Visible-light-induced thiol-mediated transfer hydrogenation/deuteration of activated alkenes, imines and azo compounds

Abstract

We have reported photochemical transfer hydrogenation/deuteration of activated alkenes using H₂O/D₂O as the H/D-source under metal-free conditions. Importantly, this protocol showed excellent chemoselectivity towards activated CC double bonds, and good tolerance towards unactivated CC and CO bonds. Both triethylamine and thiol function as the reducing agent. Mechanistic studies implied that the photochemical olefin hydrogenation proceeds via thio-Michael addition/reductive desulfurization. Furthermore, this transformation was suitable for other unsaturated compounds containing CN and NN bonds.