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A solution of a carbonyl compound is added to a Grignard reagent. (See gallery) An example of a Grignard reaction (R 2 or R 3 could be hydrogen). The Grignard reaction (French:) is an organometallic chemical reaction in which, according to the classical definition, carbon alkyl, allyl, vinyl, or aryl magnesium halides (Grignard reagent) are added to the carbonyl groups of either an aldehyde or ...
Phenylsilane is produced in two steps from Si(OEt) 4.In the first step, phenylmagnesium bromide is added to form Ph−Si(OEt) 3 via a Grignard reaction.Reduction of the resulting Ph−Si(OEt) 3 product with LiAlH 4 affords phenylsilane.
Hydrogen is more electronegative than silicon (hence the naming convention of silyl hydrides), which results in the polarization of the Si-H bond to be the reverse of that for the C-H bond. Generally silyl hydrides are colourless with physical properties (solubility, volatility) comparable to hydrocarbons.
The products after silylation, namely silyl ethers and silyl amines, are resilient toward basic conditions. [2] Protection is typically done by reacting the functional group with a silyl halide by an SN2 reaction mechanism, typically in the presence of base. [3] The protection mechanism begins with the base deprotonating the alcohol group.
To increase the rate of reaction, trimethylsilyl triflate may also be used in the place of trimethylsilyl chloride as a more electrophilic substrate. [ 4 ] [ 5 ] When using an unsymmetrical enolizable carbonyl compound as a substrate, the choice of reaction conditions can help control whether the kinetic or thermodynamic silyl enol ether is ...
The major advantage of this method over addition of organometallic reagents to more typical acyl compounds is that it avoids the common problem of over-addition. For these latter reactions, two equivalents of the incoming group add to form an alcohol rather than a ketone or aldehyde. This occurs even if the equivalents of nucleophile are ...
The reaction is named for Pierre Bruylants (1855–1950), [2] who first reported it in 1924. [3] The reaction mechanism appears to involve ejection of the nitrile to form an iminium that is then attacked by the Grignard rather than a direct displacement such as an S N 2 reaction.
The methylchlorosilanes react with water to produce hydrogen chloride, giving siloxanes. In the case of trimethylsilyl chloride, the hydrolyzed product is hexamethyldisiloxane: 2 ((CH 3) 3 SiCl + H 2 O → [(CH 3) 3 Si] 2 O + 2 HCl. The analogous reaction of dimethyldichlorosilane gives siloxane polymers or rings: n (CH 3) 2 SiCl 2 + n H 2 O ...