A metal-free photosensitized three-component reaction of oxime esters, alkenes, and DABCO·(SO2)2 was developed. This protocol could accommodate a wide substrate scope, including activated and unactivated alkenes and aryl and aliphatic carboxylic acid oxime esters, delivering a broad range of β-amino sulfones in moderate to high yields. The insertion of SO2 as a linker moiety allows the manipulation of the functionality in the reaction process, expanding the utility of oxime esters as bifunctional reagents.