Visible-Light-Induced Regioselective Thioesterification/Thiocyanation of Unactivated Alkenes Enabled by Spiro-NHC-Ir(III) Catalysis

The visible-light-induced regioselective thioesterification and thiocyanation of unactivated alkenes has been successfully achieved for the first time. This transformation is facilitated by a novel pincer CCC-Ir(III) photocatalyst incorporating a spiro-<i>N</i>-heterocyclic carbene (NHC) and a 1,4-diaza ligand. A wide range of compounds bearing thioester and thiocyanate functional groups were obtained in moderate to excellent yields, with high regioselectivity. Control experiments suggest that the reaction proceeds via an energy transfer mechanism.