Junichi Ishikawa

Disproportionation reactions of organohydrosilanes in the presence of base catalysts

Abstract Alkoxides, alkyl compounds, amides and hydrides of alkali metals (M) and barium, such as MOR, Ba(OR) 2 , n -BuM, PhM, MN(SiMe 3 ) 2 and MAlH 4 showed high catalytic activities versus the disproportionation reactions of PhSiH 3 to produce SiH 4 , Ph 2 SiH 2 and Ph 3 SiH. A good correlation between the catalyst basicities and the catalytic activities was observed, and a reaction mechanism involving the metal hydride and alkyl metal was proposed. A considerable amount of SiH 4 was produced in the reduction of PhSiCl 3 with LiAlH 4 when over three moles of LiAlH 4 was used.

Dehydrogenative cross-coupling reactions between phenylsilane and ethynylbenzene in the presence of metal hydrides

Dehydrogenative cross-coupling reactions occurred between phenylsilane and ethynylbenzene in the presence of the metal hydrides, such as LiAlH4, NaAlH4, LiBH4 and LiAlH(Ot–Bu)3 to produce some ethynyl compounds. Phenylsilane and diethynylbenzene produced a highly thermally stable polymer, poly[(phenylsilylene)ethynylenephenyleneethynylene]. The activities and selectivities of the reactions were discussed on the basis of the mechanism involving the alkynylaluminate anion.