Aryl Thiocyanate as an Organic 'CN' Source: Access to Thiocyano-Thioesters from Cyclic Thioacetals

Abstract

A facile, transition metal-free method has been developed for the synthesis of thiocyano–thioesters. It employs cyclic thioacetals and aryl thiocyanate as an organic ‘CN’ source, facilitated by organophotocatalyst under the visible light irradiation. Additionally, the diaryl disulfide by-products have been efficiently repurposed as a recyclable and reusable substrates for the sustainable synthesis of aryl thiocyanates, supporting the circular chemical economy. This method exhibits broad functional group tolerance and is applicable to five- to eight-membered cyclic thioacetals. The method also proved to be scalable on gram quantity. A series of control experiments, fluorescence quenching, and cyclic voltammetry analysis supported the proposed reaction mechanism.