Visible-light-induced sulfonylation of Baylis-Hillman acetates under metal- and oxidant-free conditions

A metal-free and oxidant-free procedure for the sulfonylation of Baylis-Hillman acetates with sulfonyl hydrazides under the irradiation of visible light and open-air conditions at room temperature is described. This transformation has high yields (up to 92%), excellent stereoselectivity, broad substrate scope, good functional group tolerance, and mild reaction conditions. Moreover, mechanistic studies indicate that a sulfonyl radical pathway is involved in this reaction. A visible-light-driven metal- and oxidant-free procedure for the sulfonylation of Baylis-Hillman acetates with sulfonyl hydrazides under open-air conditions at room temperature is reported. The methods provide a green and facile synthetic route to access allylic sulfones.