Copper-Catalyzed Double S-Arylation of Potassium Thioacetate with Dibenziodolium Triflates: Facile Synthesis of Unsymmetrical Dibenzothiophenes

Much interest has been paid to cyclic diaryliodonium salts as bis(electrophile)s in transition-metal-catalyzed annulation reactions to produce polycyclic (hetero)aromatic hydrocarbons. Herein, we report that dibenziodolium triflates smoothly react with potassium thioacetate in the presence of CuCl2 in THF or DMSO at 100–110 °C to afford the corresponding dibenzothiophenes in good-to-high yields. The coupling reaction tolerates reactive functional groups such as chloro and cyano and serves as a facile and reliable method for the synthesis of unsymmetrical dibenzothiophenes.