Organomagnesiums silicon halides

The reactions of silicon halides with organomagnesium or organolithium compounds for the synthesis of organosilicon compounds are oversimplified in Eqs. (3) and (4). If several reactive groups are attached to the silicon atom, as in C2H5SiCl3, the reaction cannot be controlled so as to yield a particular substitution product, since all possible substitutions will occur simultaneously. All that can be done is to favor the yield of the desired compound by manipulation of reaction conditions. 

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