Silicon-carbon unsaturated compounds. 36. Chemical behavior of 1,2,2,2-tetramethylphenylvinyldisilane in the presence of a nickel(0) catalyst

Activation of the Si-Si Bond by Transition Metal Complexes

“…122 With this catalyst no dimerization-double-silylated products were obtained with disilanes having the electronegative substituents fluorine and chlorine; however, with the palladium catalysts, Pd(PPh3)2Cl2 or Pd(PPh3)4, a mixture of 1,4-addition and dimerization-addition was reported.107 Furthermore, using Pt(CO)2(PPh3)2 as catalyst, phenyl-substituted disilanes quantitatively added to 1,3-butadienes to form only 1,4addition products.123 A similar result was noted with vinyl-substituted disilanes using (PPh3)4Ni as catalyst. 124 These various results perfectly illustrate the subtle distinctions available with changing catalysts and silicon substituents and thereby both the interest in, and complexity of, such systems.…”

Element−Element Addition to Alkynes Catalyzed by the Group 10 Metals

“…115 Ni complexes were shown to catalyze the reaction of sym-tetramethyldisilane with a variety of acetylenes, albeit not with dimethyl acetylenedicarboxylate, to give 1-silacyclopentadiene derivatives in good yields (based on the acetylene). The authors suggested that the reaction involved an R-elimination of the methyldisilicon hydride with loss of "dimethylsilylene" (Scheme 106).…”

“…The formation of Ni complexes with Si-Ni-Si bonds as intermediates in disilylation reactions has been suggested in many cases, for example, in the NiL 4 -catalyzed reactions of disilanes with vinylsilane or dienes. 115 Ni complexes were shown to catalyze the reaction of sym-tetramethyldisilane with a variety of acetylenes, albeit not with dimethyl acetylenedicarboxylate, to give 1-silacyclopentadiene derivatives in good yields (based on the acetylene). The authors suggested that the reaction involved an R-elimination of the methyldisilicon hydride with loss of "dimethylsilylene" (Scheme 106).…”

Stereoselective 1,4-Silaboration of 1,3-Dienes Catalyzed by Nickel Complexes

“…Recently, we found that nickel complexes were also able to activate the silicon−boron bond, promoting a silaborative dimerization of alkynes . This finding opened up new possibilities in bismetalation chemistry, since nickel catalysts have scarcely been employed for activation of inter-element σ -bonds . Herein, we wish to report that nickel complexes catalyzed the stereoselective 1,4-addition of the silicon−boron bond of silylborane to acyclic as well as cyclic 1,3-dienes effectively.…”

“…Although various bismetalations of acyclic dienes have been reported so far, only a few examples have been known for cyclic dienes. 3e,10b,c The nickel catalyst generated from Ni(acac) 2 and DIBAH did not promote the silaboration of 1,3-cyclohexadiene. However, it was found that the use of the appropriate phosphine ligand on nickel remarkably increased the catalytic activity as well as the stereoselectivity of the silaboration (Table ).…”