Copper(II)-Catalyzed Four-Component Oxysulfonylation/Diazenylation: Synthesis of α‑Arylhydrazo-β-keto Sulfones

A new and convenient method for one-pot
synthesis of α-arylhydrazo-β-keto
sulfones is developed via Cu (II)-catalyzed oxysulfonylation/diazenylation
of alkenes. This four-component cascade reaction enables a series
of α-arylhydrazo-β-keto sulfone derivatives accessed from
readily available alkenes, sulfinates, and diazonium salts under aerobic
conditions. Furthermore, the 3-sulfonyl cinnolin-4­(1H)-one skeleton is successfully constructed from the corresponding
α-arylhydrazo-β-keto sulfone product under basic conditions.