Carbon-carbon bond formation in the reaction of benzoyl cyanide with nickel(II)β-diketonates

Abstract

Nickel β-diketonates react with benzoyl cyanide to give C–C bond formation between the methine and the cyano carbon atoms. The resulting reddish compounds are square-planar iminodiketonato complexes, which are likely catalytic intermediates in the synthesis of β-enaminodiones from β-diketones and PhCOCN. The acetylacetonato derivative [Ni(acac·PhCOCN)₂] can be obtained in the solid state in two stable forms; an X-ray single-crystal analysis of form II indicates that the unit cell [monoclinic, space group P2₁/c, a= 11.408(5)Å, b= 15.109(4)Å, c= 14.515(5)Å, β= 108.93(3)°] contains two couples of independent, structurally very similar, molecules of the complex. The nickel atom is always centro-symmetrically co-ordinated to the ligand in a N,O bonding configuration, which is preferred to the alternative O,O one.