cas 77-63-4, 2,4,6,8-tetramethyl-2,4,6,8-tetraphenylcyclotetrasiloxane

Articles about 77-63-4Total 6 be found

Controlled synthesis of cyclosiloxanes by NHC-catalyzed hydrolytic oxidation of dihydrosilanes
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.
Qing, Guoping,Cui, Chunming
supporting information
p. 8746 - 8750
(2017/07/22)

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
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
Taori, Vijay P.,Buchmeiser, Michael R.
supporting information
p. 14820 - 14823
(2015/02/19)

cis-trans-cis-Tetrabromotetramethylcyclotetrasiloxane: A versatile precursor of ladder silsesquioxanes
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.
Unno, Masafumi,Chang, Shengho,Matsumoto, Hideyuki
p. 1105 - 1109
(2007/10/03)

A facile and efficient synthesis of organocyclosiloxanes
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.
Zuev, Vjacheslav V.,Kalinin, Alexei V.
p. 1289 - 1294
(2007/10/03)

THE SILICON-OXYGEN DOUBLE-BONDED INTERMEDIATES. A NEW METHOD FOR THE FORMATION OF ORGANOSILANONES
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.
Tomadze, A. V.,Yablokova, N. V.,Yablokov, V. A.,Razuvaev, G. A.
p. 43 - 50
(2007/10/02)