- Radical-regulating and antiviral properties of ascorbic acid and its derivatives
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The ability of ascorbic acid and a number of its derivatives to suppress replication of Herpes simplex virus type I was investigated in human rhabdomyosarcoma cell line. In parallel, interaction of the test compounds with carbon- and oxygen-centered radicals formed on radiolysis of hydroxyl-containing organic compounds was studied using the steady state radiolysis method. It has been shown that 2-O-glycoside of ascorbic acid, displaying marked antiviral properties against Herpes simplex virus type I, is also capable of inhibiting fragmentation and recombination reactions of α-hydroxyl-containing carbon-centered radicals while not affecting processes involving oxygen-centered radicals.
- Brinkevich, Sviatoslav D.,Boreko, Eugene I.,Savinova, Olga V.,Pavlova, Natalia I.,Shadyro, Oleg I.
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- The effects of ascorbic acid on homolytic processes involving α-hydroxyl-containing carbon-centered radicals
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Effects of ascorbic acid and 5,6-O-isopropylidene-2,3-O-dimethylascorbic acid on final product formation in radiolysis of ethanol, aqueous solutions of ethanol, ethylene glycol, α-methylglycoside, maltose, α-glycerophosphate, and α-glucose phosphate were studied. It was found that ascorbic acid is able to suppress reactions involving various α-hydroxyl-containing carbon-centered radicals and depending on the experimental conditions can either oxidize or reduce α-hydroxyethyl radicals.
- Brinkevich,Shadyro
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- Reactions of cyclopentanone, γ-butyrolactone, and their derivatives with α-hydroxyethyl radicals
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The interaction of cyclopentanone, 2-cyclopentenone, 1,3-cyclopentanedione, 3-methyl-1,2-cyclopentanedione, γ-butyrolactone, 2(5H)-furanone, ascorbic acid, and 5,6-O-isopropylidenyl-2-3-O-dimethylascorbic acid with α-hydroxyethyl radicals (α-HER) generated during the radiolysis of deaerated ethanol has been studied in the continuous irradiation mode. The test compounds, except γ-butyrolactone, oxidize α-HER. 2(5H)-Furanone and 2-cyclopentenone give hydroxyethylation products via the free-radical chain mechanism. In contrast to 2(5H)-furanone and 2-cyclopentenone, ascorbic and 5,6-O-isopropylidenyl-2,3-O-dimethyl-L-ascorbic acids are weaker oxidants for α-HER and attach these radicals at the multiple carbon-carbon bonds.
- Brinkevich,Reztsov,Shadyro
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- Effects of different techniques of malolactic fermentation induction on diacetyl metabolism and biosynthesis of selected aromatic esters in cool- climate grape wines
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Thr effects of different malolactic bacteria fermentation techniques on the bioconversion of aromatic compounds in cool-climate grape wines were examined. During three wine seasons, red and white grape wines were produced using various malolactic fermentation induction techniques: Coinoculation, sequential inoculation, and spontaneous process. Volatile compounds (diacetyl and the products of its metabolism, and selected ethyl fatty acid esters) were extracted by solid phase microextraction. Compounds were identified with a multidimensional gas chromatograph-GC × GC-ToFMS with ZOEX cryogenic (N2) modulator. Sensory evaluation of the wines was also performed. It was found that the fermentation-derived metabolites studied were affected by the malolactic bacteria inoculation regime. Quantitatively, ethyl lactate, diethyl succinate, and ethyl acetate dominated as esters with the largest increase in content. The total concentration of ethyl esters was highest for the coinoculation technique, while the highest concentration of diacetyl was noted for the spontaneous technique. Controlled malolactic fermentation, especially using the coinoculation technique, can be proposed as a safe and efficient enological practice for producing quality cool-climate grape wines enriched with fruity, fresh, and floral aromas.
- Lasik-Kurdys, Ma?gorzata,Majcher, Ma?gorzata,Nowak, Jacek
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- Particle size and surface chemistry in photoelectrochemical reactions at semiconductor particles
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In the present paper reactions at small and large ZnS particles have been investigated. It has been shown that ethanol is selectively oxidized at large (micrometer) particles to acetaldehyde without side products by a "two hole" process. In the case of nanometer particles the primarily formed α-hydroxyethyl radicals in a "one hole" process undergo a secondary reaction, i.e., the dimerization and disproportionation of the free radicals. It has been shown that a two hole process on nanometer particles becomes impossible because the time interval between two successive photon absorption incidents which lead to a successful hole transfer process in a 1-nm particle is much longer than the maximum lifetime of the α-hydroxyethyl radicals formed in the first step. The different mechanisms of ethanol oxidation and the influence of surface chemistry are discussed in detail.
- Müller,Majoni,Memming,Meissner
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- Efficient production of acetoin by the newly isolated Bacillus licheniformis strain MEL09
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In this study, a new bacterial strain MEL09, which produces acetoin at high concentrations, was isolated from solid cultures of traditional Chinese vinegar. Based on physiological and biochemical characteristics as well as the 16S rDNA gene sequence, strain MEL09 was identified as Bacillus licheniformis. To improve acetoin production by B. licheniformis MEL09, medium composition and culture conditions were optimized by varying one factor at a time and using orthogonal array tests. Under these optimized conditions, the maximum acetoin concentration achieved was 41.26 g l-1, with 41.26% glucose conversion efficiency (84.39% of theoretical glucose conversion efficiency). This increase is 84.86% over the initial condition and is, to our knowledge, the highest acetoin level ever reported using fermentation methods.
- Liu, Yongfeng,Zhang, Shuling,Yong, Yang-Chun,Ji, Zhixia,Ma, Xin,Xu, Zhenghong,Chen, Shouwen
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- Electrosynthesis of 2,3-butanediol and methyl ethyl ketone from acetoin in flow cells
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Acetoin could shortly become a platform molecule due to current progress in fermentation technology, the megatrend for shifting from an oil-based economy to the one based on biomass, the quest for green manufacturing processes and its two highly reactive carbonyl and hydroxyl moieties. In this paper, the successful electro-conversion of acetoin into two valuable chemicals, 2,3-butanediol (2,3-BD) and methyl ethyl ketone (MEK), at a constant electrical current in an aqueous phase at room temperature using both divided and undivided 20 cm2 filter-press flow cells under experimental conditions suitable for industrial production is reported. Cathode material is the key parameter to drive the electroreduction towards one or another chemical. 2,3-BD is the major chemical produced by electrohydrogenation when low hydrogen overvoltage cathodes, such as Pt and Ni, of high surface areas obtained by PVD coating on a carbon gas diffusion layer are used, while MEK is the principal product produced by electrohydrogenolysis when high hydrogen overvoltage cathodes, such as graphite, Pb and Cd foils, are employed. 2,3-BD and MEK can be obtained, respectively, in 92.8% and 85.7% selectivities, 71.7% and 80.4% current efficiencies, with 1.21 and 1.08 kg h-1 m-2 productivities and power consumptions of 2.94 and 4.1 kWh kg-1 using undivided cells and aqueous K2HPO4 electrolysis media at pH values of 3.6 and 5.5. The reported electroconversion of acetoin is highly flexible because 2,3-BD and MEK can be produced by changing just the cathode but using the same cell, with the same electrolyte at the same current density.
- Ochoa-Gómez, José R.,Fernández-Carretero, Francisco,Río-Pérez, Francisca,García-Luis, Alberto,Roncal, Tomás,García-Suárez, Eduardo J.
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- Amplified Rate Acceleration by Simultaneous Up-Regulation of Multiple Active Sites in an Endo-Functionalized Porous Capsule
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Using the hydrolysis of epoxides in water as a model reaction, the effect of multiple active sites on Michaelis-Menten compliant rate accelerations in a porous capsule is demonstrated. The capsule is a water-soluble Ih-symmetry Keplerate-type complex of the form, [{MoVI6O21(H2O)6}12{MoV2O4(L)}30]42-, in which 12 pentagonal "ligands," {(MoVI)MoVI5O21(H2O)6}6-, are coordinated to 30 dimolybdenum sites, {MoV2O4L}1+ (L = an endohedrally coordinated ν2-bound carboxylate anion), resulting in 20 Mo9O9 pores. When "up-regulated" by removal of ca. one-third of the blocking ligands, L, an equal number of dimolybdenum sites are activated, and the newly freed-up space allows for encapsulation of nearly twice as many substrate guests, leading to a larger effective molarity (amplification), and an increase in the rate acceleration (kcat/kuncat) from 16,000 to an enzyme-like value of 182,800.
- Kopilevich, Sivil,Müller, Achim,Weinstock, Ira A.
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- Properties of a 2,3-butanediol dehydrogenase from taiwanofungus camphorata
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2,3-Butanediol dehydrogenase (Bdh) plays important roles in reduction of acetoin to 2,3-butanediol, an important platform chemical with many industrial applications. Here, a TcBdh cDNA (1348 bp, GenBank accession JF896462) encoding a putative Bdh was cloned from Taiwanofungus camphorata. The deduced amino acid sequence is similar to the Bdhs from other species. A 3-D structural model of TcBdh has been constructed based on the known structure of Pseudomonas putida formaldehyde dehydrogenase (PpFdh, PDB code 1KOL). To characterize the TcBdh protein, the coding region was subcloned into an expression vector pYEX-S1 and transformed into Saccharomyces cerevisiae. The recombinant His6-tagged TcBdh was expressed and purified by Ni2+-nitrilotriacetic acid Sepharose. The purified enzyme showed a single band of 49 kDa on 12% sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The Michaelis constant (KM) value of the recombinant enzyme for acetoin was 8.5 mM. The enzyme's optical pH was 6. The thermal inactivation of the enzyme showed a half-life of 5.3 min at 45°C.
- Ken, Chuian-Fu,Tsai, Wei-Wei,Wen, Lisa,Sheu, Dey-Chyi,Lin, Chi-Tsai
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- Selective Photocatalytic C-C Coupling of Bioethanol into 2,3-Butanediol over Pt-Decorated Hydroxyl-Group-Tunable TiO2 Photocatalysts
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2,3-Butanediol (2,3-BD) was synthesized through TiO2-photocatalytic C-C coupling of bioethanol synchronously with the liberation of an energy H2 molecule in an anaerobic atmosphere. It was found that the selectivity of 2,3-BD is controlled by the amount of .OH. The less the .OH, the higher the 2,3-BD selectivity. Furthermore, it was revealed that the amount of .OH increases with the increasing of the surface OH groups on TiO2 photocatalyst. The introduction of water is in favor of the C-C coupling pathway. This can be attributed to the stronger interaction between water and TiO2, which is beneficial to recovering the OH groups and promoting the desorption of .CH(OH)CH3 intermediates, thus suppressing the thermodynamically favorable overoxidation of .CH(OH)CH3 into acetaldehyde and promoting the C-C coupling into 2,3-BD. Based on the findings, the 2,3-BD selectivity was greatly enhanced from approximately 2.6 % to approximately 65 % over Degussa P25-TiO2 photocatalyst through fluorine substitution of surface OH groups.
- Yang, Pengju,Zhao, Jianghong,Cao, Baoyue,Li, Li,Wang, Zhijian,Tian, Xuxia,Jia, Suping,Zhu, Zhenping
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- Hydrogenation of diacetyl over composite-supported egg-shell noble metal catalysts
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Two composite supports with a mixed inorganic-organic structure were synthesized: BTAl and UTAl. Hydrophilic-hydrophobic dual properties of the supports were suitable for preparing egg-shell-supported metal catalysts for selective hydrogenation reactions. The catalysts were characterized by ICP, XRD, OM, TEM, EPMA, XPS and TGA. Their mechanical resistance was assessed. Activity and selectivity were tested with the hydrogenation of 2,3-butanedione (diacetyl) to 3-hydroxy-2-butanoneacetoin (acetoin). The same order of increasing metal particle size was found for the two tested supports: Pt +). It was rationalized that the hydrogen bond cleavage was performed on the Me° active sites, while reactant adsorption occurred on the Me+ sites. The differences in activity and selectivity between the composite catalysts were attributed to electronic effects on the different metals and to different adsorptive properties of the different polymers. The high selectivity to acetoin was attributed to the preferential adsorption of diacetyl as compared to the adsorption of acetoin. The BTAl catalysts were slightly more active and selective than the UTAl ones. This was attributed to electronic effects caused by remnant organic groups on the composite supports (urethane or biphenyl on UTAl or BTAl, respectively). Pd-BTAl was the most active and selective catalyst, a fact related to electronic effects of both palladium and the support.
- Carrara,Badano,Coloma-Pascual,Vera,Quiroga
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- Effects of indole and imidazole derivatives on the radiation- and peroxide-induced transformations of ethanol
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The interaction of indole, imidazole, and their derivatives with α-hydroxyethyl radicals has been studied by the radiation and peroxide initiation of free-radical processes. The enthalpies of H-atom addition to the multiple bonds of the test compounds, which characterize their oxidation properties, have been calculated within the framework of the density functional theory. The set of experimental and theoretically calculated data indicate that serotonin or β-carboline alkaloids (harmine, harman, and harmaline) inhibit the formation of 2,3-butanediol - the main radiolysis product of deaerated ethanol - mainly due to reduction and addition or the oxidation of α-hydroxyethyl radicals, respectively. Enhancement of oxidation properties in the above order of β-carboline alkaloids has been observed. Pyrrole, indole, melatonin, imidazole, 1-methylimidazole, and 2-mercapto-1- methylimidazole exhibit low reactivity toward α-hydroxyethyl radicals.
- Brinkevich,Sverdlov,Shadyro
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- Direct C-C coupling of bio-ethanol into 2,3-butanediol by photochemical and photocatalytic oxidation with hydrogen peroxide
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Theoretically, selective C-H manipulation in ethanol can result in a direct C-C coupling synthesis of 2,3-butanediol (2,3-BDO). However, this process is typically extremely difficult to achieve because of the high complexity of the involved chemical bonds. In this work, we determine that hydroxide radicals generated from the photolysis of H2O2 can selectively attack the α-hydrogen atom in ethanol aqueous solutions and crack the C-H bond to produce hydroxyethyl radicals, which subsequently undergo C-C coupling to form 2,3-BDO. This selective C-H breakage is determined by the reaction rate, which is primarily controlled by the local H2O2 concentration at a given irradiation intensity. At a moderate reaction rate of ethanol (37 mmol h-1), the 2,3-BDO selectivity reaching as high as 91% can be obtained. The introduction of a catalyst can further increase ethanol conversion and enhance the 2,3-BDO formation rate by controlling the reaction rate. This result provides an environment-friendly approach to convert bio-ethanol directly to 2,3-BDO and to manipulate a single bond selectively in complex bonding situations.
- Li, Na,Yan, Wenjun,Yang, Pengju,Zhang, Hongxia,Wang, Zhijian,Zheng, Jianfeng,Jia, Suping,Zhu, Zhenping
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- Effects of α-tocopherol and related compounds on reactions involving various organic radicals
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Effects of α-tocopherol, PMC, and a number of the respective sulfur-containing analogues on reactions involving various organic radicals were studied. The test compounds were found to interact with alkyl radicals more effectively than with peroxyl radicals. The presence of a sulfur atom in structures of the respective analogues did not produce significant effects on reactivity. Derivatives of 5-hydroxy-1,3-benzoxathiol-2-one and 6-hydroxy-1,4-benzoxathiin-2(3H)-one displayed a high reactivity toward α-hydroxyalkyl radicals.
- Povalishev,Polozov,Shadyro
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- Application of robust ketoreductase from Hansenula polymorpha for the reduction of carbonyl compounds
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Enzyme-catalysed asymmetric reduction of ketones is an attractive tool for the production of chiral building blocks or precursors for the synthesis of bioactive compounds. Expression of robust ketoreductase (KRED) from Hansenula polymorpha was upscaled and applied for the asymmetric reduction of 31 prochiral carbonyl compounds (aliphatic and aromatic ketones, diketones and β-keto esters) to the corresponding optically pure hydroxy compounds. Biotransformations were performed with the purified recombinant KRED together with NADP+ recycling glucose dehydrogenase (GDH, Bacillus megaterium), both overexpressed in Escherichia coli BL21(DE3). Maximum activity of KRED for biotransformation of ethyl-2-methylacetoacetate achieved by the high cell density cultivation was 2499.7 ± 234 U g–1DCW and 8.47 ± 0.40 U·mg–1E, respectively. The KRED from Hansenula polymorpha is a very versatile enzyme with broad substrate specificity and high activity towards carbonyl substrates with various structural features. Among the 36 carbonyl substrates screened in this study, the KRED showed activity with 31, with high enantioselectivity in most cases. With several ketones, the Hansenula polymorpha KRED catalysed preferentially the formation of the (R)-secondary alcohols, which is highly valued.
- Petrovi?ová, Tatiana,Gyuranová, Dominika,Pl?, Michal,Myrtollari, Kamela,Smonou, Ioulia,Rebro?, Martin
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- Method for preparing 1, 3-butanediol
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The invention provides a method for preparing 1, 3-butanediol. The method comprises the following steps: (1) carrying out condensation cyclization reaction on butadiene, water and an aldehyde ketone compound according to a certain material ratio in the presence of hydrogen peroxide and a catalyst A to obtain a reaction solution containing an intermediate I; and (2) mixing the reaction solution containing the intermediate I with a certain amount of water, and carrying out hydrolysis reaction in the presence of a catalyst B to obtain 1, 3-butanediol and a corresponding aldehyde ketone compound.Compared with the existing production method, the method has the advantages of accessible reaction raw materials, high reaction conversion rate, high selectivity and the like, and is suitable for industrial production.
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Paragraph 0061; 0064-0066; 0076; 0077
(2020/11/22)
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- C-H activations of methanol and ethanol and C-C couplings into diols by zinc-indium-sulfide under visible light
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Herein, an environmentally friendly CoP/Zn2In2S5 catalyst is reported as a visible-light photocatalyst for the selective activation of the α-C-H bond of methanol to generate ethylene glycol with a selectivity of as high as 90%. The catalytic system also illustrates the first example of visible-light-driven dehydrogenative coupling of ethanol to 2,3-butanediol.
- Zhang, Haikun,Xie, Shunji,Hu, Jinyuan,Wu, Xuejiao,Zhang, Qinghong,Cheng, Jun,Wang, Ye
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p. 1776 - 1779
(2020/02/20)
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- Energy- And cost-effective non-sterilized fermentation of 2,3-butanediol by an engineered: Klebsiella pneumoniae OU7 with an anti-microbial contamination system
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Microbial contamination is a serious challenge that needs to be overcome for the successful biosynthesis of 2,3-butanediol (2,3-BD). However, traditional strategies such as antibiotic administration or sterilization are costly, have high energy demands, and may increase the risk of antibiotic resistance. Here, we intend to develop a robust strategy to achieve non-sterilized fermentation of 2,3-BD. Briefly, the robust strain can metabolize unconventional chemicals as essential growth nutrients, and therefore, outcompete contaminant microbes that cannot use unconventional chemicals. To this end, Klebsiella pneumoniae OU7, a robust strain, was confirmed to rapidly exploit urea and phosphite (unconventional chemicals) as the primary sources of nitrogen (N) and phosphorus (P), and withstand deliberate contamination in the possibly contaminated systems. Secondly, metabolic engineering, pathogenicity elimination and adaptive laboratory evolution were successively performed, endowing the best strain with an excellent fermentation performance for safe 2,3-BD production. Finally, 84.53 g L-1 of 2,3-BD was synthesized with a productivity of 1.17 g L-1 h-1 and a yield of 0.38 g g-1 under the non-sterilized system. In summary, our technique reduces labor and energy costs and simplifies the fermentation process because sterilization does not need to be performed. Thus, our work will be beneficial for the sustainable synthesis of 2,3-BD. This journal is
- Guo, Ze-Wang,Ou, Xiao-Yang,Xu, Pei,Gao, Hui-Fang,Zhang, Liao-Yuan,Zong, Min-Hua,Lou, Wen-Yong
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p. 8584 - 8593
(2020/12/31)
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- Olefin reaction in the catalyst and the olefin production
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PROBLEM TO BE SOLVED: To provide a catalyst for obtaining an olefin in high selectivity with a vicinal diol as a raw material.SOLUTION: A catalyst for olefination reaction for use in a reaction to produce an olefin by a reaction of a polyol, having two adjacent carbon atoms each having a hydroxy group, with hydrogen comprises: a carrier; at least one oxide selected from the group consisting of oxides of the group 6 elements and oxides of the group 7 elements supported on the carrier; and at least one metal selected from the group consisting of silver, iridium, and gold supported on the carrier.SELECTED DRAWING: None
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Paragraph 0145-0146; 0149
(2020/10/31)
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- One-pot synthesis of 1,3-butanediol by 1,4-anhydroerythritol hydrogenolysis over a tungsten-modified platinum on silica catalyst
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Chemical production of 1,3-butanediol from biomass-derived compounds was first reported by 1,4-anhydroerythritol hydrogenolysis over a Pt-WOx/SiO2 catalyst. The reaction proceeded by ring opening hydrogenolysis of 1,4-anhydroerythritol followed by selective removal of secondary OH groups in 1,2,3-butanetriol, and an overall 1,3-butanediol yield up to 54% was then obtained. The performance of the Pt-WOx/SiO2 catalyst for 1,4-anhydroerythritol hydrogenolysis was closely correlated with that for glycerol hydrogenolysis to 1,3-propanediol. The optimized Pt-WOx/SiO2 (Pt: 4 wt% and W: 0.94 wt%) catalyst showed 57% yield of 1,3-propanediol.
- Asano, Takehiro,Liu, Lujie,Nakagawa, Yoshinao,Tamura, Masazumi,Tomishige, Keiichi
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supporting information
p. 2375 - 2380
(2020/05/14)
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- PNN tridentate ligand, ruthenium complex, and preparation method and application of ruthenium complex
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The invention discloses a PNN tridentate ligand, a ruthenium complex, and a preparation method and an application of the ruthenium complex. The structure of the ruthenium complex is represented by formula I, and the ruthenium complex has good catalytic activity in a reaction of converting cyclic carbonate into methanol and a reaction of hydrogenating and degrading polyester and polycarbonate. In addition, the PNN tridentate ligand and the ruthenium complex of the PNN tridentate ligand are good in stability, and the synthesis process is simple.
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Paragraph 0187-0192
(2020/06/04)
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- Selective Hydrogenation of Diketones on Supported Transition Metal Catalysts
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Abstract: The hydrogenation of α-diketones yields α-hydroxyketones or vic-diols, both compounds of great interest in fine chemistry. The reaction tests were the liquid phase hydrogenation of 2,3-butanedione and 2,3-pentanedione at mild conditions. The objectives of this work were evaluating the effect over the activity and selectivity of: (a) different transition metallic phase based catalysts supported on activated carbon, (b) the symmetry of the reactants and (c) solvents. The physicochemical characterization of the catalysts was carried out by ICP, XRD, TEM, N2 adsorption and XPS. The keto-enol equilibrium of diketones was studied by 1H-NMR. All the catalysts were active in both reactions. In terms of activity, Pt and Rh were the best active phases. For both reactants the highest selectivity towards hydroxyketones were achieved with Pd, while Ru was the most selective towards the diol. Both the activity and selectivity followed similar patterns in the hydrogenation of both diketones. The greater activity of Pt was attributed to the high dispersion of the active metal phase in this catalyst and the high efficiency of Pt for C = O bond reduction. The high selectivity of the Pd catalysts towards the intermediate product was attributed to many effects: (i) a lower interaction of the hydroxyketone with the active site as compared to the diketone, (ii) the easy reducibility of the C = C double bond on Pd, provided by the keto-enol tautomerism of diketones.
- Carrara,Badano,Vailard,Vera,Quiroga
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p. 461 - 470
(2019/11/13)
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- The hydrolysis of epoxides catalyzed by inorganic ammonium salts in water: Kinetic evidence for hydrogen bond catalysis
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Naturally-occurring inorganic ammonium ions have been recently reported as efficient catalysts for some organic reactions in water, which contributes to the understanding of the chemistry in some natural environments (soils, seawater, atmospheric aerosols, .) and biological systems, and is also potentially interesting for green chemistry as many of their salts are cheap and non-toxic. In this work, the effect of NH4+ ions on the hydrolysis of small epoxides in water was studied kinetically. The presence of NH4+ increased the hydrolysis rate by a factor of 6 to 25 compared to pure water and these catalytic effects were shown not to result from other ions, counter-ions or from acid or base catalysis, general or specific. The small amounts of amino alcohols produced in the reactions were identified as the actual catalysts by obtaining a strong acceleration of the reactions when adding these compounds directly to the epoxides in water. Replacing the amino alcohols by other strong hydrogen-bond donors, such as trifluoroethanol (TFE) or hexafluoroisopropanol (HFIP) gave the same results, demonstrating that the kinetics of these reactions was driven by hydrogen-bond catalysis. Because of the presence of many hydrogen-bond donors in natural environments (for instance amines and hydroxy-containing compounds), hydrogen-bond catalysis is likely to contribute to many reaction rates in these environments.
- Nozière,Fache,Maxut,Fenet,Baudouin,Fine,Ferronato
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p. 1583 - 1590
(2018/02/06)
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- An artificial synthetic pathway for acetoin, 2,3-butanediol, and 2-butanol production from ethanol using cell free multi-enzyme catalysis
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Upgrading ethanol to higher order alcohols is desired but difficult using current biotechnological methods. In this study, we designed a completely artificial reaction pathway for upgrading ethanol to acetoin, 2,3-butanediol, and 2-butanol in a cell-free bio-system composed of ethanol dehydrogenase, formolase, 2,3-butanediol dehydrogenase, diol dehydratase, and NADH oxidase. Under optimized conditions, acetoin, 2,3-butanediol, and 2-butanol were produced at 88.78%, 88.28%, and 27.25% of the theoretical yield from 100 mM ethanol, respectively. These results demonstrate that this artificial synthetic pathway is an environmentally-friendly novel approach for upgrading bio-ethanol to acetoin, 2,3-butanediol, and 2-butanol.
- Zhang, Liaoyuan,Singh, Raushan,Sivakumar,Guo, Zewang,Li, Jiahuan,Chen, Fanbing,He, Yuanzhi,Guan, Xiong,Kang, Yun Chan,Lee, Jung-Kul
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p. 230 - 242
(2018/01/12)
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- Highly efficient and recyclable chiral Pt nanoparticle catalyst for enantioselective hydrogenation of activated ketones
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Thermoregulated phase-separable chiral Pt nanoparticle catalyst exhibited excellent ee (>99%) in the enantioselective hydrogenation of activated ketones for preparing chiral α-hydroxy acetals and chiral 1,2-diols. More importantly, the chiral catalyst could be easily separated by phase separation and directly reused in the next cycle without any loss in catalytic activity and enantioselectivity, even in the gram-scale reaction. The leaching of Pt was under the detection limit of the instrument.
- Xue, Xiuru,Chen, Pu,Xu, Peng,Wang, Yanhua
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- Investigation of the Reaction Pathways of Biomass-Derived Oxygenate Conversion into Monoalcohols in Supercritical Methanol with CuMgAl-Mixed-Metal Oxide
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Reaction pathways for the conversion of cellulose into C2–C6 monoalcohols by supercritical methanol depolymerization and hydrodeoxygenation (SCM-DHDO) over a CuMgAl oxide catalyst have been elucidated using a range of model compounds. SCM-DHDO of intermediate oxygenates including glycerol, methyl lactate, and 1,2-ethanediol produces similar products as those produced from the SCM-DHDO of cellulose. The pathway to C2–C6 monoalcohols occurs through rapid C?C coupling reactions between methanol and diols followed by C?C scission between vicinal alcohol groups to produce two monoalcohols. Methyl-branched monoalcohols are produced through a methyl shift in a secondary diol followed by dehydration. Esters are produced by dehydrogenative coupling between an adsorbed methoxy and a primary alcohol. Both dehydrogenation to a ketone and esterification to a methyl ester are in equilibrium with the corresponding alcohol and were reversible. Dehydration of diols is the slowest observed reaction and not a main pathway to monoalcohols. SCM-DHDO of glucose, dihydroxyacetone, and cellulose all produced similar high molecular weight species indicating that condensation of intermediates can produce undesired side products.
- Galebach, Peter H.,Thompson, Sean,Wittrig, Ashley M.,Buchanan, J. Scott,Huber, George W.
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p. 4007 - 4017
(2018/11/23)
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- Method for synthesizing o-glycol compounds by virtue of bifunctional characteristic catalyst
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The invention belongs to the technical field of organic chemical synthesis and particularly relates to a method for synthesizing o-glycol compounds by virtue of a bifunctional characteristic catalyst.The o-glycol compounds are prepared from olefin and an oxidizing agent through reaction under the effect of the bifunctional characteristic catalyst, wherein the bifunctional characteristic catalystcontains the following components in percentage by mass: 25%-75% of a titanium silicalite molecular sieve, 20%-70% of nano-silicon dioxide and 5%-10% of heteropolyacid. The method provided by the invention has the beneficial effects that a process for synthesizing o-glycol by virtue of a traditional two-step method is simplified; the catalyst can still remain good catalytic performance under a long-period operation condition in the method, the raw material conversion rate is high, and the yields of the o-glycol compounds are high; and the olefin raw material conversion rate is 80.2%-94.6%, andthe selectivity of o-glycol generated through reaction is 85.7%-96.3%.
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Paragraph 0034-0035; 0036-0037; 0039-0045
(2018/04/26)
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- Method for synthesizing vicinal diol compound by virtue of one-step process
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The invention belongs to the technical field of organic chemical synthesis, and in particular relates to a method for synthesizing a vicinal diol compound by virtue of a one-step process. The vicinaldiol compound is obtained by carrying out reaction on olefin and an oxidizing agent in presence of a bifunctional catalyst, wherein the bifunctional catalyst comprises 25-75% of titanium silicalite molecular sieves, 20-70% of nano alumina and 3-8% of boric oxide in percentage by mass with the titanium silicalite molecular sieves, nano alumina and boric oxide as the benchmarks. The method for synthesizing the vicinal diol compound has the advantages that the traditional two-step vicinal diol synthesis technology is simplified; in the synthetic method, a catalyst still maintains good catalytic performance under long-period operation condition, raw material conversion rate is high, and yield of the vicinal diol compound is high; and olefin raw material conversion rate is 80.2-94.6%, and vicinal diol reaction generation selectivity is 85.7-96.3%.
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Paragraph 0032-0041
(2018/04/26)
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- Hydrogenolysis of sorbitol into valuable C3-C2 alcohols at low H2 pressure promoted by the heterogeneous Pd/Fe3O4 catalyst
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The hydrogenolysis of sorbitol and various C5-C3 polyols (xylitol; erythritol; 1,2- 1,4- and 2,3-butandiol; 1,2-propandiol; glycerol) have been investigated at low molecular hydrogen pressure (5 bar) by using Pd/Fe3O4, as heterogeneous catalyst and water as the reaction medium. Catalytic experiments show that the carbon chain of polyols is initially shortened through dehydrogenation/decarbonylation and dehydrogenation/retro-aldol mechanisms followed by a series of cascade reactions that include dehydrogenation/decarbonylation and dehydration/hydrogenation processes. At 240 °C, sorbitol is fully converted into lower alcohols with ethanol being the main reaction product in liquid phase.
- Gumina, Bianca,Mauriello, Francesco,Pietropaolo, Rosario,Galvagno, Signorino,Espro, Claudia
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p. 152 - 160
(2018/02/17)
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- Aluminum-Mediated Formation of Cyclic Carbonates: Benchmarking Catalytic Performance Metrics
-
We report a comparative study on the activity of a series of fifteen binary catalysts derived from various reported aluminum-based complexes. A benchmarking of their initial rates in the coupling of various terminal and internal epoxides in the presence of three different nucleophilic additives was carried out, providing for the first time a useful comparison of activity metrics in the area of cyclic organic carbonate formation. These investigations provide a useful framework for how to realistically valorize relative reactivities and which features are important when considering the ideal operational window of each binary catalyst system.
- Rintjema, Jeroen,Kleij, Arjan W.
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p. 1274 - 1282
(2017/03/29)
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- Method for synthesizing ortho-diol compound by using macroporous anion exchange resin as catalyst
-
The invention discloses a method for synthesizing an ortho-diol compound by using macroporous anion exchange resin as a catalyst. According to the method, hydrocarbon epoxide is used as a raw material, the anion exchange resin is used as the catalyst, and a fixed bed continuous hydrolysis reaction technology is adopted for preparing the ortho-diol compound; the anion exchange resin is halogen ortho-substituted macroporous polystyrene-divinyl benzene quaternary phosphonium salt type anion exchange resin. The synthesis method is simple, the catalyst can be used repeatedly, the conversion rate of the raw material is high, and the yield of the ortho-diol compound is high.
- -
-
Paragraph 0024; 0025; 0026; 0028; 0029; 0030-0035
(2017/05/27)
-
- Synthetic method for o-glycol compounds
-
The invention discloses a synthetic method for o-glycol compounds. The method prepares the o-glycol compounds by using a fixed-bed continuous hydrolysis reaction process with hydrocarbon epoxides as raw materials and anion exchange resin as a catalyst, wherein the anion exchange resin is halogen-p-substituted macroporous polystyrene-divinyl benzene quaternary phosphonium salt anion exchange resin. The synthetic method is simple; the catalyst can be repeatedly used a plurality of times; the conversion rate of the raw materials is high; and the yield of the o-glycol compounds is high.
- -
-
Paragraph 0026-0027; 0029-0036
(2017/08/28)
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- Method for preparing vicinal diol compound through ring-opening reaction
-
The present invention discloses a method for preparing a vicinal diol compound through a ring-opening reaction. The method takes a hydrocarbons epoxide as a raw material and takes an anion exchange resin as a catalyst. The vicinal diol compound is prepared by using a fixed bed continuous hydrolysis reaction technology. The anion exchange resin is a halogen-substituted macroporous polystyrene-divinyl benzene quaternary ammonium salt type anion exchange resin. The synthesis method is simple, the catalyst can be used many times, the raw material conversion rate is high, and the yield of the vicinal diol compound is high.
- -
-
Paragraph 0015; 0031; 0033; 0036
(2017/03/28)
-
- Method of using anion exchange resin as catalyst to synthesize vicinal diol compound
-
The invention discloses a method of using anion exchange resin as a catalyst to synthesize a vicinal diol compound. The method includes: using hydrocarbon epoxide as a raw material and the anion exchange resin as the catalyst; adopting a fixed bed continuous hydrolysis reaction process to obtain the vicinal diol compound, wherein the anion exchange resin is halogen substituted macroporous polystyrene-divinyl benzene quaternary ammonium salt type anion exchange resin. The method is simple, the catalyst can be utilized repeatedly, the raw material is high in conversion rate, and the vicinal diol compound is high in yield.
- -
-
Paragraph 0027; 0029; 0030; 0036
(2017/07/06)
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- METHOD FOR MANUFACTURING 2,3-BUTANEDIOL
-
The present disclosure relates to a process for manufacturing 2,3-butanediol by electroreduction of 3-hydroxybutan-one in an aqueous media.
- -
-
Paragraph 0040
(2018/02/03)
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- Selective C?O Hydrogenolysis of Erythritol over Supported Rh-ReOx Catalysts in the Aqueous Phase
-
Bimetallic Rh-ReOx (Re/Rh molar ratio 0.4–0.5) catalysts supported on TiO2 and ZrO2 were prepared by the successive impregnation of dried and calcined unreduced supported Rh catalysts. Their catalytic performances were evaluated in the hydrogenolysis of erythritol to butanetriols (BTO) and butanediols (BDO) in aqueous solution at 150–240 °C under 30–120 bar H2. The activity depended on the nature of the support, and the highest selectivity to BTO and BDO at 80 % conversion was 37 and 29 %, respectively, in the presence of 3.7 wt %Rh-3.5 wt %ReOx/ZrO2 at 200 °C under 120 bar. The characterization of the catalysts by CO chemisorption, TEM with energy-dispersive X-ray spectroscopy, thermogravimetric analysis with MS, and X-ray photoelectron spectroscopy suggests a different distribution and reducibility of Re species over the supported Rh nanoparticles, which depends on the support.
- Said, Achraf,Da Silva Perez, Denilson,Perret, Noémie,Pinel, Catherine,Besson, Michèle
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p. 2768 - 2783
(2017/07/28)
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- Iridium Clusters Encapsulated in Carbon Nanospheres as Nanocatalysts for Methylation of (Bio)Alcohols
-
C?H methylation is an attractive chemical transformation for C?C bonds construction in organic chemistry, yet efficient methylation of readily available (bio)alcohols in water using methanol as sustainable C1 feedstock is limited. Herein, iridium nanocatalysts encapsulated in yolk–shell-structured mesoporous carbon nanospheres (Ir@YSMCNs) were synthesized for this transformation. Monodispersed Ir clusters (ca. 1.0 nm) were encapsulated in situ and spatially isolated within YSMCNs by a silica-assisted sol–gel emulsion strategy. A selection of (bio)alcohols (19 examples) was selectively methylated in aqueous phase with good-to-high yields over the developed Ir@YSMCNs. The improved catalytic efficiencies in terms of activity and selectivity together with the good stability and recyclability were contributable to the ultrasmall Ir clusters with oxidation chemical state as a consequence of the confinement effect of YSMCNs with interconnected nanostructures.
- Liu, Qiang,Xu, Guoqiang,Wang, Zhendong,Liu, Xiaoran,Wang, Xicheng,Dong, Linlin,Mu, Xindong,Liu, Huizhou
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p. 4748 - 4755
(2017/12/15)
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- Synthesis, Characterization and Catalytic Application of Pyridine-Bridged N-Heterocyclic Carbene–Ruthenium Complexes in the Hydrogenation of Carbonates
-
A series of bulky pyridine-bridged NHC–Ru complexes have been rationally designed and synthesized; these exhibited very high catalytic activity in the hydrogenation of cyclic and linear carbonates under mild reaction conditions. In the presence of catalytic amounts of a weak base, a broad range of substrates with different ring size and steric bulk were well tolerated, providing methanol and the corresponding diols in excellent yields with a catalyst loading as low as 0.5 mol %.
- Chen, Jiangbo,Zhu, Haibo,Chen, Jinjin,Le, Zhang-Gao,Tu, Tao
-
supporting information
p. 2809 - 2812
(2017/10/23)
-
- Making H2 from light and biomass-derived alcohols: The outstanding activity of newly designed hierarchical MWCNT/Pd@TiO2 hybrid catalysts
-
Hydrogen evolution is among the most investigated catalytic processes given the importance of H2 from an industrial and an energy perspective. Achieving H2 production through green routes, such as water splitting or more realistically photoreforming of alcohols, is particularly desirable. In this work, we achieve a remarkable H2 productivity through photoreforming of either ethanol or glycerol as a sacrificial electron donor by employing a hybrid nanocatalyst where the properties of multi-walled carbon nanotubes (MWCNTs), Pd nanoparticles and crystalline TiO2 are optimally merged through appropriate engineering of the three components and an optimised synthetic protocol. Catalysts were very active both under UV (highest activity 25 mmol g-1 h-1) and simulated solar light (1.5 mmol h-1 g-1), as well as very stable. Critical to such high performance is the intimate contact of the three phases, each fulfilling a specific task synergistically with the other components.
- Beltram,Melchionna,Montini,Nasi,Fornasiero,Prato
-
supporting information
p. 2379 - 2389
(2017/07/15)
-
- A site-holding effect of TiO2 surface hydroxyl in the photocatalytic direct synthesis of 1,1-diethoxyethane from ethanol
-
To understand the mechanism of the photocatalytic direct synthesis of 1,1-diethoxyethane (DEE) from ethanol is vital for enhancing the reaction efficiency. Based on photocatalytic data of different phase TiO2 and F-TiO2 catalysts, radical trapping data, and GC-MS data, we proposed a photocatalytic mechanism for the preparation of both DEE in neat ethanol and 2,3-butanediol (2,3-BD) in ethanol-H2O using photocatalytic methods. In neat ethanol, hydroxyl isn’t involved in the catalytic cyclic process but hydroxyl has an indirect site-holding effect, thus leading to more hydroxyl groups with higher activity. In ethanol-H2O, although the strong oxidant ?OH radical is involved, fewer OH groups lead to higher selectivity of 2,3-BD. The interaction of the reactant/solvent with the surface group of the catalyst is important in the activity and selectivity of photocatalytic reactions. This finding gives fundamental insight into the role of TiO2 surface hydroxyl in the photocatalytic dehydrogenation process of alcohols and opens a promising path to obtaining both high selectivity and high conversion in TiO2-based photocatalytic activity.
- Zhang, Hongxia,Zhang, Wenqin,Zhao, Min,Yang, Pengju,Zhu, Zhenping
-
supporting information
p. 1518 - 1521
(2017/02/05)
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- Influence of the functional groups of multiwalled carbon nanotubes on performance of Ru catalysts in sorbitol hydrogenolysis to glycols
-
Different functional groups (i.e. [sbnd]NH2, [sbnd]COOH, [sbnd]OH and nitrogen-doping) modified CNTs (denoted as AMCN, CMCN, HMCN and NMCN, respectively) supported ruthenium catalysts (Ru/AMCN, Ru/CMCN, Ru/HMCN and Ru/NMCN) were prepared by incipient wetness impregnation method. They were fully characterized by XRD, TG, Raman, XPS, TPD and TEM to elucidate the relationship between the physical property and their catalytic performance. TEM results shown that Ru particles were well dispersed on the surface for all the samples with the size of 1.48–1.99 nm. The effects of functional groups of carbon nanotubes (CNTs), nitrogen doping and base additive types on activity and selectivity of ethylene glycol (EG) and propylene glycol (1,2-PD) were investigated. In addition, the activity and final products distribution were much influenced by the properties of functional groups on CNTs and the type of metal cation of the base promoters, which probably participated in the reaction for accelerating a retro-aldol reaction for C[sbnd]C cleavage. Among the catalysts, Ru supported on AMCN exhibited the best catalytic activities and glycols selectivities than on MCN, CMCN, HMCN and NMCN.
- Guo, Xingcui,Dong, Huihuan,Li, Bin,Dong, Linlin,Mu, Xindong,Chen, Xiufang
-
-
- Method for synthesizing vicinal diol compound which takes hydrocarbon epoxide as raw material
-
The present invention discloses a method for preparing a vicinal diol compound which takes a hydrocarbon epoxide as a raw material. The method takes the hydrocarbon epoxide as the raw material and takes an anion exchange resin as a catalyst. The vicinal diol compound is prepared by using a fixed bed continuous hydrolysis reaction technology. The anion exchange resin is a halogen-substituted macroporous polystyrene-divinyl benzene quaternary ammonium salt type anion exchange resin. The synthesis method is simple, the catalyst can be used many times, the raw material conversion rate is high, and the yield of the vicinal diol compound is high.
- -
-
Paragraph 0027-0028; 0032; 0037
(2017/08/03)
-
- METHOD FOR MANUFACTURING 2,3-BUTANEDIOL
-
The invention relates to a process for manufacturing 2,3-butanediol by hydrogenation of acetoin using a heterogeneous hydrogenation catalyst and under conditions leading to a selectivity higher than 90%. In a preferred embodiment, the hydrogenation is carried out in the presence of no solvent or in the presence of a solvent like water or 2,3-butanediol.
- -
-
Paragraph 0041
(2017/12/07)
-
- Photocatalytic decarboxylation of lactic acid by Pt/TiO2
-
A photocatalytic route for the conversion of lactic acid to acetaldehyde in water is demonstrated. Direct UV photolysis of lactic acid yields CO2 and ethanol via a radical mechanism. Pt/TiO2 considerably increases the rate of lactic acid decarboxylation with acetaldehyde, H2 and CO2 as the main products. A concerted photodecarboxylation/dehydrogenation mechanism is proposed.
- Liu, Kaituo,Litke, Anton,Su, Yaqiong,Van Campenhout, Bart G.,Pidko, Evgeny A.,Hensen, Emiel J. M.
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p. 11634 - 11637
(2016/10/04)
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- RECOMBINANT STRAIN FOR PRODUCING 2,3-BUTANEDIOL, COMPRISING (A) INACTIVATED LACTATE DEHYDROGENASE AND (B) INACTIVATED SUCROSE REGULATOR
-
The present invention relates to a recombinant strain for producing 2,3-butanediol, comprising (a) an inactivated lactate dehydrogenase and (b) an inactivated sucrose regulator. According to the present invention, it is possible to economically produce 2,3-butanediol using a cheap carbon source, and the efficiency and productivity of 2,3-butanediol is remarkable compared with a wild type.
- -
-
Paragraph 0050-0072
(2016/08/03)
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- RECOMBINANT MICROORGANISM WITH INCREASED PRODUCTIVITY OF 2,3-BUTANEDIOL, AND METHOD FOR PRODUCING 2,3-BUTANEDIOL USING SAME
-
Disclosed herein is a recombinant microorganism having enhanced 2,3-butanediol producing ability, wherein a pathway for converting pyruvate to acetyl-CoA, a pathway for converting pyruvate to formic acid, or a pathway for converting pyruvate to lactate is inhibited in a microorganism having acetyl-CoA and lactate biosynthetic pathways.
- -
-
Paragraph 0057; 0058
(2016/03/19)
-
- Improved bioethanol production from metabolic engineering of Enterobacter aerogenes ATCC 29007
-
This study investigates the enhancement of bioethanol production using a genetic engineering approach. The bioethanol-producing strain, E. aerogenes ATCC 29007, was engineered by deleting the D-lactate dehydrogenase (ldhA) gene to block the production of lactic acid. The Open-reading frame coding region of ldhA gene was replaced with a kanamycin cassette flanked by FLP recognition target sites by using a one-step method to inactivate chromosomal genes and primers designed to create in-frame deletions upon excision of the resistance cassette. The colony PCR was used to confirm the deleted gene. Glycerol, a useful byproduct in the biodiesel industry, was employed to convert into bioethanol, using engineered E. aerogenes SUMI014. Under optimal conditions of fermentation (34 °C, pH 7.5, 78 h), bioethanol production by the mutant strain was 34.54 g/L, 1.5 times greater than that produced by its wild type (13.09 g/L). Subsequent overexpression of alcohol dehydrogenase (adhE) gene in the mutant strain; increased the production of bioethanol up to 38.32 g/L. By the combination of gene deletion and overexpression, the bioethanol yield was 0.48 g/g when employing 80 g/L glycerol. Hence, a significant enhancement in ethanol production was observed. These results may provide valuable guidelines for further engineering bioethanol producers.
- Thapa, Laxmi Prasad,Lee, Sang Jun,Yang, Xiaoguang,Lee, Ju Hun,Choi, Han Suk,Park, Chulhwan,Kim, Seung Wook
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p. 2051 - 2060
(2015/12/12)
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- Engineering Pichia pastoris for improved NADH regeneration: A novel chassis strain for whole-cell catalysis
-
Many synthetically useful reactions are catalyzed by cofactor-dependent enzymes. As cofactors represent a major cost factor, methods for efficient cofactor regeneration are required especially for large-scale synthetic applications. In order to generate a novel and efficient host chassis for bioreductions, we engineered the methanol utilization pathway of Pichia pastoris for improved NADH regeneration. By deleting the genes coding for dihydroxyacetone synthase isoform 1 and 2 (DAS1 and DAS2), NADH regeneration via methanol oxidation (dissimilation) was increased significantly. The resulting Δdas1 Δdas2 strain performed better in butanediol dehydrogenase (BDH1) based whole-cell conversions. While the BDH1 catalyzed acetoin reduction stopped after 2 h reaching ～50% substrate conversion when performed in the wild type strain, full conversion after 6 h was obtained by employing the knockout strain. These results suggest that the P. pastoris Δdas1 Δdas2 strain is capable of supplying the actual biocatalyst with the cofactor over a longer reaction period without the over-expression of an additional cofactor regeneration system. Thus, focusing the intrinsic carbon flux of this methylotrophic yeast on methanol oxidation to CO2 represents an efficient and easy-to-use strategy for NADH-dependent whole-cell conversions. At the same time methanol serves as co-solvent, inductor for catalyst and cofactor regeneration pathway expression and source of energy.
- Geier, Martina,Brandner, Christoph,Strohmeier, Gernot A.,Hall, Mélanie,Hartner, Franz S.,Glieder, Anton
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p. 1741 - 1748
(2016/04/10)
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- IMPROVED BUTANEDIOL MANUFACTURING PROCESS
-
The disclosed process provides an improved process for manufacturing and recovering butanediol. More particularly, the disclosed process relates to an improved process for manufacturing and recovering butanediol from feedstock comprising butynediol in a reaction zone at reaction conditions, comprising the steps of reacting butynediol in the liquid phase and hydrogen in a reaction zone containing hydrogenation catalyst, recovering liquid phase product from the reaction zone, passing the recovered liquid phase product into a first liquid pressure let down vessel maintained at specific conditions, recovering first and second streams from the first liquid pressure let down vessel as liquid bottoms and overhead vent gas, respectively, passing the first stream liquid bottoms recovered to a second liquid pressure let down vessel maintained at specific conditions, and the second stream vent gas recovered to a vent gas cooler maintained at specific conditions, passing the gas from the vent gas cooler to a hydrogen recovery zone comprising a membrane filter, whereby the permeate comprises high purity hydrogen gas and the retentate comprises contaminants, recycling the permeate to the reaction zone, and recovering first and second streams from the second liquid pressure let down vessel as liquid bottoms comprising butanediol and overhead vent gas, respectively.
- -
-
Paragraph 0043-0045
(2015/11/10)
-
- Molecular Catalysts Capable of Catalyzing Oxidation of Hydrocarbons and Method for Oxidizing Hydrocarbons
-
This invention relates to molecular catalysts and chemical reactions utilizing the same, and particularly to molecular catalysts for efficient catalytic oxidation of hydrocarbons, such as hydrocarbons from natural gas. The molecular catalytic platform provided herein is capable of the facile oxidation of hydrocarbons, for example, under ambient conditions such as near room temperature and atmospheric pressure.
- -
-
Paragraph 0137; 0138; 0139
(2015/04/15)
-
- PRODUCTION METHOD OF 2,3-BUTANEDIOL
-
PROBLEM TO BE SOLVED: To obtain 2,3-butanediol efficiently in a high yield from 3-hydroxy-2-butanone, especially by hydrogenation of an acetoin in a fermentation product obtained by biological fermentation. SOLUTION: A production method of 2,3-butanediol comprises subjecting a raw material containing 2-hydroxy-3-butanone to a reductive reaction in a hydrogen gas atmosphere in the presence an inhomogeneous metal catalyst to convert 2-hydroxy-3-butanone to 2,3-butanediol. The method especially improves the efficiency of the fermentation production of 2,3-butanediol by microorganisms. COPYRIGHT: (C)2016,JPO&INPIT
- -
-
Paragraph 0060
(2016/10/20)
-
- Exploring the reaction conditions for Ru/C catalyzed selective hydrogenolysis of xylitol alkaline aqueous solutions to glycols in a trickle-bed reactor
-
The hydrogenolysis of an alkaline aqueous solution of xylitol to mainly ethylene- and propylene-glycols was studied over a Ru/C catalyst in a high pressure fixed-bed reactor run in the trickle-bed mode with co-current downflow of liquid feed and hydrogen. The effects of reaction parameters including H 2 pressure (40-80 bar), temperature (190-200 °C) and pH values (NaOH/xylitol molar ratio in the range 0.1-0.2, pH 9-12) and residence time have been explored to increase the selectivity of this reaction to the desired ethyleneglycol product. The activity and final products distribution were much influenced by the hydrogen pressure. An optimum to afford a high conversion and a high selectivity to ethyleneglycol at different space times was found at 60 bar. The effects observed are in agreement with the reaction pathways previously proposed and the relative reaction rates of the dehydrogenation/hydrogenation and base-catalyzed reactions of the intermediates are affected by the hydrogen pressure and the concentration of the alkaline promoter.
- Auneau, Florian,Berchu, Maeva,Aubert, Guillaume,Pinel, Catherine,Besson, Michèle,Todaro, Daniela,Bernardi, Marco,Ponsetti, Tiziano,Di Felice, Renzo
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p. 100 - 106
(2014/07/07)
-
- Synthesis of ferrocene derivatives with planar chirality via palladium-catalyzed enantioselective C-H bond activation
-
The first catalytic and enantioselective C-H direct acylation of ferrocene derivatives has been developed. A series of 2-acyl-1-dimethylaminomethylferrocenes with planar chirality were provided under highly efficient and concise one-pot conditions with up to 85% yield and 98% ee. The products obtained could be easily converted to various chiral ligands via diverse transformations.
- Pi, Chao,Cui, Xiuling,Liu, Xiuyan,Guo, Mengxing,Zhang, Hanyu,Wu, Yangjie
-
supporting information
p. 5164 - 5167
(2014/12/11)
-
- 1-Butanol production from glycerol by engineered Klebsiella pneumoniae
-
To utilize the by-product of biodiesel production, Klebsiella pneumoniae, a well-known glycerol-fermenting microorganism, was engineered to produce 1-butanol. The modified CoA-dependent and 2-keto acid pathways were established by expressing the genes ter-bdhB-bdhA and kivd, respectively. The 1-butanol titer and specific BuOH yield were 15.03 mg L-1 and 27.79 mg-BuOH per g cell in KpTBB (K. pneumoniae overexpressing the genes ter-bdhB-bdhA), and 28.7 mg L-1 and 51.58 mg-BuOH per g cell in Kp-kivd (K. pneumoniae overexpressing the gene kivd), respectively. Moreover, the native products in K. pneumoniae fermentation were down regulated using the antisense RNA strategy. The resulting yield of 1,3-propanediol and 2,3-butanediol was reduced by 81% and 15%, respectively. This work reports a new strain, K. pneumoniae, for 1-butanol production and the application of an antisense RNA strategy as an effective method for reducing the main by-products.
- Wang, Miaomiao,Fan, Lihai,Tan, Tianwei
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p. 57791 - 57798
(2015/02/18)
-
- METHOD FOR PREPARING TRIOLS AND DIOLS FROM BIOMASS-DERIVED REACTANTS
-
A method to make triols and diols is described. The method includes the steps of performing an aqueous-phase hydrodeoxygenation reaction on a feedstock containing a biomass-derived reactant in aqueous solution. The feedstock is contacted with a heterogeneous metal-containing bifunctional catalyst or a combination of two or more heterogeneous metal-containing catalysts that catalyze cleavage of C—C and C—O bonds, for a time, temperature, pressure, and weight hourly space velocity to yield a product mix comprising triols, diols, or combinations thereof.
- -
-
Paragraph 0092; 0093
(2014/09/30)
-
- Thermal decomposition of diethylketone cyclic triperoxide in polar solvents
-
The thermolysis of diethylketone cyclic triperoxide (3,3,6,6,9,9-hexaethyl- 1,2,4,5,7,8-hexaoxacyclononane, DEKTP) was studied in different polar solvents (ethanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-2-propanol, and acetonitrile). The rate constant values (kd) are higher for reactions performed in secondary alcohols probably because of the possibility to form a cyclic adduct with the participation of the hydrogen atom bonded to the secondary carbon. The kinetic parameters were correlated with the physicochemical properties of the selected solvents. The products of the DEKTP thermal decomposition in different polar solvents support a radical-based decomposition mechanism. CSIRO 2014.
- Barreto, Gaston P.,Alvarez, Elida E.,Eyler, Gladys N.,Canizo, Adriana I.,Allegretti, Patricia E.
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p. 881 - 886
(2014/07/07)
-
- Developing an efficient catalyst for controlled oxidation of small alkanes under ambient conditions
-
The tricopper complex [CuICuICuI(7-N- Etppz)]1+, where 7-N-Etppz denotes the ligand 3,3′-(1,4- diazepane-1,4-diyl)bis[1-(4-ethyl piperazine-1-yl)propan-2-ol], is capable of mediating facile conversion of methane into methanol upon activation of the tricopper cluster by dioxygen and/or HO at room temperature. This is the first molecular catalyst that can catalyze selective oxidation of methane to methanol without over-oxidation under ambient conditions. When this CuICu ICuI tricopper complex is activated by dioxygen or H 2O2, the tricopper cluster harnesses a "singlet oxene", the strongest oxidant that could be used to accomplish facile O-atom insertion across a C-H bond. To elucidate the properties of this novel catalytic system, we examine here methane oxidation over a wider range of conditions and extend the study to other small alkanes, including components of natural gas. We illustrate how substrate solubility, substrate recognition and the amount of H2O2 used to drive the catalytic oxidation can affect the outcome of the turnover, including regiospecificity, product distributions and yields of substrate oxidation. These results will help in designing another generation of the catalyst to alleviate the limitations of the present system. This journal is the Partner Organisations 2014.
- Nagababu, Penumaka,Yu, Steve S.-F.,Maji, Suman,Ramu, Ravirala,Chan, Sunney I.
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p. 930 - 935
(2014/04/03)
-
