N -Boryl Pyridyl Radical-Mediated Reductive Homocoupling of Arylsulfonyl Chlorides to Diaryl Disulfides

Arylsulfonyl chlorides were found to undergo 4-cyanopyridine-catalyzed, bis(pinacolato)diboron-mediated reductive homocoupling to afford a variety of symmetrical diaryl disulfides. Preliminary mechanistic studies suggest that arylsulfonyl radicals are involved and that diaryl disulfide formation likely proceeds through successive single-electron reductions mediated by N-boryl pyridyl radicals.