Annulation Cascades of Cyclosulfonium Salts and Alkenes towards Sulfur‐Containing N‐Heterocycles by Visible Light/Copper Catalysis

Comprehensive Summary 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 long chain alkyl radicals for this strategy 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.