نتایج جستجو برای: epoxidation catalyst

تعداد نتایج: 45578  

2013
Tim Danks Ian Hamerton

The catalysis by S, 1 0, IS,20-tetrakis(pentafluorophenyl)-21H,23H-porphyrin iron(III) chloride (F20 TPPFeCl) of alkene epoxidation by H20 2 has been investigated. Extensive catalyst decomposition was observed during the reaction. A kinetics and product yield analysis has shown that this decomposition does not occur via either the oxoperferryl intermediate (F 20 TPP·+)F e =0 or the oxoferryl in...

Journal: :iranian journal of chemistry and chemical engineering (ijcce) 2015
shaoxiang wu qi wang yao-feng wang pran gopal karmaker fu-xue chen

trifluoromethylated organic compounds, especially chiral quaternary alcohols bearing trifluoromethyl group are of important intermediates in drugs, agrochemicals and etc.an efficient epoxidation of β-cf3-β,β-disubstituted unsaturated ketones (6) has been developed with environmental benign hydrogen peroxide as the oxidant and f5-substituted chiral quaternary ammonium salt (1g or 5) derived from...

Journal: :journal of the iranian chemical research 0
mohammad taghi taghizadeh department of physical chemistry, faculty of chemistry, university of tabriz, tabriz, iran tahere shaidaii department of physical chemistry, faculty of chemistry, university of tabriz, tabriz, iran narges sabouri department of physical chemistry, faculty of chemistry, university of tabriz, tabriz, iran

kinetic study of epoxidation of unsaturated ketone of mesityl oxide was studied by usinghydrogen peroxide in the presence of dodecyltrimethyl ammonium bromide (dtab) as aninverse phase transfer catalyst. the reaction was carried out in the two-phase media of waterheptanewith 1:1 ratio in 25 °c. it was found that the order of reaction for mesityl oxide forketone concentration in the range of 0.0...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2004
Matthew Hickey David Goeddel Zackary Crane Yian Shi

Asymmetric epoxidation of various styrenes using carbocyclic oxazolidinone-containing ketone 3 has been investigated. High enantioselectivity (89-93% enantiomeric excess) has been attained for this challenging class of alkenes. Mechanistic studies show that substituents on the ketone catalyst can have electronic influences on secondary orbital interactions, which affects the competition between...

Journal: Nanochemistry Research 2017

In this study, a new recoverable catalyst for the epoxidation of olefins was developed using a layered polysiloxane as a support for immobilizing  (salen) molybdenum(VI) complex by electrostatic interaction between the surface of the solid support and the electrically charged molybdenum complex. Characterization of the heterogeneous catalyst by Fourier transform infrared, XRD,1H NMR,...

1998
Jaana K. Karjalainen David C. Sherrington

Homogeneous linear poly(tartrate ester) ligands provide high chemical yields and enantiomeric excesses in the epoxidation of trans-hex-2-en-1-ol using Ti(OPr)4-tert-butyl hydroperoxide. Branched poly(tartrate ester) can be use as heterogeneous ligands in the epoxidation of trans-hex-2-en-1-ol using Ti(OPr)4-tert-butyl hydroperoxide. Removal and recovery of the polymer catalyst is a simple filtr...

   Mo-doped SnO2 nanoparticles were prepared using hydrothermal method. The average grain size obtained by varying calcinations temperature from 160 to 500 oC showed the different sizes. Prepared materials characterized by X-Ray diffraction (XRD) and scanning electron microscopy (SEM). Also the FTIR and the UV–Vis absorptive spectra have been carried out. Mo- doped SnO...

Journal: :Dalton transactions 2014
Junkuo Gao Linlu Bai Qian Zhang Yongxin Li Ganguly Rakesh Jong-Min Lee Yanhui Yang Qichun Zhang

A new hexaprismane Co(II)6(μ3-OH)6 cluster-based three-dimensional coordination polymer ({Co(μ3-OH)(HCOO)0.72(CH3COO)0.28}n, Co6-CP) was successfully synthesized and characterized with single-crystal XRD, IR spectra, TGA spectra and elemental analysis. Co6-CP was used as an effective heterogeneous catalyst for the aerobic epoxidation of various alkenes. For the catalytic epoxidation of trans-st...

Journal: :Dalton transactions 2007
Michael Pratt Jason B Harper Stephen B Colbran

A (perarylcyclopentadienyl)molybdenum(VI) dioxo complex is shown to catalyse epoxidation of cyclooctene by t-butylhydroperoxide, but decomposition to a much more active non-cyclopentadienyl containing catalyst occurs as the reaction proceeds.

Journal: :Chemical communications 2011
Samiran Bhattacharjee Da-Ae Yang Wha-Seung Ahn

A manganese(II) acetylacetonate complex has been immobilized to the metal-organic framework IRMOF-3 through a one-step post-synthetic route for the first time, providing an effective and recyclable heterogeneous catalyst for epoxidation of alkenes.

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