Visible-Light-Mediated Late-Stage Sulfonylation of Boronic Acids via N-S Bond Activation of Sulfonamides

A visible-light-mediated late-stage arylation of N-S bonds in sulfonamides has been developed with using readily available imines as sulfonyl radical source. Diverse complex sulfones could be synthesized by prefunctionalizaiton and subsequent N-S bond arylation, demonstrating the advantages of using sulfonamides as sulfonylation reagents. Additionally, the mechanism research revealed that probably both EDA complex chemistry and photo-redox catalysis were responsible for the formation of sulfones. This methodology characterized by broad substrate scope and simple reaction conditions also has high atom economy, since the aldehyde for the synthesis of imines could be recovered after workup of the reactions.