Visible-Light-Driven Photocatalytic Synthesis of Polysubstituted Pyrrolidines via Desulfurative Tandem Cyclization of Thiols with 1,6-Enynes

A metal-free visible-light photoredox-catalyzed tandem cyclization of 1,6-enynes with thiols was successfully developed. This method provides efficient access to a wide range of five-membered heterocyclic compounds in good to excellent yields with high regioselectivity through a desulfurative/cyclization/HAT process. The versatility of this reaction is demonstrated by its compatibility with a variety of N-tethered 1,6-enynes, encompassing diverse electronic and steric properties. Notably, the cascade reaction demonstrates remarkable operational simplicity, high bond-forming efficiency, and potential scalability, as exemplified by its successful implementation in gram-scale synthesis, which is expected to have potential applications in organic synthesis.