Diazenylation of active methyne compounds via arylazo sulfones

Abstract

A diazenylation reaction between active methyne compounds and arylazo sulfones is reported. The mild reaction involves an initial azotization, followed by a nucleophilic addition–elimination. The acyl group plays a dual role, acting as an electron-withdrawing substituent to activate the methyne site and as a readily leaving group to promote azo-rearrangement. The presented results shed light on a practical approach to synthesize hydrazones and will provide new possibilities for the late-stage ring-opening and diazenylation of complex molecules.