PCl3 or PCl3/SnCl4-promoted fluoroalkylthiolation of arenes with fluoroalkanesulfinyl chlorides

Abstract

A practical method for the fluoroalkylthiolation of arenes has been developed using fluoroalkanesulfinyl chlorides as fluoroalkylthiolating reagents and PCl₃ or PCl₃/SnCl₄ as the promoter. A series of fluoroalkylthiolated arenes were obtained in moderate to high yields under mild conditions. The reaction of highly activated arenes worked smoothly in the presence of PCl₃ at room temperature, while less nucleophilic arenes required cooperative promotion of PCl₃ and SnCl₄ at higher temperature. Based on ¹⁹F NMR monitoring of the reaction systems, two plausible reaction pathways were proposed, involving either a fluoroalkylsulfinylated intermediate or a fluoroalkanesulfenyl chloride species.