- Silylated Sulfuric Acid: Preparation of a Tris(trimethylsilyl)oxosulfonium [(Me3Si?O)3SO]+ Salt
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The chemistry of silylated sulfuric acid, O2S(OSiMe3)2 (T2SO4, T=Me3Si; also known as bis(trimethylsilyl) sulfate), has been studied in detail with the aim of synthesizing the formal autosilylation products of silylated sulfuric acid, [T3SO4]+ and [TSO4]?, in analogy to the known protonated species, [H3SO4]+ and [HSO4]?. The synthesis of the [TSO4]? ion only succeeds when a base, such as OPMe3 that forms a weakly coordinating cation upon silylation, is reacted with T2SO4, resulting in the formation of [Me3POT]+[TSO4]?. [T3SO4]+ salts could be isolated starting from T2SO4 in the reaction with [T?H?T]+[B(C6F5)4]? or T+[CHB11Br6H5]? when a weakly coordinating anion is used as counterion. All silylated compounds could be crystallized and structurally characterized.
- Bl?sing, Kevin,Labbow, Rene,Schulz, Axel,Villinger, Alexander
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supporting information
p. 13798 - 13802
(2021/05/17)
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- Catalytic Disproportionation of Formic Acid to Methanol by using Recyclable Silylformates
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A novel strategy to prepare methanol from formic acid without an external reductant is presented. The overall process described herein consists of the disproportionation of silyl formates to methoxysilanes, catalyzed by ruthenium complexes, and the production of methanol by simple hydrolysis. Aqueous solutions of MeOH (>1 mL, >70 percent yield) were prepared in this manner. The sustainability of the reaction has been established by recycling of the silicon-containing by-products with inexpensive, readily available, and environmentally benign reagents.
- Cantat, Thibault,Chauvier, Clément,Imberdis, Arnaud,Thuéry, Pierre
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supporting information
p. 14019 - 14023
(2020/06/09)
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- Green synthesis method for 1,2-bi(trialkyl siloxy) cyclohexene
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The invention relates to a green synthesis method for 1,2-bi(trialkyl siloxy) cyclohexene. The method comprises the step of causing 1,2-cyclohexanone, bi(trialkyl silicon) sulphate and reactive metalreact in an inert solvent, thereby acquiring 1,2-bi(trialkyl siloxy) cyclohexene. The bi(trialkyl silicon) sulphate is prepared according to the steps of preparing hexalkyl disiloxane by dehydrating by-product trialkyl silanol in consequent reaction and then continuing to react with concentrated sulfuric acid. The environmental issue of siloxane effluent is completely solved through the recyclingof silicon protecting group; the produced solid waste has a single component and can be prepared into byproduct for sale after simple treatment; the emission of three wastes is less; the technology isenvironment-friendly.
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Paragraph 0070-0071
(2018/12/14)
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- The efficient method for the preparation of alkenylsilanes from organoaluminums
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Silyl esters of sulfonic acids are convenient and efficient silylating agents for β,β- and β-substituted 1-alkenylaluminums. The reaction proceeds at room temperature in CH2Cl2 or hexane for 18 h to give corresponding alkenylsilanes in high yield. At the same time, α,β-disubstituted and α,β,β-trisubstituted 1-alkenylaluminums were inert in the reaction under study. The reaction with aluminacyclopen-2-enes and aluminacyclopentanes takes place on the less sterically hindered reaction center. Using electron-donating solvents (diethyl ether, THF) inhibits the reaction. A new convenient procedure of silylation was developed, which consists in obtaining the silyl tosylate by the reaction of chlorosilanes with anhydrous sodium tosylate in toluene solution. The resulting reaction mixture was reacted with organoaluminum compounds without isolation of silyl tosylate.
- Kadikova, Rita N.,Zosim, Tat'Yana P.,Dzhemilev, Usein M.,Ramazanov, Ilfir R.
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- A PROCESS FOR PREPARING SI BOND
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The present invention relates to an economical process to modify Si-X bond, wherein X is selected from a group consisting of radicals of 0, Cl, Br, I and hydrolysable group and more particularly, the present invention relates to process to incorporate desired functional group in a compound having Si-X bond.
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Page/Page column 7
(2008/06/13)
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- Reactivity of Tris(trimethylsilyl) Borate
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Reactions of tris(trimethylsilyl) borate with water (on heating), sulfuric acid, and acetic anhydride yield boric acid, bis(trimethylsilyl) sulfate, and acetoxytrimethylsilane, respectively.
- Voronkov,Roman,Maletina
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p. 1047 - 1048
(2007/10/03)
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- REACTION OF SULFUR TRIOXIDE WITH SLILYLAMINES, SILAZANES, AND SILYLATED AMIDES OF CARBOXYLIC ACIDS
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The reaction of sulfur trioxide with silylamines, silazanes, and silylamides of carboxylic acids proceeds with the formation of products of insertion at one or two nitrogen-silicon bonds.The latter are unstable in some cases and change into bis(trimethylsilyl) sulfate or bis(trimethylsilyl hydrogen sulfate) anhydride through β decomposition.
- Pudovik, M. A.,Kibardina, L. K.,Pudovik, A. N.
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p. 267 - 268
(2007/10/02)
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- On the Mechanism of the Baeyer-Villiger Oxidation of Ketones by Bis(trimethylsilyl) Peroxomonosulfate. Intermediacy of Dioxiranes
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The Baeyer-Villiger oxidation of cyclohexanone (2a) and of acetophenone (2b) by bis(trimethylsilyl)peroxomonosulfate (1) has been reinvestigated using (18)O-labeling techniques.Starting with doubly labeled Me3Si(18)O(18)OSO3SiMe3, mass spectrometric analyses allowed determination of the amount of label appearing in the carbonyl and the OR moiety of the ester (or of the lactone).It has been observed that 2a also promotes the decomposition of 1 to yield oxygen gas, which was analyzed for its (18)O content.Furthermore, ketones 2a, 4-heptanone, and acetone were foundto enhance significantly the rate of oxidation of 1-methylcyclohexene (10) and of trans-β-methylstyrene (13) by 1, yielding 2-methylcyclohexanone (12) and 1-phenylpropanone (15) derived from the isomerization of the initially formed epoxides.These observations, most notably the (18)O-tracer results, point to a mechanism involving the intermediacy of dioxiranes as the prevailing pathway.
- Camporeale, Michele,Fiorani, Tiziana,Troisi, Luigino,Adam, Waldemar,Curci, Ruggero,Edwards, John O.
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- UBER PEROXOVERBINDUNGEN 17 DARSTELLUNG UND EIGENSCHAFTEN VON ALKYL- UND TRIMETHYLSILYLDERIVATEN VON PEROXOSCHWEFELSAEUREN
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The novel peroxides Me3SiOSO2OOR (3; R = n-C3H7, n-C4H9, n-C5H11), Na+-OSO2OOR (5; R = n-C3H7, n-C4H9), and HOSO2OOR (6; R = n-C3H7, n-C4H9) are obtained by insertion of SO3 in Me3SiOOR, NaOOR, and HOOR respectively (temperature below -20 deg C, solvent CH2Cl2).The solid compounds 5 are stable up to 40-50 deg C, the liquids 3 and 6 deflagrate at ca. -10 deg C.Hydrolysis of the sulfonyl peroxides generates HOOR in each case.Thermolysis of 3 affords the corresponding aldehydes by heterolysis of the (O-O)-bond.In CH2Cl2 at room temperature, Me3SiOSO2OOSiMe3 (1) undergoes a slow nucleophilic 1,2-rearrangement, forming the isomer Me3SiOSO2OSi(OMe)Me2 (7).The constitution of 7 is confirmed by chemical evidence, e. g. hydrolytic and thermal degradation.Thermolysis of Me3SiOSO2OOSO2OSiMe3 (2) at room temperature in CH2Cl2 occurs by a rather rapid free radical pathway, the solvent being attacked by H and/or Cl abstraction (main products: HCl, CO, ClSO2OSiMe3, Me3SiOSO2OSiMe3).The new trimethylsilyl(n-alkyl)-peroxides Me3SiOOR with R = n-C3H7, n-C4H9, and C5H11 were prepared and characterised.
- Blaschette, Armand,Safari, Hassan
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