Catalytic Hydrosulfenylation of Maleic Anhydride and Its Derivatives Enabled by Proton-Coupled Electron Transfer

We herein report a practical method for the efficient hydrosulfenylation of maleic anhydride and its derivatives by decavanadate-induced proton-coupled electron transfer. Preliminary mechanistic studies suggest that a thiyl radical is generated from the decavanadate polyanion and thiol through an oxidative PCET process. This method utilizes readily available thiols as a sulfur source and air as an oxidant and is capable of hydrosulfenylating a variety of maleic anhydrides and maleate esters with good diastereoselectivity.