CARBON-CARBON BOND FORMATION IN THE REACTION OF BENZOYL CYANIDE WITH NICKEL(II) BETA-DIKETONATES

Nickel beta-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 beta-enaminodiones from beta-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 P2(1)/c, a = 11.408(5) angstrom, b = 15.109(4) angstrom, c = 14.515(5) angstrom, beta = 108.93(3)-degrees] contains two couples of independent, structurally very similar, molecules of the complex. The nickel atom is always centrosymmetrically co-ordinated to the ligand in a N,O bonding configuration, which is preferred to the alternative O,O one.