Visible-Light Photoredox-Catalyzed Sulfonyl Lactonization of Alkenoic Acids with Sulfonyl Chlorides for Sulfonyl Lactone Synthesis

A visible-light photoredox-catalyzed sulfonyl lactonization of unsaturated carboxylic acids with sulfonyl chlorides is described. This reaction features good functional group tolerance and a broad substrate scope, providing a simple and efficient protocol to access a wide range of sulfonyl lactones in high to excellent yields. Preliminary mechanistic investigations suggested that a free-radical pathway should be involved in the process.