Desulfurative Tandem Cyclization of 1,6‐Enynes and Thiols via Photoredox Catalysis: Access to Polysubstituted Piperidines

A visible‐light photoredox‐catalyzed radical cascade cyclization of 1,6‐enynes 1 with thiols 2 has been developed, enabling the efficient synthesis of polysubstituted piperidines 3 in good to excellent yields with high regioselectivity. Mechanistically, the reaction proceeds through a desulfurative/cyclization/hydrogen atom transfer (HAT) cascade, and features broad functional group compatibility, a wide substrate scope, high bond‐formation efficiency, and scalability to gram‐scale synthesis.