Aryl Thiocyanate as an Organic ‘CN’ Source: Circular Chemical Economy Approach to Access Thiocyano-Thioesters from Cyclic Thioacetals

We report a mild, transition metal-free, organophotoredox-catalyzed visible light mediated strategy for accessing thiocyano-thioesters from cyclic thioacetals, using aryl thiocyanate as an organic ‘CN’ source. Additionally, the by-product diaryl disul-fide is efficiently repurposed as a recyclable and reusable substrate for the sustainable synthesis of phenyl thiocyanates, supporting the circular chemical economy. This method exhibits broad functional group tolerance and is applicable to 5- to 8-membered cyclic thioacetals. The reaction is also scalable to gram quantity. A series of control experiments, fluorescence quenching and cyclic voltammetry analysis supported a plausible reaction mechanism.