2031-67-6Relevant academic research and scientific papers
Metastable Ion Study of Organosilicon Compounds VI - Triethoxymethylsilane and Tetraethoxysilane
Tabei, Eiichi,Mori, Shigeru,Okada, Fumio,Tajima, Susumu,Ogino, Kazuo,et al.
, p. 412 - 420 (1993)
The fragmentations of triethoxymethylsilane ((C2H5O)3SiCH3 (1)) and tetraethoxysilane ((C2H5O)4Si (3)) induced by electron impact were investigated by mass-analysed ion kinetic energy (MIKE) spectrometry and a deuterium-labelling study.These molecular ions begin to fragment by the loss of methyl, ethyl and/or ethoxy radicals.Almost complete scrambling of methylene hydrogen takes place in these resultant intermediate ions, prior to the elimination of acetaldehyde molecule.The fragmentations of +. and +. were compared with those of the corresponding carbon analogues, 1,1,1-triethoxyethane ((C2H5O)3CCH3 (2)) and tetraethoxymethane ((C2H5O)4C (3)), respectively.
THE PROCESS FOR THE PREPARATION AND USE OF HAIR TREATMENT COMPOSITIONS CONTAINING ORGANIC C1-C6 ALKOXY SILANES
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, (2022/01/12)
The subject of the present application is a method for the preparation and use of an agent for the treatment of keratinous material, in particular human hair, comprising the following steps: (1) Mixing one or more organic C1-C6 alkoxy silanes with water,(2) optionally, partial, or complete removal from the reaction mixture of the C1-C6 alcohols liberated by the reaction in step (1),(3) if necessary, addition of one or more cosmetic ingredients,(4) Filling of the preparation into a packaging unit,(5) Storage of the preparation in the packaging unit for a period of at least about 5 days; and(6) Application of the preparation on the keratinous material.
METHOD FOR TREATING HAIR, COMPRISING THE APPLICATION OF AN ORGANIC SILICON COMPOUND, AN ALKALISING AGENT AND A FILM-FORMING POLYMER
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, (2022/01/08)
It is an object of the present disclosure to provide a method for treating keratinous material, in particular human hair, comprising the following steps: Application of a water-containing agent (a) to the keratinous material, wherein the agent (a) has and contains a pH of at least 9.6:(a1) at least one organic silicon compound selected from the group including silanes having one, two or three silicon atoms, and(a2) at least one alkalizing agent selected from the group including ammonia, alkanolamines and basic amino acids, andApplication of an agent (b) to the keratinous material, wherein the agent (b) includes:(b1) at least one film-forming polymer.
Sustainable Catalytic Synthesis of Diethyl Carbonate
Putro, Wahyu S.,Ikeda, Akira,Shigeyasu, Shinji,Hamura, Satoshi,Matsumoto, Seiji,Lee, Vladimir Ya.,Choi, Jun-Chul,Fukaya, Norihisa
, p. 842 - 846 (2020/12/07)
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.
Nucleophile induced ligand rearrangement reactions of alkoxy- and arylsilanes
Docherty, Jamie H.,Dominey, Andrew P.,Thomas, Stephen P.
, p. 3330 - 3335 (2019/05/10)
The ligand-redistribution reactions of aryl- and alkoxy-hydrosilanes can potentially cause the formation of gaseous hydrosilanes, which are flammable and pyrophoric. The ability of generic nucleophiles to initiate the ligand-redistribution reaction of commonly used hydrosilane reagents was investigated, alongside methods to hinder and halt the formation of hazardous hydrosilanes. Our results show that the ligand-redistribution reaction can be completely inhibited by common electrophiles and first-row transition metal pre-catalysts.
Preparation method of methyl triethoxysilane
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Paragraph 0021-0026, (2019/02/04)
The invention discloses a preparation method of methyl triethoxysilane. The prepaeration method comprises the following steps of continuously adding an ethanol solution of sodium ethoxide into methyltrichlorosilane to perform alcoholysis; performing pressure-relief sucking and filtering, removing filter residue, rectifying, separating, purifying, and the like. The preparation method has the advantages that the reaction conditions are mild, the technology is easy to operate, the equipment investment is small, the scale production is convenient, the yield rate of the product is high, and the content of chloride in the product is low.
Synthesis of Polycyclic and Cage Siloxanes by Hydrolysis and Intramolecular Condensation of Alkoxysilylated Cyclosiloxanes
Sugiyama, Tomoaki,Shiba, Hiroya,Yoshikawa, Masashi,Wada, Hiroaki,Shimojima, Atsushi,Kuroda, Kazuyuki
, p. 2764 - 2772 (2019/02/01)
The controlled synthesis of oligosiloxanes with well-defined structures is important for the bottom-up design of siloxane-based nanomaterials. This work reports the synthesis of various polycyclic and cage siloxanes by the hydrolysis and intramolecular condensation of monocyclic tetra- and hexasiloxanes functionalized with various alkoxysilyl groups. An investigation of monoalkoxysilylated cyclosiloxanes revealed that intramolecular condensation occurred preferentially between adjacent alkoxysilyl groups to form new tetrasiloxane rings. The study of dialkoxy- and trialkoxysilylated cyclotetrasiloxanes revealed multistep intramolecular condensation reactions to form cubic octasiloxanes in relatively high yields. Unlike conventional methods starting from organosilane monomers, intramolecular condensation enables the introduction of different organic substituents in controlled arrangements. So-called Janus cubes have been successfully obtained, that is, Ph4R4Si8O12, in which R=Me, OSiMe3, and OSiMe2Vi (Vi=vinyl). These findings will enable the creation of siloxane-based materials with diverse functions.
A process for the production of alkoxy silane (by machine translation)
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Paragraph 0033; 0034, (2017/07/15)
The invention belongs to the field of chemical industry, relates to a production process of alkoxy silane, in order to improve the purity of the product. The production process comprises the following steps: A, eliminates the water mellowly enters into the reaction equipment, an esterification reaction with the organic silane; B, after the esterification reaction of the material entering the evaporation apparatus, and distilled to remove the material in a small amount of alcohol; C, in and after the distillation product to get the alkoxysilane; production process the start-up phase, the steps of adding excessive mellow A, the reaction apparatus in the backflow of appears mellowly; in the case of when the mellow backflow, add organochlorosilane, joins the quantity mellowly is reduced to the amount of consumption by the reaction. The invention relates to a simple process for the production of the realization of the alkoxy silane, in particular methyl triethoxy silane production. Relative to the other process reduces the rectifying tower, the circulation evaporator replace, increased water removal system and in the fixed-bed and system. In the reaction process through the control of the temperature, pressure and feed rate, the obtained alkoxy silane in the HCl content of 10 ppm following, purity 99.0% wt or more. (by machine translation)
Mechanism of the Iron(II)-Catalyzed Hydrosilylation of Ketones: Activation of Iron Carboxylate Precatalysts and Reaction Pathways of the Active Catalyst
Bleith, Tim,Gade, Lutz H.
supporting information, p. 4972 - 4983 (2016/05/10)
A detailed mechanistic study of the catalytic hydrosilylation of ketones with the highly active and enantioselective iron(II) boxmi complexes as catalysts (up to >99% ee) was carried out to elucidate the pathways for precatalyst activation and the mechanism for the iron-catalyzed hydrosilylation. Carboxylate precatalysts were found to be activated by reduction of the carboxylate ligand to the corresponding alkoxide followed by entering the catalytic cycle for the iron-catalyzed hydrosilylation. An Eyring-type analysis of the temperature dependence of the enantiomeric ratio established a linear relationship of ln(S/R) and T-1, indicating a single selectivity-determining step over the whole temperature range from -40 to +65°C (ΔΔG?sel,? 233? K = 9 ± 1 kJ/mol). The rate law as well as activation parameters for the rate-determining step were derived and complemented by a Hammett analysis, radical clock experiments, kinetic isotope effect (KIE) measurements (kH/kD = 3.0 ± 0.2), the isolation of the catalytically active alkoxide intermediate, and DFT-modeling of the whole reaction sequence. The proposed reaction mechanism is characterized by a rate-determining σ-bond metathesis of an alkoxide complex with the silane, subsequent coordination of the ketone to the iron hydride complex, and insertion of the ketone into the Fe-H bond to regenerate the alkoxide complex.
Chlorosilane alcoholysis acid removing agent and regeneration method thereof
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Paragraph 0017, (2017/04/28)
The invention discloses a chlorosilane alcoholysis acid removing agent and a regeneration method thereof. The regeneration method is characterized in that at a temperature of -10-130 DEG C, a substituting agent and an acid removing agent are added into a reactor in advance, chlorosilane is gradually added, the liquid phase obtained through filtration separation is subjected to rectification after the alcoholysis reaction is completed so as to obtain a silane finished product and the excessive substitution agent, the excessive substitution agent is recycled, and the acid removing agent obtained through filtration separation is recycled after being regenerated. According to the present invention, the yield of the silane prepared by using the process is more than or equal to 95%, and the recovery rate of the acid removing agent is more than or equal to 95%.
