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. On the basis of this sequence of stoichiometric reactions, a catalytic carbene transfer reaction is demonstrated.