- Method for removing methyldichlorosilane and silicon tetrachloride impurities in trimethyl chlorosilane
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The invention relates to a method for removing methyldichlorosilane and silicon tetrachloride impurities in trimethyl chlorosilane, which comprises a hydrosilylation reaction, a partial esterification reaction and a complete esterification reaction. Firstly, a mixture of trimethylsilyl chloride containing methyldichlorosilane and silicon tetrachloride impurities is added to a reactor for hydrosilylation reaction, and the reaction product enters a separation system. The silicon tetrachloride in the mixture is partially esterified and reacted by adding the low-carbon alcohol as an esterifying agent, and the reaction product enters a separation system. Finally, the partially esterified product is further fully esterified to valuable tetraalkoxy silicon products. The high-efficiency recycling of trimethylchlorosilane is realized, and high-value utilization is also realized.
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Paragraph 0065-0068; 0076
(2021/08/25)
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- PROCESS FOR THE STEPWISE SYNTHESIS OF SILAHYDROCARBONS
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The invention relates to a process for the stepwise synthesis of silahydrocarbons bearing up to four different organyl substituents at the silicon atom, wherein the process includes at least one step a) of producing a bifunctional hydridochlorosilane by a redistribution reaction, selective chlorination of hydridosilanes with an ether/HCI reagent, or by selective chlorination of hydridosilanes with SiCI4, at least one step b) of submitting a bifunctional hydridochloromonosilane to a hydrosilylation reaction, at least one step c) of hydrogenation of a chloromonosilane, and a step d) in which a silahydrocarbon compound is obtained in a hydrosilylation reaction.
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Page/Page column 71; 72
(2021/12/08)
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- Preparation, characterization and evaluation of a series of heterogeneous platinum catalysts immobilized on magnetic silica with different acid ligands
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Platinum was immobilized on magnetic silica gel by means of boronic, nitric, carboxylic or sulfuric acid ligands to give four heterogeneous Pt nano-catalysts, designated as Fe3O4@SiO2-BA@Pt, Fe3O4@SiO2-NA@Pt, Fe3O4@SiO2-CA@Pt and Fe3O4@SiO2-SA@Pt, respectively. Particles of these mono-dispersible Pt catalysts were 10–20?nm in size and could be separated for recycling by means of a magnet. Fe3O4@SiO2-BA@Pt (0.174?mmol/g Pt) showed the best catalytic activity and selectivity, which were better than Speier’s catalyst. Its turnover numbers were up to 1.7 × 106 and 1.1 × 106 for hydrosilylation of 1-hexene or styrene, respectively. This material could also catalyze the hydrosilylation of a broad range of alkenes and alkynes as substrates and methyldichlorosilane or triethoxysilane as silanes. Similar yields of 1-hexyl-methyldichlorosilane at the first and eighth runs (96.5% and 95.2%, respectively), together with a final Pt content of 0.171?mmol/g indicated the outstanding stability of Fe3O4@SiO2-BA@Pt under the catalytic reaction conditions.
- Li, Laiming,Li, Youxin,Assefa, Aschenaki,Bao, James J.
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p. 779 - 787
(2019/08/12)
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- Preparation of polycarboxylic acid-functionalized silica supported Pt catalysts and their applications in alkene hydrosilylation
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A series of novel immobilized platinum catalysts was prepared by loading Pt onto silica particles modified with polycarboxylic acid groups such as diethylenetriaminepentaacetic acid (DTPA), nitrolotriacetic acid (NTA) and succinic acid (SA). The three modified heterogeneous Pt catalysts were characterized using infrared spectroscopy (IR), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDS) and atomic absorption spectroscopy (AAS). The residual H2PtCl6 solutions were characterized using ultraviolet spectroscopy (UV). The polycarboxylic acid-functionalized silica supported Pt catalysts were used to catalyze alkene hydrosilylation and 1-hexene was chosen as a model alkene. The data indicated that the catalytic performance was strongly dependent on the properties of the polycarboxylic acid group bonded to the silica particles. Among them, DTPA-functionalized silica supported Pt (SiO2-DTPA-Pt) showed the best catalytic activity and reusability. Furthermore, some hydrosilylation reactions between other linear alkenes (1-heptene, 1-octene, 1-decene, 1-do-decene, 1-tetra-decene, 1-hexa-decene, 1-octa-decene, styrene or cis-hex-2-ene), or ring type alkenes (norbornene) with methyldichlorosilane could be catalyzed in the presence of these three Pt catalysts. Their high activities were more than 90%, and their selectivities were more than 99%, which were apparently better than homogeneous Pt catalysts. In addition, reactions with cyclohexene were also successfully catalyzed by the Pt catalysts. These results indicate that the polycarboxylic acid-functionalized silica gel supported Pt catalysts have potential value in industrial hydrosilylation reactions.
- Shao, Dongyun,Li, Youxin
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p. 20379 - 20393
(2018/06/11)
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- Super-microporous silica-supported platinum catalyst for highly regioselective hydrosilylation
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Super-microporous micelle-templated platinum on silica catalysts were successfully prepared by an improved one-pot procedure, using a water/acetonitrile/n-dodecylamine mixture. The catalyst showed high surface area and narrow pore size and was further characterized by powder X-ray diffraction and inductively coupled plasma mass spectrometry. The unique super-microporous materials were proven to be highly active for the microwave-assisted hydrosilylation reaction of terminal alkenes or alkynes using dichloromethylsilane as silicon source. The super-microporous structure was beneficial for the control of hydrosilylation regioselectivity, as the selectivity to the β-adduct reached 99%. Moreover, the catalyst could be easily recovered by simple filtration and re-used seven times without appreciable loss of activity and selectivity.
- Hu, Wenbin,Xie, Huilin,Yue, Hangbo,Prinsen, Pepijn,Luque, Rafael
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- Regiospesific addition of methyldichlorosilane to styrene
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Influence of various Pt-containing catalytic systems and additives to them on regioselectivity of styrene hydrosilylation by methyldichlorosilane was studied. The regiospesific approach to methyl(2-phenylethyl)dichlorosilane in the presence of tetrakis(triphenylphosphine)platinum Pt(0) is developed.
- Frantsuzova,Khoroshavina,Nikolaev
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p. 277 - 279
(2014/04/17)
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- SATURATED N-HETEROCYCLIC CARBENE-LIGAND METAL COMPLEX DERIVATIVES, PREPARING METHOD THEREOF, AND PREPARING METHOD OF SILANE COMPOUND BY HYDROSILYLATION REACTION USING THE SAME AS CATALYST
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Provided are a saturated N-heterocyclic carbene-ligand metal complex derivative, a method for preparing the same, and a method for preparing a silane compound by hydrosilylation using the same as a catalyst. To describe in more detail, the metal complex derivative has a saturated N-heterocyclic carbene derivative and an olefin ligand at the same time. A silane compound is prepared by hydrosilylation in the presence of the metal complex derivative as a catalyst. The provided metal complex derivative of the present invention has superior stability during hydrosilylation reaction and is capable of effectively performing the hydrosilylation reaction at low temperature even with small quantity. Further, a product with superior regioselectivity may be obtained. In addition, after the hydrosilylation reaction is completed, the metal complex derivative may be recovered and recycled.
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Page/Page column 11
(2011/07/08)
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- SATURATED N-HETEROCYCLIC CARBENE-LIGAND METAL COMPLEX DERIVATIVES, PREPARING METHOD THEREOF, AND PREPARING METHOD OF SILANE COMPOUND BY HYDROSILYLATION REACTION USING THE SAME AS CATALYST
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Provided are a saturated N-heterocyclic carbene-ligand metal complex derivative, a method for preparing the same, and a method for preparing a silane compound by hydrosilylation using the same as a catalyst. To describe in more detail, the metal complex derivative has a saturated N-heterocyclic carbene derivative and an olefin ligand at the same time. A silane compound is prepared by hydrosilylation in the presence of the metal complex derivative as a catalyst. The provided metal complex derivative of the present invention has superior stability during hydrosilylation reaction and is capable of effectively performing the hydrosilylation reaction at low temperature even with small quantity. Further, a product with superior regioselectivity may be obtained. In addition, after the hydrosilylation reaction is completed, the metal complex derivative may be recovered and recycled.
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Page/Page column 18-19
(2011/07/30)
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- The first alkene-platinum-silyl complexes: Lifting the hydrosilation mechanism shroud with long-lived precatalytic intermediates and true Pt catalysts
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The synthesis, characterization, and exploratory chemistry of two classes of alkene-platinumsilyl complexes, which have been postulated as hydrosilation intermediates, are described in this report. The unique dimeric complexes 1, [R3Si(u-Cl)(η2-COD)Pt]2 {R3Si = Et3Si, MeCl2Si, Me2ClSi, "(EtO)3Si", PhMe2Si, and (Me3SiO)Me2Si: COD = cycloocta-1,5-diene}, and the bis-silyl complexes 2, (η4-COD)Pt-(SiR3)2 (R3Si = Cl3Si, MeCl2Si, Me2ClSi, and PhMe2Si), are formed from the sequential reaction of 2 and 4 equiv of the corresponding hydrosilanes, respectively, with Pt(COD)Cl2 in the presence of a small excess of COD. Complexes 1 are stable for many days in solution at room temperature but decompose via slow elimination of chlorosilane. Some of the bis-silyl compounds 2 are stable for extended periods under inert atmosphere and especially below 0 °C, either in the solid state or in solution (in the presence of a small excess of free COD). Complexes 2 display catalytic activity as discrete, molecular, and mononuclear species for hydrosilation and isomerization reactions. Compound 2c (R3Si = MeCl2Si) MeCl2Si) was fully characterized via multinuclear NMR spectroscopy and x-ray crystal structure analysis. The facile H-transfer rather than Si-transfer to bound COD provides experimental support for the sequence of insertive steps in the Chalk-Harrod catalytic cycle, at least for Pt-catalyzed hydrosilation.
- Roy, Aroop K.,Taylor, Richard B.
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p. 9510 - 9524
(2007/10/03)
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- Method of preparing an organosilicon compound
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A method of preparing an organosilicon compound comprising effecting a hydrosilylation reaction between (a) unsaturated compounds with terminal unsaturated groups and (b) silane compounds described by formula HSiR0mW3-m, where W is selected from the group consisting of C1 to C6 alkoxy groups, C6 to C10 aryloxy groups, and halogen atoms, R0 is an organic group, and m is 0, 1, or 2 in the presence of (c) a platinum catalyst and (d) an auxiliary catalyst selected from the group consisting of (1) silyl esters of acids derived from oxo acids of sulfur; (2) amide compounds having N-Si bonds; (3) urea compounds; (4) silyl esters of carbamic acid; (5) phosphoric acid compounds; and (6) cyclic compounds selected from the group consisting of (i) hydroxypyridine compounds, (ii) 8-hydroxyquinoline compounds, (iii) oxazolidinone compounds, and (iv) N-hydroxysuccinimide compounds.
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- Method of preparing an organosilicon compound
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A method of preparing an organosilicon compound comprising effecting a hydrosilylation reaction between (a) unsaturated compounds with terminal unsaturated groups and (b) silane compounds described by formula HSiR0mW3?m, where W is selected from the group consisting of C1to C6alkoxy groups, C6to C10aryloxy groups, and halogen atoms, R0is an organic group, and m is 0, 1, or 2 in the presence of (c) a platinum catalyst and (d) an auxiliary catalyst selected from the group consisting of (1) silyl esters of acids derived from oxo acids of sulfur; (2) amide compounds having N—Si bonds; (3) urea compounds; (4) silyl esters of carbamic acid; (5) phosphoric acid compounds; and (6) cyclic compounds selected from the group consisting of (i) hydroxypyridine compounds, (ii) 8-hydroxyquinoline compounds, (iii) oxazolidinone compounds, and (iv) N-hydroxysuccinimide compounds.
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- Method of making an aromatic chlorosilane compound by a hydrosilation reaction
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A process comprising the hydrosilation of an aromatic vinyl compound by a hydridochlorosilane compound in the present of platinum or platinum compound and a carboxylic acid. The process favors the formation of the β-adduct of the hydrosilation reaction.
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- Effect of the substituents at the silicon of (ω-chloroalkyl)silanes on the alkylation to benzene
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(ω-Chloroalkyl)silanes [Cl3-mMemSi(CH2)n-Cl: m=0-3, n=1-3] underwent Friedel-Crafts alkylation with benzene in the presence of aluminum chloride to give alkylated products. Such alkylation reactions took place at temperatures ranging from room temperature (m=0-1, n=2, 3; m=3, n=1) to 80 (m=1, 2; n=1) and 200°C (m=0; n=1), depending on the substituent(s) of the silicon and the alkylene-chain spacer between the silicon and C-Cl bond of (ω-chloroalkyl)silanes. In the alkylation to benzene, the reactivities of (ω-chloroalkyl)silanes increase as the number (m) of methyl-group(s) at the silicon and the alkylene length between the silicon and C-Cl bond increases. While decomposition of alkylation products was observed at two more methyl groups substituted at silicon in the cases of (chloromethyl)silanes such as (chloromethyl)dimethylchlorosilane and (chloromethyl)trimethylsilane. The reaction with (chloromethyl)trimethylsilane occurred at room temperature to give trimethylchlorosilane, toluene and xylene via a decomposition reaction of the products. No (trimethylsilylmethyl)benzene was formed. In the alkylation to benzene, the reactivity of (ω-chloroalkyl)silanes decreases in the following order: m=3>2>1>0; n=3>2?1. The results are consistent with the stability of the carbocation generated by the complexation of (ω-chloroalkyl)silanes with aluminum chloride.
- Yoo, Bok Ryul,Hyun Kim, Jeong,Lee, Ho-Jin,Lee, Kang-Bong,Nam Jung, Il
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p. 239 - 245
(2007/10/03)
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- Syntheses of Organofunctional Siloxanes containing Metal-ligating Sidechains
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A range of tri-, tetra-, and penta-siloxanes of general formula Me3SiOnSiMe3 (R=vinyl, n=1-3; R=an alkyl chain terminated by the potential metal-ligating entities CH=CH2, Ph, CN, cyclohexenyl, pyridine, and PPh2, n=1 or 2) have been synthesised from commercially avilable dichlorosilanes by one of three procedures.The products are air-stable oils with the exception of the pyridine- and phosphine-functionalised compounds which react vigorously with oxygen, and the spectroscopic properties of corresponding organofunctional siloxanes are very similar showing little dependence on n.
- Brisdon, Brian J.,Watts, Andrew M.
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p. 2191 - 2194
(2007/10/02)
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