- Chromium-Catalyzed Production of Diols From Olefins
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Processes for converting an olefin reactant into a diol compound are disclosed, and these processes include the steps of contacting the olefin reactant and a supported chromium catalyst comprising chromium in a hexavalent oxidation state to reduce at least a portion of the supported chromium catalyst to form a reduced chromium catalyst, and hydrolyzing the reduced chromium catalyst to form a reaction product comprising the diol compound. While being contacted, the olefin reactant and the supported chromium catalyst can be irradiated with a light beam at a wavelength in the UV-visible spectrum. Optionally, these processes can further comprise a step of calcining at least a portion of the reduced chromium catalyst to regenerate the supported chromium catalyst.
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Paragraph 0111
(2021/03/19)
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- Iodine-catalyzed alcohol disproportionation method
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The invention relates to the technical field of catalysis, in particular to an iodine-catalyzed alcohol disproportionation method which comprises the following steps: sequentially adding alcohol, iodine and a solvent into a high-temperature and high-pressure reaction kettle, introducing a certain amount of nitrogen, conducting reacting for a certain time, collecting an organic phase after the reaction is ended, and conducting fractionating to obtain corresponding alkane and aldehyde/ketone. Alcohol disproportionation is efficient and atom-economical conversion without any additional oxidizing agent and reducing agent, and hydrocarbon and aldehyde/ketone molecules which are easy to separate can be formed at the same time. Meanwhile, the method has wide functional group tolerance, various substrate samples including aryl alcohol derivatives, heterocyclic alcohol derivatives, allyl alcohol derivatives and dihydric alcohol are tested, and the result shows that most of the substrate samples show good or extremely good yield.
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Paragraph 0038-0039
(2021/06/13)
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- METHOD FOR PRODUCING CROSS ALDOL CONDENSATE USING AMINE-CARRYING CATALYST
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PROBLEM TO BE SOLVED: To provide a method for producing a cross aldol condensate with improved selectivity of a cross aldol condensate, the target material. SOLUTION: A method for producing a cross aldol condensate has a step of performing a cross aldol condensation reaction of different two substrates in the presence of an amine-carrying catalyst with an amine compound immobilized to a carrier, the substrate containing two compounds selected from aldehyde and/or ketone having α hydrogen. SELECTED DRAWING: None COPYRIGHT: (C)2021,JPO&INPIT
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Paragraph 0033; 0038; 0040; 0043
(2021/01/16)
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- An Engineered Alcohol Oxidase for the Oxidation of Primary Alcohols
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Structure-guided directed evolution of choline oxidase has been carried out by using the oxidation of hexan-1-ol to hexanal as the target reaction. A six-amino-acid variant was identified with a 20-fold increased kcat compared to that of the wild-type enzyme. This variant enabled the oxidation of 10 mm hexanol to hexanal in less than 24 h with 100 % conversion. Furthermore, this variant showed a marked increase in thermostability with a corresponding increase in Tm of 20 °C. Improved solvent tolerance was demonstrated with organic solvents including ethyl acetate, heptane and cyclohexane, thereby enabling improved conversions to the aldehyde by up to 30 % above conversion for the solvent-free system. Despite the evolution of choline oxidase towards hexan-1-ol, this new variant also showed increased specific activities (by up to 100-fold) for around 50 primary aliphatic, unsaturated, branched, cyclic, benzylic and halogenated alcohols.
- Heath, Rachel S.,Birmingham, William R.,Thompson, Matthew P.,Taglieber, Andreas,Daviet, Laurent,Turner, Nicholas J.
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p. 276 - 281
(2019/01/04)
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- Selective catalytic oxidation of alkenes employing homobinuclear manganese(II) catalysts with TBHP
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The two novel homobinuclear compounds [Mn2(II,II) (μ1,1-4-CH3-C6H4COO)2(phen)4](ClO4)2 (1) and [Mn2(II,II) (μ1,3-4-CH3-C6H4COO)2(bipy)4](ClO4)2 (2), where bipy = 2,2-bipyridine and phen = 1,10-phenanthroline, have been synthesized and characterized by elemental analyses and spectral methods (UV–Vis, FTIR, and X-ray). A single-crystal X-ray diffraction structure analysis of the compounds revealed that the manganese atom is octahedrally coordinated. In compound 1, the binuclear(II) structure is monodentate, bridged with one oxygen atom of carboxylate ligand in μ1,1 mode, and each Mn(II) center is coordinated with two phen ligands. In compound 2, the binuclear(II) structure is syn–anti bidentate, bridged with two oxygen atoms of carboxylate ligand in μ1,3 mode, and each Mn(II) center is coordinated with two bipy ligands. The Mn–Mn separation is 3.441 (1) ? and 4.450 (1) ? for 1 and 2, respectively. The catalytic potentials of these compounds have been tested for the oxidation reaction of various olefins (i.e., styrene, cyclohexene, ethyl benzene, 1-hexene, 1-octene). The oxidation reactions were carried out in the presence of catalytic amounts of 1 and 2 with a peroxide oxygen donor (TBHP = tert-Butyl hydroperoxide) in acetonitrile at 70 °C. On comparing the catalytic activities of 1 and 2, both catalysts showed good activity (~100% conv. in 24 h) in the oxidation of studied alkenes, and excellent conversion was obtained for cyclohexene (~100% conv. in 3 h; TON = 265 and TON = 257, respectively, for 1 and 2).
- K?l??, Yal??n,Kani, ?brahim
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p. 352 - 359
(2018/01/10)
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- A carboxylate-bridged Mn(II) compound with 6-methylanthranilate/bipy: oxidation of alcohols/alkenes and catalase-like activity
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A novel manganese compound, [Mn2(μ1,3-6-CH3-2-NH2C6H4COO)2(bipy)4](ClO4)2 (bipy?=?2,2′-bipyridine), was synthesized and used as a catalyst precursor in the oxidation of alkenes and primary alcohols to corresponding aldehydes, ketones, and acids. The six-coordinate compound has a binuclear structure in which two Mn(II) ions adopt a syn-anti μ1,3-bridging mode with two carboxylate groups and two chelated bipy ligands. The compound exhibits good activity in the oxidation of cyclohexene to 2-cyclohexene-1-one as the major product (93% conv. in 3?h, 79.3% selectivity) and of cinnamyl alcohol to cinnamaldehyde as the major product with 46% selectivity (100% conv. in 1.5?h) with tert-butyl hydroperoxide (TBHP) in acetonitrile at 70?°C. Furthermore, the catalase-like activity of the compound was studied in different solvents (acetonitrile, methanol, Tris-HCl buffer; TOF?=?29,910?h?1 in Tris-HCl buffer).
- Kilic, Yalcin,Bolat, Serkan,Kani, Ibrahim
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p. 2293 - 2303
(2018/05/14)
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- Aerobic oxidation of alcohols over Ru-Mn-Ce and Ru-Co-Ce catalysts: The effect of calcination temperature
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Two ternary mixed oxides, Ru-Mn-Ce and Ru-Co-Ce, were prepared by a co-precipitation method and used in the aerobic oxidation of alcohols to corresponding aldehydes (ketones). Interestingly, different catalytic results were obtained when these compounds were calcined. The calcination temperature had an adverse effect on the catalytic performance of Ru-Mn-Ce catalysts, while being beneficial to the Ru-Co-Ce catalysts. To illustrate these effects, these materials were characterized using X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), Temperature-programmed reduction (TPR), Electron paramagnetic resonance (EPR) and other techniques. The data showed that ruthenium oxides were uniformly dispersed in the mixed oxides, and phase transformations occur after calcination. Mn3O4was transformed to MnO2for the Ru-Mn-Ce catalyst, while CoO(OH) was transformed to Co3O4in the Ru-Co-Ce catalyst.The interactions between ruthenium oxides and Co (Mn)-Ce mixed oxides of the former strengthened while the latter weakened. Calcination decreased the content of adsorbed oxygen and restricted oxygen transfer mechanism in the manganese system, while the opposite effect was observed with the cobalt-containing catalyst. Under optimal reaction conditions, various kinds of alcohols were transformed to corresponding aldehydes (ketones) in high yields over the Ru-Mn-Ce catalyst suggesting these ternary oxides are environmental friendly and economical catalytic systems.
- Liu, Gui,Liu, Junhua,Li, Wenxiu,Liu, Cheng,Wang, Fang,He, Junkai,Guild, Curtis,Jin, Jing,Kriz, David,Suib, Steven L.
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- The synthesis of Aldehyde by oxidation of the alcohol
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The present invention relates to an aldehyde synthesis method which includes a step of synthesizing aldehyde by carrying out a reaction with alcohol having an allyl group in the presence of a catalyst. By controlling pressure and types of catalysts, induction of selective oxidation of alcohol is possible, thereby ensuing excellent economic feasibility as well as favorable yields and reaction time.COPYRIGHT KIPO 2017
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Paragraph 0051; 0052
(2017/08/23)
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- Synthesis method of 2-hexenal
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The invention discloses a synthesis method of 2-hexenal. The method includes: adding a mixed solution of n-butanal and vinyl alkyl ether into a catalyst boron trifluoride diethyl etherate solution dropwise to carry out reaction, subjecting the obtained acetal to heating hydrolysis distillation under the catalytic action of a Lewis acid aqueous solution, and subjecting an obtained 2-hexenal crude product to continuous pressure reduction distillation, thus obtaining high purity 2-hexenal. The method provided by the invention has the characteristics of stable route and process and high yield, and the product has competitive edge.
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Paragraph 0014; 0015; 0016; 0017
(2017/04/29)
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- Highly efficient Au hollow nanosphere catalyzed chemo-selective oxidation of alcohols
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Micelles of poly(styrene-b-2-vinyl pyridine-b-ethylene oxide) (PS-PVP-PEO) with core-shell-corona structures have been used as a scaffold for the fabrication of gold (Au) hollow nanospheres of particle size 26 ± 2 nm using HAuCl4 and NaBH4 as metal precursor and reducing agent, respectively. The PS core acts as a template for hollow void, the PVP shell serves as reaction sites for inorganic precursors, and PEO corona stabilizes the composite particles. Under acidic conditions, the PVP shell domain becomes positively charged pyridinum-species that electrostatically interacts with negatively charged AuCl4- ions. On reduction of these composite particles and subsequent solvent extraction leads to the formation of Au hollow nanospheres. Various analytical tools such as powder X-ray diffraction (XRD), transmission electron microscope (TEM), thermogravimetric analyses (TG/DTA), dynamic light scattering of (DLS) have been employed to characterize the polymeric micelles and hollow nanoparticles. The TEM and XRD studies confirmed the formation of highly crystalline Au hollow nanospheres. The Au hollow nanosphere/H2O2 system efficiently catalyzes the chemoselective oxidation of allylic-type unsaturated alcohols into aldehydes and ketones under mild liquid-phase conditions. The versatility of present catalytic system for the oxidation of other substrates like aliphatic-, acylic-, aromatic-, and heteroaromatic alcohols to their respective keto compounds has also been reported.
- Sasidharan, Manickam,Anandhakumar, Sundaramurthy,Bhanja, Piyali,Bhaumik, Asim
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- Method to oxidize alcohols selectively to aldehydes and ketones with heterogeneous supported ruthenium catalyst at room temperature in air and catalyst thereof
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The present invention relates to a method for selectively oxidizing alcohol by using a heterogeneous catalyst for producing aldehyde and ketone in an organic synthesis process used in the laboratory and chemical industries, and a catalytic system thereof. The method can be used as an intermediate product for synthesizing medicine, scent, fragrance, and precise chemical products, and can use a heterogeneous catalyst at room temperature in air by using the catalytic system and producing alcohol and ketone.COPYRIGHT KIPO 2016
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Paragraph 0021; 0022
(2016/10/07)
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- Alpha, beta-unsaturated carbonyl compound production method
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The present invention relates to an alpha, beta-unsaturated carbonyl compound production method comprising the following steps: (1) oxidizing reaction of a primary alcohol with 3-20 carbon atoms under the effect of an oxidase for selective oxidation of a terminal alcoholic hydroxyl group into an aldehyde group to obtain an aldehyde group compound; (2) Reformatsky reaction of the aldehyde group compound and a halide under the catalytic effect of a metal to produce a corresponding alpha, beta-unsaturated carbonyl compound, the alpha, beta-unsaturated carbonyl compound production method is low-cost, less in environmental pollution, moreover, by alcohol oxidizing reaction by use of the oxidase, the quantitative and high selectivity corresponding alpha, beta-unsaturated carbonyl compound can be obtained, and the after processing is convenient.
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Paragraph 0047
(2016/11/21)
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- Design and synthesis of nanoporous perylene bis-imide linked metalloporphyrin frameworks and their catalytic activity
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Two nanoporous perylene bis-imide linked metalloporphyrin framework catalysts have been synthesized via condensation of 5,10,15,20-tetrakis-(4 ′ -aminophenyl) iron(III) porphyrin chloride or 5,10, 15,20-tetrakis-(4 ′ -aminophenyl) manganese(III) porphyrin chloride with perylene-3,4,9,10-tetracarboxylic dianhydride. Both the materials were crystalline in nature and were characterized by electron microscopy techniques, solid-state 1H- 13C CP/MS NMR, powder X-ray diffraction (PXRD), and magnetic susceptibility measurements. The nitrogen gas physisorption study has indicated that both materials are porous in nature and have BET surface area with 653 m2/g and 974 m2/g with uniform pore size of 2.8 nm. These materials were found to act as very good heterogeneous catalysts for selective oxidation of alkanes and alkenes with tert-butyl hydroperoxide and were not degraded even after multiple uses up to 10 cycles.
- Singh, Manoj Kumar,Bandyopadhyay, Debkumar
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- In situ one-step synthesis of metal-organic framework encapsulated naked Pt nanoparticles without additional reductants
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The encapsulation of metal nanoparticles (MNPs) into metal-organic frameworks has generated recent research because of the promising novel physical and chemical properties originating from synergetic interactions between MNPs and MOFs. However, the development of a facile one-step approach for the incorporation of tiny MNPs within MOFs without additional stabilizing agents and reductants remains a great challenge. Herein, we report a new and general synthesis strategy for MNPs@MOFs that allows preferential self-assembly of MOFs around the in situ formed MNP surface by directly mixing both the reactive metal (e.g., H2PtCl6) and MOF precursors in DMF. This in situ one-step assembly approach is applicable to various MOFs, affording well-defined Pt@MOF composites with highly dispersed naked Pt NPs in narrow diameter distribution. The resulting Pt@MOF nanocomposites exhibit excellent stability, significantly enhanced catalytic activity and selectivity as compared to the commercial Pt/C in liquid-phase aerobic oxidation of alcohols.
- Liu, Hongli,Chang, Lina,Chen, Liyu,Li, Yingwei
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p. 8028 - 8033
(2015/04/14)
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- Enzyme-inspired functional surfactant for aerobic oxidation of activated alcohols to aldehydes in water
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We describe an enzyme-inspired catalytic system based on a rationally designed multifunctional amphiphile. The resulting micelles feature metal-binding sites and stable free radical moieties as well as fluorous pockets that attract and preconcentrate molecular oxygen. In the presence of copper ions, the micelles effect chemoselective aerobic alcohol oxidation under ambient conditions in water, a transformation that is challenging to achieve nonenzymatically.
- Chen, Ba-Tian,Bukhryakov, Konstantin V.,Sougrat, Rachid,Rodionov, Valentin O.
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p. 1313 - 1317
(2015/02/19)
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- Highly regio- And enantioselective synthesis of g,d-unsaturated amido esters by catalytic hydrogenation of conjugated enamides
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An efficient and highly regio- and enantioselective catalytic asymmetric hydrogenation of a,γ-dienamido esters to g,d-unsaturated amido esters has been achieved using Rh/ TangPhos as the catalyst. A series of γ,δ-unsaturated amido acids were furnished in excellent yields with up to 99%ee. This effective methodology was applied in the asymmetric synthesis of key intermediate of Ramipril, an ACE inhibitor.
- Min, Gao,Jing-jing, Meng,Hui, Lv,Xumu, Zhang
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supporting information
p. 1885 - 1887
(2015/02/19)
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- Palladium supported on magnetic core-shell nanoparticles: An efficient and reusable catalyst for the oxidation of alcohols into aldehydes and ketones by molecular oxygen
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In continuing our efforts to develop economical and ecofriendly synthetic protocols, we present a proline-palladium catalyst supported on magnetic nanoparticles (0.5 mol %) for oxidation by molecular oxygen. The supported Pd catalyst shows high activity in the oxidation of alcohols into the corresponding carbonyl compounds where easy catalyst recovery and excellent recycling efficiency are observed. It is possible to recover and reuse the grafted palladium catalysts at least eight times without significant loss of its catalytic activity. Copyright
- Zhang, Lei,Li, Pinhua,Yang, Jin,Wang, Min,Wang, Lei
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p. 217 - 222
(2014/03/21)
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- Selective oxidation of allylic alcohols over highly ordered Pd/meso-Al 2O3 catalysts
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Highly ordered mesoporous alumina was prepared via evaporation induced self assembly and was impregnated to afford a family of Pd/meso-Al2O 3 catalysts for the aerobic selective oxidation (selox) of allylic alcohols under mild reaction conditions. CO chemisorption and XPS identify the presence of highly dispersed (0.9-2 nm) nanoparticles comprising heavily oxidised PdO surfaces, evidencing a strong palladium-alumina interaction. Surface PdO is confirmed as the catalytically active phase responsible for allylic alcohol selox, with initial rates for Pd/meso-Al2O 3 far exceeding those achievable for palladium over either amorphous alumina or mesoporous silica supports. Pd/meso-Al2O3 is exceptionally active for the atom efficient selox of diverse allylic alcohols, with activity inversely proportional to alcohol mass.
- Parlett, Christopher M.A.,Durndell, Lee J.,Wilson, Karen,Bruce, Duncan W.,Hondow, Nicole S.,Lee, Adam F.
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- Combined heterogeneous metal/chiral amine: Multiple relay catalysis for versatile eco-friendly synthesis
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Herein is described a versatile and broad synergistic strategy for expansion of chemical space and the synthesis of valuable molecules (e.g. carbocycles and heterocycles), with up to three quaternary stereocenters, in a highly enantioselective fashion from simple alcohols (31 examples, 95:5 to >99.5:0.5 e.r.) using integrated heterogeneous metal/chiral amine multiple relay catalysis and air/O2 as the terminal oxidant. A novel highly 1,4-selective heterogeneous metal/amine co-catalyzed hydrogenation of enals was also added to the relay catalysis sequences. Relay switch: A versatile strategy for expansion of chemical space and the synthesis of valuable molecules, having up to three quaternary stereocenters, in a highly enantioselective fashion from simple alcohols is described. The method employs integrated heterogeneous metal/chiral amine multiple relay catalysis and air/O2 as the terminal oxidant.
- Deiana, Luca,Jiang, Yan,Palo-Nieto, Carlos,Afewerki, Samson,Incerti-Pradillos, Celia A.,Verho, Oscar,Tai, Cheuk-Wai,Johnston, Eric V.,C?rdova, Armando
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supporting information
p. 3447 - 3451
(2014/04/03)
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- Chemoselective hydrogen peroxide oxidation of allylic and benzylic alcohols under mild reaction conditions catalyzed by simple iron-picolinate complexes
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Chemoselective oxidation of allylic alcohols to α,β-unsaturated carbonyl compounds proceeded efficiently using hydrogen peroxide with iron-picolinate catalysts. The in situ generated [Fe(Me-Pic)3] (Me-Pic = 6-methylpicolinate) catalyzed oxidation of the alcohol moiety of primary allylic alcohols while the [Fe(Pic)3] (Pic = picolinate) and [Fe(Me-Pic)2(Pic)] did not show sufficient catalytic activity. the Partner Organisations 2014.
- Tanaka, Shinji,Kon, Yoshihiro,Nakashima, Takuya,Sato, Kazuhiko
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p. 37674 - 37678
(2014/11/07)
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- Chemoselective hydrogen peroxide oxidation of allylic and benzylic alcohols under mild reaction conditions catalyzed by simple iron-picolinate complexes
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Chemoselective oxidation of allylic alcohols to α,β-unsaturated carbonyl compounds proceeded efficiently using hydrogen peroxide with iron-picolinate catalysts. The in situ generated [Fe(Me-Pic)3] (Me-Pic = 6-methylpicolinate) catalyzed oxidation of the alcohol moiety of primary allylic alcohols while the [Fe(Pic)3] (Pic = picolinate) and [Fe(Me-Pic)2(Pic)] did not show sufficient catalytic activity. This journal is
- Tanaka, Shinji,Kon, Yoshihiro,Nakashima, Takuya,Sato, Kazuhiko
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p. 37674 - 37678
(2014/12/11)
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- Thiol-functionalized fructose-derived nanoporous carbon as a support for gold nanoparticles and its application for aerobic oxidation of alcohols in water
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Gold nanoparticles supported on thiol-functionalized fructose-derived nanoporous carbon (AuNPs@thiol-Fru-d-NPS) were found to be a simple bench-top, biocompatible, recyclable and selective catalytic system for the aerobic oxidation of various types of alcohols into their corresponding aldehydes and ketones at room temperature under the environmentally friendly conditions with excellent yields. Copyright
- Mahyari, Mojtaba,Shaabani, Ahmad,Behbahani, Mohammad,Bagheri, Akbar
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p. 576 - 583
(2014/08/05)
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- Hypervalent iodine/TEMPO-mediated oxidation in flow systems: A fast and efficient protocol for alcohol oxidation
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Hypervalent iodine(III)/TEMPO-mediated oxidation of various aliphatic, aromatic and allylic alcohols to their corresponding carbonyl compounds was successfully achieved by using microreactor technology. This method can be used as an alternative for the oxidation of various alcohols achieving excellent yields and selectivities in significantly shortened reaction times.
- Ambreen, Nida,Kumar, Ravi,Wirth, Thomas
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p. 1437 - 1442
(2013/08/23)
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- Selective oxygenation of α-olefins by means of metalloporphyrin catalysts mimicking cytochrome P-450
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A significant problem associated with synthetic metalloporphyrin catalysts used to mimic oxygenation function of cytochrome P-450 is their deactivation due to the formation of inactive μ-oxo dimer. We prepared a series of porphyrin-based catalysts mimicking cytochrome P-450 potentially resistant to deactivation by varying the central metal ion, porphyrin ring substitution, and catalyst support. The influence of the nature of a solid support, the type of central cation and the chemical modification of the porphyrin ring on the catalytic efficiency was studied. The oxygenation ability of the synthesized catalysts was tested using 1-hexene as a substrate and tert-butyl hydroperoxide as an oxidant under various reaction conditions. Identification of the oxygenation products was performed with gas chromatography-mass spectrometry (GC-MS). Quantification of the products formed was based on GC with flame ionization detection (FID). It was found that the application of low GC injection temperature (150 °C) was necessary to detect primary products of the oxygenation, peroxo alkenes, from which secondary oxygenation products, mainly epoxides, alcohols, aldehydes and ketones, were formed slowly. The efficiency of the individual catalysts depended on their structure and varied significantly. The most active catalysts were Fe(II)- tetraphenylporphyrin (TPP) immobilized on aminopolystyrene (aminoPS) and Mn(II)-TPP immobilized on aminoPS.
- Zachar, Pavel,Petkova, Galina,Sykora, David,Kral, Vladimir
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experimental part
p. 1163 - 1175
(2012/01/04)
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- Model studies on the degradation of phenylalanine initiated by lipid hydroperoxides and their secondary and tertiary oxidation products
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The reaction of methyl 13-hydroperoxyoctadeca-9,11-dienoate (MeLOOH), methyl 13-hydroperoxyoctadeca-9,11,15-trienoate (MeLnOOH), methyl 13-hydroxyoctadeca-9,11-dienoate (MeLOH), methyl 13-oxooctadeca-9,11-dienoate (MeLCO), methyl 9,10-epoxy-13-hydroxy-11-octadecenoate (Me-LEPOH), and methyl 9,10-epoxy-13-oxo-11-octadecenoate (MeLEPCO) with phenylalanine was studied to determine the comparative reactivity of primary, secondary, and tertiary lipid oxidation products in the Strecker degradation of amino acids. All assayed lipids were able to degrade the amino acid to a high extent, although the lipid reactivity decreased slightly in the following order: MeLEPCO ≥ MeLCO > MeLEPOH ≥ MeLOH > MeLOOH ≈ MeLnOOH. These data confirmed the ability of many lipid oxidation products to degrade amino acids by a Strecker-type mechanism and suggested that, once the lipid oxidation is produced, a significant Strecker degradation of surrounding amino acids should be expected. The contribution of different competitive mechanisms to this degradation is proposed, among which the conversion of the different lipid oxidation products assayed into the most reactive MeLEPCO and the fractionation of long-chain primary and secondary lipid oxidation products into short-chain aldehydes are likely to play a major role.
- Zamora, Rosario,Gallardo, Emerenciana,Hidalgo, Francisco J.
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experimental part
p. 7970 - 7975
(2010/03/30)
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- Activation of nitrous oxide and selective oxidation of alcohols and alkylarenes catalyzed by the [PV2MO10O40]5- polyoxometalate ion
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A vanadium-substituted polyoxomolybdate ion ([PV2Mo10O40]5-, top right) can activate nitrous oxide to promote the highly selective catalytic oxidation of primary and secondary alcohols to aldehydes and ketones, and the oxidation of various alkylaromatic substrates (see scheme).
- Ben-Daniel, Revital,Neumann, Ronny
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- Highly selective oxidation of allylic alcohols catalysed by monodispersed 8-shell Pd nanoclusters in the presence of molecular oxygen
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Treatment of Pd4phen2(CO)2(OAc)4 with metal nitrates such as Cu(NO3)2 produced monodispersed Pd nanoclusters with a mean diameter and standard deviation (d±σ) of 38±2.1 A (σ/d = 6%). The Pd nanoclusters act as heterogeneous catalysts for the selective oxidation of primary aromatic allylic alcohols using molecular oxygen as an oxidant. This unique catalysis can be ascribed to multiple interactions between the alcohol and specific ensemble sites consisting of Pd0, Pd+, and Pd2+ on the cluster surface.
- Choi, Kwang-Min,Akita, Tomoki,Mizugaki, Tomoo,Ebitani, Kohki,Kaneda, Kiyotomi
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p. 324 - 328
(2007/10/03)
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- 1-(benzoylamino)-3-methylimidazolium chlorochromate (BAMICC), a new selective and mild reagent for the oxidation of allylic and benzylic alcohols
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A new mild chromium(VI) oxidizing reagent, the 1-(benzoylamino)-3-methylimidazolium chlorochromate (BAMICC) has been prepared as a stable yellow-orange solid which selectively oxidizes allylic and benzylic alcohols, including those bearing basic nitrogens, to carbonyl compounds.
- Martinez, Yolanda,De Las Heras, Maria A.,Vaquero, Juan J.,Garcia-Navio, Jose L.,Alvarez-Builla, Julio
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p. 8513 - 8516
(2007/10/02)
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- Oxidative Cleavage of Ethers by Metallic Nitrates Supported on Silica Gel
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Metallic nitrates supported on silica gel efficiently cleave and oxidize ethers to the corresponding aldehydes or ketones under mild conditions.Silica gel is essential for the efficient oxidation, and Cu(NO3)2 and Zn(NO3)2 are suitable for practical use.Overoxidation of the product aldehydes is not observed.In some cases alkyl nitrites are isolated in addition to the carbonyl compounds, and the decomposition of alkyl nitrites to the corresponding carbonyl compounds is promoted by the presence of metallic nitrates supported on silica gel.Mechanistic study suggests nitrogen dioxide is an active species.
- Nishiguchi, Takeshi,Bougauchi, Masahiro
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p. 5606 - 5609
(2007/10/02)
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- A NEW FACILE SYNTHESIS OF α-DICARBONYL COMPOUNDS BY OXIDATION OF ALKYNES WITH Mo(VI) PEROXOCOMPLEX PROMOTED BY MERCURIC ACETATE
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Mercuric acetate promoted oxidation of diaryl-, dialkyl-, and aralkylalkynes with (HMPA)MoO(O2)2 in 1,2-dichloroethane affords the corresponding α-diketones in good yields.Likewise, terminal alkynes can be converted into α-ketoaldehydes in excellent yields by using the same oxidizing system.
- Ballistreri, Francesco P.,Failla, Salvatore,Tomaselli, Gaetano A.,Curci, Ruggero
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p. 5139 - 5142
(2007/10/02)
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- Preparation of Methine Homologues of Aldehydes and Carboxylic Acids
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Dilithium salts of carboxylic acids add to glyoxal mono(dimethylhydrazone) (5) to give salts of β-hydroxy carboxylic acids.Reaction with tosyl chloride affords via decarboxylation the corresponding unsaturated aldehyde hydrazones 10 or 15, which are easily hydrolyzed and oxidized to form unsaturated carboxylic acids.By this method aldehydes and/or carboxylic acids may be extended by one methine group.Extension by three methine groups can be achieved with vinylogous monohydrazones such as 23.
- Zimmermann, Birgit,Lerche, Holger,Severin, Theodor
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p. 2848 - 2858
(2007/10/02)
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- ETHERS D'ENOLS β-LITHIES; SYNTHESES D'ALDEHYDES α-ETHYLENIQUES
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β-Bromoenol ethers readily undergo bromine-lithium exchange with t-butyllithium in ether or THF at -70 deg C.The resulting lithium products react with aldehydes and ketones to produce, after hydrolysis, β-hydroxyenol ethers (basic medium) or α-unsaturated aldehydes (acidic medium).
- Duhamel, Lucette,Tombret, Francis,Mollier, Yves
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- PALLADIUM-CATALYZED OXIDATION OF ALCOHOLS VIA THEIR ALLYL CARBONATES UNDER NEUTRAL CONDITIONS
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Treatment of alkyl allyl carbonates derived from various alcohols with a palladium catalyst in MeCN affords ketones and aldehydes in high yields.This new method of oxidation of alcohols can be applied to various alcohols except simple primary alcohols.
- Tsuji, Jiro,Minami, Ichiro,Shimizu, Isao
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p. 2791 - 2792
(2007/10/02)
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- The Catalyzed Liquid-Phase Oxidation of cis- and trans-Oct-4-ene
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The influences of MoO2(acac)2, MoO3 and Co(acac)3 on the liquid-phase oxidation of cis- and trans-oct-4-ene at 110 deg C were studied.In the presence of molybdenum catalysts the yield of epoxides and the stereoselectivity of epoxide formation are increased.The results are in good agreement with the hypothesis that molybdenum compounds effect only the stereospecific reaction of the hydroperoxides formed with the starting olefin yielding the corresponding epoxide. The cobaltic complex increases the rate of autoxidation, but has no remarkable influence on the yield of epoxides.In the presence of Co(acac)3 more trans-epoxide is formed from cis-oct-4-ene than in the uncatalyzed reaction.This can be explained by an increase of the lifetime of the intermediate peroxyalkyl radical, effected by complex formation of the radical with a cobalt species.
- Rothe, D.,Schnurpfeil, D.
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p. 596 - 608
(2007/10/02)
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