- Sustainable Catalytic Synthesis of Diethyl Carbonate
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New sustainable approaches should be developed to overcome equilibrium limitation of dialkyl carbonate synthesis from CO2 and alcohols. Using tetraethyl orthosilicate (TEOS) and CO2 with Zr catalysts, we report the first example of sustainable catalytic synthesis of diethyl carbonate (DEC). The disiloxane byproduct can be reverted to TEOS. Under the same conditions, DEC can be synthesized using a wide range of alkoxysilane substrates by investigating the effects of the number of ethoxy substituent in alkoxysilane substrates, alkyl chain, and unsaturated moiety on the fundamental property of this reaction. Mechanistic insights obtained by kinetic studies, labeling experiments, and spectroscopic investigations reveal that DEC is generated via nucleophilic ethoxylation of a CO2-inserted Zr catalyst and catalyst regeneration by TEOS. The unprecedented transformation offers a new approach toward a cleaner route for DEC synthesis using recyclable alkoxysilane.
- Putro, Wahyu S.,Ikeda, Akira,Shigeyasu, Shinji,Hamura, Satoshi,Matsumoto, Seiji,Lee, Vladimir Ya.,Choi, Jun-Chul,Fukaya, Norihisa
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p. 842 - 846
(2020/12/07)
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- Gamma-chloropropyl triethoxy silane synthesis method
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The invention relates to a gamma-chloropropyl triethoxy silane synthesis method and belongs to the field of fine chemical synthesis. The gamma-chloropropyl triethoxy silane synthesis method provided by the invention comprises the following steps: (1) uniformly filling a fixed bed with a catalyst Ru-B/gamma-Al2O3, performing nitrogen blowing firstly, performing heating later, uniformly mixing 3-chloropropene with triethoxy silane by using a stirrer firstly so as to obtain a mixed raw material liquid, feeding the obtained mixed raw material liquid through the fixed bed of a certain temperature,and performing a reaction for a certain time in the presence of the catalyst so as to obtain a mixed liquid of a product and raw materials through the reaction; and 2) firstly distilling the mixed liquid obtained in the step (1), separating unreacted 3-chloropropene so as to obtain a distillation bottom material, introducing the distillation bottom material into a rectification tower, and performing vacuum distillation to implement purification, so as to obtain a product.
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Paragraph 0020-0046; 0053
(2019/12/25)
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- Synthetic process of silicon-based imidazole epoxy resin curing agent
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The invention discloses a synthetic process of a silicon-based imidazole epoxy resin curing agent and belongs to the technical field of synthesis of curing agents. The synthetic process comprises the following steps: taking chloropropyl trichlorosilane and alcohol as raw materials, synthesizing chloropropyl siloxane by adopting a continuous method and then conducting reaction with an imidazole substance to obtain the silicon-based imidazole epoxy resin curing agent. The synthetic process of the silicon-based imidazole epoxy resin curing agent, disclosed by the invention, has the benefits that some raw materials used in the production process are simple and easy to obtain; in the whole production process, conditions are milder, the operation is simple, the equipment requirements are low, and high temperature, high pressure and other special processes are not required, so that the safety and the economy are good; wastewater containing COD is not generated, and byproducts are less; in the first step of esterification, no waste is generated, by-product hydrochloric acid is also a product with economic benefits, and the influence on the environment is less; chloropropyl silane is continuously produced, so that the reaction is favorably promoted, and the by-products are reduced.
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Paragraph 0022
(2017/07/21)
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- Process for manufacturing polysiloxane microcapsules that are functionalized and are not very porous
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A method is provided for encapsulating products that can have lipophilic or hydrophilic, including volatile, properties in a polysiloxane membrane that is particularly impervious. A method is also provided for evaluating the imperviousness of capsules. The present method includes the following steps: a) formation of droplets by an emulsion between an oily phase containing the product to be encapsulated and an acidic aqueous phase heated to around 50° C. and in the presence of surfactants; b) addition and hydrolysis of at least one silane in order to obtain a silanol; c) increasing the pH in order to start condensation of the silanol to form a first membrane around the droplets of the product to be encapsulated; d) lowering the pH; e) increasing the pH, optionally preceded by adding a silane, in order to obtain a new condensation of silanol around the droplets of the product to be encapsulated.
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Page/Page column 3
(2016/09/26)
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- Hydrosilylation Synthesis of Haloalkylorganosilanes Using Peroxide Promoters
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This invention is directed to a process for producing a haloorganoalkoxysilane product comprising reacting an olefinic halide, an alkoxysilane, a catalytically effective amount of ruthenium-containing catalyst; and a reaction-promoting effective amount of a peroxy compound, optionally in the presence of an electron-deficient aromatic compound.
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Paragraph 0123-0124
(2014/05/07)
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- Method for Attachment of Silicon-Containing Compounds to a Surface and for Synthesis of Hypervalent Silicon-Compounds
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A method for inducing a hypervalent state within silicon-containing compounds by which they can be chemically attached to a surface or substrate and/or organized onto a surface of a substrate. The compounds when attached to or organized on the surface may have different physical and/or chemical properties compared to the starting materials.
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- Mechanistic insights into the hydrosilylation of allyl compounds - Evidence for different coexisting reaction pathways
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The hydrosilylation of allyl compounds is often accompanied by the formation of high amounts of byproducts. The formation processes have not been fully understood so far. In this work, the allyl hydrosilylation mechanism is investigated in detail and experimental and theoretical evidence for multiple, coexisting reaction pathways is provided. Based on earlier reports and the observations during an extensive catalytic study, different pathways, leading to the observed byproducts, were identified and proven by labeling experiments and DFT calculations. Oxidative addition of the silane and the insertion of the allyl compound into the Pt-H bond turned out to be the crucial, selectivity-determining steps within the catalytic cycle. Based on these findings, it should be possible to systematically influence these steps and pave the way to a rational and straightforward design of more selective catalysts.
- Gigler, Peter,Drees, Markus,Riener, Korbinian,Bechlars, Bettina,Herrmann, Wolfgang A.,Kuehn, Fritz E.
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- PREPARATION OF ORGANOMONOALKOXY (OR MONOHYDROXY) SILANES FROM ALKOXYSILANES/ORGANOMETALLIC COMPOUNDS
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Organomonoalkoxy/monohydroxy silanes, particularly halogenated or aklenylated organomonoalkoxy (or monohydroxy) silanes, which are useful intermediates in organic syntheses, are prepared by reacting an alkoxysilane with an organometallic compound suited for substituting at least certain of the alkoxy functions of the alkoxysilane with a monovalent hydrocarbon radical other than alkoxy and co-preparing a metallic alkoxylate by-product capable of denaturing the substituted silanes thus obtained, including contacting the metallic alkoxylate with at least one agent (A) reactive with the alkoxy functions of the alkoxylate to generate one or more species inert relative to the alkoxysilane, such agent (A) being selected from among the electrophile and/or mineral acid groups.
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Page/Page column 8
(2010/08/07)
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- Effect of catalysts on the reaction of allyl esters with hydrosilanes
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The reaction of hydrosilylation of allyl esters XOCH 2CH=CH 2 (X = MeCO, CF 3CO, C 3F 7CO) and PhOCH 2CH=CH 2 with hydrosilanes HSiY 3 (Y = Cl, OEt) in the presence of the Speier catalyst, the Speier catalyst with additives, and of various nickel complexes was studied. The catalytic hydrosilylation reaction in the presence of the Speier catalyst is accompanied by the reduction. Additives to the Speier catalyst (vinyltriethoxysilane and some ethers) allow to suppress considerably the reduction reaction. In the presence of the studied nickel complexes mainly reduction and isomerization reactions occurred. The best nickel catalysts of hydrosilylation were the mixtures of NiCl 2 or Ni(acac) 2 with phosphine oxides. In contrast to allyl esters, the hydrosilylation of simple olefins proceeds easier, the content of the product of hydrosilylation in the reaction mixture reaches 94.3%. Pleiades Publishing, Ltd., 2010.
- Belyakova,Pomerantseva,Efimova,Chernyshev,Storozhenko
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experimental part
p. 728 - 733
(2011/01/05)
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- PROCESS FOR THE PREPARATION OF HALOALKYLALKOXYSILANCS AND HALOALKYLHALOSILANES
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This invention involves a process for the preparation of haloalkylalkoxysilanes and haloalkylhalosilancs. The process comprises reacting an alkoxyhydridosilane or a halohydridosilanc silane with an alkenylhalide compound in the presence of a catalytic amount of an iridium containing catalyst. When a halohydridosilane is the silane rcactant. the resulting haloalkylhalosilane may be alkoxylatcd by reaction with a C1-C6, alcohol, In another aspect of the invention, the reacting is conducted under a reduced oκygen atmosphere to improve the catalyst activity and the yield of the resulting haloalkylhalosilane or halυalkylalkυx vsi lane.
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Page/Page column 17-19
(2009/10/22)
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- Highly efficient O-silylation of alcohol with vinylsilane using a Rh(l)/HCl catalyst at room temperature
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Highly efficient O-silylation of alcohol with vinylsilane was developed using a catalyst system consisting of [(COE)2RhCl]2 and HCl. In this reaction, a key intermediate is chlorosilane, generated from vinylsilane and HCl, which can be regenerated in the catalytic cycle. Various alcohols and vinylsilanes were applied to the preparation of silyl ether compounds with this catalyst system.
- Park, Jung-Woo,Jun, Chul-Ho
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p. 4073 - 4076
(2008/02/11)
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- SURFACE MODIFIED ORGANIC·INORGANIC HYBRID GLASS, PROTECTING GROUP INDUCED ALCOHOL OR ITS DERIVATIVE AND PRODUCING METHOD THEREOF
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Disclosed are a protected alcohol or derivative thereof, a surface- modified organic-inorganic hybrid glass, and preparation methods thereof. More specifically, disclosed are a protected alcohol or derivative thereof and a surface-modified organic-inorganic hybrid glass, which are prepared by allowing a silane compound, having vinyl or a vinyl derivative, to react with an alcohol or derivative thereof or with an organic-inorganic hybrid glass, in the presence of an acid catalyst, a transition metal catalyst and an organic solvent, so as to introduce an organic group thereto even at room temperature, as well as preparation methods thereof. The disclosed invention allows a functional group to be effectively introduced into alcohol or a derivative thereof or into an organic-inorganic hybrid glass, not only high temperatures but also room temperature, and thus is highly effective in introducing compounds having a thermally sensitive functional group, for example, natural compounds or proteins. Also, the invention makes it possible to introduce various organic groups and to separate and purify organic macromolecule-bonded organosilane compounds using a silica gel column so as to effectively introduce large organic functional groups to inorganic materials. Accordingly, the invention is highly useful in the chemical industry.
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Page/Page column 40-41
(2010/11/28)
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- Process for the manufacture of blocked mercaptosilanes
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A process for the manufacture of a blocked mercaptosilane comprising: reacting at least one polysulfane-containing organosilicon compound of the general formula: (R13SiG)2Sn (a) in which each R1is independently methoxy, ethoxy or alkyl of from 1 to about 6 carbon atoms, provided, that at least one R1group is methoxy or ethoxy, G is an alkylene group of from 1 to about 12 carbon atoms and n is from 2 to about 8, with at least one alkali metal, alkaline earth metal or a basic derivative of an alkali metal or alkaline earth metal to provide the corresponding metal salt of the polysulfane-containing organosilicon compound and; (b) reacting the metal salt of the polysulfane-containing organosilicon compound with an acyl halide or carbonyl dihalide to provide a blocked mercaptosilane.
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Page column 7-9
(2010/02/08)
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- Process for making haloalkylalkoxysilanes
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A haloalkylalkoxysilane is prepared by reacting an olefinic halide with an alkoxysilane in which the alkoxy group(s) contain at least two carbon atoms in the presence of a catalytically effective amount of ruthenium-containing catalyst. The process can be used to prepare, inter alia, chloropropyltriethoxysilane which is a key intermediate in the manufacture of silane coupling agents.
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- Process for preparing low-chloride or chloride-free alkoxysilanes
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A process for preparing an alkoxysilane with an acidic chloride content of less than 10 ppm by weight, comprising: reacting a chlorosilane with an alcohol in a water-free and solvent-free phase to form a product mixture containing alkoxysilane and residual acidic chloride, with removal of resultant hydrogen chloride from the product mixture, then adding liquid or gaseous ammonia, in an amount corresponding to a stoichiometric excess, based on the content of acidic chloride, to form an ammonia-containing product mixture, treating the ammonia-containing product mixture at a temperature between 10 and 50 DEG C., wherein the ammonia and acidic chloride undergo neutralization, to form a crude product, and optionally, then separating off a salt formed in the course of neutralization, from the crude product, and recovering the alkoxysilane by distilling the crude product.
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- The influence of additives to the Speier catalyst on hydrosilylation of functionalized alkenes
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Hydrosilylation of several unsaturated compounds with triethoxysilane in the presence of the Speier catalyst with various additives influencing the reaction rate and selectivity was studied. The mechanism of hydrosilylation is discussed.
- Chernyshev,Belyakova,Knyazeva,Pomerantseva,Efimova
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p. 1374 - 1378
(2007/10/03)
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- Process for the preparation of 3-halo-and pseudohalo-alkylsilane esters
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3-Halo- and pseudohalo-alkylsilane esters are prepared by reacting an allyl X compound or a compound containing an allyl X structure with a hydridosilane ester in the presence of an iridium catalyst prepared under specific conditions and/or the reaction medium containing a 0.01-100 mol % excess of the allyl X compound or compound containing the allyl X unit relative to the amount of hydridosilane ester reactant.
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- Method and apparatus for preparing 3-[N-(2-aminoethyl)]aminopropylalkoxysilane
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The invention produces a 3-[N-(2-aminoethyl)]aminopropylalkoxysilane in high yields by reacting a 3-chloropropylalkoxysilane with ethylene diamine. A distillation pot is charged with ethylene diamine and heated above the boiling point of ethylene diamine for evaporating ethylene diamine, which is then condensed into a liquid. The liquid ethylene diamine is mixed for reaction with a 3-chloropropylalkoxysilane in such a proportion to give a molar ratio of ethylene diamine/3-chloropropylalkoxysilane of at least 12/1, thereby forming a 3-[N-(2-aminoethyl)]aminopropylalkoxysilane. The reaction solution is fed back to the pot where the unreacted ethylene diamine in the reaction solution is evaporated again and then condensed for use in a next cycle of reaction. The apparatus includes a distillation pot, a reflux condenser, a feed means and a reactor connected to form a recirculating system.
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- Packing for use in resolution
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The packing for use in resolution proposed for the liquid chromatography for particularly the opti-cal resolution of racemic compounds is prepared by reacting a silica gel carrier with a so-called silane treating agent to introduce a spacer part therein and chemically bonding it with a copper salt of a carboxylic or thiocarboxylic acid selected from the group consisting of optically active D- and L-2--acetizinecaroxylic acid, proline, hydroxyproline and allohydroxyproline. The steric bulkiness, the distance between the silica gel and the optically active group and the degree of hydrophobicity are specified so as to obtain an excellent resolving power.
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- Organosilicon compound having polysulfide linkages and a rubber composition comprising the same
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The novel organosilicon compound of the invention has two polysulfide linkages in a molecule and is represented by the general formula in which R1 is an alkyl group having from 1 to 4 carbon atoms, R2 is a divalent hydrocarbon group having from 1 to 10 carbon atoms, R3 is a divalent hydrocarbon group having from 2 to 10 carbon atoms or a divalent hydrocarbon group additionally containing one or more of the linking units of the formula --O-- or --CO--O-- in the structure and X is a positive integer of from 2 to 6. The compound is useful as an additive in a rubber composition based on natural rubber or a diene-based synthetic rubber and a non-carbon inorganic filler to greatly improve the mechanical properties of the vulcanizate without increasing the Mooney viscosity of the unvulcanized rubber composition.
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- ESTERIFICATION OF CHLOROSILANES IN CYCLOHEXENE SOLUTION.
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The authors have developed a method for production of organoalkoxysilanes by interaction of organochlorosilanes with alcohols in cyclohexene solutions in presence of catalytic amounts of tin tetrachloride. As the result of the synthesis, formation of alkoxysilanes (yield 59-91%) is accompanied by formation of cyclohexyl chloride in 73-90% yield. This compound is an intermediate for production of tricyclohexylhydroxystannane, the principal component of Plictrin. The annual demand for cyclohexyl chloride for this purpose is 250-300 tons. At the same time, cyclohexene obtained as a waste product during manufacture of Kapron is destroyed by burning. Its use as a hydrogen chloride acceptor in esterification of chlorosilanes makes it possible to obtain, virtually without additional cost, a second valuable product, cyclohexyl chloride, in a yield of 1-2 parts by weight per 1 part of organoalkoxysilane.
- Pomerantseva,Belyakova,Shryaev,Efimova,Sheludyakov
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p. 1314 - 1315
(2007/10/02)
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- PREPARATION OF ALKOXYSILANES BY ETHERIFICATION OF CHLOROSILANES WITH REMOVAL OF HYDROGEN CHLORIDE BY VAPOR OF THE BOILING SOLVENT.
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Etherification of chlorosilanes with alcohols is the usual method of obtaining alkoxysilanes. Hydrogen chloride formed as a byproduct must be removed so as to avoid side reactions and increase the yield. The vapor of boiling solvent was used as an agent to remove hydrogen chloride from the reaction zone. Various solvents were tried and their effect on yield was studied. Removal of hydrogen chloride with the vapor of the boiling solvent during etherification of chlorosilanes makes it possible to obtain alkoxysilanes in 80-90% yield as the result of strong suppression of side reactions.
- Belyakova,Pomerantseva,Efimova,Chernyshev
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p. 426 - 427
(2007/10/02)
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- Polymer-Based Sensitizers for Photochemical Reactions. Silica gel as a Support
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Silica gel has been converted to silylated derivatives which can be converted to sensitizers for singlet oxygen formationn.The silica gel sensitizers, Si>-rose bengals, are versatile and useful in both polar and nonpolar media. Si>-Rose bengal has been studied as a source of singlet oxygen and its uses in reactions of sulfite ion, tryptophan, and 2,3-diphenyldioxene are reported.Results are compared with unbound and polystyrene-based rose bengal (-rose bengal).
- Tamagaki, Seizo,Liesner, Cathy E.,Neckers, Douglas C.
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p. 1573 - 1576
(2007/10/02)
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