A process for preparing trimethylchlorosilane (M3) and methyltrichlorosilane (M1) by disproportionation of dimethyldichlorosilane (M2) in the presence of an Al.sub.2O.sub.3 catalyst is described herein. The dimethyldichlorosilane used is in the form of a silane mixture that includes 80-100% by weight of dimethyldichlorosilane (M2). The difference in content from 100% by weight includes M1 and M3.

A method for converting organosilanes by reacting at least one silane (1) of the general formula

R.sub.aSiCl.sub.4-a  (I)

with at least one further silane (2) of the general formula

R.sub.bSiCl.sub.4-b  (II)

wherein silane (2) is identical or different from silane (1), optionally with additional use of silanes (3) which contain Si-bonded hydrogen and have the formula

R.sub.dH.sub.eSiCl.sub.4-d-e  (III)

in the presence of aluminum salts, preferably aluminum halides, as catalysts and in the presence of cocatalysts, to obtain at least one silane (4) which differs from silanes (1) and (2) and has the general formula

R.sub.cSiCl.sub.4-c  (IV).

A halosilane compound: R.sup.1CH.sub.2CH.sub.2SiR.sup.5.sub.2X is prepared by hydrosilylation reaction of a vinyl compound: R.sup.1CH═CH.sub.2 with a halogenodiorganosilane compound having formula: HSiR.sup.5.sub.2X in the co-presence of an iridium catalyst, an internal olefin compound, and an allyl halide. The halosilane compound is prepared on an industrial scale with the advantages of low costs, high yields, and high selectivity, using a small amount of iridium catalyst.

The invention relates to halogenated tetrasilylboranates of the general formula

M.sup.z+[B(SiR.sub.mX.sub.n).sub.4.sup.−].sub.z  (I),

where the radicals and indices have the meanings indicated in claim 1, with the proviso that m+n=3,
processes for the production thereof and also the use.

A process for dehydrogenating and methylating silanes. The process includes providing methyl chloride that is reacted with a silane selected from the group consisting of SiH.sub.4, H.sub.2SiMe.sub.2, H.sub.2SiMeCl, H.sub.3SiMe, H.sub.3SiCl and HSiMe.sub.2Cl, in the presence of at least one ammonium and/or phosphonium salt at a temperature in the range of 70-350° C.

A method of synthesizing a high purity acryloxyalkyldimethylchlorosilane involves (a) reacting an acrylate salt with a haloalkyldimethylalkoxysilane to form an acryloxy-substituted alkyldimethylalkoxysilane; and (b) displacing the alkoxy group in the acryloxy-substituted alkyldimethylalkoxysilane using a chloride-containing compound to form the acryloxyalkyldimethylchlorosilane. The acryloxyalkyldimethylchlorosilane, which may be used as an end-capper for AROP, has a purity of greater than about 99% and contains no detectable isomeric or hydrogenated impurities.

A method of making a diakyl-, diaryl-, or alkylaryl-dihalosilane in a Grignard coupling reaction with a high degree of selectivity is provided. More specifically, a Grignard reagent comprising an alkyl- or aryl-magnesium halide is allowed to react with an alkyl- or aryl-trihalosilane precursor or reagent to produce a product mixture of R.sub.2SiX.sub.2 and R.sub.3SiX, wherein each R is independently selected to be an alkyl or aryl group and X is a halogen group, such that the R.sub.2SiX.sub.2 product is formed with a high degree of selectivity. High selectivity is defined as the mass ratio of R.sub.2SiX.sub.2 product to the R.sub.3SiX product that is formed in the reaction being greater than 7:1.

Methods of synthesizing fluorosilanes containing cyano-substituted alkyl groups are provided. For example, 3-cyano-propyldimethylfluorosilane may be produced by reacting tetramethyldisiloxane and boron trifluoride to obtain fluorodimethylsilane and then reacting the fluorodimethylsilane with allyl cyanide, in the presence of a hydrosilylation catalyst

A halosilane compound: R.sup.1CH.sub.2CH.sub.2SiR.sup.5.sub.2X is prepared by hydrosilylation reaction of a vinyl compound: R.sup.1CH═CH.sub.2 with a halogenodiorganosilane compound having formula: HSiR.sup.5.sub.2X in the co-presence of an iridium catalyst, an internal olefin compound, and an allyl halide. The halosilane compound is prepared on an industrial scale with the advantages of low costs, high yields, and high selectivity, using a small amount of iridium catalyst.

A process for producing a dimethylchlorosilane compound of formula (2) below:

##STR00001## wherein X represents a halogen atom or an acyloxy group having 2 to 20 carbon atoms, the process including the step of: reacting an allyl compound of formula (1) below:

##STR00002## wherein X has a meaning same as above, with dimethylchlorosilane in presence of an iridium catalyst, wherein the dimethylchlorosilane has a content of 1,1,3,3-tetramethyldisiloxane of 5.0 wt % or less.