Transition-Metal-Free Synthesis of Unsymmetrical Disulfides via Three-Component Reaction of Thiosulfonates, Thiourea and Alkyl halides

A transition-metal-free approach to synthesize unsymmetrical disulfides is reported that relies on a K2CO3-promoted one-pot reaction of thiosulfonates, thiourea and alkyl halides under mild conditions. The protocol tolerates a wide range of substrates, leading to various types of unsymmetrical disulfides in moderate to excellent yields. More importantly, the late-stage modification of natural products and drug molecules was also achieved.