546-45-2Relevant academic research and scientific papers
Controlled synthesis of cyclosiloxanes by NHC-catalyzed hydrolytic oxidation of dihydrosilanes
Qing, Guoping,Cui, Chunming
supporting information, p. 8746 - 8750 (2017/07/22)
Hydrolytic oxidation of various hydrosilanes in acetonitrile and in the absence of organic solvents catalyzed by an N-heterocyclic carbene organocatalysis is described. The NHC organocatalyst exhibited a very high activity with only 0.1 mol% loading of the catalyst in acetonitrile for aryl-substituted dihydrosilanes to produce hydrogen gas and cyclosiloxanes almost quantitatively in several minutes. The calculated TOF (15 000 h-1) of this organocatalyst is comparable to those of precious metal-based heterogeneous catalysts and much superior to those of the existing homogeneous metal catalysts. The catalytic reaction selectively yielded cyclosiloxanes in high yield without the contamination of silanols. Furthermore, the catalytic reaction can also be furnished under solvent-free conditions at elevated temperatures with 2.5 mol% loading of the NHC in 5-12 hours.
Synthesis of borasiloxanes by oxidative hydrolysis of silanes and pinacolborane using Cu3(BTC)2 as a solid catalyst
Dhakshinamoorthy, Amarajothi,Asiri, Abdullah M.,Concepcion, Patricia,Garcia, Hermenegildo
supporting information, p. 9998 - 10001 (2017/09/12)
A convenient method for the synthesis of borasiloxanes from silanes and pinacolboranes using Cu3(BTC)2 as a heterogeneous catalyst in acetonitrile at 70 °C is reported. This procedure is more convenient than Ru and Pd based homogeneous catalysts because it avoids the use of noble metals, easy handling of starting materials and the catalyst can be reused.
Tandem-reduction of DMF with silanes via necklace-type transition over Pt(0) nanoparticles: Deciphering the dual Si-H effect as an extension of steric effects
Taori, Vijay P.,Buchmeiser, Michael R.
supporting information, p. 14820 - 14823 (2015/02/19)
Dimethylformamide (DMF) undergoes double-reduction to yield trimethylamine as a result of the concerted activation of DMF by two Si-H bonds (from different Si atoms) over Pt(0) nanoparticles as catalytic centers. Sterics on the Si atom govern the reaction and are also decisive for the structure of siloxane products due to potential limitations on the concerted activation. This journal is
cis-trans-cis-Tetrabromotetramethylcyclotetrasiloxane: A versatile precursor of ladder silsesquioxanes
Unno, Masafumi,Chang, Shengho,Matsumoto, Hideyuki
, p. 1105 - 1109 (2007/10/03)
The title compound was isolated for the first time by a novel procedure including dephenylbromination of cyclotetrasiloxane. The stereostructure of the tetrabromide was confirmed by condensation with diphenylsilanediol, affording anti-tricyclo[7.3.1.13.7]hexasiloxane. This tetrabromide spontaneously decomposed in air to afford a white powder insoluble in organic solvents. Measurements of the TG, IR, and solid-state NMR spectra of the product revealed that a ladder polysilsesquioxane with high thermal stability and stereoregularity was obtained.
A facile and efficient synthesis of organocyclosiloxanes
Zuev, Vjacheslav V.,Kalinin, Alexei V.
, p. 1289 - 1294 (2007/10/03)
A new facile preparative method for the synthesis of organocyclosiloxanes is reported. Ring closure of the dichlorosilanes with NaHCO3 and pyridine gave mixture of organocyclosiloxanes with cyclotrisiloxane as a main product.
Conversion of hydrosilanes to alkoxysilanes catalyzed by Cp2TiCl2/nBuLi
Bedard, Thomas C.,Corey, Joyce Y.
, p. 315 - 333 (2007/10/02)
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.
THE SILICON-OXYGEN DOUBLE-BONDED INTERMEDIATES. A NEW METHOD FOR THE FORMATION OF ORGANOSILANONES
Tomadze, A. V.,Yablokova, N. V.,Yablokov, V. A.,Razuvaev, G. A.
, p. 43 - 50 (2007/10/02)
The kinetics and mechanism of thermal decomposition of R1R2(H)SiOOR3 silylperoxides have been studied.It has been shown that peroxides generated diorganosilanones, R1R2Si=O, with a high yield in the temperature range 130-180 deg C.A mechanism is suggested for the silanone formation.The interaction of silanones with cyclosiloxanes, triethylsilane, α-methylstyrene has been investigated as well as the cyclisation of silanones.
