Fluorosulfonylation of arenediazonium tetrafluoroborates with Na2S2O5 and N-fluorobenzenesulfonimide

A transition-metal-free Sandmeyer-type fluorosulfonylation reaction has been achieved by the three-component reaction of arenediazonium tetrafluoroborates, Na2S2O5, and N-fluorobenzenesulfonimide (NFSI). The reaction proceeds through a radical tandem process, affording various arenesulfonyl fluorides in moderate to high yields. This protocol not only provides a complement to the previous fluorosulfonylation reactions, but also extends the applications of Sandmeyer reaction.