Nitrogen–Nitrogen Bond Formation via a Substrate-Bound Anion at a Mononuclear Nickel Platform

The nickel-C4F8 fragment coordinates an aminoaryl N–H ketimine to form a stable complex, which upon treatment with base and oxidant leads to an N–N bond-forming reaction and the release of indazole product. A key and previously unidentified intermediate in the formation of the indazole was a diimine complex of nickel bearing significant charge on the aryl ring that initially contained the amine substituent. The C4F8 coligand was key for the redox transformation and for stabilization of the intermediate for characterization.