نتایج جستجو برای: epoxidation of alkenes

تعداد نتایج: 21164396  

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: :Green Chemistry 2021

Cobaltabis(dicarbollide), Na[3,3?-Co(?5-1,2-C2B9H11)2] Na[1]), is an efficient photoredox catalyst for the epoxidation of alkenes in water, at low loading and requiring short reaction times (15–30 min).

Journal: :Journal of the American Chemical Society 2001
B S Lane K Burgess

Benign Method for Alkene Epoxidations Benjamin S. Lane and Kevin Burgess* Department of Chemistry, Texas A & M UniVersity PO Box 30012, College Station, Texas 77842-3012 ReceiVed NoVember 17, 2000 This paper reports a simple method wherein manganese (2+) salts, for example, MnSO4, catalyze epoxidation of alkenes using 30% aqueous hydrogen peroxide as the terminal oxidant. The reactions are perf...

A magnetically recoverable catalyst consisting of Mn (III) salophen complex was prepared. The synthesized catalyst was characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), vibrating sample magnetometry (VSM), inductively coupled plasma atomic emission spectroscopy (ICP-AES) and Fourier transform infrared (FT-IR). The immobilized catalyst was shown to be an ef...

Journal: :Applied and environmental microbiology 2000
K McClay B G Fox R J Steffan

Several toluene monooxygenase-producing organisms were tested for their ability to oxidize linear alkenes and chloroalkenes three to eight carbons long. Each of the wild-type organisms degraded all of the alkenes that were tested. Epoxides were produced during the oxidation of butene, butadiene, and pentene but not hexene or octadiene. A strain of Escherichia coli expressing the cloned toluene-...

2015
Anja Fingerhut Olga V. Serdyuk Svetlana B. Tsogoeva

Through catalytic epoxidation and aziridination of olefins versatile synthetic intermediates and subunits of biologically active compounds and pharmaceuticals –epoxides and aziridines– can be obtained. The focus of this review is on recent advances in the epoxidation and aziridination of challenging terminal alkenes with respect to safety of solvents or reagents used and atom economy aspects, a...

Journal: :Chemical communications 2013
Nicola Scotti Nicoletta Ravasio Federica Zaccheria Rinaldo Psaro Claudio Evangelisti

The epoxidation of alkenes was carried out over a CuO/Al(2)O(3) catalyst using cumene as an oxygen carrier, through a one-pot reaction, giving high conversion and selectivity with different substrates. Trans-β-methylstyrene gave the corresponding epoxide in 95% yield after 3 h.

Journal: :Organic & biomolecular chemistry 2010
Pattama Saisaha Dirk Pijper Ruben P van Summeren Rob Hoen Christian Smit Johannes W de Boer Ronald Hage Paul L Alsters Ben L Feringa Wesley R Browne

A practical method for the multigram scale selective cis-dihydroxylation of electron deficient alkenes such as diethyl fumarate and N-alkyl and N-aryl-maleimides using H(2)O(2) is described. High turnovers (>1000) can be achieved with this efficient manganese based catalyst system, prepared in situ from a manganese salt, pyridine-2-carboxylic acid, a ketone and a base, under ambient conditions....

2017
A. W. van der Made P. M. F. C. Groot R. J. M. Nolte

Using low-temperature trapping experiments with 1 ,l-diphenyl-2-picrylhydrazine moni­ tored by UV/Vis spectroscopy, it is shown that the rate-determining step in the epoxidation of alkenes by hypochlorite, catalysed by manganese(III) porphyrins, involves the formation of the active oxo-manganese species [(P)MnO]+.

Journal: :Chemical communications 2015
Mirza Cokoja Iulius I E Markovits Michael H Anthofer Saner Poplata Alexander Pöthig Danny S Morris Peter A Tasker Wolfgang A Herrmann Fritz E Kühn Jason B Love

Organic-phase supramolecular ion pair (SIP) host-guest assemblies of perrhenate anions (ReO4(-)) with ammonium amide receptor cations are reported. These compounds act as catalysts for the epoxidation of alkenes by aqueous hydrogen peroxide under biphasic conditions and can be recycled several times with no loss in activity.

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