摘要
Enantioenrichedγ-butenolides are valuable structural cores in many pharmaceuticals and natural products,but their direct and catalytically asymmetric assembly remains rare.Here,we report an efficient,atom-economic synthetic strategy for enantioenrichedγ-butenolides via a unique enantioselective reaction of cyclopropene carboxylic acids with imines under the synergistic catalysis of Rh2(esp)2/chiral Brønsted acid system.The reaction involved trapping of carboxylic oxonium ylides,generated from cyclopropene carboxylic acids,which presented as the first asymmetric trapping reactive intermediate in the process.
基金
supported by National Natural Science Foundation of China(no.21901259)
Guangdong Basic and Applied Basic Research Foundation(no.2020A1515011116)
the Program for Guangdong Introducing Innovative and Entrepreneurial Teams(no.2016ZT06Y337)
the National Science&Technology Major Project“Key New Drug Creation and Manufacturing Program”of China(no.2018ZX09711002-006).