Synthesis of Monofluoroalkenes through Visible-Light-Promoted Defluorinative Alkylation of gem-Difluoroalkenes with 4-Alkyl-1,4-dihydropyridines
摘要:
In this study, a facile and efficient method to synthesize monofluoroalkenes by photoredox catalytic defluorinative alkylation of gem-difluoroalkenes with 4-alkyl-1,4-dihydropyridines under mild conditions (room temperature) is described. This novel strategy is applicable for a broad range of gem-difluoroalkene substrates with good functional group tolerance and a variety of 4-alkyl-1,4-dihydropyridines (including primary, secondary, and even tertiary alkyl radicals). Moreover, it also allows the challenging radical coupling with glycosyl-based 4-alkyl-1,4-dihydropyridines (DHPs) to synthesize monofluoroalkenylated saccharides.
Efficient Synthesis of 2,2-Diaryl-1,1-difluoroethenes via Consecutive Cross-Coupling Reactions of 2,2-Difluoro-1-tributylstannylethenyl <i>p</i>-Toluenesulfonate
作者:Seung Yeon Han、In Howa Jeong
DOI:10.1021/ol1024037
日期:2010.12.3
2,2-Difluoro-1-tributylstannylethenyl p-toluenesulfonate (2) was reacted with aryl iodides in the presence of 10 mol % of Pd(PPh3)4 and 10 mol % of CuI in DMF at 80 °C for 10−20 h to give the cross-coupled products 3 in 35−97% yields. Further coupling reaction of 3 with arylstannanes in the presence of 5 mol % of Pd(PPh3)4 and 3 equiv of LiBr in DMF at 100 °C for 2−24 h afforded the desired products
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 %