<i>gem-</i>Difluoroolefination of Diazo Compounds with TMSCF<sub>3</sub> or TMSCF<sub>2</sub>Br: Transition-Metal-Free Cross-Coupling of Two Carbene Precursors
作者:Mingyou Hu、Chuanfa Ni、Lingchun Li、Yongxin Han、Jinbo Hu
DOI:10.1021/jacs.5b09888
日期:2015.11.18
fragment resulting from a diazocompound and a difluorocarbene fragment derived from Ruppert-Prakash reagent (TMSCF3) or TMSCF2Br, has been developed. This gem-difluoroolefination proceeds through the direct nucleophilic addition of diazocompounds to difluorocarbene followed by elimination of N2. Compared to previously reported Cu-catalyzed gem-difluoroolefination of diazocompounds with TMSCF3, which possesses
Visible light photocatalytic decarboxylative monofluoroalkenylation of α-amino acids with gem-difluoroalkenes
作者:Jingjing Li、Quentin Lefebvre、Haijun Yang、Yufen Zhao、Hua Fu
DOI:10.1039/c7cc05758j
日期:——
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.
Consecutive cross-coupling reactions of 2,2-difluoro-1-iodoethenyl tosylate with boronic acids: efficient synthesis of 1,1-diaryl-2,2-difluoroethenes
作者:Ju Hee Kim、Su Jeong Choi、In Howa Jeong
DOI:10.3762/bjoc.9.286
日期:——
The cross-coupling reactions of 2,2-difluoro-1-iodoethenyl tosylate (2) with 2 equiv of boronic acids in the presence of catalytic amounts of Pd(OAc)2 and Na2CO3 afforded the mono-coupled products 3 and 5 in high yields. The use of 4 equiv of boronic acids in the presence of catalytic amount of Pd(PPh3)2Cl2 and Na2CO3 in this reaction resulted in the formation of symmetrical di-coupled products 4 in high yields. Unsymmetrical di-coupled products 4 were obtained in high yields from the reactions of 3 with 2 equiv of boronic acids in the presence of catalytic amounts of Pd(OAc)2 and Na2CO3.
Direct α-Monofluoroalkenylation of Heteroatomic Alkanes via a Combination of Photoredox Catalysis and Hydrogen-Atom-Transfer Catalysis
作者:Hao Tian、Qing Xia、Qiang Wang、Jianyang Dong、Yuxiu Liu、Qingmin Wang
DOI:10.1021/acs.orglett.9b01491
日期:2019.6.21
In this study, a new C(sp3)–H monofluoroalkenylation reaction involving cooperative visible-light photoredoxcatalysis and hydrogen-atom-transfer catalysis to afford products generated by selective hydrogen abstraction and radical–radical cross-coupling was described. This mild, efficient reaction shows high regioselectivity for the α-carbon atoms of amines, ethers, and thioethers and thus allows the
A novel method for the synthesis of 2,2-diaryl-1,1-difluoroethenes
作者:Ji Hoon Choi、In Howa Jeong
DOI:10.1016/j.tetlet.2007.12.028
日期:2008.2
β,β-Difluoro-α-phenylvinylstannane 3 was prepared in 60% yield from the reaction of β,β-difluoro-α-phenylvinylsulfone 2 with tributyltin hydride in refluxing benzene for 5 h. The cross-coupling reaction of 3 with aryl iodides bearing substituents such as proton, fluoro, chloro, bromo, methoxy, methyl, trifluoromethyl, and nitro on ortho, meta, para positions of the benzene ring in the presence of 10 mol %