- Synthesis of functionalized tetrahydrofuran derivatives from 2,5-dimethylfuran through cascade reactions
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A three-step strategy is proposed for the functionalization of the methyl group of 2,5-dimethylfuran, encompassing the ring opening of 2,5-dimethylfuran to 2,5-hexanedione, its further aldol condensation with aldehydes, and hydrogenation-cyclization of the condensation intermediate to generate alkylated tetrahydrofuran. Active and selective catalysts could be identified for the aldol condensation and hydrogenation-cyclization reactions.
- Li,Muller,Pera-Titus,Jér?me,De Oliveira Vigier
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- UN ANION β-ACYLE MASQUE DANS LES REACTIONS D'ACYLATION: LE DERIVE LITHIE DU DIOXOLANNE DU LEVULATE DE TRIMETHYLSILYLE
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An organolithium reagent derived form trimethylsilyl-4,4-ethylenedioxypentanoate reacts with mixed carboxylic-carbonic anhydrides as a homoenolate anion equivalent.Several monoethylene acetals of 1,4-diketones and the corresponding diketones are synthesized by this way.
- Moreau, Jean-Louis,Couffignal, Renee
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- Dehydrogenation of Cyclic and Bicyclic Secondary Alkyl Peroxides during Flash Vacuum Pyrolysis
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Dehydrogenation to the corresponding diketone occurs to the extent of 16percent and 42percent respectively in the flash vacuum pyrolysis of 3,6-dimethyl-1,2-dioxacyclohexane and 2,3-dioxabicyclooctane, but is unimportant in similar pyrolyses of 3,5-dimethyl-1,2-dioxacyclopentane and 2,3-dioxabicycloheptane.
- Bloodworth, A. J.,Baker, David S.
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- A facile synthesis of 1,4-diketones
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1,4-Diketones may conveniently be synthesized by the addition of 2-methylcyclopropenyllithium to N-methoxy-N-methylcarboxamides followed by hydrolysis of intermediate cyclopropyl ketone adducts on silica gel. The new method has been applied to the synthesis of cis-jasmone.
- Bergman,Nilsson,Wickberg
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- Ether formation in the hydrogenolysis of hydroxymethylfurfural over palladium catalysts in alcoholic solution
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5-Hydroxymethylfurfural, a product from renewable feedstock, was subjected to hydrogenolysis over palladium catalysts in 1-propanol aiming at the synthesis of 2,5-dimethylfuran, a potential transportation fuel enhancer. Intermediates are 5-hydroxymethyl-2-(propyloxymethyl)furan, formed with high selectivity, and 5-methyl-2-(propyloxymethyl)furan. Acetals are assumed to be initially formed. Acetalisation and hydrogenolysis are catalysed by traces of a Bronsted acid. Important variables are the palladium support and the solvent. In 2-propanol also ether formation takes place. In 1,4-dioxane mainly 2,5-bis(hydroxymethyl)furan is formed, in water ring opening becomes a major reaction. The formation of some side-products is discussed.
- Luijkx, Gerard C.A.,Huck, Nina P.M.,Van Rantwijk, Fred,Maat, Leendert,Van Bekkum, Herman
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- A two-step approach for the catalytic conversion of glucose to 2,5-dimethylfuran in ionic liquids
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Lignocellulosic biomass is an attractive resource for producing transportation fuels, and consequently novel approaches are being sought for transforming the lignin and cellulosic constituents of biomass to fuels or fuel additives. Glucose, the monomer of cellulose, is a good starting material for exploring such chemistries. We report here the results of an investigation aimed at identifying catalysts for the dehydration of glucose to 5- hydroxymethylfurfural (HMF) dissolved in ionic liquids and the subsequent conversion of HMF to 2,5-dimethylfuran (DMF), a high-energy content product that could be used as a fuel or fuel additive. Heteropoly acids were found to be exceptionally active and selective catalysts for the dehydration of glucose. Nearly 100% yield of HMF could be achieved using 12-molybdophosphoric acid (12-MPA) in a solution of 1-ethyl-3-methylimidazolium chloride (EMIMCl) and acetonitrile. The addition of acetonitrile to EMIMCl suppressed the formation of humins from glucose. The high HMF selectivity achievable with heteropoly acid catalysts is ascribed to stabilization of 1,2-enediol and other intermediates involved in the dehydration of glucose and the avoidance of forming the 2,3-enediol intermediate leading to furylhydroxymethyl ketone (FHMK). Carbon-supported metals, and in particular Pd/C, were effective in promoting the hydrogenation of HMF dissolved in EMIMCl and acetonitrile to DMF. The following intermediates were observed in the hydrogenation of HMF to DMF: 5-methylfurfural (MF), 5-methylfurfyl alcohol (MFA), and 2,5- dihydroxymethylfuran (DHMF). The relative rate of formation and consumption of these compounds was explored by using each of them as a reactant in order to identify the reaction pathway from HMF to DMF. It was also observed that HMF produced via glucose dehydration could be converted to DMF without isolation, if the dehydration catalyst, 12 MPA, was replaced by the hydrogenation catalyst, Pd/C. This two-step catalytic approach provides the basis for completely converting glucose to HMF and further converting HMF to DMF. The Royal Society of Chemistry 2010.
- Chidambaram, Mandan,Bell, Alexis T.
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- Efficient desymmetrization of 1,2 and 1,3 diols by dimethyldioxirane
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Dimethyldioxirane was used to monooxide 1,2 and 1,3 sec,sec-diols to the corresponding ketoalcohols, exploiting the inhibiting effect of the formed carbonyl group on the course of the process.
- Bovicelli, Paolo
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- Producing methylcyclopentadiene dimer and trimer based high-performance jet fuels using 5-methyl furfural
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Methylcyclopentadiene dimer and trimer based fuels are synthesized from 5-methyl furfural for the first time with yields as high as 74.4%. They exhibit both high density and high thermal stability that are better than those of widely used fossil based jet fuels such as JP-10 and JP-7, and represent types of high-performance fuels. This work also provides a potential and scale-up feasible route for synthesizing high-performance jet fuels from biomass.
- Dai, Yiying,Liu, Qing,Liu, Yakun,Liu, Yanan,Ma, Chi,Nie, Genkuo,Pan, Lun,Shi, Chengxiang,Zhang, Xiangwen,Zou, Ji-Jun
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- Catalytic dehydration of d-xylose to 2-furfuraldehyde in the presence of Zr-(W,Al) mixed oxides. Tracing by-products using two-dimensional gas chromatography-time-of-flight mass spectrometry
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Zirconium-tungsten mixed oxides (ZrW) are effective catalysts in the aqueous-phase dehydration of d-xylose to 2-furfuraldehyde (Fur), at 170 °C. The texture and acid properties of ZrW materials were modified to enhance Fur yields. The catalysts prepared by co-condensation without a templating agent (ZrW(X), X = NO3, Cl; X is related to the type of zirconium precursor) possess relatively low specific surface area and amounts of accessible acid sites, leading to a modest Fur yield of ca. 35% at 99% conversion. The use of a templating agent in the preparation of mesoporous ZrW (ZrW-MP) increased considerably the specific surface area and the amount of accessible acid sites, which resulted in enhanced Fur yields (42%) reached at comparable conversions. Further improvements in Fur yields at high conversions were accomplished by introducing aluminium in the catalyst preparation procedure to give ZrAlW-MP (51% yield at 98% conversion). Fairly good catalytic results were also obtained in the case of the ZrAlW-MP catalyst, using solely water as solvent (46% yield at 93% conversion). A study of the identification of the reaction by-products by two-dimensional gas chromatography (GC × GC) combined with time-of-flight mass spectrometry (ToFMS) was carried out.
- Antunes, Margarida M.,Lima, Sérgio,Fernandes, Auguste,Candeias, Joana,Pillinger, Martyn,Rocha, Sílvia M.,Ribeiro, Maria Filipa,Valente, Anabela A.
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- Facile Synthesis of 1,4-Diketones via Palladium Complex Catalyzed Isomerization of Alkynediols
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Alkynediols isomerized under the catalysis of Pd(dba)3*CHCl3 + 2n-Bu3P in acetonitrile at 80 deg C to give 1,4-diketones in high yields.This experimentally simple and economically synthetic method is illustrated with examples including substituents such as alkyl, alkenyl, and aryl groups.The order of reactivity of the substituents in this reaction is aryl >/= alkenyl > alkyl.Alkenyl-substituted alkynediols chemoselectively isomerized to the corresponding α,β-unsaturated 1,4-diketones.The usefulness of this novel method is examplified by the synthesis of dihydrojasmone.
- Lu, Xiyan,Ji, Jianguo,Ma, Dawei,Shen, Wei
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- 2-Ethoxy-2-propenyl Diethyl Phosphate. An Efficient Halo Acetone Equivalent for the Pd-Catalyzed Cross-coupling with Tin Enolates
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In the presence of Pd(0) complexes, 2-ethoxy-2-propenyl diethyl phosphate was found to react with organotins to give the corresponding coupling products, showing to be a more efficient halo acetone equivalent compared with the corresponding acetate or carbonate.Reaction with tin enolates gave the 1,4-diketone in moderate to good yields.
- Kosugi, Masanori,Ohashi, Kenji,Akuzawa, Kazuko,Kawazoe, Takashi,Sano, Hiroshi,Migita, Toshihoko
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- Radical cyclisation of α,ω-dinitroalkanes
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2,6-Dinitroalkanes have been cyclised to yield vicinal dinitrocyclopentanes via stereoselective intramolecular addition of nitronate anions to α-nitroalkyl radicals. A "cyclohexane type" transition state is proposed for this radical anion cyclisation.
- Russell Bowman,Jackson, Stuart W.
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- On the Photochemical Behaviour of Ethyl Acetoacetate in Water
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Irradiation of ethyl acetoacetate in water yielded acetic acid, ethyl acetate, acetonylacetone and diethyl succinate.The possible route of their formation is the recombination of the radicals resulting from the cleavage of the bonds between α-β and β-γ carbon atoms of the β-keto ester and /or their interaction with the solvent. - Keywords: Ethyl acetoacetate; Homolytic photocleavage; Solvent effect
- Markov, Peter,Petkov, Ivan,Roumian, Christian
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- SYNTHESE DE MONODIOXOLANNES DE DICETONES-1,4 ET DE DICETONES-1,4 AU MOYEN DES ANHYDRIDES MIXTES CARBOXYLIQUES ET CARBONIQUES: APPLICATION A LA PREPARATION DE LA DIHYDROJASMONE, DE LA Z-JASMONE ET DE LA DEHYDROJASMONE
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Levulinic acid 1 is easily converted by two steps into mixed carboxylic and carbonic anhydride 3 which reacts with the organolithium reagent issued from trimethylsilyl esters.Monoethylene acetal of 1,4-diketones 4 can be prepared; it is also possible to obtain 1,4-diketones 5 in one step by hot acid hydrolysis.The preparation of the dihydrojasmone 6d, Z-jasmone 6e and dehydrojasmone 6f shows the efficiency of the process.
- Moreau, J.-L.,Couffignal, R.,Arous-Chtara, R.
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- Self-oscillating reaction in the Furan series
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It was found for the first time that the acid hydrolysis of 2,5-dimethylfuran in water-ethanol solutions has self-oscillating character. Oscillations in the concentrations of the two products 2,5-hexanedione and an unidentified compound X were detected by GLC. The ranges of hydrochloric acid and ethanol concentrations in which these oscillations appear were determined. It is suggested that the formation of compound X results from tautomeric transformations of 2,5-hexanedione under the reaction conditions. Quantum-chemical calculations showed that the possible tautomers are formed with equal probability.
- Gubina,Pankratov,Labunskaya,Rogacheva
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- MECHANISM OF RECYCLIZATION OF FURANS TO THIOPHENES AND SELENOPHENES UNDER ACID CATALYSIS. 1. KINETIC STUDIES OF THE REACTION OF 2,5-DIALKYLFURANS WITH HYDROGEN SULFIDE IN THE PRESENCE OF HYDROCHLORID ACID
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The transformation of 2,5-dialkylfurans to thiophene by reaction with hydrogen sulfide in the presence of hydrochloric acid was studied.The reaction was found to be first order with respect to the furan; the rate of consumption of the furan did not change with the increasing length of one of the alkyl substituents.Recrystalization in the presence of acid proceeds in two independent directions: through the formation of an intermediate dicarbonyl compound, and by direct conversion of the furan to a thiophene.Kinetic data showed that the reaction occurs mainly by the second route.
- Voronin, S. P.,Gubina, T. I.,Markushina, I. A.,Kharchenko, V. G.
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- Electrochemical reductive biomass conversion: Direct conversion of 5-hydroxymethylfurfural (HMF) to 2,5-hexanedione (HD): Via reductive ring-opening
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2,5-Hexanedione (HD), which can be produced by reduction of 5-hydroxymethylfurfural (HMF), one of the most important biomass intermediates, can serve as a precursor to produce various biofuels and key building block chemicals. The conversion of HMF to HD requires reduction of both the alcohol and aldehyde groups to alkane groups as well as opening of the furan ring. In this study, a direct electrochemical conversion of HMF to HD at ambient pressure and temperature was demonstrated without using H2 or precious metal catalysts. Water was used as the hydrogen source and zinc was used as the catalytic electrode, which enabled hydrogenolysis and Clemmensen reduction coupled with furan ring opening. Optimum conditions to achieve high Faradaic efficiency (FE) and selectivity for HD production were investigated and plausible mechanisms were proposed. The environmentally benign one-step procedure to produce HD reported in this study will serve as a new route to valorize biomass intermediates.
- Roylance, John J.,Choi, Kyoung-Shin
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- Cooperative dehydrogenation coupling of isopropanol and hydrogenation coupling of acetone over a sodium tantalate photocatalyst
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Photocatalytic organic syntheses are often limited by their low system efficiency and product selectivity. We demonstrate herein that intermolecular hydrogen transfer from isopropanol to acetone can be achieved efficiently on the surfaces of NaTaO3 photocatalysts, on which 2-hydroxyisopropyl radicals are produced selectively from both oxidation and reduction half-reactions and then coupled to form 2,3-dimethyl-2,3-butanediol. Such a process effectively increases the total reaction efficiency. We also found that the two half-reactions occur at different crystal facets and display a remarkably promotive interaction, which dramatically speeds up the reactions by one order of magnitude and significantly restrains side reactions. The sodium ions on the NaTaO3 surfaces play an important role in the promotive effect, likely facilitating the proton transfer between the oxidation and reduction sites. These factors make the production rate of 2,3-dimethyl-2,3- butanediol reach a very high level (10.87 mmol g-1 h-1), emphasizing the potential of photocatalytic hydrogenation and dehydrogenation in improving system efficiency of photocatalytic organic syntheses. Double couple: Dehydrogenation coupling of isopropanol and hydrogenation coupling of acetone can be performed simultaneously on a single NaTaO3 photocatalyst through intermolecular hydrogen transfer and display a remarkable promotive interaction, which speeds the reactions by one order of magnitude and restrains side reactions. CB=conduction band, VB=valence band.
- Cao, Baoyue,Zhang, Jian,Zhao, Jianghong,Wang, Zhijian,Yang, Pengju,Zhang, Hongxia,Li, Li,Zhu, Zhenping
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- Bromine-Hydrolysis Control in the Cerium Ion-Bromate Ion-Oxalic Acid-Acetone Belousov-Zhabotinskii Oscillator
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Chemical oscillations in reacting systems containing BrO3(1-) have been interpreted as a switching phenomenon in which control of the overall reaction is passed back and forth between a set of radical reactions, whose major effect is the removal of Br(1-).Control switches to the radical reactions when is driven low enough.Oscillation occurs because Br(1-) is an indirect product of the radical reactions, causing control to be returned to the nonradical reactions.Bromide ion control of BrO3(1-)-driven oscillations has been challanged on the basis that in some systems the usual source of Br(1-) from the radical reactions is absent.It has been suggested that the oscillations are fact Br2 controlled.It is shown here that one of these puzzling oscillators can be simulated as Br(1-) controlled.By implication the others also can be.Bromine is an important intermediate in these systems as the controlling Br(1-) comes from Br2 hydrolysis and is in equilibrium with Br2 and HOBr.We call such an oscillator Br2-hydrolysis controlled.The simulation is based on 31 elementary reactions of which 9 are reversible.It was constructed on the basis of a large number of experiments on simpler, nonoscillatory reactions involving the same reactants and is much simpler than the mechanism of other BrO3(1-)-driven oscillators because of the relative simplicity in it of the reactions of oxalic acid and acetone.The rate constants thus determined were used without modification to obtain an essentially quantitative simulation of the oscillatory system.It is thus the most complete and quantitatively accurate simulation of a BrO3(1-)-driven oscillator with an organic substrate yet carried out.The complete mechanism can be reduced to a simple five-variable Oregonator-like model that contains no expendable stoichiometric factor and whose rate parameters all can be related directly to the concentration of a principal reactant.
- Field, Richard J.,Boyd, Patrick M.
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- HYDROXYMETHYLATION OF METHYLSUBSTITUTED PYRROLE, THIOPHENE, AND FURAN IN THE PRESENCE OF H+ CATION EXCHANGERS
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In the reaction of formalin with the 2,5-dimethyl derivatives of pyrrole, thiophene, and furan in the presence of the sulfo cation exchanger Amberlyst 15 electrophilic substitution takes place at various positions of the rings with the formation of 2,5-dimethyl-1-hydroxymethylpyrrole, 1,3-dioxacycloheptano-2,5-dimethylthiophene (an intermediate in the formation of which is 2,5-dimethyl-3,4-dihydroxymethylthiophene), and 2,5-hexanedione respectively.Bis(5-methyl-2-thienyl)methane was obtained from 2-methylthiophene.
- Iovel', I. G.,Gol'dberg, Yu. Sh.,Shimanskaya, M. V.
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- Production of 2,5-hexanedione and 3-methyl-2-cyclopenten-1-one from 5-hydroxymethylfurfural
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A novel approach for the production of 2,5-hexanedione (HDN) and 3-methyl-2-cyclopenten-1-one (3-MCO) from 5-hydroxymethylfurfural (HMF) by water splitting with Zn is reported for the first time. The use of high temperature water (HTW) conditions is the key for the efficient conversion of HMF to HDN and 3-MCO. Parameters regarding the Zn amount, temperature and reaction time are optimized and HDN and 3-MCO are produced in 27.3% and 30.5% yields, respectively. The roles of HTW and ZnO obtained by oxidation of Zn in water for the conversion of HMF, together with intermediate structures, are discussed to understand the mechanism of the reaction.
- Ren, Dezhang,Song, Zhiyuan,Li, Lu,Liu, Yunjie,Jin, Fangming,Huo, Zhibao
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- Photocatalytic hydrogenation coupling of acetone into pinacol using formic acid as hydrogen source
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We demonstrated photocatalytic hydrogenation coupling of acetone into 2,3-dimethyl-2,3-butanediol with formic acid as a hydrogen source. In this synergetic system, the conversion of acetone and formic acid was dramatically increased than that in the individual reaction system. Consequently, the selectivity of 2,3-dimethyl-2,3-butanediol was relatively high over that of NaTaO3 and Na2Ti3O7 photocatalysts. Additionally, in this acetoneformic acid reaction system, the presence of acetone can effectively restrain the generation of CO during the decomposition of formic acid.
- Cao, Bao Y.,Xu, Shan,Ren, You L.,Yu, Yan,Guo, Jin Y.,Zhang, Li,Li, Na,Zhang, Guo C.,Zhou, Chun S.
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- Synthesis of Renewable Triketones, Diketones, and Jet-Fuel Range Cycloalkanes with 5-Hydroxymethylfurfural and Ketones
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A series of renewable C9–C12triketones with repeating [COCH2CH2] units were synthesized in high carbon yields (ca. 90 %) by the aqueous-phase hydrogenation of the aldol-condensation products of 5-hydroxylmethylfurfural (HMF) and ketones over an Au/TiO2catalyst. Compared with the reported routes, this new route has many advantages such as being environmentally friendly, having fewer steps, using a cheaper and reusable catalyst, etc. The triketones as obtained can be used as feedstocks in the production of conducting or semi-conducting polymers. Through a solvent-free intramolecular aldol condensation over solid-base catalysts, the triketones were selectively converted to diketones, which can be used as intermediates in the synthesis of useful chemicals or polymers. As another application, the tri- and diketones can also be utilized as precursors for the synthesis of jet-fuel range branched cycloalkanes with low freezing points (224–248 K) and high densities (ca. 0.81 g mL?1).
- Li, Shanshan,Chen, Fang,Li, Ning,Wang, Wentao,Sheng, Xueru,Wang, Aiqin,Cong, Yu,Wang, Xiaodong,Zhang, Tao
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- Photolysis of Alcohols and Alkanones in Acetone Solutions. Photochemical Cycloaddition Reaction between Acetone and Aliphatic Enols
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Transient enols including those of acetaldehyde, acetone, cyclopentanone, 3-pentanone, 2,4-dimethyl-3-pentanone, 2-butanone, and 2-methyl-3-pentanone were trapped photochemically with acetone via a cycloaddition and isolated as corresponding 3-oxetanols in reasonable yields in the photolysis of six different secondary alcohols and two alkanones, 3-octanone and hexanal, in acetone solutions.The trapping experiments indicated the photodehydrogenation of unsymmetrical alcohols, 2-butanol and 2-methyl-3-pentanol, in acetone to be highly regioselective in preference for the formation of the less alkylated enol.
- Shimizu, Nobujiro,Miyahara, Toru,Mishima, Masaaki,Tsuno, Yuho
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- A Synthesis of 4-Oxo Carboxylic Acids, 4-Oxo Aldehydes, and 1,4-Diketones from γ-Lactones
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The α-methyldiphenylsilyl derivatives of γ-butyrolactone, γ-valerolactone, and the cis lactone of 2-hydroxycyclohexaneacetic acid have been reacted with Grignard reagents.The α-silylated lactones of γ-butyrolactone and γ-valerolactone react with a single equivalent of Grignard reagent to give a 2-substituted 4,5-dihydrofuran, which can be hydrolyzed and oxidized to 4-oxo carboxylic acids, 1,4-diketones, or 4-oxo aldehydes.The α-silylated fused lactone failed to react with ethylmagnesium bromide in refluxing tetrahydrofuran.An X-ray crystal structure of this silylated lactone indicated that this lack of reactivity is due to steric factors.
- Betancourt de Perez, Rosa M.,Fuentes, Lelia M.,Larson, Gerald L.,Barnes, Charles L.,Heeg, Mary Jane
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- Nitroalkanes in Aqueous Medium as an Efficient and Eco-Friendly Source for the One-Pot Synthesis of 1,4-Diketones, 1,4-Diols, δ-Nitroalkanols, and Hydroxytetrahydrofurans
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The Michael addition of primary aliphatic nitro compounds to α,β-unsaturated enones, performed in aqueous media, provides the one-pot synthesis of 1,4-diketones, 1,4-diols, δ-nitroalkanols, and hydroxytetrahydrofurans, respectively, by the appropriate cho
- Ballini, Roberto,Barboni, Luciano,Giarlo, Guido
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- STUDY OF THE MECHANISM OF RECYCLIZATION OF FURANS INTO THIOPHENES AND SELENOPHENES IN CONDITIONS OF ACID CATALYSIS. 4. STUDY OF THE EFFECT OF THE SOLVENT AND DIRECTION OF REACTIONS OF HYDROLYSIS AND RECYCLIZATION OF 2,5-DIMETHYLFURAN
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The kinetics of hydrolysis of 2,5-dimethylfuran and its recyclization into the corresponding thiophene were investigated in water-alcohol medium in 95, 80, and 50percent ethyl alcohol in the presence of HCl.It was found that the rates of these reactions are a function of both the initial concentration of the acid component and the concentration of water in the alcohol.The rate of hydrolysis is a function of the dilution of the alcohol to a greater degree than the rate of recyclization.
- Gubina, T. I.,Labunskaya, V. I.,Kornienko, G. K.,Borodina, L. A.,Kharchenko, V. G.
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- Unique Catalysis of Nickel Phosphide Nanoparticles to Promote the Selective Transformation of Biofuranic Aldehydes into Diketones in Water
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Although the development of metal nanoparticle catalysts for organic synthesis has been widely studied, the catalytic potential of "metal phosphide nanoparticles" has little been studied. Herein, we describe that nickel phosphide nanoparticles (Ni2P NPs) act as a highly efficient heterogeneous catalyst for the selective transformation of biofuranic aldehydes into diketones, which is a useful biorefining technology. The biofuranic aldehydes are hydrogenated in water without any additives, giving the corresponding diketones in high yields. The catalytic performance of Ni2P NPs demonstrated here is significantly different from conventional Ni(0) and NiO NPs, and other metal phosphide NPs, which show no activity, indicating the unique catalysis of Ni2P NPs. Spectroscopic analyses showed that bifunctional Ni2P NP catalysis combining their hydrogen-activating ability and surface acidity plays a crucial role, leading to the transformations of selective biofuranic aldehydes.
- Fujita, Shu,Jitsukawa, Koichiro,Mitsudome, Takato,Mizugaki, Tomoo,Nakajima, Kiyotaka,Yamasaki, Jun
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- Hydrogenation/hydrolytic ring opening of 5-HMF by Cp-Iridium(III) half-sandwich complexes for bioketones synthesis
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A new method for one-step synthesis of ketones from biobased 5-hydroxymethylfurfural (5-HMF) and its derivatives is reported. Bipyridine coordinated Cp-Iridium(III) complexes (Cp, 1,2,3,4,5-pentamethylcyclopenta-1,3-diene) exhibit highly efficient catalytic performance for hydrogenation/hydrolytic ring opening of 5-HMF and derivatives to produce ketones. The catalytic mechanism is proposed to proceed via carbonyl hydrogenation, hydroxyl group promoted and directed hydrolytic furan ring opening, followed by hydrogenation of α,β-unsaturated carbonyl compound based on the experimental and independent events' statistical calculation results. (Chemical Equation Presented).
- Xu, Zhanwei,Yan, Peifang,Xu, Wenjuan,Liu, Xiumei,Xia, Zhi,Chung, Benjamin,Jia, Songyan,Zhang, Z. Conrad
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- A continuously operated bimembrane reactor process for the biocatalytic production of (2R,5R)-hexanediol
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Alcohol dehydrogenase-catalyzed reductions of prochiral ketones to chiral alcohols require the regeneration of consumed cofactors such as NADH or NADPH. In the substrate-coupled cofactor regeneration approach, where 2-propanol is oxidized to acetone, comp
- Schroer, Kirsten,Luetz, Stephan
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- Ruthenium and Formic Acid Based Tandem Catalytic Transformation of Bioderived Furans to Levulinic Acid and Diketones in Water
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Efficient tandem catalytic transformations of bioderived furans, such as furfural, 5-hydroxymethylfurfural (5-HMF), and 5-methylfurfural (5-MF), to levulinic acid (LA) and diketones, 1-hydroxyhexane-2,5-dione (1-HHD), 3-hydroxyhexane-2,5-dione (3-HHD), and hexane-2,5-dione (2,5-HD), was achieved by using water-soluble arene-RuII complexes, containing ethylenediamine-based ligands, as catalysts in the presence of formic acid. The catalytic conversion of furans depends on the catalyst, ligand, formic acid concentration, reaction temperature, and time. Experimental evidence, including time-resolved 1H NMR spectral studies, indicate that the catalytic reaction proceeds first with formyl hydrogenation followed by hydrolytic ring opening of furans. The ruthenium-formic acid tandem catalytic transformation of fructose to diketones and LA was also achieved. Finally, the molecular structures of the four representative arene-RuII catalysts were established by single-crystal X-ray diffraction studies.
- Dwivedi, Ambikesh D.,Gupta, Kavita,Tyagi, Deepika,Rai, Rohit K.,Mobin, Shaikh M.,Singh, Sanjay K.
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- Reversion of Paal-Knorr synthesis: A new strategy for ring-opening and N-substituent change in 1H-pyrroles
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1H-Pyrroles were converted into 1,4-dicarbonyl compounds, and then into 1H-pyrroles with a different N-substituent by heating at 110 °C under nitrogen in 0.3 M sodium citrate buffer, pH 3, and in the presence of alkyl or aryl amines. The new pyrroles were obtained in low to very high yields depending upon the pH, the reaction time, the initial pyrrole and amine involved, and the proportion between both reagents. Georg Thieme Verlag Stuttgart.
- Zamora, Rosario,Hidalgo, Francisco J.
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- Catalytic transformation of bio-derived furans to valuable ketoacids and diketones by water-soluble ruthenium catalysts
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Bio-derived furans such as 2-furfural (furfural), 5-hydroxymethyl-2-furfural (5-HMF) and 5-methyl-2-furfural (5-MF) were successfully transformed to a ketoacid, levulinic acid (LA), and diketones, 1-hydroxyhexane-2,5-dione (1-HHD), 3-hydroxyhexane-2,5-dione (3-HHD) and hexane-2,5-dione (HD), under moderate reaction conditions using water soluble and recyclable 8-aminoquinoline coordinated arene-ruthenium(ii) complexes. Under the optimized reaction conditions using 1 mol% catalyst in the presence of 12 equivalents of formic acid at 80-100 °C, complete conversion of furfural to LA with high selectivity was achieved. Several experiments along with 1H NMR spectral studies are described which provide more insights into the mechanism underlying the transformation of furans to open ring components. Experiments performed using structural analogues of the active catalyst inferred a structure-activity relationship for the observed superior catalytic activity of the 8-aminoquinoline coordinated arene-ruthenium(ii) complex. Furthermore, due to the high aqueous solubility of the studied complexes, high recyclability, up to 4 catalytic runs, was achieved without any significant loss of activity. Molecular identities of the studied 8-aminoquinoline coordinated arene-ruthenium(ii) complex were also confirmed using single-crystal X-ray diffraction studies.
- Gupta, Kavita,Tyagi, Deepika,Dwivedi, Ambikesh D.,Mobin, Shaikh M.,Singh, Sanjay K.
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- Highly efficient and stereoselective biosynthesis of (2S,5S)-hexanediol with a dehydrogenase from Saccharomyces cerevisiae
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The enantiopure (2S,5S)-hexanediol serves as a versatile building block for the production of various fine chemicals and pharmaceuticals. For industrial and commercial scale, the diol is currently obtained through bakers' yeast-mediated reduction of 2,5-hexanedione. However, this process suffers from its insufficient space-time yield of about 4 g L-1 d-1 (2S,5S)-hexanediol. Thus, a new synthesis route is required that allows for higher volumetric productivity. For this reason, the enzyme which is responsible for 2,5-hexanedione reduction in bakers' yeast was identified after purification to homogeneity and subsequent MALDI-TOF mass spectroscopy analysis. As a result, the dehydrogenase Gre2p was shown to be responsible for the majority of the diketone reduction, by comparison to a Gre2p deletion strain lacking activity towards 2,5-hexanedione. Bioreduction using the recombinant enzyme afforded the (2S,5S)-hexanediol with >99% conversion yield and in >99.9% de and ee. Moreover, the diol was obtained with an unsurpassed high volumetric productivity of 70 g L-1 d-1 (2S,5S)-hexanediol. Michaelis-Menten kinetic studies have shown that Gre2p is capable of catalysing both the reduction of 2,5-hexanedione as well as the oxidation of (2S,5S)-hexanediol, but the catalytic efficiency of the reduction is three times higher. Furthermore, the enzyme's ability to reduce other keto-compounds, including further diketones, was studied, revealing that the application can be extended to α-diketones and aldehydes.
- Mueller, Marion,Katzberg, Michael,Bertau, Martin,Hummel, Werner
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- N-Ethyldiisopropylamine and Sulfur Dioxide Solutions. 2. Reactions with Conjugate Acceptors
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Solutions of sulfur dioxide and N-ethyldiisopropylamine (EDIA) are able to reduce α,β-unsaturated-γ-dicarbonyl compounds (esters or ketones) into α-dicarbonyl alkanes.In contrast, monoactivated Michael acceptors, such as acrylates, give symmetrical sulfones.These processes involve the conjugate addition of HSO2(-), formed from a charge-transfer complex between EDIA and SO2.Secondary amines are formed as byproducts.Triethylamine, which forms a more stable complex with sulfur dioxide than EDIA, is far less reactive toward the same substrates.
- Eugene, Fabrice,Langlois, Bernard,Laurent, Eliane
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Read Online
- Initiation and Abstraction Reaction in the Pyrolysis of Acetone
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The rates of the reactions, (CH3)2CO -> CH3 + CH3CO (1) and CH3 + (CH3)2CO -> CH4 + CH2COCH3 (3) have been studied in the flow pyrolysis of acetone at 825-940 K and 10-180 Torr.Yields of products were mesured by gas chromatography.The rate constant, k1, for the initiation reaction, determined from the sum of the yields of the termination products, was observed to be pressure dependent at 928 K.The Arrhenius expression for this reaction at the high-pressure limit (obtained from a nonlinear least-squares fit to the experimental data using the Troe factorization procedure) was found to be k1infinite (s-1) = 1017.9+/-0.8 exp(-353 +/- 14 kJ mol-1/RT).The Troe method has also been used to find the high-pressure limits of the cross-combination ratio for CH3 and CH3COCH2 radicals (1.9 +/- 0.1) and of the qoutient k5/k32, where reaction 5 is 2CH3 -> C2H6.Calculated rate constants for reaction 3, when combined with values reported from photolysis experiments at lower temperatures, were found to exhibit a curved Arrhenius plot.A transition state theory model was fitted to the data for k3 to determine the average transitional vibrational term value in the transition state (279 +/- 8 cm-1), the effective activation barrier height (46 +/- 1 kJ mol-1), and the full width of the barrier at half its height (52 +/- 3 pm).
- Mousavipour, S. Hosein,Pacey, Philip D.
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Read Online
- Electrochemical and photoelectrochemical reduction of furfurals
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Electrochemical cells and photoelectrochemical cells for the reduction of furfurals are provided. Also provided are methods of using the cells to carry out the reduction reactions. Using the cells and methods, furfurals can be converted into furan alcohols or linear ketones.
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Page/Page column 14-15
(2021/05/19)
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- Method for preparing 2, 5-hexanedione
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The invention discloses a method for preparing 2, 5-hexanedione, which is characterized in that a polyhydroxy compound and a derivative thereof are used as substrates, and the 2, 5-hexanedione is obtained through a carbon growth-wacker oxidation reaction under the action of a catalyst and an oxidizing agent. According to the method disclosed by the invention, a large amount of by-product glycerol generated in a biodiesel production process is used as a raw material, so that the production cost of 2, 5-hexanedione can be reduced, and a high-added-value conversion and utilization path is provided for glycerol.
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Paragraph 0031-0053
(2021/06/22)
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- 2,5-hexanedione synthesis method
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The invention provides a 2,5-hexanedione synthesis method, which comprises: carrying out a reaction on tert-butyl acetoacetate and chloroacetone under the action of an alkali to generate tert-butyl 3-acetylmethyl acetoacetate, hydrolyzing under acidic conditions, and deacidifying to obtain 2,5-hexanedione. According to the invention, the method has beneficial effects of low technical cost, easilyavailable raw materials and high yield.
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Paragraph 0018; 0020-0021; 0023-0024
(2020/03/09)
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- Preparation of 1-Hydroxy-2,5-hexanedione from HMF by the Combination of Commercial Pd/C and Acetic Acid
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The development of a simple and durable catalytic system for the production of chemicals from a high concentration of a substrate is important for biomass conversion. In this manuscript, 5-hydroxymethylfurfural (HMF) was converted to 1-hydroxy-2,5-hexanedione (HHD) using the combination of commercial Pd/C and acetic acid (AcOH) in water. The influence of temperature, H2 pressure, reaction time, catalyst amount and the concentration of AcOH and HMF on this transformation was investigated. A 68% yield of HHD was able to be obtained from HMF at a 13.6 wt% aqueous solution with a 98% conversion of HMF. The resinification of intermediates on the catalyst was characterized to be the main reason for the deactivation of Pd/C. The reusability of the used Pd/C was studied to find that most of the activity could be recovered by being washed in hot tetrahydrofuran.
- Duan, Ying,Yang, Dexi,Yang, Yanliang,Zhang, Chi,Zheng, Min
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- Method for preparing N-aryl pyrrole compound
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The present invention relates to a method for preparing an N-aryl pyrrole compound. Furan containing different substituents, aromatic amine containing different substituents and a solid Lewis acid catalyst are mixed and placed in a closed reactor, and an N-aryl pyrrole compound with different substituents is prepared under certain catalytic conditions. The reaction temperature of the catalytic reaction condition is 140-210 DEG C. The solid Lewis acid catalyst is prepared by a sol-gel method, Hf is used as a core metal element, and a mesoporous molecular sieve SBA-15 is used as a carrier. According to the method, the catalyst is simple to prepare, low in cost, high in reaction activity, good in water resistance and structural stability and high in catalytic reaction yield; meanwhile, the Lewis acid type catalyst does not generate acid protons, the corrosion of the catalyst to equipment at high temperature is avoided, the post-reaction treatment is convenient, and the catalyst is renewable and environment-friendly.
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Paragraph 0062-0064
(2020/09/09)
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- Method for preparing 2,5-acetonyl acetone
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The invention relates to a method for preparing 2,5-acetonyl acetone from raw biomass, paper products, cotton products and lignocellulose platform chemical compounds. A reaction system is an acid water solution and organic solvent two-phase system; a catalyst is a supported noble metal catalyst; under the conditions of certain temperature and hydrogen gas pressure, the raw biomass, the paper products, the cotton products and the lignocellulose platform chemical compounds can be used for preparing 2,5-acetonyl acetone products with high yield in one step. The method has the characteristics of mild reaction temperature and high product selectivity; an effective path for preparing the 2,5-acetonyl acetone from biomass is provided.
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Paragraph 0023-0026
(2019/07/04)
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- Selective conversion of 5-hydroxymethylfurfural to diketone derivatives over Beta zeolite-supported Pd catalysts in water
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Conversion of 5-hydroxymethylfurfural (HMF) in water to the linear diketone derivatives 1-hydroxyhexane-2,5-dione (HHD) and 2,5-hexanedione (HXD) was investigated over a series of Beta zeolite-supported transition metal catalysts (Co, Ni, Cu, Ru, Pd). Their catalytic performance was tested in a batch stirred reactor (T = 110 °C, PH2 = 20 bar) with Pd showing the highest activity and selectivity to HHD and HXD. The effects of Pd particle size, zeolite Si/Al ratio and reaction conditions (T = 80–155 °C, PH2 = 5–60 bar) were also investigated. The incorporation of Pd into Beta zeolite by the deposition-coprecipitation method produced the most efficient catalyst, affording complete HMF conversion (T = 110 °C, PH2 = 60 bar) predominantly to HHD (68% selectivity) and HXD (8% selectivity). The combination of a bifunctional acid/redox solid catalyst and water enhances the hydrolytic ring-opening and subsequent hydrogenation of the furan ring. Catalytic activity can be partially restored by a simple regeneration treatment. This work establishes a catalytic route to produce valuable diketone derivatives from renewable furanic platform sources in water.
- Ramos, Rubén,Grigoropoulos, Alexios,Griffiths, Ben L.,Katsoulidis, Alexandros P.,Zanella, Marco,Manning, Troy D.,Blanc, Frédéric,Claridge, John B.,Rosseinsky, Matthew J.
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p. 224 - 233
(2019/06/19)
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- Efficient Palladium(0) supported on reduced graphene oxide for selective oxidation of olefins using graphene oxide as a ‘solid weak acid’
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Selective oxidation of olefin derivatives to ketones has made innovative development over palladium(0) supported on reduced graphene oxide. Compared to traditional Wacker oxidation, the novel method offers an economical and environment-friendly option by using graphene oxide (GO) as a ‘solid weak acid’ instead of classical homogeneous catalysts like H2SO4 and CF3COOH. X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscope and transmission electron microscopy images of Pd0/RGO showed that the nanoscaled Pd particles generated at the flake structure of reduced graphene oxide. Under optimized condition, up to 44 kinds of ketones with different structures can be prepared with excellent yields.
- Gao, Xi,Zhou, Jianhao,Peng, Xinhua
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- Synthesis of gamma dicarbonyl and pyrrole compounds
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The present invention discloses processes for producing γ-dicarbonyl compounds by contacting an aldehyde compound, an α,β-unsaturated carbonyl compound, and a catalyst composition in the presence of an amide diluent. The resultant γ-dicarbonyl compounds then can be used to synthesize pyrrole compounds, such as 2,5-dimethylpyrrole.
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Page/Page column 18-19
(2019/03/01)
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- Switching on the activity of 1,5-diaryl-pyrrole derivatives against drug-resistant ESKAPE bacteria: Structure-activity relationships and mode of action studies
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Antibiotic resistance represents a major threat worldwide. Gram-positive and Gram-negative opportunistic pathogens are becoming resistant to all known drugs mainly because of the overuse and misuse of these medications and the lack of new antibiotic development by the pharmaceutical industry. There is an urgent need to discover structurally innovative antibacterial agents for which no pre-existing resistance is known. This work describes the identification, synthesis and biological evaluation of a novel series of 1,5-diphenylpyrrole compounds active against a panel of ESKAPE bacteria. The new compounds show high activity against both wild type and drug-resistant Gram + ve and Gram-ve pathogens at concentrations similar or lower than levofloxacin. Microbiology studies revealed that the plausible target of the pyrrole derivatives is the bacterial DNA gyrase, with the pyrrole derivatives displaying similar inhibitory activity to levofloxacin against the wild type enzyme and retaining activity against the fluoroquinolone-resistant enzyme.
- Masci, Domiziana,Hind, Charlotte,Islam, Mohammad K.,Toscani, Anita,Clifford, Melanie,Coluccia, Antonio,Conforti, Irene,Touitou, Meir,Memdouh, Siham,Wei, Xumin,La Regina, Giuseppe,Silvestri, Romano,Sutton, J. Mark,Castagnolo, Daniele
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p. 500 - 514
(2019/06/18)
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- Insight into the hydrogenation of pure and crude HMF to furan diols using Ru/C as catalyst
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5-hydroxymethylfurfural (HMF) is one of the most important renewable platform-chemicals, a very valuable precursor for the synthesis of bio-fuels and bio-products. In this work, the hydrogenation of HMF to two furan diols, 2,5-bis(hydroxymethyl)furan (BHMF) and 2,5-bis(hydroxymethyl)tetrahydrofuran (BHMTHF), both promising renewable monomers, was investigated. Three commercial catalysts, Ru/C, Pd/C and Pt/C, were tested in the hydrogenation of aqueous HMF solutions (2–3 wt%), using a metal loading of 1 wt% respect to HMF content. By appropriate tuning of the process conditions, either BHMF or BHMTHF were obtained in good yields, and Ru/C resulted the best catalyst for this purpose, allowing us to obtain BHMF or BHMTHF yields up to 93.0 and 95.3 mol%, respectively. This catalyst was also tested for in the hydrogenation of a crude HMF-rich hydrolyzate, obtained by one-pot the dehydration of fructose. The influence of each component of this hydrolyzate on the hydrogenation efficiency was investigated, including unconverted fructose, rehydration acids and humins, in order to improve the yields towards each furan diol. Moreover, ICP-OES and TEM analysis showed that the catalyst was not subjected to important leaching and sintering phenomena, as further confirmed by catalyst recycling study.
- Fulignati, Sara,Antonetti, Claudia,Licursi, Domenico,Pieraccioni, Matteo,Wilbers, Erwin,Heeres, Hero Jan,Raspolli Galletti, Anna Maria
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p. 122 - 133
(2019/04/17)
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- Preparation method of benzofuran compound
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The invention relates to a preparation method of a benzofuran compound. The preparation method comprises the following steps: putting a furan compound, acetic acid and a Lewis acid catalyst in a reaction vessel, reacting for 0.5-24 h at 80-160 DEG C, and separating and purifying to obtain the benzofuran compound. According to the preparation method provided by the invention, the furan compound isused as a reaction raw material, an acetic acid water solution is used as a solvent, Lewis acid is used as a catalyst, and at a mild reaction temperature (80-160 DEG C), the benzofuran compound is directly obtained through one-step reaction. The preparation method provided by the invention can synthesize the benzofuran compound with a corresponding structure and functional groups based on the structure and functional groups of the furan compound as a raw material, the raw material components are simple , and the process is convenient to operate; wherein the selectivity of the obtained benzofuran is as high as 99% in the process of synthesizing benzofuran by using furan, so that the method has industrial application prospects.
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Paragraph 0110-0113
(2019/04/04)
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- Toward an Integrated Conversion of 5-Hydroxymethylfurfural and Ethylene for the Production of Renewable p-Xylene
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The use of biomass as a solution to satisfy the pressing needs for a fully sustainable biocommodity industry has been explored for a long time. However, limited success has been obtained. In this study, a highly effective two-stage procedure for the direct preparation of para-xylene (PX) from 5-hydroxymethylfurfural (HMF) and formic acid in one pot is described; these chemicals are two of the major bio-based feedstocks that offer the potential to address urgent needs for the green, sustainable production of drop-in chemical entities. The use of a robust, efficient heterogeneous catalyst, namely, bimetallic Pd-decorated Au clusters anchored on tetragonal-phase zirconia, is crucial to the success of this strategy. This multifunctional catalytic system can not only facilitate a low-energy-barrier H2-free pathway for the rapid, nearly exclusive formation of 2,5-dimethylfuran (DMF) from HMF but also enable the subsequent ultraselective production of PX by the dehydrative aromatization of the resultant DMF with ethylene. With increasing pressure around the world to move toward a bio-based economy, it is essential that industrially important commodity chemicals can be readily accessed from biomass resources. Para-xylene (PX) synthesis is one such target that is being actively pursued through the development of several biorefinery schemes based on integrated biomass processing. Significant progress has recently been achieved either in the selective synthesis of biorenewable PX from Diels-Alder-like coupling of ethylene with 2,5-dimethylfuran (DMF) or making DMF from 5-hydroxymethylfurfural (HMF) using hydrogen as the terminal reductant. However, a green and direct conversion of HMF, an essential feedstock source for future biorefinery schemes, into PX has yet to be developed. We have established an integrated process that directly converts HMF to PX in a highly compact and hydrogen-independent manner, thereby providing a new perspective on the potential of advanced biorefinery technologies. Cao and colleagues describe an alternative strategy for producing para-xylene through a more sustainable method than the current bio-based approaches. The strategy relies on an integrated conversion of 5-hydroxymethylfurfural with formic acid and ethylene, made possible by the use of a single multifunctional catalyst based on bimetallic Pd-decorated Au deposited on tetragonal-phase zirconia. The proposed process is particularly appealing because it is fully fossil independent, implying a viable and greener biorefinery scheme.
- Tao, Lei,Yan, Tian-Hao,Li, Wenqin,Zhao, Yi,Zhang, Qi,Liu, Yong-Mei,Wright, Mark M.,Li, Zhen-Hua,He, He-Yong,Cao, Yong
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supporting information
p. 2212 - 2227
(2018/10/02)
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- Cyclopentadienyl-Ru(II)-Pyridylamine Complexes: Synthesis, X-ray Structure, and Application in Catalytic Transformation of Bio-Derived Furans to Levulinic Acid and Diketones in Water
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A series of cationic half-sandwich cyclopentadienyl-ruthenium(II)-pyridylamine complexes, [(η5-C5H5)Ru(κ2-L)(PPh3)]+ (L = Namine-substituted pyridylamine ligands) ([Ru]-1-[Ru]-6), along with the analogous cyclopentadienyl-ruthenium(II)-N-isopropylpyridylimine complex [(η5-C5H5)Ru(κ2-L)(PPh3)]+ (L = N-isopropylpyridylimine) ([Ru]-7), have been synthesized in good yields. Structural identities of all the complexes have been authenticated by 1H, 13C, and 31P NMR, mass spectrometry, and X-ray crystallography. The synthesized complexes exhibited high catalytic activity for the transformation of the bio-derived furans, 2-furfural (furfural), 5-methyl-2-furfural (5-MF), and 5-hydroxymethyl-2-furfural (5-HMF) to levulinic acid (LA) and the diketones, 3-hydroxyhexane-2,5-dione (3-HHD), 1-hydroxyhexane-2,5-dione (1-HHD), and hexane-2,5-dione (HD) in water. Efficient transformation of furfural to LA over a range of η5-Cp-Ru-pyridylamine complexes is substantially affected by the Namine-substituents, where a η5-Cp-Ru-N-propylpyridylamine complex ([Ru]-2) exhibited higher catalytic activity in comparison to other η5-Cp-Ru-pyridylamine and η5-Cp-Ru-pyridylimine complexes. The relative catalytic activity of the studied complexes demonstrated a substantial structure-activity relationship which is governed by the basicity of Namine, steric hindrance at Namine, and the hemilabile nature of the coordinated pyridylamine ligands.
- Dwivedi, Ambikesh D.,Sahu, Vinod K.,Mobin, Shaikh M.,Singh, Sanjay K.
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supporting information
p. 4777 - 4787
(2018/04/25)
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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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- Method for coupling and synthesizing 2, 5-hexanedione by oxidative dehydrogenation of acetone
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The invention discloses a method for coupling and synthesizing 2, 5-hexanedione by oxidative dehydrogenation of acetone. According to the method, hydrogen peroxide solution and photocatalyst are added into acetone-water reaction liquid, vacuum pumping is performed in a magnetic stirring manner, or nitrogen is led, air in a system is removed, and photocatalysis/ photochemical decomposition of hydrogen peroxide is performed under the condition of an ultraviolet lamp or a visible light source, so that carbon-carbon coupling of the acetone is initiated to synthesize the 2, 5-hexanedione. The method is a green synthetic route, performed under normal temperature and pressure, easy to operate, high in economic benefit and suitable for industrial production.
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Paragraph 0026; 0027; 0028; 0029; 0030; 0031; 0032-0043
(2017/07/21)
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- Poisoning of Ru/C by homogeneous Br?nsted acids in hydrodeoxygenation of 2,5-dimethylfuran via catalytic transfer hydrogenation
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It has been proposed that the combination of metal and acid sites is critical for effective ring opening of biomass-derived furans to linear molecules, a reaction that holds promise for the production of renewable polymer precursors and alkanes. In this work, we use 2,5-dimethylfuran (DMF) as a model compound to investigate hydrogenolysis and hydrogenation pathways using a combination of H2SO4 and Ru-mediated catalytic transfer hydrogenation in 2-propanol. Acid-catalyzed hydrolytic ring opening of DMF to 2,5-hexanedione (HDN) occurs readily at 80?°C with a selectivity of 89% in 2-propanol. Over Ru/C, HDN is fully converted after only 2?h at 80?°C, forming a mixture of both ring-closed products (~68% total yield), i.e., 2,5-dimethyltetrahydrofuran (DMTHF) and 2,5-dimethyl-2,3-dihydrofuran (DMDHF), as well as ring opened products (~28% total yield), i.e., 2,5-hexanediol (2,5-HDL) and 2-hexanol (HOL). Rather than observing sequential hydrolysis/hydrogenation reactions, we observe severe suppression of metal chemistry when having both Ru/C and H2SO4 in the reaction system. While minor leaching of Ru occurs in the presence of mineral acids, X-ray photoelectron spectroscopy coupled with CO chemisorption studies suggest that the primary cause of the lack of Ru-mediated chemistry is poisoning by strongly adsorbed sulfate species. This hypothesis is supported by the observation of Ru-catalyzed chemistry when replacing H2SO4 with Nafion, a solid Br?nsted acid, as sulfonic acid groups tethered to the polymer backbone cannot adsorb on the metal sites.
- Gilkey, Matthew J.,Vlachos, Dionisios G.,Xu, Bingjun
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p. 327 - 335
(2017/06/19)
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- Conversion of HMF to methyl cyclopentenolone using Pd/Nb2O5 and Ca-Al catalysts: Via a two-step procedure
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The catalytic conversion of HMF to 2-hydroxy-3-methyl-2-cyclopenten-1-one (MCP), which is a valuable edible essence that has traditionally been obtained from adipic acid, was achieved with an isolated yield of 58%. This procedure comprised two steps: the hydrogenation of 5-hydroxymethylfurfural (HMF) to 1-hydroxy-2,5-hexanedione (HHD) in water on Pd/Nb2O5 catalysts and then the isomerization of HHD to MCP in the presence of a base. The Nb2O5 supports, which were acidic, were characterized by FTIR, XRD and NH3-TPD. The supported Pd/Nb2O5 catalysts, in which Pd was highly dispersed, were synthesized employing cyclohexene as a reductant and were characterized by XRD, TEM, ICP-AES, XPS, EDX and CO pulse chemisorption. The high conversion of HMF was attributed to the high dispersion of Pd, and the acidity of the supports led to high selectivity for HHD. The conversion of HHD to MCP was an intramolecular aldol condensation reaction, and the protonic solvent favored this reaction. Ca-Al was proved to be an effective solid base for the conversion of HHD to MCP in water.
- Duan, Ying,Zheng, Min,Li, Dongmi,Deng, Dongsheng,Ma, Lu-Fang,Yang, Yanliang
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p. 5103 - 5113
(2017/11/09)
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- (OTf)2 as a homogeneous catalyst for the hydrogenation of biomass derived 2,5-hexanedione and 2,5-dimethyl-furan in aqueous acidic medium
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The complex [Ru(triphos)(CH3CN)3](OTf)2 is an effective catalyst for the hydrogenation of 2,5-hexanedione and 2,5-dimethyl-furan in aqueous acidic medium at temperatures between 150 and 200 °C realizing up to 96% combined yields of 2,5-hexanediol and 2,5-dimethyl-tetrahydrofuran with the product distribution being sensitive to the amount of acid co-catalyst (HOTf) present. For the furan, the reaction pathway is through an acid-catalyzed hydrolysis to the dione rather than direct hydrogenation of the ring. The hydrogenation of the dione shows a first order dependence on hydrogen pressure as determined by direct hydrogen uptake rate measurements at temperature and pressure (1.38-6.90 MPa at 150 °C) and is postulated to operate through a heterolytic activation of hydrogen gas by [Ru(H)x(triphos)(Y)y]n+ (Y = solvent, water, counter ion) species formed in situ by loss and hydrogenation of the nitrile ligands. In water the catalyst is deactivated by dimerization to [Ru2(μ-OH)3(triphos)2](OTf).
- Latifi, Elnaz,Marchese, Austin D.,Hulls, Margaret C.W.,Soldatov, Dmitriy V.,Schlaf, Marcel
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p. 4666 - 4679
(2017/10/13)
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- A Pd-Catalyzed in situ domino process for mild and quantitative production of 2,5-dimethylfuran directly from carbohydrates
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An in situ domino process has been developed to be highly efficient for direct and mild conversion of various hexose sugars to the biofuel 2,5-dimethylfuran in almost quantitative yields, without separation of unstable intermediates at 120 °C in n-butanol, by using polymethylhydrosiloxane and hydrophobic Pd/C as a H-donor and a bifunctional catalyst, respectively. Among the cascade reactions, the hydrosilylation process was confirmed by deuterium-labeling and kinetic studies to be favorable for sugar dehydration and exclusively acts on deoxygenation of in situ formed intermediates including furanic alcohols and aldehydes to DMF via a hydride transfer process that was facilitated by an alcoholic solvent. The catalytic system is more selective than the H2- participated counterpart, and could be scaled up with only 0.04 mol% catalyst loading, giving DMF in a comparable yield of 85%. Moreover, Pd(0) was demonstrated to be the active species for deoxygenation, and the heterogeneous catalyst exhibited good recyclability with little elemental leaching.
- Li, Hu,Zhao, Wenfeng,Riisager, Anders,Saravanamurugan, Shunmugavel,Wang, Zhongwei,Fang, Zhen,Yang, Song
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supporting information
p. 2101 - 2106
(2017/07/22)
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- Effect of Cp*Iridium(III) Complex and acid co-catalyst on conversion of furfural compounds to cyclopentanones or straight chain ketones
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In this paper, Cp*Ir (III) Complex and acid co-catalyst system was developed. By using Cp*Ir and γ-Al2O3 (Lewis acid), 5-hydroxymethylfurfural (5-HMF) can be converted efficiently to 3-hydroxymethyl cyclopentanone (HCPN). Meanwhile, Cp*Ir and Br?nsted acid can promote conversion of 5-HMF to 1-Hydroxy-2,5-hexanedione (HHD). The effect of Lewis acid and Br?nsted acid on the hydrogenation of furan derivatives was studied. Mechanism of conversion of 5-HMF to HCPN was discussed in detail and mechanism proposed by our predecessors was revised. Instead of being an intermediate for the formation of HCPN, it is believed that, HHD is a product of another reaction pathway. HHD condensed via Aldol reaction to produce 3-methylcyclopenten-2-ol-1-one (MCP) instead of HCPN. Under the promotion of Lewis acid, 5-HMF firstly convert to the precursor of HHD. After that, the reaction is through 4 π-electrocyclic ring closure process and HCPN was formed ultimately. Furthermore, we found that our Cp*Ir and acid co-catalyst system is suitable for a variety of furfural compounds. By using Cp*Ir, Br?nsted acid can promote conversion of furfural compounds to straight chain ketones and Lewis acid can promote the rearrangement of furfural compounds to cyclopentanone derivatives.
- Xu, Yong-Jian,Shi, Jing,Wu, Wei-Peng,Zhu, Rui,Li, Xing-Long,Deng, Jin,Fu, Yao
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p. 266 - 273
(2017/07/13)
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- Effect of silica content on production of p-Xylene from dimethylfuran/ethylene over mesoporous SiO2-Al2O3 catalysts
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Mesoporous SiO2-Al2O3 (SA) catalysts with different SiO2 contents were prepared, for the selective production of p-xylene from dimethylfuran/ethylene through the combination of cycloaddition and dehydrative aromatization reactions, by a co-precipitation method. For comparison, commercial SiO2-Al2O3 and ZSM-5 zeolites (Si/Al2 = 30, Si/Al2 = 80) were also employed as catalysts in the same reaction. The pore size of the catalysts played an important role in determining the catalytic performance in the production of p-xylene. Among the catalysts tested, the order of the yield and production rate of p-xylene was as follows: mesoporous SA > commercial SiO2-Al2O3 > commercial ZSM-5. In the mesoporous SA catalysts in particular, p-xylene yields showed a volcano-shaped trend with respect to the catalyst's SiO2 content. The SA-60 catalyst, with SiO2 = 52.3, showed the highest yield (75%) and production rate (57.7 mmol/g-cat · h) because of a catalyst structure with moderate pore size, which prevented side reactions.
- Lee, Jin Sil,Kim, Sang Yun,Kim, Tae-Wan,Jeong, Soon-Young,Kim, Chul-Ung,Lee, Kwan-Young
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p. 2695 - 2699
(2017/03/09)
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- Selective hydrodeoxygenation of 5-hydroxymethylfurfural to 2,5-dimethylfuran on Ru-MoOx/C catalysts
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Selective hydrogenation of 5-hydroxymethylfurfural (HMF) has potential application in high quality biofuels. Herein, the catalytic hydrodeoxygenation (HDO) of HMF to 2,5-dimethylfuran (DMF) was investigated using bi-functional Ru-MoOx/C catalyst prepared by initial wetness impregnation. The high dispersion and electronic transfer between Ru and MoOx were demonstrated by a series of characterization techniques. During this HDO process, the synergy effect between metallic Ru and acidic MoOx species in the Ru-MoOx/C catalyst plays an essential role in obtaining maximized target product DMF (79.4%) via effective aldehyde group hydrogenation by Ru followed by dehydration over MoOx. This work also elucidated that DMF production proceeded through two distinct pathways: the 2,5-hydroxymethyl furan intermediate was preferable by the aldehyde group hydrogenation of HMF over the Ru-MoOx/C catalyst. Over MoOx/C catalyst, comparatively, 5-methyl furfural was the key intermediate by direct hydrogenolysis of the hydroxyl group in HMF. This kind of catalyst is stable for the first two runs by maintaining the target product yield. After the third run, the catalyst showed deactivation gradually but could be almost completely recovered after regeneration by H2 reduction.
- Yang, Yue,Liu, Qiying,Li, Dan,Tan, Jin,Zhang, Qi,Wang, Chenguang,Ma, Longlong
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p. 16311 - 16318
(2017/03/24)
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- Highly efficient and green oxidation of alkanes and alkylaromatics with hydrogen peroxide catalysed by silver and vanadyl on mesoporous silica-coated magnetite
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A heterogeneous catalyst (FeSi/Ag/VO) based on silver and vanadyl as active sites and mesoporous silica-coated nanospheres of magnetite (Fe3O4@m-SiO2) as support was successfully prepared by deposition of Ag nanoparticles and the covalent grafting of vanadyl(IV) acetylacetonate on Fe3O4@m-SiO2. The catalyst exhibited excellent activity for the oxidation of alkanes, benzene and alkylaromatics using green oxidant H2O2 and oxalic acid in acetonitrile at 60?°C.
- Nouri, Seyed Hadi,Hosseini-Monfared, Hassan
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- METAL OXIDE-ORGANIC HYBRID MATERIALS FOR HETEROGENEOUS CATALYSIS AND METHODS OF MAKING AND USING THEREOF
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Catalysts prepared from abundant, cost effective metals, such as cobalt, nickel, chromium, manganese, iron, and copper, and containing one or more neutrally charged ligands (e.g., monodentate, bidentate, and/or polydentate ligands) and methods of making and using thereof are described herein. Exemplary ligands include, but are not limited to, phosphine ligands, nitrogen-based ligands, sulfur-based ligands, and/or arsenic-based ligands. In some embodiments, the catalyst is a cobalt-based catalyst or a nickel-based catalyst. The catalysts described herein are stable and active at neutral pH and in a wide range of buffers that are both weak and strong proton acceptors. While its activity is slightly lower than state of the art cobalt-based water oxidation catalysts under some conditions, it is capable of sustaining electrolysis at high applied potentials without a significant degradation in catalytic current. This enhanced robustness gives it an advantage in industrial and large-scale water electrolysis schemes.
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Paragraph 0209
(2016/06/28)
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- Cooperative catalysis of Pt/C and acid resin for the production of 2,5-dimethyltetrahydrofuran from biomass derived 2,5-hexanedione under mild conditions
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Conversion of biomass into 2,5-dimethyltetrahydrofuran (DMTHF), an excellent fuel additive, solvent, and industrial intermediate, is an important reaction in green chemistry. In this work, different combinations of supported metal catalysts and solid acids were investigated for the synthesis of DMTHF from biomass derived diketone (2,5-hexanedione, 2,5-HD). The results showed that commercial Pt/C and solid acid AmberliteIR-120H had an excellent cooperative effect on the reaction. 2,5-HD could be converted into DMTHF with a yield up to 99% under milder conditions. Further experiments indicated that 2,5-hexanediol (2,5-HDO) is a key intermediate in the reaction. The catalyst system could be facilely recovered due to the heterogeneity and reused several times without notable change in the performance.
- Zhou, Huacong,Song, Jinliang,Meng, Qinglei,He, Zhenhong,Jiang, Zhiwei,Zhou, Baowen,Liu, Huizhen,Han, Buxing
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supporting information
p. 220 - 225
(2015/12/31)
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- Method for synthesizing 2,5-hexanedione by two-phase process
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The invention provides a method for synthesizing 2,5-hexanedione by a two-phase process, which comprises the steps of mixing 2,5-dimethylfuran with a weak-polarity organic solvent, adding an aqueous solution of an acid catalyst, quenching a reaction system, quickly cooling the system temperature to the room temperature, and taking the reaction liquid out, wherein the reaction temperature is 60 to 180 DEG C, and the reaction time is 30 minutes to 24 hours. An organic phase is split; an aqueous phase is filtered or separated through centrifugation; organic phases are collected. The obtained organic phases are subjected to reduced pressure distillation, and the organic solvent is removed so that the product 2,5-hexanedione is obtained. The method has the advantages of efficiency, economy, environment friendliness, and high yield.
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Paragraph 0026; 0027
(2016/10/08)
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- Ruthenium-8-quinolinethiolate-phenylterpyridine versus ruthenium-bipyridine-phenyl-terpyridine complexes as homogeneous water and high temperature stable hydrogenation catalysts for biomass-derived substrates
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[(4′-Ph-terpy)(bipy)Ru(L)](OTf)n and [(4′-Ph-terpy)(quS)Ru(L)](OTf)n (n = 0 or 1 depending on the charge of L, L = labile ligand, e.g., H2O, CH3CN or OTf, bipy = 2,2′-bipyridine, quS = quinoline-8-thiolate) have been evaluated as catalysts for the hydrogenation of the biomass-derivable C6-substrates 2,5-dimethylfuran (obtainable from 5-hydroxymethylfurfural) and 2,5-hexanedione (the hydrolysis product of 2,5-dimethylfuran). Operating in aqueous acidic medium at T = 175-225 °C the bipy complex is only marginally active, while the quinoline-8-thiolate complex realizes yields of hydrogenated products up to 97% starting from 2,5-hexanedione and up to 66% starting from 2,5-dimethylfuran. The catalyst can also convert the 5-HMF derived acetone 4-(5-methyl-2-furanyl)-3-buten-2-one into 2,5,8-nonatriol, a potentially valuable cross-linker for polymer formulations. On the basis of DFT calculations, the higher activity of the quinoline-8-thiolate complex is proposed to be rooted in a metal-ligand bifunctional mechanism for the heterolytic activation and transfer of dihydrogen to the carbonyl substrate with the hydride-thiol complex [(4′-Ph-terpy)(quSH)Ru(H)]+ as the active catalyst.
- Sullivan, Ryan J.,Kim, Jin,Hoyt, Caroline,Silks, Louis A.,Schlaf, Marcel
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p. 104 - 114
(2016/04/26)
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- Method for preparing 2,5-hexanedione under catalysis of solid acid
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The invention provides a method for preparing 2,5-hexanedione under the catalysis of solid acid. The method comprises the following steps: adding an organic solvent with weak polarity, a solid acid catalyst and distilled water into a raw material 2,5-dimethylfuran and carrying out a reaction at a temperature of 80 to 200 DEG C for 1 to 12 h; quenching a reaction system so as to allow the temperature of the system to rapidly drop to normal temperature, taking out a reaction solution, then subjecting the reaction solution to filtering or centrifugation, drying the solid catalyst and recovering the dried solid catalyst; and collecting an organic phase, subjecting the obtained organic phase to reduced-pressure distillation and removing the organic solvent so as to obtain 2,5-hexanedione. The method provided by the invention has the advantages of easiness in separation and no pollution.
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Paragraph 0047; 0048
(2016/10/31)
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- Method for catalytically preparing 2, 5-hexanedione
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The invention discloses a method for catalytically preparing 2, 5-hexanedione. The method includes steps of adding ethyl acetate, solid acid catalysts and distilled water into 2, 5-dimethylfuran which is used as a raw material and carrying out reaction for 4-8 hours at the temperature of 110-150 DEG C; quenching a reaction system after reaction is completely carried out, rapidly reducing the temperature of the system until the temperature of the system reaches the normal temperature, taking out reaction liquid, filtering the reaction liquid, drying the solid catalysts, repeatedly recycling and applying the solid catalysts and carrying out reduced pressure distillation and refinement on filtrate to obtain the 2, 5-hexanedione which is a target product. A method for preparing modified nanometer attapulgite includes steps of dispersing, by weight, 35-45 parts of nanometer attapulgite in 40-50 parts of sodium hydroxide solution with the mass fraction of 10-20%; heating the sodium hydroxide solution until the temperature of the sodium hydroxide solution reaches 50-60 DEG C; stirring the sodium hydroxide solution for 20-30 min; adjusting the stirring speeds so that the stirring speeds are 200-240 r/min; adding 10-20 parts of metasilicic acid into the solution; adjusting the rotational speeds so that the rotational speeds are 300-500 r/min; carrying out stirring reaction for 2-4 h to obtain reaction products; cooling and then filtering the reaction products; drying the reaction products to obtain the modified nanometer attapulgite. The method for catalytically preparing the2, 5-hexanedione has the advantages that the method for catalytically preparing the 2, 5-hexanedione is simple and is easy to implement and high in conversion rate; the solid catalysts can be repeatedly applied after being separated from the reaction liquid.
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Paragraph 0016; 0017; 0018; 0019; 0020; 0021; 0022-0038
(2017/06/22)
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- From Biomass-Derived Furans to Aromatics with Ethanol over Zeolite
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We report a novel catalytic conversion of biomass-derived furans and alcohols to aromatics over zeolite catalysts. Aromatics are formed via Diels–Alder cycloaddition with ethylene, which is produced in situ from ethanol dehydration. The use of liquid ethanol instead of gaseous ethylene, as the source of dienophile in this one-pot synthesis, makes the aromatics production much simpler and renewable, circumventing the use of ethylene at high pressure. More importantly, both our experiments and theoretical studies demonstrate that the use of ethanol instead of ethylene, results in significantly higher rates and higher selectivity to aromatics, due to lower activation barriers over the solid acid sites. Synchrotron-diffraction experiments and proton-affinity calculations clearly suggest that a preferred protonation of ethanol over the furan is a key step facilitating the Diels–Alder and dehydration reactions in the acid sites of the zeolite.
- Teixeira, Ivo F.,Lo, Benedict T. W.,Kostetskyy, Pavlo,Stamatakis, Michail,Ye, Lin,Tang, Chiu C.,Mpourmpakis, Giannis,Tsang, Shik Chi Edman
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supporting information
p. 13061 - 13066
(2016/10/30)
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- Method for preparing 2,5-hexanedione and 3-methyl cyclopentenone from 5-hydroxymethyl furfural
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The invention provides a method for preparing 2,5-hexanedione and 3-methyl cyclopentenone from 5-hydroxymethyl furfural. The method includes the following steps that after 5-hydroxymethyl furfural, a reducing agent and a solvent are mixed, in an inert atmosphere, a hydrothermal reaction is conducted at the temperature of 100-250 DEG C; after the hydrothermal reaction is completed, the product is subjected to solid-liquid separation, and 2,5-hexanedione and 3-methyl cyclopentenone are harvested. Compared with the prior art, the method has the following advantages that a biomass derivative 5-hydroxymethyl furfural is used as a raw material for synthesizing 2,5-hexanedione and 3-methyl cyclopentenone, 5-hydroxymethyl furfural can be prepared from biomass resource lignocellulose (coming from plants widely existing in the nature), fossil energy does not need to be consumed, and global energy problems at present can be partially relieved.
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Paragraph 0028; 0029; 0030; 0031; 0032
(2016/12/01)
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- METHODS OF PRODUCING ALKYLFURANS
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Provided herein are methods of producing dialkylfurans, such as 2,5-dimethylfuran, and other alkyl furans, such as 2-methylfuran. For example, 2,5-dimethylfuran may be produced by hydrogenation of (5-methylfuran-2-yl) methanol or 2-(chloromethyl)-5-methylfuran in the presence of a solid supported metal catalyst having an excess of either basic or acidic sites (as determined by chemisorption of CO2 or NH3). The process could further include a urea reagent (TMU, DMPU, TMI) and an alkyl benzene.
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Paragraph 0303; 0304
(2016/02/29)
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- Simultaneous hydrogenation and acid-catalyzed conversion of the biomass-derived furans in solvents with distinct polarities
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Furfural and 5-hydroxymethylfurfural (HMF), the two typical biomass-derived furans, can be converted into biofuels and value-added chemicals via hydrogenation or acid catalysis or both. The potential competition between the hydrogenation and the catalyzed-conversion of HMF and furfural has been investigated with Pd/C and Amberlyst 70 as the catalysts at 170°C in various solvents. In water, the hydrogenation of HMF or the derivatives of HMF could take place, but the acid-catalyzed conversion of HMF to the diketones (2,5-hexanedione) was the dominant reaction pathway. On the contrary, with ethanol as the solvent, the full hydrogenation of HMF to 2,5-tetrahydrofurandimethanol was the dominant route, and the acid-catalyzed routes became insignificant. The efficiency for hydrogenation of HMF was much higher in ethanol than in water. As for furfural, its hydrogenation proceeded more efficiently in the polar solvents (i.e. ethanol, diethyl ether) than in non-polar solvents (i.e. toluene): a polar solvent tended to favor the hydrogenation of the furan ring in furfural over that of the carbonyl group in the same furfural.
- Hu, Xun,Kadarwati, Sri,Song, Yao,Li, Chun-Zhu
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p. 4647 - 4656
(2016/01/29)
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- Lewis acid zeolites for tandem Diels-Alder cycloaddition and dehydration of biomass-derived dimethylfuran and ethylene to renewable p-xylene
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Lewis acid zeolites including Zr-, Sn-, and Ti-BEA were examined for tandem [4 + 2] Diels-Alder cycloaddition of 2,5-dimethylfuran (DMF) and ethylene to oxanorbornene with subsequent dehydration to produce biorenewable p-xylene. Zr-BEA (Si/Zr = 168) exhibited superior performance with improved recalcitrance to deactivation, which was attributed to its low activity for the hydrolysis of DMF to 2,5-hexanedione and subsequent condensation. Zr-BEA also achieved the highest selectivity to p-xylene of 90% at 99% conversion of DMF. For low catalyst loading within a three-phase reactor, the reaction rate to form p-xylene was linearly proportional to the number of Lewis acid sites, while high catalyst loading exhibited zero order dependence on Lewis acid sites. A maximum achievable reaction rate was shown to be consistent with a transition in rate-limiting reactions from dehydration of oxanorbornene, the Diels-Alder product, to the Diels-Alder cycloaddition of DMF and ethylene.
- Chang, Chun-Chih,Je Cho, Hong,Yu, Jingye,Gorte, Ray J.,Gulbinski, Jason,Dauenhauer, Paul,Fan, Wei
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supporting information
p. 1368 - 1376
(2016/03/09)
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- SYNTHESIS OF DIKETONE COMPOUNDS FROM CARBOHYDRATES
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Providing a catalytic process for preparing 1,4-diketone compounds from furanic compounds and their precursors in a liquid medium, using an acid catalytic system and optionally in the presence of hydrogen and a hydrogenation catalyst, wherein the acidic catalytic system comprises a solid acid catalyst or a mixture of water and CO 2·
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Paragraph 0075
(2015/09/28)
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- Production of renewable p-xylene from 2,5-dimethylfuran via Diels-Alder cycloaddition and dehydrative aromatization reactions over silica-alumina aerogel catalysts
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We report the selective conversion of biomass-derived 2,5-dimethylfuran (DMF) to p-xylene (~ 70% selectivity) through Diels-Alder cycloaddition and subsequent dehydration with silica-alumina aerogel (SAA) catalysts. The high activity of SAA can be attributed to its high surface area, large mesoporous volume, and high acid site concentrations. The conversion of DMF and the yield of p-xylene were strongly dependent on the silica alumina ratio of SAA. A higher aluminum content in SAA led to a progressive increase in the concentration of Br?nsted acid sites and a corresponding increase in the p-xylene production rate. The effect of solvent on the production of p-xylene was examined, and it was found that the p-xylene production rate increases significantly in polar aprotic solvents (i.e. 1,4-dioxane).
- Wijaya, Yanuar Philip,Suh, Dong Jin,Jae, Jungho
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supporting information
p. 12 - 16
(2015/08/18)
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- Rational design of Ni-based catalysts derived from hydrotalcite for selective hydrogenation of 5-hydroxymethylfurfural
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Selective hydrogenation of 5-hydroxymethylfurfural (HMF) is of great importance for future energy and chemical supply. Herein, we propose for the first time that non-noble Ni-Al2O3 catalysts derived from hydrotalcite-like compounds can efficiently and selectively convert HMF into 2,5-dimethylfuran (DMF), 2,5-dimethyltetrahydrofuran (DMTHF) and 2,5-dihydroxymethyltetrahydrofuran (DHMTHF). Homogeneous elemental distributions of the hydrotalcite-like precursor facilitate good dispersion of Ni and Al2O3 species and strong interaction between them over the resulting catalysts. The catalysts therefore exhibited superior reactivity. Through fine modulation of surface metal-acid bifunctional sites and control of reaction conditions, high yields of DMF (91.5%), DMTHF (97.4%) and DHMTHF (96.2%) can be diversely achieved. The results demonstrate the feasibility of Ni catalysts for selective hydrogenation of C=O, C=C and C-O bonds, which have great potential for biomass utilization.
- Kong, Xiao,Zheng, Runxiao,Zhu, Yifeng,Ding, Guoqiang,Zhu, Yulei,Li, Yong-Wang
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p. 2504 - 2514
(2015/04/22)
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- Upgrading biomass-derived furans via acid-catalysis/hydrogenation: The remarkable difference between water and methanol as the solvent
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In methanol 5-hydroxymethylfurfural (HMF) and furfuryl alcohol (FA) can be selectively converted into methyl levulinate via acidcatalysis, whereas in water polymerization dominates. The hydrogenation of HMF, furan and furfural with the exception of FA is
- Hu, Xun,Westerhof, Roel J. M.,Wu, Liping,Dong, Dehua,Li, Chun-Zhu
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p. 219 - 224
(2018/04/16)
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