Photoredox‐Catalyzed Preparation of Sulfones Using Bis‐Piperidine Sulfur Dioxide – An Underutilized Reagent for SO2 Transfer

Abstract Sulfonyl groups are widely observed in biologically relevant molecules and consequently, SO 2 capture is an increasingly attractive method to prepare these sulfonyl‐containing compounds given the range of SO 2 ‐surrogates now available as alternatives to using the neat gas. This, along with the advent of photoredox catalysis, has enabled mild radical capture of SO 2 to emerge as an effective route to sulfonyl compounds. Here we report a photoredox‐catalyzed cross‐electrophile sulfonylation of aryl and alkyl bromides making use of a previously under‐used amine‐SO 2 surrogate; bis (piperidine) sulfur dioxide (PIPSO). A broad selection of alkyl and aryl bromides were photocatalytically converted to their corresponding sulfinates and then trapped with various electrophiles in a one‐pot multistep procedure to prepare sulfones and sulfonamides.