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Cyclohexyl silicone

Cyclohexyl silicone resembles benzyl silicone quite closely. Compositions of the type (CeHnSiOi.g) are gluelike in consistency, as Kipping described them, and they may be converted to ether-insoluble resins.34 Almost all chemical manipulations of the lower polymeric forms result in conversion of these into more of the gluelike higher polymers. [Pg.76]

Addition, chloroform, to olefins to form 1,1,3 tnchloroalkanes, 46, 106 chlorosulfonyl isocyanate to isobutylene to give 0-isovaleiolactam-N-sulfonyl chloride, 46, SI cyclohexyl amine to silicon tetraiso-cyanate, 46, 69... [Pg.120]

Equivalent amounts of aldehydes and alkoxytrimethylsilanes react to form unsymmetrical ethers in near quantitative yields in the presence of either trimethylsilane or triethylsilane and catalytic amounts (ca. 10 mol%) of TMSI in dichloromethane.329,333,334,341 The procedure is particularly convenient experimentally when trimethylsilane is used with TMSI because the catalyst provides its own color indicator for the reduction step (color change from deep violet to vivid red-gold) and the only silicon-containing product following aqueous workup is the volatile hexamethyldisiloxane (bp 99-100°). It is possible to introduce trimethylsilane (bp 7°) either as a previously prepared solution in dichloromethane or by bubbling it directly into the reaction mixture. Cyclohexyloxytrimethylsilane and n-butanal react by this method to give a 93% isolated yield of n-butyl cyclohexyl ether (Eq. 183).334... [Pg.67]

Reaction of silicon tetrafluoride with phenylmagnesium bromide at 0 C in diethyl ether provides fluorotriphenylsilane and fluorodiphenylsilane in 59.5 and 5% yield, respectively.3 Chloro(cy-clohexyl)(l-naphthyl)silane is converted into (cyclohexyl)fluoro(l-naphthyl)silane by reaction with a reagent which is prepared by bubbling silicon tetrafluoride through a mixture of tet-rahydrofuran and water.12... [Pg.642]

Until recently it was thought that silicon substituents beyond the /-position have no effect on reactivity71. Fessenden and coworkers72 found that the rates of ethanolysis of els- and /raw.s-4-(trirncthylsilyl)cyclohexyl tosylates were almost identical to those of the cis- and fraws-4-tert-butylcyclohexyl tosylates. [Pg.380]

The kinetic influence of a 5-silicon substituent on the solvolysis of cyclohexyl tosylates is insignificant. Fessenden and coworkers101 found virtually identical rates of ethanolysis of cis and trans 263 to those of the t-butyl reference compounds 264. However, no evidence for a rate-determining kc solvolysis was provided. [Pg.641]

When a toluene solution of a mixture of cyclotrisilane 34 and cyclohexyl isocyanate (or f-butyl isocyante) was heated at 70 °C, cyclic di- and trisiloxanes 37 and 38, i.e. the cyclic dimer and trimer of the silanone 36, were obtained together with the corresponding isonitrile RN=C. The formation of 37 as well as 38 was completely suppressed in the presence of hexamethylcyclotrisiloxane (19 D3) instead, quantitative conversion of 35 into 39, the formal insertion product of the silanone 36 into the Si—O bond of D3, occurred (Scheme 14). Since neither cyclodisiloxane 37 nor cyclotrisiloxane 38 reacted with D3 under the reaction conditions, the possibility that 37 or 38 is the precursor of 39 was ruled out. Whereas the oxidation of 35 with cyclohexyl and t-butyl isocyanates proceeded with exclusive formation of 37 and 38 (as the silicon-containing compounds) the reaction of 35 with phenyl isocyanate resulted in the formation of 37 in low yield. Furthermore, in this case the presence of D3 did not totally suppress the formation of 37. According to the authors, these results indicate that the oxidation of 35 with cyclohexyl and f-butyl isocyanates appears to use other reaction channels than that with phenyl isocyanate. [Pg.1076]

The phosphenium cation [(Cy3N)2P]+ (Gy = cyclohexyl) adds to the silicon atom in silylene 83 to give the transient cation 100. The cation 100 is trapped by chloride anion and the chlorosilane 101 was observed as the final product (Scheme 7) <2004CC546>. [Pg.676]

A TG-DTA study of the thermochemical processes occurring at vulcanisation temperatures with N-oxydiethylene-2-benzthiazyl sulphenamide and N-cyclohexyl-2-benzthiazyl sulphenamide and their mixtures with sulphur showed the formation of high molecular weight polysulphides [73]. The influence of metallic oxides (Fe203, Sn02) on hot air ageing of one-pack room temperature vulcanised fluorosilicone rubber has been studied by means of TG-DTA [74, 75]. TG-DTA and TG were both applied to study the thermal characteristics of room temperature vulcanised silicone rubber [76]. [Pg.32]

The sample is dissolved in methanol/tetrahydrofuran (50 50, v/v) containing di-cyclohexyl phthalate as internal standard. Separation is carried out by gas-liquid chromatography with a flame ionization detector on a column of Chromosorb W-HP (or equivalent) coated with silicon AN-600. Etofenprox is determined by comparison with calibration solutions. [Pg.62]

Over the past few years, the debate over the origin of the p-silicon effect on carbocations has narrowed to one of the relative magnitudes of inductive and hyperconjugative factors. Theory and experiment are finally in agreement that hyperconjugation is by far the dominant factor—29 kcal/mol calculated to be from P-stabilization ( ) versus 9 kcal/mol from induction and polarization. The realization of these effects is dramatically revealed in the SnI solvolyses of the conformationally locked cyclohexyl trifluoroacetates (OTFA) (3-5), The relative solvolysis rates at 25 °C for compounds 3-5 are 1, 4 X 10, and 2.4 X 10, respectively. Compound 4 cannot attain the necessary anti-coplanar relationship of the Si-C and C-O bonds, which is present in 5 and required for full hyperconjugative interaction with the cation formed as the C-O bond suffers heterolysis. [Pg.11]

The photostadDility of boron-containing orgamic complexes has been discussed, amd a study maule of the luminescent properties of p-diketonates of disubstituted boron amd of bis-p-diketonatoboron. A novel photochemical alkyl migration from B to C in the dialkyIboryl acetylacetonate complexes (1) ( R-cyclohexyl, Bu, isopinocaunpheyl, R -H R-cyclohexyl, Bu, R -Me ) has appeared. Crossover experiments show that the alkyl migration is essentially intraunolecular Silicon... [Pg.140]


See other pages where Cyclohexyl silicone is mentioned: [Pg.125]    [Pg.339]    [Pg.343]    [Pg.762]    [Pg.285]    [Pg.126]    [Pg.72]    [Pg.350]    [Pg.121]    [Pg.908]    [Pg.364]    [Pg.71]    [Pg.121]    [Pg.622]    [Pg.623]    [Pg.635]    [Pg.51]    [Pg.244]    [Pg.142]    [Pg.168]    [Pg.37]    [Pg.232]    [Pg.180]    [Pg.245]    [Pg.90]    [Pg.238]    [Pg.296]    [Pg.3251]    [Pg.52]    [Pg.504]    [Pg.506]   
See also in sourсe #XX -- [ Pg.76 ]




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