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.