- 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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- CATALYST AND RELATED METHODS INVOLVING HYDROSILYLATION AND DEHYDROGENATIVE SILYLATION
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A catalyst having a specific structure and a method fop rearing the catalyst is disclosed. A composition is also disclosed, which comprises: (A) an unsaturated compound including at least one aliphatically unsaturated group per molecule, subject to at least one of the following two provisos: (1) the (A) unsaturated compound also includes at least one silicon-bonded hydrogen atom per molecule; and/or (2) the composition further comprises (B) a silicon hydride compound including at least one silicon-bonded hydrogen atom per molecule. The composition further comprises (C) the catalyst. A method of preparing a hydrosilylation reaction product and a dehydrogenative silylation reaction product are also disclosed.
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Paragraph 00152-00154; 00157; 00160; 00155
(2019/02/06)
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- Fe and Co Complexes of Rigidly Planar Phosphino-Quinoline-Pyridine Ligands for Catalytic Hydrosilylation and Dehydrogenative Silylation
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Co and Fe dihalide complexes of a new rigidly planar PNN ligand platform are prepared and examined as precatalysts for hydrosilylation of alkenes. Lithiation of Thummel's 8-bromo-2-(pyrid-2′-yl)quinoline followed by treatment with (i-Pr)2PCl and (C6F5)2PCl afforded the phosphine-quinoline-pyridine ligands, abbreviated RPQpy for R = i-Pr and C6F5, respectively. These ligands form 1:1 adducts with the dichlorides and dibromides of iron and cobalt. Crystallographic characterization of FeBr2(iPrPQpy), FeBr2(ArFPQpy), CoCl2(iPrPQpy), CoBr2(iPrPQpy), and CoCl2(ArFPQpy) confirmed that the M-P-C-C-N-C-C-N portion of these complexes is planar within 0.078 ? unlike previous generations of PNN complexes where deviations from planarity were ~0.35 ?. Bond distances as well as magnetism indicate that the Fe complexes are high spin and the cobalt complexes are high spin or participate in spin equilibria. Also investigated were the NNN analogues of the RPQpy ligands, wherein the phosphine group was replaced by the mesityl ketimine. The complexes FeBr2(MesNQpy) and CoCl2(MesNQpy) were characterized crystallographically. Reduction of MX2(RPQpy) complexes with NaBHEt3 generates catalysts active for anti-Markovnikov silylation of simple and complex 1-alkenes with a variety of hydrosilanes. Catalysts derived from MesNQpy exhibited low activity. Fe-RPQpy derived catalysts favor hydrosilylation, whereas Co-RPQpy based catalysts favor dehydrogenative silylation. Catalysts derived from CoX2(iPrPQpy) convert hydrosilanes and ethylene to vinylsilanes. Related experiments were conducted on propylene to give propenylsilanes.
- Basu, Debashis,Gilbert-Wilson, Ryan,Gray, Danielle L.,Rauchfuss, Thomas B.,Dash, Aswini K.
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p. 2760 - 2768
(2018/09/10)
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- New vinyl alkoxy silane preparation process
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The present invention discloses a new vinyl alkoxy silane preparation process, which is characterized in that hydrogen chloride produced during a preparation process is adopted as a reactant to synthesize an initial raw material trichlorosilane, the hydrogen chloride is recycled, and the byproduct bis(trialkoxy)silyl ethane is adopted as a reaction solvent during a hydrogen silicon addition process, such that the byproduct emission is reduced, the new impurity introduction is avoided, and the product purity is improved. According to the present invention, the new process has characteristics of stable production, simple preparation process, and mild reaction conditions, and the yield of the product vinyl alkoxy silane is high, and the product purity is more than 99%.
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Paragraph 0041; 0042
(2016/10/08)
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- COSMETIC TREATMENT METHOD COMPRISING THE APPLICATION OF A COATING BASED ON AN AEROGEL COMPOSITION OF LOW BULK DENSITY
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The present invention relates to a cosmetic treatment method comprising the formation of a coating on keratin fibres characterized in that it comprises: 1) the preparation of an aerogel precursor composition comprising:—at least one organic solvent chosen from acetone, C1-C4 alcohols, C1-C6 alkanes, C1-C4 ethers, which may or may not be perfluorinated, and mixtures thereof and at least one precursor compound that contains:—at least one atom chosen from silicon, titanium, aluminium and zirconium,—at least one hydroxyl or alkoxy function directly attached to the atom chosen from silicon, titanium, aluminium and zirconium by an oxygen atom, and,—optionally an organic group directly attached to the atom chosen from silicon, titanium, aluminium and zirconium by a carbon atom, 2) the removal of the solvent or solvents resulting in the formation of an aerogel composition having a bulk density less than or equal to 0.35 g/cm3, 3) the application to the keratin fibres of the aerogel composition resulting from step 2) or of the aerogel precursor composition resulting from step 1). Advantageously, the molar ratio between the precursor compounds and the solvent is at most 1/20.
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Paragraph 0070
(2014/02/15)
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- Ruthenium-catalyzed dealkenative N-silylation of amines by substituted vinylsilanes
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The ruthenium hydride complex-catalyzed N-silylation of primary and secondary amines with substituted vinylsilanes, with the general formula R1CHCHSiR′3 (where R1 = H, Ph, n-Bu, Si(OEt)3), leading to the formation of a Si-
- Marciniec, Bogdan,Kostera, Sylwia,Wyrzykiewicz, Bozena,Pawlu, Piotr
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supporting information
p. 782 - 786
(2015/02/19)
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- POLYMER-BOUND BISACYLPHOSPHINE OXIDES
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The invention pertains to an oligomer or polymer substituted by one or more bisacylphosphine oxide moieties, characterized in that said bisacylphosphine oxide moiety is linked via the phosphorous atom, optionally via a spacer group, to the oligomer or polymer backbone; as well as to specifically functionalized bisacylphosphine oxides, suitable to prepare said polymers or oligomers.
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- COMPOUNDS WITH GUANIDINE STRUCTURE AND USES THEREOF AS ORGANOPOLYSILOXANE POLYCONDENSATION CATALYSTS
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A compound having a guanidine structure and uses thereof as organopolysiloxane polycondensation catalysts are described.
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- Stereoselective synthesis of (E)- and (Z)-triethoxy(vinyl-d 2)silanes by hydrosilylation of acetylene-d 2
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The hydrosilylation of deuterated acetylene with triethoxysilane can be directed to the synthesis of either cis or trans triethoxy(vinyl-d 2)silanes by an appropriate choice of metal catalyst. In addition, we have demonstrated the viability of designing hydrosilylation-arylation sequential processes in which acetylene can be converted into styrenes or stilbenes using the same Pd catalyst for both reactions.
- Gordillo, Alvaro,Forigua, Johan,Lopez-Mardomingo, Carmen,De Jesus, Ernesto
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experimental part
p. 352 - 355
(2011/03/21)
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- COMPOSITION FOR RESIST UNDERLAYER FILM AND PROCESS FOR PRODUCING SAME
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A composition for a resist underlayer film is provided. The composition has excellent storage stability and can form a resist underlayer film which has excellent adhesion to a resist film, can improve reproducibility of a resist pattern and is resistant to an alkaline liquid used in development and to oxygen asking during the removal of a resist. The composition comprises a hydrolyzate and/or a condensate of a silane compound of the following formula (A), [in-line-formulae]R1bR2cSi (OR3)4-a??(A)[/in-line-formulae] wherein R1 is a monovalent organic group having at least one unsaturated bond, R2 individually represents a hydrogen atom, a halogen atom or a monovalent organic group, R3 individually represents a monovalent organic group, R1 is a group other than OR3, a is an integer of 1 to 3, b is an integer of 1 to 3, and c is an integer of 0 to 2, provided that a=b+c.
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- Reaction of organylalkoxysilanes with ethanolamine and disproportionation of transetherification products
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Transetherification of organylalkoxysilanes with monoethanolamine was carried out. Disproportionation in mixtures containing organylalkoxysilanes with an amino group in the substituent was studied by means of NMR spectroscopy. It was shown that the disproportionation rate decreases with increase size of substituents on the silicon atom. The equilibrium composition of disproportionation products corresponds to the normal statistical distribution, except for mixtures containing tris(1-methylpropylideneaminooxy)(vinyl)-silane.
- Kovyazin,Boev,Kopylov,Sokol'Skaya
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p. 216 - 222
(2008/09/19)
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- Effect of substituents on the silicon atom on etherification of organochlorosilanes with ethanol
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The kinetics of etherification of organochlorosilanes with various substituents on the silicon atom with ethanol were studied. The etherification rate is mostly controlled by the inductive constants of the substituents and increases as the electron-acceptor power of the substituents increases. The ρ* value in the Taft equation for etherification of organochlorosilanes with ethanol was determined.
- Chernyshev,Belyakova,Komarov,Bykovchenko
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p. 1038 - 1040
(2007/10/03)
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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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- Reaction of Tetraalkoxysilanes with Alkyl(aryl)chlorosilanes
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Alkyl(aryl)trichloro- or dialkyl(diaryl)dichlorosilanes react with tetraalkoxysilanes Si(OMe)4, Si(OEt)4, and Si(OBu)4 to give partially etherfied alkyl(aryl)chlorosilanes RSiCl2(OAlk), RSiCl(OAlk)2, and R2SiCl(OAlk).
- Chernyshev, E. A.,Komalenkova, N. G.,Tagachenkov, A. A.,Bykovchenko, V. G.
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p. 241 - 243
(2007/10/03)
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- Alkoxylation of C-chlorovinylsilanes
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The alkoxylation and isopropylideneiminoxylation of C-chlorovinylmethylchlorosilanes with various alcohols and acetone oxime were investigated.A series of new C-chlorovinylmethylalkoxy- and isopropylideneiminoxysilanes was characterized by IR and new 1H NMR spectra.The effect of the number of chlorine atoms in C-chlorovinylmethylchlorosilanes on their reactivity in these reactions was determined. - Key words: C-chlorovinylmethylchlorosilanes, etherification; C-chlorovinylmethylalkoxysilanes, alcohols, IR spectra; 1H NMR spectra.
- Lakhtin, V. G.,Ryabkov, V. L.,Polyakova, M. V.,Nosova, V. M.,Kisin, A. V.,Chernyshev, E. A.
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p. 718 - 723
(2007/10/02)
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- PALLADIUM COMPLEXES IN THE HYDROSILYLATION OF ACETYLENE
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The catalytic activities of triphenylphosphine-, trialkylphosphine-, and acetylacetone-palladium complexes in the hydrosilylation of acetylene with trichloro-, alkyldichloro-, triethyl, and triethoxy-silanes were investigated.The yields of the corresponding (triorganylsilyl)ethylenes and 1,2-bis(triorganylsilyl)ethanes (conditions: 70-80 deg C, solvent xylene) depend on the nature of the ligands on the palladium atom and the character of the substituents on the silicon atom in the hydride silane.
- Kopylova, L. I.,Pukhnarevich, V. B.,Voronkov, M. G.
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p. 276 - 278
(2007/10/02)
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- Preparation of polymer polyols
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A novel family of modified polyols suitable for use in the preparation of fluid polymer/polyols. The modified polyols are the reaction product obtained by reacting a silicon atom containing compound with an unmodified polyol, the silicon atom compound being one which has (a) at least olefinically unsatured hydrocarbyl group and (b) at least one functional group which is reactable with the hydroxy groups on the polyol. Examples of such silicon atom containing compounds include vinyltriethoxysilane and vinyltrimethoxysilane. Modified polyols of the type described are particularly useful in the preparation of polymer/polyols containing high levels of polymer since they reduce the viscosity of the final polymer/polyol and decrease the tendency of the polymer/polyol to produce polymer sediment.
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- Process for preparing vinyl-tri-(tertiary substituted) alkoxysilanes
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A process for preparing vinyl-tri-t-oxysilanes by reacting a tri-t-alkoxysilane with an alkyne in the presence of a platinum hydrosilation catalyst at a reaction temperature greater than 150° C. forms a vinyl-tri-t-alkoxysilane in high yields and of high quality.
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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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- 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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- AN ACTIVE AND STABLE HYDROSILYLATION CATALYST: A SILICA SUPPORTED POLY-γ-MERCAPTOPROPYLSILOXANE-PLATINUM COMPLEX
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A silica-supported poly-γ-mercaptopropylsiloxane-platinum complex was prepared and used as hydrosilylation catalyst with 1-hexene and acetylene.When it was used as the catalyst for addition of triethoxysilane to 1-hexene at 80 deg C or room temperature, the product was n-hexyltriethoxysilane only, and the catalyst could be reused over twenty times (turnover numbers achieved were about 10.000) without any appreciable loss in the catalytic activity.The addition of triethoxysilane to acetylene by this catalyst at 80 deg C or room temperature under an atmospheric pressure gave vinyltriethoxysilane and bis(triethoxysilyl)ethane in good yields.
- Wang, Lin-Zhi,Jiang, Ying-Yan
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- Process for the preparation of organoalkoxysilanes
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An improvement in a process for the esterification of a organochlorosilane by feeding alcohol into a chlorosilane maintained within a reaction zone without said alcohol contacting said chlorosilane in the gas phase wherein the esterification is performed stepwise with extraction of hydrogen chloride which has developed, the improvement which comprises employing in at least a final esterification step an organochlorosilane of the formula wherein R represents an optionally halogen-substituted alkyl radical which can also contain an oxygen or sulfur atom in the chain, or a halogen or a NO2 group or a protected phenolic group containing aryl radical, a equals 0, 1, or 2, b equals 1 or 2, and a+b amounts to a maximum of 3, said final esterification step being performed with the addition of heat.
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- CONVENIENT LABORATORY SYNTHESIS OF VINYLIC SILICON COMPOUNDS VIA THE REACTIONS OF ACETYLENE WITH HYDROSILANES CATALYZED BY GROUP-VIII METAL PHOSPHINE COMPLEXES
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The hydrosilylation of acetylene (HCCH) with trichlorosilane, triethoxysilane, methyldichlorosilane, methyldiethoxysilane and -hexyldichlorosilane in an inert solvent in the presence of various phosphine complexes of Group-VIII metals such as Ru, Rh, Pd and Pt, as well as chloroplatinic acid, was investigated.Among the complexes studied, RuCl2(PPh3)3, PtCl2(PPh3)2, RhCl(PPh3)3, RhH(PPh3)4 and Pt(PPh3)4 were found to be the catalysts of choice for the selective syntheses of vinyltrichlorosilane, vinyltriethoxysilane, methylvinyldichlorosilane, methylvinyldiethoxysilane and -hexylvinyldichlorosilane, respectively.
- Watanabe, Hamao,Asami, Muneo,Nagai, Yoichiro
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p. 363 - 374
(2007/10/02)
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- Preparation of organically modified silicon dioxides
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Process for the preparation of modified, porous silicon dioxides by the hydrolytic polycondensation of tetraalkoxysilanes or polyalkoxysiloxanes in the heterogenous phase in the presence of an organoalkoxysilane.
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