The silicon−boron bond of (dimethylphenylsilyl)pinacolborane was stereoselectively added to acyclic 1,3-dienes in a 1,4-fashion to give (Z)-4-boryl-1-silyl-2-alkene derivatives in the presence of a Ni(0) catalyst generated from Ni(acac) 2 and diisobutylaluminum hydride. 1,4-Silaboration of cyclic 1,3-dienes required the use of cyclohexyldiphenylphosphine with the Ni(0) catalyst to afford cis-4-boryl-1-silyl-2-cycloalkene derivatives in high yields with high stereoselectivities.Transition-metal catalyzed insertion reactions of carboncarbon multiple bonds to inter-element σ-bonds such as SiSi, 1 Si-Sn, 2 and B-B 3 have provided powerful methods for the preparation of organometallic compounds containing multiple metallic elements in regio-and stereodefined fashions. The synthetic applications of these organometallic compounds have been extensively explored. 4,5 We have reported regioselective additions of the siliconboron bond of silylboranes to alkynes 6 and alkenes, 7 which are catalyzed by palladium and platinum complexes. Moreover, silaboration of 1,3-dienes was found to be catalyzed by a platinum complex, giving 1,4-conjugate adducts as a 1:1 mixture of the corresponding Z-and E-isomers. 8 Re-(1) (a) Horn, K. A. Johann, T. R. F.; Marder, T. B.; Norman, N. C.; Orpen, A. G.; Peakman, T. M.; Quayle, M. J.; Rice, C. R.; Scott, A. J. J. Chem. Soc., Dalton Trans. 1998, 1431 and references therein. (4) For recent reviews on the synthetic utilization of organosilicon compounds, see: (a) Langkopf, E.; Schinzer, D. Chem. ReV. 1995, 95, 1375. (b) Fleming, I.; Barbero, A.; Walter, D. For examples of the use of bis-silylation for stereoselective organic synthesis, see: (a) Murakami, M.; Suginome, M.; Fujimoto, K.; Nakamura, H.; Andersson, P. G.; Ito, Y.