Pd-catalyzed decarboxylative allylic coupling of acetates of Baylis–Hillman alcohols with propiolic acids: a highly regio- and stereoselective synthesis of 1,5-diarylpent-1-en-4-yne derivatives

Abstract

Pd-catalyzed decarboxylative allylic coupling of acetates of Baylis–Hillman alcohols with alkynyl carboxylic acids leading to the formation of an important class of 1,5-diarylpent-1-en-4-ynes in a highly regio- and stereoselective manner has been developed. Decarboxylative coupling happened via an exclusively S_N2′ pathway. Acetates of the Baylis–Hillman alcohols derived from alkyl acrylates, ethyl vinyl ketone and phenyl vinyl sulfone provided exclusively (E)-1,5-diarylpent-1-en-4-ynes while the acetates of the Baylis–Hillman alcohols derived from acrylonitrile provided exclusively (Z)-1,5-diarylpent-1-en-4-ynes.