CuBr-Catalyzed Oxidative Difluoromethylation of Tertiary Amines with Difluoroenol Silyl Ethers
摘要:
CuBr-catalyzed oxidative difluoromethylation of readily available tertiary amines with difluoroenol silyl ethers was performed under mild conditions to afford beta-amine-alpha,alpha-difluoro ketones.
The Catalytic Mannich Reaction of 1,1-Difluoro-2-trialkyl(aryl)silyl-2-trimethyl-silyloxyethenes: Preparation of β-Amino Acid Derivatives
作者:Woo Jin Chung、Masaaki Omote、John T. Welch
DOI:10.1021/jo050953l
日期:2005.9.1
Catalytic Mannich reactions of 1,1-difluoro-2-trialkyl(aryl)silyl-2-trimethylsilyloxyethenes (3) with a variety of sulfonylimines were utilized for the preparation of α,α-difluoro-β-amino acidderivatives (7). The influence of the Lewis acid on the reaction was examined. Methods for the conversion of α,α-difluoroacylsilanes to α,α-difluorocarboxylic acids were also explored.
Lewis acid promoted aldol reaction of fluorinated silyl enol ethers from new fluoroacetylsilane derivatives
作者:Woo Jin Chung、Silvana C. Ngo、Seiichiro Higashiya、John T. Welch
DOI:10.1016/j.tetlet.2004.05.055
日期:2004.7
Newfluorinated silyl enol ethers with various trialkylsilyl groups were synthesized. Various fluorinated β-hydroxy ketones were synthesized by Lewisacid promoted aldol reaction of silyl enol ethers with diverse aldehydes. Reactivity of various trialkylsilyloxy groups toward Lewisacid was also studied.
CuBr-Catalyzed Oxidative Difluoromethylation of Tertiary Amines with Difluoroenol Silyl Ethers
作者:Lingling Chu、Xingang Zhang、Feng-Ling Qing
DOI:10.1021/ol900541n
日期:2009.5.21
CuBr-catalyzed oxidative difluoromethylation of readily available tertiary amines with difluoroenol silyl ethers was performed under mild conditions to afford beta-amine-alpha,alpha-difluoro ketones.
Synthesis of Mono- and Difluoroacetyltrialkylsilanes and the Corresponding Enol Silyl Ethers
作者:Seiichiro Higashiya、Woo Jin Chung、Dong Sung Lim、Silvana C. Ngo、Kelly、Paul J. Toscano、John T. Welch
DOI:10.1021/jo049551o
日期:2004.9.1
A variety of mono- and difluoroacetylsilanes and the corresponding silyl enolethers were prepared from trifluoroethanol and chlorotrialkylsilanes in the presence of LDA through retro-Brook rearrangement. Sterically demanding silyl groups, especially those bound to oxygen, resulted in higher yields of difluoroacetylsilanes. The yields of difluoroacetylsilanes were also dramatically affected by the