Organocatalytic asymmetric [4+4]-annulation reaction between ynones and benzylidene thiazolones: synthesis of eight-membered ether containing 4,5-fused thiazoles

Abstract

An asymmetric (4+4)-annulation of benzylidene thiazolones and ynones by aminocatalysis is described. An enantioselective synthesis of eight-membered ether embedded 4,5-fused thiazoles is reported for the first time in this work. The reaction's scope is wide, and cyclic ether containing 4,5-fused thiazoles were produced in moderate to good yields with high diastereo- and enantioselectivities.