A catalyst- and thiol-free protocol for arene C–H thioetherification via photoactive electron donor–acceptor complexes

Abstract

We present a catalyst- and thiol-free protocol for arene C–H thioetherification under visible light irradiation, yielding a diverse array of aryl alkyl thioethers, including d₃-methyl aryl thioethers. A key discovery is that tetramethylthiourea can serve as both a sulfur source and an electron donor, facilitating the formation of the EDA complex with arylsulfonium salts. The method's effectiveness in gram-scale synthesis and adaptability for continuous flow processes underscore its significant synthetic potential and versatility.