Electrochemically Enabled Nickel-Catalyzed Intramolecular Amination of Aryl Chlorides with Hydrazones.

Herein, we report the electrochemical Ni-catalyzed intramolecular C-N coupling reaction with aryl chlorides, providing a novel catalytic approach for the synthesis of medicinally important indazole scaffold. The method enables challenging C-Cl activation and C=N bond isomerization in hydrazones at room temperature under constant-current electrolysis in an undivided cell. Mechanistic and DFT studies suggest that rapid ligand exchange drives the Ni(I)/Ni(III) catalytic cycle as the primary pathway. The methodology has been successfully applied for the late-stage functionalization and formal synthesis of lificiguat (YC-1), YD-3, and axitinib.