Phenyl trimethylsilyl

The effect of the counterion on the diastereomer ratio was investigated in detail for the Peterson condensation3 of phenyl(trimethylsilyl)methanide with benzaldehyde2 or substituted cyclohexanones4 and was found to be remarkably low. The variation of the solvent and the temperature has an influence of similar magnitude. 

The TT-electron system-substituted organodisilanes such as aryl-, alkenyl-, and alkynyldisilanes are photoactive under ultraviolet irradiation, and their photochemical behavior has been extensively studied (1). However, much less interest has been shown in the photochemistry of polymers bearing TT-electron substituted disilanyl units (2-4). In this paper, we report the synthesis and photochemical behavior of polysiloxanes involving phenyl(trimethylsilyl)-siloxy units and silicon polymers in which the alternate arrangement of a disilanylene unit and a phenylene group is found regularly in the polymer backbone. We also describe lithographic applications of a double-layer system of the latter polymers. 

Insertion of phenyl, trimethylsilyl, and nitrile-stabilized metalated epoxides into zircona-cyclcs gives the product 160, generally in good yield (Scheme 3.37). With trimethylsilyl-substituted epoxides, the insertion/elimination has been shown to be stereospecific, whereas with nitrile-substituted epoxides it is not, presumably due to isomerization of the lithiated epoxide prior to insertion [86]. With lithiated trimethylsilyl-substituted epoxides, up to 25 % of a double insertion product, e. g. 161, is formed in the reaction with zirconacyclopentanes. Surprisingly, the ratio of mono- to bis-inserted products is little affected by the quantity of the carbenoid used. In the case of insertion of trimethylsilyl-substituted epoxides into zirconacydopentenes, no double insertion product is formed, but product 162, derived from elimination of Me3SiO , is formed to an extent of up to 26%. 

The latter reaction involves the addition of the pcrfluoro(l-iodohexane) to phenyl trimethylsilyl ketone and a Brook rearrangement with lithium fluoride and fluorotrimethylsilane elimination. In the case of the corresponding magnesium derivative, which is more stable at the reaction temperature, warming up to room temperature before hydrolysis is necessary.214... 

Phenyl trimethylsilyl telluride. C6H5TeSi(CH3)3 (1). The tellurosilane is accessible by cleavage of diphenyl ditelluride with sodium followed by reaction with ClSi(CH3)3 (74% yield). It is sensitive to 02 and HzO. 

Phenyl trimethylsilyl telluride, 248 Tetrabutylammonium iodide-Boron trifluoride etherate, 287 of oxetanes... 

When phenyl(trimethylsilyl)diazomethane (20) is pyrolyzed in the gas phase, typical reactions of carbene 21 can be observed (see Section III.E.4). However, copyrolysis with alcohols or carbonyl compounds generates again products which are derived from silene 2239,40 (equation 6). Thus, alkoxysilanes 23 are obtained in the presence of alcohols and alkenes 24 in the presence of an aldehyde or a ketone. 2,3-Dimethylbuta-l,3-diene traps both the carbene (see Section ni.E.4) and the silene. 

Phenyl(trimethylsilyl)carbene (21) has been generated from phenyl(trimethylsilyl)diazo-methane (20) by gas-phase pyrolysis39,40 as well as by thermolysis97 or photolysis33,40,98,99 in solution, by flash thermolysis of the tosylhydrazone lithium salt 18040, and by pyrolysis... 

We have already mentioned the synthetic versatility of silyl thioketones249 which is confirmed because they react with 1,3-dipoles (nitrile oxides, nitrile imines and nitrile ylides) to give regiospecifically silyl thiaheterocycles462. Equation 135 illustrates the reaction between phenyl trimethylsilyl thioketone and diphenyl nitrihmine. 

After the elucidation of the reaction of phenylisocyanide dichloride with phenyl(trimethylsilyl)phosphane, several other differently substituted isocyanide dichlorides react extremely slowly, so that high temperatures are necessary which prevent the... 

In 1981, Becker and coworkers reported a reaction of lithium phenyl(trimethylsilyl) phosphide (6) with benzophenone to generate phosphaethene PhP=CPh2 (equation 45)31. 

Phenyl[(trimethylsilyl)ethynyl]iodonium triflate has also been employed for alkynylations of diethyl 2-phthalimidomalonate and the (2-oxoazetidinyl)malonates shown in equation 126. However, unlike the result with the [(diphenyl)amino]malonate system (equation 125), the trimethylsilyl group is lost, and the ethynyl group is ultimately introduced. 

Also widely employed are organoselenium compounds containing group 14 elements. Phenyl trimethylsilyl selenide 102 can be easily prepared from diphenyl diselenide 8 and is a good source for selenium nucleophiles (Scheme 24). In the presence of methanol selenols are generated for use in Michael reactions or in ring-... 

Benzenetellurolwas detected by 1H-NMR spectroscopy [<5(TeH) — 2.4 ppm] in the reaction mixture obtained from phenyl trimethylsilyl tellurium and water4 ... 

It was claimed that benzenetellurol was also formed from phenyl trimethylsilyl tellurium and methanol in tetrahydrofuran5. 

The extreme sensitivity of tellurols to oxygen make the isolation of these tellurium compounds difficult. Therefore, tellurols are almost always used in situ. In the literature, tellurols are sometimes claimed to be the product of the reduction of diaryl ditelluriums in ethanol as the reaction medium. Tellurols are probably present under these conditions in equilibrium with the tellurolates. Whether the tellurols or the tellurolates are the reactive species, for instance, in addition reactions to carbon-carbon multiple bonds, cannot be decided without additional studies. Benzenetellurol, formed in situ by methanolysis of phenyl trimethylsilyl tellurium, was much less reactive towards acetylenes than the tellurium compound obtained by reduction of diphenyl ditellurium with sodium borohydride in ethanol5. 

Similarly obtained was phenyl trimethylsilyl tellurium (66% yield volatile at 80° under vacuum)1,15. 

Phenyl Trimethylsilyl Tellurium6 38 g (0.30 mol) of powdered tellurium are added to a solution of 0.25 mol of phenyl magnesium bromide in 500 ml of tetrahydrofuran under an inert atmosphere. When the tellurium has reacted, the solution is cooled to 0°, 27 g (0.25 mol) of freshly distilled chlorotrimethylsilane are added dropwise, and the resultant mixture is stirred overnight at 20°. The mixture is then filtered, the solvent is distilled from the filtrate under vacuum at 0°, and the red liquid residue is distilled under vacuum yield 28 g (40%) b.p. 70°/0.1 torr. 

Methyl trimethylsilyl tellurium and phenyl trimethylsilyl tellurium exchanged the organyltelluro group for halogen in reactions with silyl, germyl, stannyl and plumbyl halides2. 

Trimethylstannyl chloride reacted smoothly with methyl and phenyl trimethylsilyl tellurium at 25°. Methyl trimethylstannyl tellurium (94% yield) and phenyl trimethylstannyl tellurium (89% yield) were isolated as involatile, yellow oils possessing foul, persistent odors1. 

Silyl iodide and bromide reacted with methyl and phenyl trimethylsilyl tellurium only upon heating at 60° for at least five hours. Phenyl silyl tellurium and methyl silyl tellurium were obtained in 78% and 90% yield, respectively. 

Aliphatic and aromatic carboxylic acid chlorides cleave the Te —Si bond in phenyl trimethylsilyl tellurium with formation of Te-phenyl carboxylates and trimethylsilyl chloride7. 

Phenyl trimethylsilyl tellurium reacted under mild conditions with cyclic and linear ethers and with carboxylic acid esters. Cleavage of the C — O bonds produced C-tellurated and O-silylated products in yields ranging from 15 to 98%2. 

From Phenyl Trimethylsilyl Tellurium and Epoxides, Carboxylic Acid Esters, Ethers, and... 

Unsymmetrical alkyl phenyl tellurium derivatives were prepared in good yields from phenyl trimethylsilyl tellurium and epoxides, carboxylic acid esters, and linear or cyclic ethers under very mild conditions. In these reactions, which proceed in dichloromethane in the presence of a catalytic amount of zinc iodide, a carbon-oxygen single bond is cleaved. The highly nucleophilic benzenetellurolate binds to the carbon fragment, whereas the trimethylsilyl group becomes linked to the oxygen. 

Lactones and phenyl trimethylsilyl tellurium at 20° produced phenyl otrimeihylsiloxy-carbonylalkyl tellurium compounds that were isolated as the free carboxylic acids after hydrolysis2. 

Four- and five-membered cyclic ethers reacted with phenyl trimethylsilyl tellurium at 0°, whereas the six- and seven-membered ethers required 40 2. 

Methyl-4-trimethylsiloxybutyl Phenyl Tellurium1 Into an argon-flushed, 50-ml flask fitted with a magnetic stirrer are placed 86 mg (1 mmol) of 2-methyltetrahydrofuran and 3 ml of dichloromethane. 3 mg (0.01 mmol) of zinc iodide and 375 mg (0.3 ml 1.35 mmol) of phenyl trimethylsilyl tellurium are added to the stirred solution at 20°. The mixture is stirred at 20° for 6 h, pyridine is then added, and the mixture is concentrated under vacuum at 20°. The residue is chromatographed on a short column of silica gel with chloroform as eluent. The chloroform is evaporated and the residue is rcchromatographed on a preparative gel-permeation column with chloroform as eluent yield 260 mg (71%) light-yellow oil. 

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