Silicon hydride alkyl derivative

The catalytic addition of organic and inorganic silicon hydrides to alkenes, ary-lalkenes, and cycloalkenes as well as their derivatives with functional groups leads to their respective alkyl derivatives of silicon and occurs according to the anti-Markovnikov rule. However, under some conditions (e.g., in the presence of Pd catalysts), this product is accompanied by a-adduct (i.e., the one containing an internal silyl group). Moreover, dehydrogenative silylation of alkenes with hydrosilanes, which proceeds particularly in the presence of iron- and cobalt-triad complexes as related to hydrosilylation (and very often its side reaction), is discussed. 

The 10-57-5-hydridosiliconate ion 62 is known in association with lithium,323 tetrabutylammonium,101 and bis(phosphoranyl)iminium93 cations. It is synthesized by hydride addition to the 8-.S7-4-silane 63, which is derived from hexafluoroacetone.101 Benzaldehyde and related aryl aldehydes are reduced by solutions of 62 in dichloromethane at room temperature101 or in tetrahydrofuran at 0°96 within two hours. The alkyl aldehyde, 1-nonanal, is also reduced by 62 in tetrahydrofuran at O0.96 Good to excellent yields of the respective alcohols are obtained following hydrolytic workup. The reactions are not accelerated by addition of excess lithium chloride,96 but neutral 63 catalyzes the reaction, apparently through complexation of its silicon center with the carbonyl oxygen prior to delivery of hydride from 62.101... 

In the processes described above a silicon halide, ethoxide, or hydride is brought into reaction always with an organic derivative of another metal however, a Si-C bond can also be formed by treating a silylmetal compound, e.g., (triphenylsilyl)-potassium308 or -lithium309 with an aryl or alkyl halide, thus ... 

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