The triple role of rongalite in aminosulfonylation of aryldiazonium tetrafluoroborates: synthesis of N-aminosulfonamides via a radical coupling reaction.

A simple and convenient method for N-aminosulfonamide synthesis from the cross-coupling of aryldiazonium tetrafluoroborates and rongalite under metal-free, oxidant-free, and room-temperature conditions is reported. This method does not require an external amine source, with the aryldiazonium tetrafluoroborates participating as both an aryl radical and a potential amine source in the transformation. Mechanistic studies revealed that rongalite could act as a radical initiator, a sulfur dioxide surrogate and a reducing reagent simultaneously in this reaction.