Synthesis of 1H-Isothiochromenes by Regioselective C–C and C–S Bonds Formation of Enaminothiones with Alkynes under Rhodium Catalysis

Abstract

The rhodium-catalyzed sulfur-directed C–H bond activation and tandem cyclization of enaminothiones with alkynes proceed efficiently. Most products of 1H-isothiochromenes with various substituents are achieved in good yields by regioselective C–C and C–S bonds formation. This protocol has some advantages over the traditional methods in synthesizing 1H-isothiochromenes in terms of stable and easy available coupling substrates, simple and one-pot operation, step and atom economy, and highly unique sulfur-containing heterocyclic products.