DEHYDROGENATIVE COUPLING OF STYRENE WITH TRISUBSTITUTED SILANES CATALYZED BY NICKEL-COMPLEXES

Trisubstituted silanes, e.g., Me-n(EtO)(3-n)SiH (where n = 0-2) and Me 2PhSiH in the presence of nickel complexes, e.g., [Ni(acac)(2)] and [N i(cod)(2)], undergo two reactions of dehydrogenative silylation of sty rene to yield in both cases an unsaturated product-E-1-phenyl-2-silyl- ethene as well as products of styrene hydrogenation-ethylbenzene DS-1 and of hydrogenative dimerization of styrene-1,3-diphenylbutane-DS-2. The two reactions are accompanied by the hydrosilylation products H as well as redistribution of the silanes containing at least one ethoxy substituent. The catalytic examinations and identification of nickel s quare planar complexes suggest that the intermediates containing Ni-Si (I), Ni-H (II) and Ni-C (III) bonds are responsible for the catalysis . (C) 1998 Elsevier Science B.V. All rights reserved.