Direct Photoactivation of Sulfinic Acids to Access Hydrosulfonylation and Arylsulfonylation of Alkenes.

Simple and atom-economical hydrosulfonylation and arylsulfonylation of alkenes have been developed using sulfinic acid as both the sulfonyl group source and the hydrogen atom donor under light irradiation. These reactions feature catalyst-, oxidant-, and additive-free conditions, offering a highly practical approach for the synthesis of diversely functionalized sulfones. Preliminary mechanistic studies indicate that these reactions proceed via the photoactivation of sulfinic acid to generate a sulfonyl radical, followed by a radical chain process.