- Kinetics of Gas Phase Addition Reactions of Trichlorosilyl Radicals. IV. Relative Rates of Additions to 1-Alkenes
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Trichlorosilyl radical additions to a mixture of ethene, propene, 1-butene, and 1-pentene and to a mixture of propene and 2-methylpropene have been investigated.The rate of adduct formation from each olefin was obtained relative to that from propene between 403 K and 548 K.These relative rates are in good agreement with those calculated from the rate parameters obtained previously in this laboratory.
- Dohmaru, Takaaki,Nagata, Yoshio
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- Kinetics of Gas Phase Addition Reactions of Trichlorosilyl Radicals. VIII. Reinvestigation of Addition to Ethylene
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The addition of SiCl3 radicals to ethylene has been reinvestigated using a large conversion method.The amended values are log(k3/k5) = -0.17 +/- 0.05 - (0.80 +/- 0.10) kcal mol-1/2.303 RT and log -5/k6 (mol cm-3)> = 3.4 +/- 0.3 - (22.5 +/- 0.7) kcal mol-1/2.303 RT where the reactions involved are radical-SiCl3 + CH3COCH3 (CH3)2-radical-COSiCl3, radical-SiCl3 + C2H4 radical-CH2CH2SiCl3 and radical-CH2CH2SiCl3 + HSiCl3 C2H5SiCl3 + radical-SiCl3.
- Dohmaru, Takaaki,Nagata, Yoshio
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- A novel catalyst containing a platinum complex in polyethylene glycol medium supported on silica gel for vapor-phase hydrosilylation of acetylene with trichlorosilane or trimethoxysilane
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Hydrosilylation of acetylene with trichlorosilane or trimethoxysilane was carried out using a vapor-phase flow reactor with use of tetraammineplatinum(II) chloride in polyethylene glycol medium supported on silica gel as a catalyst, which is an active and thermally stable supported liquid-phase catalyst prepared readily from easily available materials, tetraammineplatinum(II) chloride, polyethylene glycol and silica gel.
- Okamoto, Masaki,Kiya, Hironari,Yamashita, Hiromi,Suzuki, Eiichi
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- Potassium Alkylpentafluorosilicates, Primary Alkyl Radical Precursors in the C-1 Alkylation of Tetrahydroisoquinolines
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In this study, we demonstrate that potassium alkylpentafluorosilicates (RSiF5K2) are efficient primary alkyl radical precursors for selective C(sp3)-C(sp3) bond-forming reactions. RSiF5K2 reagents are white, free-flowing solids and are moisture and air stable. This class of reagents enables the direct C-1 alkylation of tetrahydroisoquinolines under mild conditions via single-electron transfer. The broad substrate scope of both alkylpentafluorosilicates and tetrahydroisoquinolines is tolerated in this transformation. Both radical scavenger and EPR capture experiments show that the primary radical is generated by the oxidation of RSiF5K2. A mechanism involving alkyl radical addition to an iminium salt followed by reduction by an amine is proposed.
- Wang, Teng,Wang, Dong-Hui
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supporting information
p. 3981 - 3985
(2019/06/14)
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- A direct method for preparing ethyldichlorosilane and its comparison with known alternative methods
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Various methods, alternative to direct synthesis, for preparing an important commercial organosilicon monomer, ethyldichlorosilane, were studied in detail. The methods, including organomagnesium and organoaluminum procedures, hydrosilylation, and combined methods, were analyzed from the viewpoint of feasibility of laboratory and small-tonnage commercial production, and their advantages and drawbacks were revealed.
- Lebedev,Sheludyakov,Lebedeva,Ovcharuk,Govorov,Kalinina
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p. 629 - 633
(2014/11/08)
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- PREPARATION OF ORGANOHALOSILANES
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A process for preparing organohalosilanes comprising combining hydrogen, a halosilane having the formula HaSiX4-a (I), and an organohalide having the formula RX (II), wherein R is C1-C10 alkyl or C4-C10 cycloalkyl, each X is independently halo, and the subscript a is 0, 1, or 2, in the presence of a sufficient amount of a catalyst effective in enabling the replacement of one or more of the halo groups of the halosilane with the R group from the organohalide, at a temperature from 200 to 800 °C, to form an organohalosilane and a hydrogen halide, wherein the volumetric ratio of hydrogen to halosilane is from 1 :3 to 1 :0.001 and the volumetric ratio of hydrogen to organohalide is from 1 : 1 to 1 :0.001, and wherein the catalyst is optionally treated with the hydrogen or the halosilane prior to the combining.
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Page/Page column 17-18
(2011/12/14)
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- PROCESS FOR CONVERTING SI-H COMPOUNDS TO SI-HALOGEN COMPOUNDS
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Silicon compounds containing Si—H groups are converted into silicon halides by reaction with hydrogen halide in the gas phase in the presence of a catalyst of gamma-alumina, which is also effective in dissociating hydrocarbons which may be present into lower boiling hydrocarbons.
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Page/Page column 1
(2010/08/03)
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- Continuous and batch organomagnesium synthesis of ethyl-substituted silanes from ethylchloride, tetraethoxysilane, and organotrichlorosilane for production of polyethylsiloxane liquids. 1. Batch one-step synthesis of ethylethoxysilanes and ethylchlorosilanes
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Development of batch one-step manufacturing process for ethylethoxy- and ethylchlorosilanes is desribed. The methodology of synthesis of ethyl-substituted silanes has been improved. The important factors for the successful synthesis have been determined. Among them are the replacement of the part tetraethoxysilane 3 by ethyltrichlorosilane 10, the optimum concentration of 3 and 10 resulting in high yield of triethylsilanes, low duration of synthesis, and high selectivity of Grignard reagent. Batch one-step synthesis has been assimilated into industry (up to a scale 240 kg of magnesium) for production of oligoethylsiloxanes with the high content (>40%) of a terminal triethylsiloxy group. The rules for R/D process of the Grignard synthesis are described.
- Klokov, Boris A.
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- Chlorohydrosilane derivatives and their preparation method
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New chlorohydrosilane derivatives having the general formula (I) and preparation method thereof. The chlorohydrosilane derivatives (I) of the present invention which have both Si--Cl and Si--H bonds are prepared by partially reducing chlorosilane of the formula (II) which have at least two Si--Cl bonds with lithiumaluminum hydride. The chlorohydrosilane derivatives (I) of the present invention, which have both Si--H and Si--Cl bonds in a molecule can be advantageously used in preparing various compounds because a Si--H bond enables the hydrosilylation with unsaturated organic compounds, while a Si--Cl bond can participate in hydrolysis or in a reaction with a nucleophilic compound such as Grignard reatent: STR1 wherein R1 is straight, branched, or cyclic alkyl group having 1 to 30 carbon atoms, which can include an aromatic group or heterocyclic group, and R2 represents chloro group, or straight, branched, or cyclic alkyl group having 1 to 30 carbon atoms, which can include an aromatic group or heterocyclic group.
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- Stepwise organomagnesium synthesis of mixtures of ethyletoxysilanes and ethylchlorosilanes
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Mixture of ethylethoxy- and ethylchlorosilanes was prepared in a toluene solution by successive reaction of magnesium with a mixture of ethyl chloride and tetraethoxysilane and then with a mixture of ethyl chloride and tetrachlorosilane.
- Klokov
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p. 1863 - 1865
(2007/10/03)
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- Isomerization of 1-Butene Catalyzed by (η6-Arene)NiR2. A Very Active Homogeneous Catalyst System
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(η6-Arene)NiR2 (R = SiCl3, SiF3, C6F5) complexes exhibit very high catalytic activity for the isomerization of 1-butene, especially in bromobenzene solution.The isomerization is generally first order in both 1-butene and Ni complex.The catalytic activity decreases in the order SiCl3 > SiF3 > C6F5.The reaction rate in toluene solution increases with increasing 1-butene concentration below a ratio of 1-C4H8/Ni = 100 but decreases at higher ratios apparently due to induced decomposition of the Ni complex.However, the rate is not adversely affected by high 1-C4H8 concentration in bromobenzene solution.The ratio of cis-2-butene to the trans isomer is also dependent on solvent, suggesting that an important step in the mechanism is the involvement of solvent in the catalytic cycle.The reaction of ethylene with (η6-arene)Ni(SiCl3)2 gives vinyltrichlorosilane and ethyltrichlorosilane.A mechanism is proposed which involves the intermediacy of nickel hydride species generated by the insertion of 1-butene into the Ni-R bond followed by β-hydride elimination.
- Kanai, Hiroyoshi,Choe, Seok Burm,Klabunde, Kenneth J.
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p. 2019 - 2023
(2007/10/02)
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- An efficient Synthesis of Alkylchlorosilanes from Alkenylchlorosilanes
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The use of nickel catalyst ("Ni/SiH") allows easy hydrogenation of alkenylchlorosilanes at atmospheric pressure, not affecting the chlorine function, and leads to quantitative synthesis of alkylchlorosilanes.
- Picard, Jean-Paul,Dunogues, Jacques,Elyusufi, Abdelaziz,Lefort, Marcel
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- Organosilane compounds
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Novel compounds of the formula STR1 or siloxane oligomers thereof, wherein R1 is an alkyl group containing 1 to 4 carbon atoms, where x is 2 to 4, m is 1 to 20, Z is hydrogen, an alkyl group containing 1 to 18 carbons or an acyl group containing 1 to 4 carbon atoms; a is 0 to 2; R2 is an alkyl group containing 1 to 18 carbon atoms; R3 is an alkyl group containing 1 to 18 carbon atoms; R4 is an alkyl, aryl or arylalkyl group containing 1 to 12 carbon atoms, a carboxy-substituted alkyl group containing 1 to 4 carbon atoms, where x, m, and Z are as defined above, or oxygen provided only one R4 is oxygen; R5 is an alkyl, aryl or arylalkyl group containing 1 to 22 carbon atoms; X is halide; and Y is nitrogen, phosphorus or sulfur. The novel compounds are useful for inclusion in a detergent composition for imparting soil release benefits to metallic and vitreous surfaces contacted therewith.
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