Metal-free and site-selective α-C(sp3)–H oxidation of thioethers to access thioester derivatives

Abstract

The site-selective α-C(sp³)–H oxidation of thioethers has been achieved using N-chlorosuccinimide (NCS) as the additive. A variety of thioester derivatives were obtained in good yields with excellent functional group compatibility. Notably, upon the use of thioethers containing α-ester groups, the reaction site shifts to the α-C(sp³)–H bond adjacent to the ester group. Mechanistic studies indicate that water serves as the oxygen source in thioester formation, and this α-C(sp³)–H functionalization strategy proceeds through a cascade α-C(sp³)–H chlorination and hydrolysis.