Abstract Vinyl substituted heterocycles such as 2-vinylfuran (Ia) and 2-vinylpyridine (Ib) react with phenylisocyanate (II) in presence of (Lig) Ni 0 (Lig= TCP) to form the tricyclohexylphosphane-5-azanickelacyclopentan-4-one derivatives (V). The structures and properties of these metallacycles are described.