Nickel(0) induzierte und katalysierte CC-Verknuepfungen zwischen Phenylisocyanat und vinylsubstituierten Heteroaromaten

Article abstract of DOI:10.1016/0022-328X(90)80027-W

Vinyl substituted heterocycles such as 2-vinylfuran (Ia) and 2-vinylpyridine (Ib) react with phenylisocyanate (II) in presence of (Lig)Ni⁰ (Lig = TCP) to form the tricyclohexylphosphane-5-azanickelacyclopentan-4-one derivatives (V).The structures and properties of these metallacycles are described.A catalytic 1/1 CC bond formation to give the α,β-unsaturated carboxylic acid amide X proceeds only with Ia (Lig = P(OⁱP)3) and not with Ib (Lig = PEt3, PPh3, P(OⁱP)3).Presumably, the different reactivities are not caused by electronic and/or steric factors of the 2-furyl- or 2-pyridyl-substituents, but by the donor properties of the N-atom in Ib.The N <-> Ni interactions in the complex bis<(triphenylphosphane)-η²-2-vinyl-μ-pyridine-nickel> (XIIb) can be detected by spectroscopic and crystal structure studies.