Trimethylchlorosilane generally

Two indirect routes to silenes, one derived from silylenes and the other from silylcarbenes, are of some generality and importance. Silylenes (e.g., Me3Si—Si—<]) (53) have been derived from the thermolysis of either methoxy or chloro polysilyl compounds. Thermolysis resulted in the elimination of trimethylmethoxy- or trimethylchlorosilane and yielded the silylene, which, based on products of trapping, clearly had rearranged in part to the isomeric silene [Eq. (5)]. Alternatively the silylene Me2Si has... 

Etherification. The reaction of alkyl halides with sugar polyols in the presence of aqueous alkaline reagents generally results in partial etherification. Thus, a tetraallyl ether is formed on reaction of D-mannitol with allyl bromide in the presence of 20% sodium hydroxide at 75°C (124). Treatment of this partial ether with metallic sodium to form an alcoholate, followed by reaction with additional allyl bromide, leads to hexaallyl D-mannitol (125). Complete methylation of D-mannitol occurs, however, by the action of dimethyl sulfate and sodium hydroxide (126). A mixture of tetra- and pentabutyloxymethyl ethers of D-mannitol results from the action of butyl chloromethyl ether (127). Completely substituted trimethylsilyl derivatives of polyols, distillable in vacuo, are prepared by interaction with trimethylchlorosilane in the presence of pyridine (128). Hexavinylmannitol is obtained from D-mannitol and acetylene at 25.31 MPa (250 atm) and 160°C (129). 

If a solvent is used, it is usually a polar one, and the bases DMF and pyridine are common. An acid catalyst such as trimethylchlorosilane (TMCS) and heating are sometimes needed to speed up the reaction. In general, the ease of reaction follows the order52 ... 

Polylithioferrocene was also derivatized with trimethylchlorosilane, yielding a mixture of polysilyl derivatives from which a crystalline tetrakis(trimethylsilyl) ferrocene was isolated and shown to be the 1,3,1, 3 derivative. Polylithioferrocene and the polylithioaromatics generally catalyze the polymerization of conjugated dienes leading to starshaped polymers. 

This reaction was first reported by Bouveault and Blanc in 1903, and was further extended by Bouveault and Locquin. It is the synthesis of symmetrical a-hydroxy ketones via the reductive condensation of esters in an inert solvent in the presence of sodium. Since symmetrical a-hydroxy ketones, the aliphatic analogs of benzoins, are generally known as acyloins, the formation of a-hydroxy ketones from esters is simply referred to as acyloin condensation. In a few cases, it is also referred to as acyloin reaction." For the individual acyloin, the name is derived by adding the suffix oin to the stem name of corresponding acid, e.g., acetoin prepared from acetate. The most common method used to make acyloin is the reductive condensation of aliphatic esters with sodium in inert solvents, such as ether, xylene or even in liquid NH3 The yield of this reaction can be greatly improved when trimethylchlorosilane presents." " Intromolecular acyloin condensation from aliphatic diesters affords cyclic ketones of different ring sizes. 

The high polymeric substance called silicone (the name was suggested by Kipping), which contains a silicon-oxygen skeleton, is a valuable synthetic material. It was developed at General Electric Co. the method was the hydrolysis of certain dimethyldichlorosilane-trimethylchlorosilane mixtures which had first been synthesized by E. G. Rochow in a direct process (see Chapter 2). Shortly thereafter, diphenyl polysiloxanes and methyl phenyl polysiloxanes were joined by dimeth-ylpolysiloxanes as another class of silicones. 

Full details have been published on the oxidative rearrangement of pyruvates to malonates. Whereas the reduction of dimethyl bismethylmalonate with sodium in xylene is reported to yield the keten acetal (9) in the presence of trimethylchlorosilane, when the solvent is ammonia a mixture of products is formed, including the cyclopropanediol di(trimethylsilyl)ether (10). This diol, on treatment with sodium methoxide, gives the products shown in Scheme 39, possibly by Cannizzaro disproportionation of the aldehyde (11). The mechanism of decarboxylation of monoethyl oxaloacetate has been studied as part of a general investigation of ) -keto-acid decarboxylation. 

Such a reaction is generally done with trimethylchlorosilane or using hexamethyldisilazane... 

An important feature of the trimethylsilyl protecting group is that it may both be introduced and removed under very mild conditions. A large number of methods have been described [40] for the trimethylsilylation of alcohols but the most common, which are inreaction between the substrate and (a) trimethylchlorosilane in the presence of base, (b) hexamethyldisilazane alone, and (c) hexamethyldisilazane in the presence of an acid catalyst (often trimethylchlorosilane in pyridine solution). The trimethylsilyl group is generally removed [40] by heating a solution of the protected intermediate in aqueous alcohol, under reflux. 

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