Application of various ylides in the [4+1] cycloaddition of enaminothiones and N-thioacylformamidines for constructing substituted thiophenes and thiazoles

Abstract

The [4+1] cycloaddition of enaminothiones and N-thioacylformamidines with various ylides has been developed. Various products of useful thiophenes and thiazoles were constructed in 61–84% yields. Synthetic applications and preliminary mechanistic investigations were carried out to gain a deeper understanding of this transformation. This strategy provides an alternative approach for the synthesis of thiophene and thiazole derivatives, and features diverse coupling substrates as well as simple, easy-to-use, metal-catalyst-free reaction conditions.