N-Sulfenyl phthalimide enabled Markovnikov hydrothiolation of unactivated alkenes via ligand promoted cobalt catalysis

In contrast to the electrophilic chemistry of N-sulfenyl phthalimide, its radical chemistry has been rarely developed for C–S bond formation. Herein, employing N-sulfenyl phthalimides as efficient radicalophile reagents enables the challenging Markovnikov radical hydrothiolation of unactivated alkenes under mild conditions by cobalt catalysis. The ligand around the cobalt center plays an important role in promoting the reaction. This protocol exhibits exclusive regio-selectivity, wide functional group tolerance and broad substrate scope. Mechanistic investigations suggest that the reaction proceeded via the Co–H mediated hydrogen atom transfer with alkenes and subsequent trapping of alkyl radicals by N-sulfenyl phthalimides. Scalable synthesis and late-stage modification of biologically active molecules demonstrate the practicality of this protocol.