A metal-free desulfurizing radical reductive C–C coupling of thiols and alkenes

An intermolecular reductive C-C coupling of electrophilic alkyl radicals and alkenes has been developed. Thiols were used as both hydrogen-donating reagents and alkyl radical precursors in the presence of triethyl phosphite and radical initiator. A wide range of alkenes, including styrenes, and aliphatic olefins were well tolerated in this transformation. Mechanistic studies indicated that a phosphite promoted radical desulfurization of thiols to access electrophilic alkyl radicals and a radical chain propagation process may be involved in this transformation.