Metal-free ring-opening reaction of cyclic sulfonium salts with elemental sulfur/selenium and secondary phosphines.

A facile and efficient strategy has been developed for the synthesis of sulfur-containing alkyl dithiophosphinates via the ring-opening reaction of cyclic sulfonium salts with secondary phosphines and elemental sulfur. Under mild conditions, this metal-free protocol displays broad substrate scope, allowing the conversion of diverse aryl, alkenyl, and alkynyl sulfonium salts into a variety of alkyl dithiophosphinates. Notably, the ring-opening reaction of sulfonium salts with selenium and secondary phosphines could also be carried out efficiently under standard conditions to provide diselenophosphinates.