Facile Synthesis of Polysubstituted Tetrahydrofurans/Tetrahydropyrans via Photoredox‐Catalyzed Desulfurative Tandem Cyclization Between Thiols and 1,6‐Enynes

We have developed a metal‐free, visible‐light‐driven photoredox‐catalyzed tandem cyclization of 1,6‐enynes 1 with thiols 2 , enabling the efficient synthesis of polysubstituted tetrahydrofurans 3 in good to excellent yields with high regioselectivity. This transformation proceeds via a desulfurative/cyclization/hydrogen atom transfer (HAT) cascade. Notably, when 1,6‐enynes 4 featuring a phenyl group at the terminal alkene position are employed as substrates, the reaction shifts to afford six‐membered tetrahydropyran derivatives 5 , demonstrating excellent substrate‐controlled regioselectivity. This metal‐free protocol exhibits broad functional group tolerance, a wide substrate scope, and high bond‐forming efficiency, while remaining amenable to gram‐scale synthesis.