01/16)
A facile and efficient method for the synthesis of (E/Z)-α-fluorovinyl phosphorus compounds from gem-difluorostyrenes with diphenylphosphine oxide/dialkyl phosphate and DBU at room temperature was developed. A series of 1-fluorovinyl phosphine oxides/phosphonates were obtained with moderate to excellent yields in these reactions. Additionally, most isomers (E/Z type) of the target compounds could be easily separated and purified by column chromatography.
Asymmetric Synthesis of Alkyl Fluorides: Hydrogenation of Fluorinated Olefins
Ponra, Sudipta,Yang, Jianping,Kerdphon, Sutthichat,Andersson, Pher G.
supporting information, p. 9282 - 9287 (2019/05/28)
The development of new general methods for the synthesis of chiral fluorine-containing molecules is important for several scientific disciplines. We herein disclose a straightforward method for the preparation of chiral organofluorine molecules that is ba
Synthesis of tetrazines from: Gem -difluoroalkenes under aerobic conditions at room temperature
Fang, Zheng,Hu, Wen-Li,Liu, De-Yong,Yu, Chu-Yi,Hu, Xiang-Guo
supporting information, p. 1299 - 1302 (2017/08/15)
An efficient and green procedure for the synthesis of tetrazines has been developed based on an old chemistry reported by Carboni in 1958. Both symmetric and asymmetric 3,6-disubstituted 1,2,4,5-tetrazines can be obtained in moderate to high yields from t
Palladium-Catalyzed Fluoroarylation of gem-Difluoroalkenes
Tang, Hai-Jun,Lin, Ling-Zhi,Feng, Chao,Loh, Teck-Peng
supporting information, p. 9872 - 9876 (2017/08/08)
A Pd-catalyzed fluoroarylation of gem-difluoroalkenes with aryl halides is reported. By taking advantage of the in situ generated α-CF3-benzylsilver intermediates derived from the nucleophilic addition of silver fluoride to gem-difluoroalkenes, this strategy bypasses the use of a strong base, thus enabling a mild and general synthetic method for ready access to non-symmetric α,α-disubstituted trifluoroethane derivatives.
Visible light photocatalytic decarboxylative monofluoroalkenylation of α-amino acids with: Gem -difluoroalkenes
Li, Jingjing,Lefebvre, Quentin,Yang, Haijun,Zhao, Yufen,Fu, Hua
supporting information, p. 10299 - 10302 (2017/09/25)
α-Amino acids are among the most common biologically active molecules in nature, and their functionalization has attracted much attention. In this communication, a novel, efficient and general visible-light photocatalytic decarboxylative monofluoroalkenylation of N-protected α-amino acids with gem-difluoroalkenes is reported, affording the corresponding α-amino monofluoroalkenes which might find applications in medical chemistry and materials science. The reaction proceeded at room temperature with high efficiency and tolerance of various functional groups.
Synthesis of Small 3-Fluoro- and 3,3-Difluoropyrrolidines Using Azomethine Ylide Chemistry
McAlpine, Indrawan,Tran-Dubé, Michelle,Wang, Fen,Scales, Stephanie,Matthews, Jean,Collins, Michael R.,Nair, Sajiv K.,Nguyen, Mary,Bian, Jianwei,Alsina, Luis Martinez,Sun, Jianmin,Zhong, Jiaying,Warmus, Joseph S.,O'Neill, Brian T.
, p. 7266 - 7274 (2015/07/28)
Here, we report accessing small 3-fluoropyrrolidines and 3,3-difluoropyrrolidines through a 1,3-dipolar cycloaddition with a simple azomethine ylide and a variety of vinyl fluorides and vinyl difluorides. We demonstrate that vinyl fluorides within α,β-unsaturated, styrenyl and even enol ether systems can participate in the cycloaddition reaction. The vinyl fluorides are relatively easy to synthesize through a variety of methods, making the 3-fluoropyrrolidines very accessible.
A versatile difluorovinylation method: Cross-coupling reactions of the 2,2-difluorovinylzinc-TMEDA complex with alkenyl, alkynyl, allyl, and benzyl halides Dedicated to Professor Iwao Ojima on the occasion of his 70th birthday.
Ichitsuka, Tomohiro,Takanohashi, Tsuyoshi,Fujita, Takeshi,Ichikawa, Junji
, p. 29 - 37 (2015/03/04)
A thermally stable 2,2-difluorovinylzinc-TMEDA complex was prepared via a deprotonation-transmetallation sequence starting from commercially available 1,1-difluoroethylene. The complex thus formed was successfully applied to transition metal-catalyzed cross-coupling reactions with a wide range of organic halides, which led to the syntheses of 2,2-difluorovinyl compounds. On treatment with the difluorovinylzinc-TMEDA complex in the presence of an appropriate palladium or copper catalyst, alkenyl, alkynyl, allyl, and benzyl halides effectively underwent difluorovinylation to afford 1,1-difluoro-1,3-dienes, 1,1-difluoro-1,3-enynes, 1,1-difluoro-1,4-dienes, and (3,3-difluoroallyl)arenes, respectively.
