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

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.