Aerobic Copper-Catalyzed Hydroxysulfonylation of Vinylarenes with Sodium Sulfinates

A novel and efficient method for the intermolecular hydroxysulfonylation of vinylarenes using sodium sulfinates has been achieved through aerobic copper catalysis. This transformation proceeded smoothly with green air as the terminal oxidant in the presence of Cu (I)/1,10-phenanthroline as an efficient catalytic system, leading to an array of β-hydroxysulfones in moderate to high yields. The significant advantages of this protocol are the mild reaction conditions, readily available starting materials, good functional-group compatibility, synthetic convenience, and practicability. Preliminary mechanistic investigation suggested that the catalytic process should undergo a cascade of radical events involving the initial generation of sulfonyl radical followed by sulfonyl radical addition across alkenes and subsequent cross-coupling with air.