- Epoxidation of olefins by molecular oxygen with clay-impregnated nickel catalysts
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With the supported "clayniac" catalyst, in the presence of i- butyraldehyde as a sacrificial reducer, olefins are epoxidized in good yields by compressed air at room temperature, in a convenient procedure.
- Bouhlel, Ezzeddine,Laszlo, Pierre,Levart, Michel,Montaufier, Marie-Therese,Singh, Girij Pal
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- Green oxidation of alkenes in ionic liquid solvent by hydrogen peroxide over high performance Fe(III) Schiff base complexes immobilized on MCM-41
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A series of Fe(III) Schiff base complexes immobilized on MCM-41 were prepared and characterized by various physicochemical and spectroscopic methods. The complexes were used for oxidation of cyclohexene by 30% hydrogen peroxide in the presence and absence of ethylmethyl imidazolium chloride (EMIM) ionic liquid as solvent. The immobilized complexes proved to be effective catalysts and generally exhibited much higher catalytic performance than their homogeneous analogue. Catalytic performance of the complexes was also found to be closely related to the Schiff base ligands used. Additionally, ion liquid solvent efficiently improved all the catalytic performances. Finally, the reaction was extended to different alkenes using the heterogeneous complex 2-L4. Among all the alkenes, those containing π-electron-withdrawing groups and trans-orientations exhibited lower tendency for oxidation.
- Goldani, Mohammad Taghi,Mohammadi, Ali,Sandaroos, Reza
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- AMINOPYRROLOTRIAZINES AS KINASE INHIBITORS
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The disclosure relates to compounds of formula I which are useful as kinase modulators including RIPK1 modulation. The disclosure also provides methods of making and using the compounds for example in treatments related to necrosis or inflammation as well as other indications.
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Page/Page column 723
(2019/08/12)
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- METHOD FOR MANUFACTURING AN EPOXY COMPOUND AND METHOD FOR EPOXIDIZING A CARBON-CARBON DOUBLE BOND
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The present invention provides a method for producing an epoxy compound, comprising oxidizing a carbon-carbon double bond of an organic compound by hydrogen peroxide in the presence of a neutral inorganic salt and a mixed catalyst of a tungsten compound (a), at least one phosphorus compound selected from the group consisting of phosphoric acids, phosphonic acids, and salts thereof (b) and a surfactant (c), and an epoxidizing method comprising oxidizing a carbon-carbon double bond by hydrogen peroxide in the presence of the catalyst and the neutral inorganic salt.
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Page/Page column 12
(2012/05/07)
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- Covalent heterogenization of a discrete Mn(II) Bis-Phen complex by a metal-template/metal-exchange method: An epoxidation catalyst with enhanced reactivity
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Considerable attention has been devoted to the immobilization of discrete epoxidation catalysts onto solid supports due to the possible benefits of site isolation such as increased catalyst stability, catalyst recycling, and product separation. A synthetic metal-template/metal-exchange method to imprint a covalently attached bis-1,10-phenanthroline coordination environment onto high-surface area, mesoporous SBA-15 silica is reported herein along with the epoxidation reactivity once reloaded with manganese. Comparisons of this imprinted material with material synthesized by random grafting of the ligand show that the template method creates more reproducible, solution-like bis-1,10-phenanthroline coordination at a variety of ligand loadings. Olefin epoxidation with peracetic acid shows the imprinted manganese catalysts have improved product selectivity for epoxides, greater substrate scope, more efficient use of oxidant, and higher reactivity than their homogeneous or grafted analogues independent of ligand loading. The randomly grafted manganese catalysts, however, show reactivity that varies with ligand loading while the homogeneous analogue degrades trisubstituted olefins and produces trans-epoxide products from cis-olefins. Efficient recycling behavior of the templated catalysts is also possible.
- Terry, Tracy J.,Daniel,Stack
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p. 4945 - 4953
(2008/09/21)
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- Catalytic process for the preparation of epoxides from alkenes
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An improved catalytic process for the preparation of epoxides from alkenes using a combination of transition metal salt, an inorganic promoter and an organic additive in absence of solvent or in the presence of a solvent with commercially available hydrogen per oxide has been disclosed. Thus, styrene oxide was prepared at a kilogram scale in 86% isolated yield with purity >95%.
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Page/Page column 6
(2008/06/13)
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- Aerobic epoxidation of alkenes catalysed by cobalt(II) 1,1,1,5,5,5-hexafluoroacetylacetonate or cobalt(II) benzoylacetonate
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The aerobic epoxidation of terminal or electron deficient alkenes with an aldehyde does not proceed with cobalt(II) acetylacetonate but goes to completion with the cobalt(II) benzoylacetonate and cobalt(II) 1,1,1,5,5,5-hexafluoroacetylacetonate complexes.
- Hunter,Turner,Rimmer
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p. 4461 - 4466
(2007/10/03)
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- Oxo Complexes of Ruthenium with N,N'-Donors as Oxidation Catalysts for Alkenes, Alkanes and Alcohols, and their Osmium Analogues
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Catalysis of the epoxidation of alkenes and oxidation of alkanes and alcohols by a variety of bis-bipy (2,2'-bipyridyl) and bis-phen (1,10-phenanthroline) ruthenium complexes with NaIO4 or IO4 as co-oxidants has been investigated together with similar oxidations with >*1.5H2O.The new complexes > and > (L-L = bipy, phen or 2,2'-dipyridylamine) have been prepared and characterised.
- Bailey, Alan J.,Griffith, William P.,Savage, Paul D.
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p. 3537 - 3542
(2007/10/03)
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- Intermediates in the Epoxidation of Alkenes by Cytochrome P-450 Models. 5. Epoxidation of Alkenes Catalyzed by a Sterically Hindered (meso-Tetrakis(2,6-dibromophenyl)porphinato)iron(III) Chloride
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Sterically hindered (meso-tetrakis(2,6-dibromophenyl)porphinato)iron(III) chloride ((Br8TPP)Fe(III)(Cl) was prepared and used as a catalyst for epoxidation of nine structurally different alkenes. (Br8TPP)Fe(III)(Cl) is an extremely efficient catalyst for epoxidation, and nearly quantitative yields of epoxides were obtained in all cases.Computer graphics docking experiments show that alkenes can approach the iron-oxo moiety of the iron(IV)-oxo porphyrin ? cation radical ((+.Br8TPP)Fe(IV)(O)(X)) from above the oxygen and distal to the iron, but with various angles ofapproach.With the exception of terminal alkenes, the bulky o-bromo substituents prevent interaction of alkenes with the iron or pyrrole nitrogens of the porphyrin ring.With alkyl-substituted terminal alkenes various degrees of porphyrin N-alkylation accompany epoxidation.Selectivity for N-alkylation parallels the selectivity observed with microsomal cytochrome P-450.Arguments are presented that support either a concerted or a radical mechanism for N-alkylation by terminal alkenes.Formation of a metallaoxetane intermediate in the epoxidation reaction via a 2a + 2s cycloaddition is discounted on the basis of (i) docking experiments, which show that all but terminal alkenes are unable to approach the iron(IV) moiety, and (ii) examination of X-ray-based computer graphics constructed metallaoxetane structures formed from (+.Br8TPP)Fe(IV)(O) + cis-stilbene or 2,3-dimethyl-2-butene regardless of whether the porphyrin ring is flat, ruffled, or saucer shaped.Evidence for rate-determining formation of the carbon radical (Br8TPP)Fe(IV)-O-C-C., carbocation (Br8TPP)Fe(III)-O-C-C(1+), and the solvent-caged intimate pair/(Br8TPP)Fe(IV)(O)***alkene.+/ in alkene epoxidation is considered.A mechanism that best correlates the results of epoxidation studies for both (+.Br8TPP)Fe(IV)(O)(X) and (Br8TPP)Cr(V)(O)(X) involves a rate-determining formation of a charge-transfer complex by partial electron transfer from the alkene to the hypervalent porphyrin metal-oxo species.
- Ostovic, Drazen,Bruice, Thomas C.
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p. 6511 - 6517
(2007/10/02)
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- Studies on the Autoxidation of Branched-chain Olefins. I. Autoxidation of 2-Methylalk-1-enes and 2-Methylalk-2-enes
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The products of the autoxidation of 2-methylpent-1-ene, 2-methylpent-2-ene, 2-methylhex-1-ene, 2-methylhex-2-ene, 2,4,4-trimethylpent-1-ene, and 2,4,4-trimethylpent-2-ene were analyzed by gas chromatography.The identification of the products corresponding to the individual peaks was possible by comparison with authentic substances or by preparative gaschromatographic separation and n.m.r.-spectroscopy of the isolated samples.In this way not only the epoxides and the products of the oxidative cleavage of the C=C double bond but also the allylic alcohols formed by LiAlH4-reduction of the oxidation mixtures could be identified and analyzed.From the results the compositions of the original oxidation mixtures were calculated.
- Bilas, W.,Hoebold, W.,Pritzkow, W.
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p. 125 - 141
(2007/10/02)
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- AN EFFECT SILICON SUBSTITUTION REMOTE FROM REACTIVE SITE
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The source of a rate retardation of the trimethylsilyl substituent in an alkylation reaction is probed.
- Trost, Barry M.,Curran, Dennis P.
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p. 5023 - 5026
(2007/10/02)
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- EPOXIDATION OF OLEFINS BY HYDROGEN PEROXIDE IN THE PRESENCE OF TETRACHLOROACETONE
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1,1,3,3-Tetrachloroacetone, an inexpensive, commercially available material, has been shown to be effective in mediating the hydrogen peroxide oxidation of a variety of olefins to epoxides.The chloroacetone is readily recovered for re-use.
- Stark, Charles J.
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p. 2089 - 2092
(2007/10/02)
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