A divergent electrochemical platform for diazene radical generation and C–N coupling reactions

Abstract

The development of sustainable methods for controlled C–N bond formation remains a central challenge in modern synthesis. Here we report an operationally simple, catalyst-free and acid/base-free electrochemical platform that enables the direct single-electron activation of N-carbazates to generate a versatile diazene-centred radical under direct current (DC) or rapid alternating polarity current (rAP). This is the first general electrochemical access to diazene radicals. The in situ–formed nitrogen radical engages aryl diazoacetates via radical coupling after dinitrogen extrusion (via blue LED), delivering a diverse library of N-acyl hydrazones. The same radical intermediate undergoes a Michael-type conjugate addition to N-aryl maleimides, affording imide-linked hydrazine derivatives, thereby establishing a rare example of radical divergence from a single electrochemically generated intermediate. The method is broadly applicable across 9 carbazate classes affording 35 products, including drug-derived motifs, and proceeds under mild conditions in the absence of external reductants or catalysts. Together, these results introduce a sustainable, redox-economical strategy for N–C bond construction and expand the synthetic utility of hydrazine radicals in electroorganic chemistry.