نتایج جستجو برای: supported silyl chromate catalyst

تعداد نتایج: 236684  

Journal: Polyolefins Journal 2014

SiO2-supported silyl chromate catalyst is an important industrial catalyst for production of high grade HDPE pipe materials. The control of the short chain branch (SCB) distribution using this catalyst system is still a great challenge. In this work, ethylene and 1-hexene copolymers were synthesized using SiO2-supported silyl chromate catalyst combined with triisobutylaluminium (TIBA), triethyl...

Journal: :polyolefins journal 2014
ning zhao ruihua cheng qi dong xuelian he zhen liu

sio2-supported silyl chromate catalyst is an important industrial catalyst for production of high grade hdpepipe materials. the control of the short chain branch (scb) distribution using this catalyst system is still a greatchallenge. in this work, ethylene and 1-hexene copolymers were synthesized using sio2-supported silyl chromatecatalyst combined with triisobutylaluminium (tiba), triethylalu...

2014
Behnaz Ghaffari Sean M. Preshlock Donald L. Plattner Richard J. Staples Peter E. Maligres Shane W. Krska Robert E. Maleczka Milton R. Smith

Ir catalysts supported by bidentate silyl ligands that contain P- or N-donors are shown to effect ortho borylations for a range of substituted aromatics. The substrate scope is broad, and the modular ligand synthesis allows for flexible catalyst design.

2011
Haruo Aikawa Tetsuro Kaneko Naoki Asao Yoshinori Yamamoto

Unprecedented alkylation of silyl enol ethers has been developed by the use of ortho-alkynylbenzoic acid alkyl esters as alkylating agents in the presence of a gold catalyst. The reaction probably proceeds through the gold-induced in situ construction of leaving groups and subsequent nucleophilic attack on the silyl enol ethers. The generated leaving compound abstracts a proton to regenerate th...

Journal: :Molecules 2016
Yoshihiro Nishimoto Aya Okita Akio Baba Makoto Yasuda

The substitution of a siloxy group using thiosilanes smoothly occurred in the presence of InI₃ catalyst to yield the corresponding thioethers. InI₃ was a specifically effective catalyst in this reaction system, while other typical Lewis acids such as BF₃⋅OEt₂, AlCl₃, and TiCl4 were ineffective. Various silyl ethers such as primary alkyl, secondary alkyl, tertiary alkyl, allylic, benzylic, and p...

Journal: :Chemical communications 2014
Hiroshi Shintaku Kiyotaka Nakajima Masaaki Kitano Michikazu Hara

A new heterogeneous catalyst, hydrophobic TiO4-deposited mesoporous silica, has been designed for the efficient Mukaiyama-aldol condensation, a water-participating Lewis acid-catalyzed reaction between a hydrophobic carbonyl compound and silyl enol ether. The prepared catalyst suspended in water exhibited high catalytic performance as a reusable catalyst for the reaction without a surfactant.

Journal: :Chemical communications 2007
Akihiro Ooguri Zenichi Ikeda Seijiro Matsubara

Treatment of thiol ester with bis(iodozincio)alkane in the presence of palladium catalyst followed by silylation affords Z-silyl enol ether chemo-, regio- and stereoselectively.

Journal: :Organic & biomolecular chemistry 2015
Jin-Sheng Yu Jian Zhou

Ph3PAuOTf is identified as a powerful catalyst for the addition of difluoroenol silyl ethers to N-Boc isatin ketimines and other two kinds of active cyclic ketimines. This represents the first Au(i)-catalyzed Mukaiyama-Mannich reaction, and the corresponding non-fluorinated enol silyl ether proves to be even much more reactive under the same conditions. This method paves the way to the total sy...

Journal: :Chemical communications 2012
Jonathan D Egbert Steven P Nolan

The complex [Rh(I(t)Bu)(2)HCl] has been shown to be an active catalyst in the hydrosilylation of carbonyl and imine complexes. This reactivity, combined with the previously reported H/D exchange catalyzed by these complexes allows for a one pot, two step reaction using a single catalyst for both H/D exchange and hydrosilylation. Using triethylsilane, [Rh(I(t)Bu)(2)Cl] catalyst, and D(2) gas, de...

Journal: :The Journal of organic chemistry 2005
Silvia Díez-González Harneet Kaur Fabiano Kauer Zinn Edwin D Stevens Steven P Nolan

The catalytic hydrosilylation of highly hindered and functionalized ketones is described. The combination of inexpensive catalyst precursors, CuCl and NHC.HX (NHC = N-heterocyclic carbene), leads to a highly efficient reduction mediator for the preparation of silyl ethers from unfunctionalized and functionalized alkyl, cyclic, bicyclic, aromatic, and heteroaromatic ketones. A series of catalyst...

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