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 first reported 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.