Electrochemical Cyclization of Alkene with Bisnucleophile to Assemble Piperazine/1,4-Diazepane Scaffolds

Piperazine and homopiperazine skeletons are widely recognized as privileged scaffolds for the construction of pharmaceuticals. Nevertheless, the facile synthesis of diverse carbon-substituted piperazine derivatives from readily available, structurally simple feedstock chemicals remains a formidable synthetic challenge. Herein, we disclose a modular electrochemical strategy for the efficient synthesis of functionalized piperazine and 1,4-diazepane derivatives. This protocol employs inexpensive and commercially available alkenes as the starting materials. Crucially, the well-designed reaction sequence including anodic oxidation and nucleophilic attack effectively forged the C–N bond formation twice, ultimately delivering the target heterocyclic products. By employing electrons as traceless oxidants, the protocol is endowed with operational simplicity, mild reaction conditions, and broad functional group tolerance.