A 1,2-Addition Pathway for C(sp2 )-H Activation at a Dinickel Imide.

A dinickel imido complex was synthesized using a redox-active naphthyridine-diimine supporting ligand. Upon coordination of an external ligand, the Ni2 core was disrupted, triggering an aromatic C-H activation reaction to generate a Ni2 (μ-NHAr)(Ar) species. This intermediate is capable of liberating free carbazole and phenanthridine products upon heating or treatment with excess tBuNC. Collectively, these studies establish a kinetically facile 1,2-addition mechanism for C(sp2 )-H activation, taking advantage of cooperative reactivity between two Ni centers.