9-Fluorenone Catalyzed visible light oxidation of hydrazides: An efficient route for the synthesis of N,N'-diacylhydrazines derivatives

Abstract

A visible light-mediated oxidative coupling of hydrazides into corresponding N,N'- diacylhydrazines using a commercially available and low-cost metal-free photocatalyst was reported. The versatility of the reaction has been demonstrated across a broad spectrum of functional groups present in hydrazides. Interestingly, the developed methodology was utilized to synthesize symmetrical and unsymmetrical N,N'-diacylhydrazines in moderate yields. Density Functional Theory (DFT) calculations, along with control reactions and quenching studies, provide evidence supporting the proposed mechanism, favoring the photoredox pathway. Additionally, NMR and UV-Vis studies confirmed the generation of H sub(2)O sub(2) in the reaction mixture, which strengthens the proposed mechanism. To our knowledge, this is the first report for the conversion of hydrazides to N,N'-diacylhydrazines using 9-fluorenone as an organic photoredox catalyst.