Synthesis of Unsymmetrical Diaryl Disulfides via I₂/DMF-Assisted Reductive Cross-Coupling of Sodium Sulfinates with Arenediazonium Tetrafluoroborates/Sodium Metabisulfite

A facile transition-metal- and base-free strategy has been explored for the synthesis of unsymmetrical (het)aryl disulfides from easily accessible sulfinate salts, sodium metabisulfite, and arenediazonium tetrafluoroborates using I2/DMF as a reducing agent. The method exploits the scarce use of sodium metabisulfite as a divalent sulfur source for the creation of S–S bond, and is endowed with good substrate scope.