ARS–TiO2 photocatalyzed direct functionalization of sp2 C–H bonds toward thiocyanation and cyclization reactions under visible light

Abstract

An ARS–TiO₂ photocatalyst has been prepared, by a simple method through stirring a mixture of ARS and TiO₂ at room temperature in the dark, to extend the photocatalytic response of titanium dioxide toward the visible light spectrum. The synergic effect of ARS and TiO₂ in the photocatalyst system has catalyzed direct C–H functionalization of sp2 C–H bonds toward thiocyanation and cyclization reactions. Several aromatic and heteroaromatic scaffolds (2-phenylamino-thiazole, phenol, aniline, indole and pyrrole derivatives) were treated with the thiocyanate anion at room temperature. Herein, the first report on thiocyanation of phenol and synthesis of 2-aminobenzothiazole derivatives under visible light is presented.