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 primary explorations on the mechanism were carried out to gain a deeper understanding of this transformation. This strategy offers an alternative approach for the synthesis of thiophene and thiazole derivatives, and exhibits advantages in terms of diverse coupling substrates, metal catalyst-free, simple and easy to operate reaction conditions.