- 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 0079-0082; 0090
(2021/08/25)
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- A methyl ethyl the cyclosiloxane preparation method
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The invention discloses a preparation method of methyl ethyl cyclosiloxane. The method comprises the following steps of: placing methyldichlorosilae into an autoclave for hydrosilylation with ethylene under the action of platinum catalyst, and then rectifying the reactant to obtain methyl ethyl dichlorosilane; dripping the methyl ethyl dichlorosilane into dilute acid solution for hydrolyzation and obtaining hydrolysate; performing pyrolysis to the hydrolysate under the action of high boiling point solvents and base catalysts, and finally rectifying the pyrolysis product to obtain trimethyl triethyl cyclotrisiloxane and tetramethyl tetraethyl cyclotetrasiloxane. The methyl ethyl cyclosiloxane is prepared by hydrosilylation of the methyldichlorosilae and the ethylene so as to greatly improve the product yield, reduce the production cost and enlarge the reaction device based on the demands to improve the capacity; the solvent is used in the pyrolysis process so as to reduce material crosslinking, improve the pyrolysis speed, reduce the pyrolysis temperature and decrease the usage amounts of the base catalysts; the method has the advantages of high efficiency and low energy consumption, etc.
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Paragraph 0049-0051
(2017/05/18)
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- Reaction of chloro(ethyl)silanes with chloro(phenyl)silanes in the presence of aluminum chloride. Synthesis of chloro(ethyl)(phenyl)silanes
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Abstract Substituent exchange at the silicon atom between chloro(phenyl)silanes (PhSiCl3, MePhSiCl2, Ph2SiCl2) and chloro(ethyl)silanes (EtSiCl3, Et2SiCl2, Et3SiCl, Et4Si) in the presence of aluminum chloride has been studied. The examined compounds, except for PhSiCl3 and Et4Si, react fairly readily to give chloro(ethyl)-(phenyl)silanes in up to 48-52% yield. A probable mechanism has been proposed.
- Lakhtin,Eremeeva,Gordeev,Ushakov,Bykovchenko,Kirilin,Chernyshev
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p. 595 - 599
(2015/05/13)
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- Silyl and σ-silane ruthenium complexes: Chloride substituent effects on the catalysed silylation of ethylene
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Silylation of ethylene by the chlorosilanes HSiMe2Cl and HSiMeCl2 was catalysed by the bis(dihydrogen) complex RuH 2(η2-H2)2(PCy3) 2 (1). Dehydrogenative silylation leading to the formation of the corresponding vinylsilanes was in competition with hydrosilylation. The rate and selectivity of the reactions were influenced by the number of chloro substituents and the ethylene pressure. A comparative mechanistic study was performed in toluene-d8 with the two chlorosilanes. Reaction of 1 with an excess of HSiMe2Cl (10 equiv.) produced the σ-silane complexes RuH2(η2-H2)(η2- HSiMe2Cl)(PCy3)2 (2Me2Cl), RuH 2(η2-HSiMe2Cl)2(PCy 3)2 (3Me2Cl) and the silyl complex RuCl(SiMe2Cl)(η2-H2)(PCy3) 2 (4Me2Cl), all characterised by multinuclear NMR spectroscopy. Complexes 2Me2Cl and 3Me2Cl adopt a cis configuration for the two bulky phosphine ligands as a result of stabilising SISHA (Secondary Interactions between Silicon and Hydrogen Atoms) interactions. Complex 4Me2Cl resulted from the stoichiometric reaction of HSiMe2Cl with 1 producing RuHCl(η2-H 2)(PCy3)2in situ which further reacted with evolution of H2 and formation of 4Me2Cl. When reacting 1 with 10 equiv. of HSiMeCl2, the corresponding complexes 3MeCl 2 and 4MeCl2 were detected as well as traces of 2MeCl 2. The reactivity toward ethylene was then examined. Under catalytic conditions (excess silane in toluene-d8, ethylene atmosphere) only two compounds could be characterised: free PCy3 and the new (η6-aryl)(disilyl) complexes of the general formula Ru(η6-C6D5CD3)(SiMe 3-nCln)2(PCy3) (6Me 3-nCln-d8, n = 1,2). The X-ray structure of 6MeCl2 was obtained on a single-crystal at 160 K. When only 2 equiv. of HSiMe2Cl were added, the ethylene(silyl) complex RuH(SiMe 2Cl)(C2H4)(PCy3)2 (7Me2Cl) was obtained in addition to the organic products resulting from catalytic hydrogenation, hydrosilylation and dehydrogenative silylation, i.e. C2H6 (major one), C2H3SiMe 2Cl and C2H5SiMe2Cl. In the case of 2 equiv. of HSiMeCl2, upon ethylene addition, 7MeCl2 was formed in minority compared to a new disilyl complex Ru(SiMeCl2) 2(PCy3)2 (8MeCl2) characterised by NMR spectroscopy and X-ray diffraction on a single crystal at 160 K. In 8MeCl2, a formal 14-electron species, stabilisation through two agostic C-H bonds of the cyclohexyl groups was ascertained by DFT calculations.
- Lachaize, Sebastien,Vendier, Laure,Sabo-Etienne, Sylviane
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experimental part
p. 8492 - 8500
(2011/01/08)
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- Quantitative substituent effects in the Grignard reaction with silanes
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Kinetics of reactions of ethyl- and phenylmagnesium chlorides with chlorosilanes, RMeSiCl2, were investigated in diethyl ether under pseudo-first order conditions with a great excess of the Grignard reagent. Rate constants for alkyl substituted silanes correlate well with Es(Si) steric parameters. A good linear correlation of rate data for substituted phenyl derivates with σ0 inductive constants together with correlations of the literature data rule out the resonance effect of substituents at least in nucleophilic displacement reactions at the silicon center. An attempt to calculate the steric constants for polar substituents was made. It appeared that the inductive constants σ* derived from the carbon chemistry are not applicable to the silicon chemistry. New scales of parameters for description of polar and steric effects in the organosilicon chemistry need to be created.
- Golubev, Oleg,Panov, Dmitri,Ploom, Anu,Tuulmets, Ants,Nguyen, Binh T.
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p. 3700 - 3705
(2008/02/08)
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- METHOD OF MAKING PHENYL-CONTAINING CHLOROSILANES WITH ALIPHATIC OR CYCLOPARAFFINIC HYDROCARBON SOLVENTS
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Phenylmethyldichlorosilanes and diphenylmethylchlorosilanes are prepared by a Grignard process involving the step of contacting a phenyl Grignard reagent, an ether solvent, a trichlorosilane, and an aliphatic or cycloparaffinic hydrocarbon coupling solvent; in a mole ratio of the ether solvent to the phenyl Grignard reagent is 2 to 5, the mole ratio of the trichlorosilane to the phenyl Grignard reagent is 0.1 to 10, and the mole ratio of the aliphatic or cycloparaffinic hydrocarbon coupling solvent to the phenyl Grignard reagent is 3 to 7. Preferred reactants include phenylmagnesium chloride as the phenyl Grignard reagent; diethyl ether as solvent; n-heptane as the aliphatic hydrocarbon coupling solvent, or cyclohexane as the cycloparaffinic hydrocarbon coupling solvent; and methyltrichlorosilane.
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Page/Page column 5-7
(2008/06/13)
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- Reaction of bis(trifluoromethyl)amino-oxyl with alkylchlorosilanes and allyldichloro(methyl)silane and of perfluoro-2,5-diazahexane 2,5-dioxyl with vinylsilanes and hydrolysis of the products
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Treatment of the silanes MeSiHCl2, Me2SiHCl and EtSiMeCl2 with the oxyl (CF3)2NO(.) (1) gives the substitution products (CF3)2NOSiMeCl2 (4) and (CF3)2NOSiMe2Cl (5), and a mixture of (CF3)2NOCHMeSiMeCl2 (8) and (CF3)2NOCH2CH2SiMeCl2 (9) (ratio 20:37), respectively, while the silane EtSiMe2Cl affords mainly the ester (CF3)2NO2CMe (7).Attack of oxyl 1 on the silane CH2=CHCH2SiMeCl2 results in both allylic substitution and addition to give the compounds CH2=CHCH(SiMeCl2)ON(CF3)2 (14) and (CF3)2NOCH2CH(CH2SiMeCl2)ON(CF3)2 (15) (ratio 56:40).Reaction of the dioxyl (.)ON(CF3)CF2CF2N(CF3)O(.) (2) with the vinylsilanes CH2=CHSiX3 (X3 = Me3, Cl3, MeCl2) gives mainly 1:1 copolymers n (17), although the cyclic 1:1 adduct (18) is also formed in low yield.Hydrolysis of the silanes 15, (CF3)2NOCH2CH(SiMeCl2)ON(CF3)2 (19a) and (CF3)2NOCH2CH(SiCl3)ON(CF3)2 (19b) affords the corresponding polysiloxanes 24 and 25, and the polysilsesquioxane 26, respectively; the polymers 25 and 26 undergo rearrangement of the type -CH(Si)ON(CF3)2 --> -CH(OSi)N(CF3)2 on storage.The 1:1 copolymers 17b (X3 = MeCl2) and 17c (X3 = Cl3) are also hydrolysed to the corresponding siloxane and silsesquioxane polymers.In contrast, hydrolysis of the compounds 4,5 and (CF3)2NOCH2CH(OSiX3)N(CF3)2 (20a; X3 = MeCl2) and (20b; X3 = Cl3) results in Si-O bond cleavage.
- Tipping, Anthony E.,Yadav, Rajendraprasad B.
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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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- Sila Perfumes, I. Sila Analogues of Tertiary Carbinols as Perfumes
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Silanols RR'R''SiOH 7 which are analog to carbinols 1 with strong odour in the region of flowery notes (lily of the valley-hyacinth-rose) were prepared via reaction steps (3) and partially unknown intermediates 6.Sila perfumes 7 are similar in intensity and spectrum of odour to 1 but a shift from lily of the valley towards hyacinth notes is generally observed.
- Wrobel, Dieter,Tacke, Reinhold,Wannagat, Ulrich,Harder, Ulrich
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p. 1694 - 1704
(2007/10/02)
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- Macrocyclic polyether compounds
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Macrocyclic polyether "crown" compounds of the formula EQU1 WHEREIN T is a C2 -C3 alkylene, A is EQU2 R being H or C1 -C18 alkyl, R2 and R3 being independently C1 -C18 alkyl, C2 -C4 alkenyl, or C6 -C14 aryl; Q and Z are independently 1,2-arylene (or saturated derivatives thereof) or substituted 1,2-arylene (or saturated derivatives thereof); a is 0, 1, 2, or 3; b is an integer from 3 to 20; y is 1 or zero; x1, x2, x3, and x4 are integers independently selected to give a 15-60 atom ring. Such crown compounds are generally useful in the formation of complexes with ionic metal compounds, thus making it possible to use certain chemical reagents in media wherein they are normally insoluble.
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