Silicon organomagnesiums

Unsolvated organomagnesium compounds have been recommended for the synthesis of organometallic derivatives of mercury, boron, aluminum, silicon, germanium, tin, phosphorus, arsenic, and antimony6-8 and have been used in procedures for the alkylation of aromatic rings and for the production of various polymerization catalysts.4 9... 

Organomagnesium alkoxides and aryloxides have been utilized in only a few applications. Methyhnagnesium f-butoxide 68 has been used in the chemical vapor deposition of MgO films onto silicon substrates . MgO films with good crystallinity were grown at 800 °C on Si(lll) surfaces, whereas polycrystalline films were formed at 400 °C. Intermediate temperatures produced multiple crystallite orientations. Similar results were obtained for deposition onto Si(lOO) surfaces over this range of temperatures. 

In 1863 Friedel and Crafts were the first to use metalorganic compounds to synthesise silicone monomers. Industiy focused on organomagnesium synthesis (the Grignard technique), in which alkyl- or arylhalogenide interacts with metallic magnesium to form organomagnesium compounds ... 

After that, the organomagnesium compound reacts with silicon tetrachloride, forming corresponding alkyl(aiyl)chlorosilanes ... 

The process of organomagnesium synthesis yields a mixture of al-kyl(aryl)chlorosilanes with various numbers of radicals attached to the silicon atom. However, by regulating the ratio of the parent components and changing the conditions of the process, one can shift the reaction towards the preferential formation of a certain monomer. 

The synthesis of hydroxyorganosilanes based on the use of organomagnesium compounds, is convenient mostly for the preparation of mono- and difunctional hydroxyorganosilanes with different radicals at the silicon atom. 

In recent years there has been a great interest to the continuous processes of organomagnesium synthesis of silicone monomers. This is caused by the increasing consumption scale of organomagnesium compounds and the synthesis of silicone monomers used in the production of poly-phenyldiethylsiloxanes. 

Continuous processes of the synthesis of organomagnesium compounds and organomagnesium synthesis of silicone monomers (1984) In series Elementorganic compounds and their application. NIITEKhim Moscow [in Russian]... 

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. 

Organomagnesium compound Silicon reagent Product (yield, %) Ref. 

Summary Novel poly(silylenemethylene)s have been prepared by ring-opening polymerization of 1,3-disilacyclobutanes followed by a protodesilylation reaction with triflic acid. Reactions of the triflate derivatives with organomagnesium compounds, LiAlH4, amines or alcohols gave functional substituted and branched poly(silylene-methylene)s, which may serve as suitable precursors for silicon carbide and Si/C/N-based materials. 

Such active magnesium reacts at room temperature with butadiene [41] to yield an organomagnesium compound which, after the addition of silicon... 

In this process, organomagnesium compounds are used to transfer organo groups to silicon ... 

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