Carbene Formation and Transfer at a Dinickel Active Site.

The synthesis and reactivity of a dinickel bridging carbene is described. The previously reported [ i-PrNDI]Ni2(C6H6) complex (NDI = naphthyridine-diimine) reacts with Ph2CN2 to generate a metastable diazoalkane adduct, which eliminates N2 at 60 °C to yield a paramagnetic Ni2(μ-CPh2) complex. The Ni2(μ-CPh2) complex undergoes carbene transfer to t-BuNC via an initial isonitrile adduct, which, upon heating, releases free t-BuNCCPh2. Based on this sequence of stoichiometric reactions, a catalytic carbene transfer reaction is demonstrated.