Visible‐Light Photoredox‐Catalyzed Thioacetalization of Aldehydes Under Metal‐Free and Solvent‐Free Conditions

Abstract A first visible‐light photoredox‐catalyzed thioacetalization of aldehydes under metal‐free and solvent‐free conditions is described. Under blue LED irradiation, a reactive thiyl radical was initially generated through single‐electron oxidation of thiol, which subsequently reacted with aldehydes to afford dithioacetals following a radical mechanism. The reaction proceeded under ambient conditions, and a wide range of acyclic and cyclic dithioacetal derivatives were afforded in good to excellent yields. magnified image