- Reactivity of dichlorosilanes with lithium ester enolates: synthesis of 3,3-disubstituted 3-silaglutarates
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3,3-Disubstituted 3-silaglutarates were synthesized by reaction of the lithium enolate of ethyl acetate with dichlorosilanes at -94 deg C.When a phenyl group is linked to the silicon atom the reaction in THF gave mainly the silaglutarate.In other cases alkylsilylketene acetals were formed in proportions similar to or greater than that of the silaglutarate.The presence of HMPA increased the ratio of C- to O-silylated products and allowed the preparation of 3,3-dialkyl 3-silaglutarates in good yield.Keywords: 3-silaglutarates; Dichlorosilanes; Lithium enolates
- Djerourou, Abdelhafid,Blanco, Luis
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- Mechanistic Studies on the Hexadecafluorophthalocyanine–Iron-Catalyzed Wacker-Type Oxidation of Olefins to Ketones**
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The hexadecafluorophthalocyanine–iron complex FePcF16 was recently shown to convert olefins into ketones in the presence of stoichiometric amounts of triethylsilane in ethanol at room temperature under an oxygen atmosphere. Herein, we describe an extensive mechanistic investigation for the conversion of 2-vinylnaphthalene into 2-acetylnaphthalene as model reaction. A variety of studies including deuterium- and 18O2-labeling experiments, ESI-MS, and 57Fe M?ssbauer spectroscopy were performed to identify the intermediates involved in the catalytic cycle of the oxidation process. Finally, a detailed and well-supported reaction mechanism for the FePcF16-catalyzed Wacker-type oxidation is proposed.
- Grinenko, Vadim,Klau?, Hans-Henning,Kn?lker, Hans-Joachim,Puls, Florian,Seewald, Felix
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p. 16776 - 16787
(2021/11/04)
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- METHOD FOR PREPARING ARYLALKOXYSILANES BY DEHYDROGENATIVE SILYLATION
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Claimed is a method involving dehydrogenative silylation of aromatic compounds under Rh-catalysis to give an arylalkoxysilane. The method includes the steps of: 1) combining, under conditions appropriate to form the arylalkoxysilane, starting materials including A) an alkoxysilane having at least one silicon bonded hydrogen atom per molecule; (I) B) an aromatic compound having a carbon-hydrogen bond; and C) a rhodium bisphospholane catalyst. Additional starting materials such as D) a hydrogen acceptor and/or E) a solvent may be added during step 1). The method may further include 2) recovering the arylalkoxysilane. In a preferred embodiment the Rhodium bisphospholane catalyst is of type (II).
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Paragraph 0029
(2018/11/10)
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- Platinum-Catalyzed Multicomponent Alcoholysis/Hydrosilylation and Bis-hydrosilylation of Alkynes with Dihydrosilanes
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A new method for the hydrosilylation of alkynes controlled by a platinum catalyst with a monophosphine ligand (called TBSO-MOP) was explored. The platinum-catalyzed multicomponent and sequential silylation reaction involving alkynes, alcohols, and dihydrosilanes resulted in the highly stereoselective and high-yielding construction of functional (E)-vinylsilyl ethers. Moreover, the one-pot bis-hydrosilylation of terminal alkynes with dihydrosilanes was also achieved with the same platinum catalyst system.
- Xu, Jian-Xing,Chen, Mu-Yi,Zheng, Zhan-Jiang,Cao, Jian,Xu, Zheng,Cui, Yu-Ming,Xu, Li-Wen
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p. 3111 - 3116
(2017/08/29)
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- Synthesis of phenyl-methyl dialkoxy silane method of the
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The invention relates to a method for synthesizing phenyl methyl dialkoxyl silane with high selectivity. The structural formula of phenyl methyl dialkoxyl silane is PhMeSi(OR)2, in which R is alkyl with 1-6 carbons. The method is characterized by comprising the following steps of: performing reaction with methyl trialkoxyl silane based on non-cyclic ether compounds such as ethyl ether as a reaction liquor and a bromobenzene Grignard reagent as a raw material; and then, obtaining the target compound, i.e., phenyl methyl dialkoxyl silane with high selectivity and high yield through simple filtering and fractional purification, and meanwhile, greatly inhibiting the generation of a byproduct diphenyl methyl alkoxyl silane.
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Paragraph 0049; 0050
(2017/03/14)
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- Selective Metal-Free Hydrosilylation of CO2Catalyzed by Triphenylborane in Highly Polar, Aprotic Solvents
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Triphenylborane (BPh3) in highly polar, aprotic solvents catalyzes hydrosilylation of CO2effectively under mild conditions to provide silyl formates with high chemoselectivity (>95 %) and without over-reduction. This system also promotes reductive hydrosilylation of tertiary amides as well as dehydrogenative coupling of silane with alcohols.
- Mukherjee, Debabrata,Sauer, Daniel F.,Zanardi, Alessandro,Okuda, Jun
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supporting information
p. 7730 - 7733
(2016/06/09)
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- N-heterocyclic carbene organocatalysts for dehydrogenative coupling of silanes and hydroxyl compounds
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Go organic! N-Heterocyclic carbene (NHC) 1,3-diisopropyl-4,5- dimethylimidazol-2-ylidene (IiPr) has been found to be an efficient and selective catalyst for the dehydrogenative coupling of a wide range of silanes and hydroxyl groups to form Si-O bonds under mild and solvent-free conditions (see scheme). Mechanistic studies indicated that the activation of hydroxyl groups by the NHC is the most plausible initial step for the process. Copyright
- Gao, Dongjing,Cui, Chunming
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supporting information
p. 11143 - 11147
(2013/09/02)
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- Utilization of bottoms of the direct synthesis of methylchlorosilanes in production of the crude mixtures of phenylethoxysilanes by continuous organomagnesium Procedure
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Utilization of the bottoms after distillation of methylchlorosilanes in continuous organomagnesium synthesis of organosilicon raw materials for production of polyphenylsiloxane resins and lacquers and enamels based on them was analyzed.
- Klokov
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p. 476 - 478
(2007/10/03)
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- An Efficient Catalyst for the Conversion of Hydrosilanes to Alkoxysilanes
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The copper(I) hydride 6 is an efficient catalyst for the alcoholysis of primary and secondary silanes.The reactions proceed at room temperature within a few hours and give the alkoxysilanes in high yields.Only with bulky alcohols or silanes are longer reaction times and/or increased temperatures required.The presence of air accelarates the reactions and gives rise to higher yields of alkoxysilanes, particularly with bulky alcohols.Diols react with PhRSiH2 (R = Me, Ph) to afford 1,3-dioxo-2-silacycloalkanes and with tertiary silanes to furnish the bissilylated diols.When unsaturated alcohols (2-propen-1-ol or 2-propyn-1-ol) are employed, the double or triple bond is retained. - Keywords: Catalytic silane alcoholysis; Alkoxysilanes
- Lorenz, Catrin,Schubert, Ulrich
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p. 1267 - 1270
(2007/10/03)
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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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- Une synthese originale et rapide de (methyldiethoxysilyl)benzenes fonctionnels
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In the presence of a catalytic amount of tetrakis(triphenylphosphine)palladium(0), the 1,1,2,2-tetraethoxydimethyldisilane reacts with various functional bromoarenes giving the corresponding aryldiethoxymethylsilanes in good yields.The creation of Si-CAr bonds involving a polyalcoxydisilane as the silylating reagent is here reported for the first time.Key words: Silyl; Palladium
- Cros, S.,Bennetau, B.,Dunogues, J.,Babin, P.
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- Conversion of hydrosilanes to alkoxysilanes catalyzed by Cp2TiCl2/nBuLi
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The combination of Cp2TiCl2 and nBuLi provides an effective catalyst for alcoholysis of the model silanes n-HexSiH3, PhMeSiH2, Ph2SiH2 and PhMe2SiH by ethanol, isopropanol, t-butyl alcohol and phenol.Increasing the steric bulk of the substituents on either the alcohol or the silane generally requires longer reaction periods and/or increasing temperature.All SiH bonds are converted to SiOEt groups by ethanol and a single SiH bond in secondary silanes and two SiH bonds in tertiary silanes are replaced by t-butyl alcohol.Diols including pinacol, 2,4-pentanediol and 2,5-hexanediol react with PhRSiH2 (R = Me, Ph) to give 1,3-dioxa-2-silacyclopentanes, -hexanes and -heptanes, respectively.Attempts to form caged structures by condensation of primary silanes and triols was unsuccessful.Hydrolysis of PhRSiH2 is promoted by Cp2TiCl2/n-BuLi and the siloxane is produced in quantitative yield when R = Ph and a mixture of linear disiloxanes and trisiloxanes in addition to cyclopolysilanes are produced when R = Me.Other protic reagents including acids, mercaptans, amines and enolizable ketones did not react.The effects of reaction parameters such as temperature, silane to catalyst ratio, solvent, transition metal and replacements for nBuLi were also determined.
- Bedard, Thomas C.,Corey, Joyce Y.
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p. 315 - 333
(2007/10/02)
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