A facile, catalyst- and additive-free, and scalable approach to the photochemical preparation of disulfides from organosulfenyl chlorides

A novel, clean and efficient protocol for the preparation of disulfides has been developed through the photochemical radical homo- and cross-coupling reaction of sulfenyl chlorides under LED irradiation and without the use of any catalyst and additive. The representative photochemical homo-coupling of trichloromethyl sulfenyl chloride has been successfully conducted on kilogram-scale in a continuous flow mode. The solvent and the main byproduct can be recovered in high yields, which makes the approach be highly atom economical.