Asymmetric α-amination reaction of alkenyl trifluoroacetates catalyzed by a chiral phosphine–silver complex
作者:Akira Yanagisawa、Ryoji Miyake、Kazuhiro Yoshida
DOI:10.1039/c3ob42111b
日期:——
The asymmetric α-amination of alkenyltrifluoroacetates with dialkyl azodicarboxylates catalyzed by the DTBM-SEGPHOS·AgOTf complex takes place in the presence of 2,2,2-trifluoroethanol with almost quantitative yield and high ees of up to 97%.
Herein is disclosed an efficient catalyticenantioselective protonation of enol acetates by means of a readily implementable transition-metal-free chemical process. By making use of simple hygrogenocarbonates as the proton source and hydroquinine anthraquinone-1,4-diyl diether as the chiral proton shuttle, a series of cyclic enol trifluoroacetates are protonated under mild conditions to yield the corresponding