Lewis Acid-Catalyzed, Copper(II)-Mediated Synthesis of Heteroaryl Thioethers under Base-Free Conditions

A Lewis acid (Ag-I, Ni-II, or Fe-II) catalyzed, Cu-II-mediated thiolation reaction between heteroarenes and thiols was achieved with good yield under base-free conditions. DMSO could serve as an effective methylthiolation reagent for the synthesis of heterocyclic methyl thioethers.