Annulation cascades of cyclosulfonium salts and alkenes towards sulfur-containing N-heterocycles by visible light/copper catalysis

Although, great achievements have been made in the synthesis of heterocycles using radical addition/cyclization strategy, developing versatile alkyl radical precursors, especially the non-stabilized ones for this method still remains a huge challenge. Herein, we report an efficient annulation cascade reaction between cyclosulfonium salts and alkenes for the synthesis of sulfur-containing N-heterocycles by visible light/copper catalysis under mild conditions. The C−S bond cleavage/radical cascade reaction delivers a variety of corresponding N-heterocycles containing aryl alkyl thioether motifs with good functional group tolerance. Significantly, the current system could be used for the late-stage functionalization of complex bioactive molecules.