Xi:Irritant;
110-15-6Relevant articles and documents
RHODIUM(III) COMPLEXES WITH O-ALKYL-S-ALKYL THIOCARBONATES AS CATALYSTS FOR THE HOMOGENEOUS HYDROGENATION OF UNSATURATED COMPOUNDS
Maistrenko, V. N.,Rusakov, I. A.,Bondareva, S. O.,Murinov, Yu. I.,Tolstikov, G. A.
, p. 2149 - 2151 (1989)
Catalytic activity was found for Rh3+ complexes with O-alkyl-S-alkyl thiocarbonates in the homogeneous hydrogenation of unsaturated compounds.Cyclic voltamperometry was used to detect the formation of rhodium hydride intermediates during the hydrogenation of alkenes in the presence of these complexes.
Marvel et al.
, p. 838,847, 851 (1951)
Conjugated microporous polymers as a visible light driven platform for photo-redox conversion of biomass derived chemicals
Chen, Bo,Chen, Lang,Chen, Shanyong,Jin, Yongdong,Kang, Jinyang,Ma, Lijian,Xia, Chuanqin,Yan, Hongjian,Yan, Zijun
, p. 3607 - 3611 (2021)
Photocatalytic conversion of biomass derived chemicals to valuable products is a highly sustainable process. Herein we report the photocatalytic hydrogenation of maleic acid to succinic acid and oxidation of 5-hydroxymethylfurfural to 2,5-diformylfuran using the same conjugated porous polymers (CMPs). The CMPs were constructed from 2,4,6-(tri-2-thienyl)-1,3,5-triazine as the knots and different benzene derivatives as linkers, and their morphologies, redox potentials, charge separation efficiency, and the consequent photocatalytic performance have been controlled. As a result, the CMP with benzene as the linker features the highest photocatalytic activities with production rates of 4.66 mmol g?1h?1for succinic acid and 0.53 mmol g?1h?1for 2,5-diformylfuran, respectively. Most importantly, high photocatalytic activity has also been achieved under natural sunlight irradiation, implying its feasibility as an efficient photocatalytic platform for solar-to-chemical energy conversion.
Metal Sub-nanoclusters Confined within Hierarchical Porous Carbons with High Oxidation Activity
Zhao, Xin,Kong, Xiangpeng,Wang, Fengliang,Fang, Ruiqi,Li, Yingwei
, p. 10842 - 10849 (2021)
Metal sub-nanoclusters (SNCs) have shown great promise for a variety of catalytic reactions. However, the fabrication of stable metal SNCs simultaneously with high dispersion and high metal contents remains a challenge. Herein, we report a novel and versatile strategy for the synthesis of various bimetal SNCs stabilized within hierarchical porous carbons (HPC). This facile synthesis only involves the self-assembly of a metal-organic framework (MOF) as the precursor, a molten salt assisted pyrolysis process and the final metal replacement. The metal SNCs (mostly less than 0.8 nm) derived from the metal nodes of the MOF are exclusively confined and homogeneously dispersed throughout the organic ligands derived HPC at high loadings (up to 11.2 wt %). The obtained Cu-Pd@HPC composite exhibits superior catalytic activity and recycling durability in the selective transformation of furfural to maleic acid, achieving 97.8 % yield of maleic acid with a TOF value as high as 20.1 h?1 under mild conditions. DFT calculations reveal that the introduction of Pd shifts the partial density of states of Cu toward the Fermi level, leading to stronger chemisorption of furfural to enhance the catalytic activity.
The contribution to kappa number from hexeneuronic acid groups in pulp xylan
Li, Jiebing,Gellerstedt, Goeran
, p. 213 - 218 (1997)
The kappa number of chemical pulps is widely used both in mill operation and in laboratory work as a measure of the degree of delignification in pulping, oxygen delignification, and prebleaching. Recently, it has been shown that the kappa number reflects not only lignin but also carbohydrate structures sensitive to oxidation by permanganate, notably hexeneuronic acid groups linked to xylan. In the present work, the kappa number units originating from hexeneuronic acid groups calculated on a molar basis have been determined in two different ways, viz. by permanganate oxidation of model compounds and by selective elimination of hexeneuronic acid groups from a series of kraft pulps. The results are in good agreement with each other and demonstrate that 10 μmol of hexeneuronic acid correspond to 0.84-0.86 kappa units. From kappa number determinations combined with hydrolysis of the pulp with mercuric acetate, it is possible to calculate the amount of hexeneuronic acid groups present in a pulp.
Encapsulation of Pt(IV) prodrugs within a Pt(II) cage for drug delivery
Zheng, Yao-Rong,Suntharalingam, Kogularamanan,Johnstone, Timothy C.,Lippard, Stephen J.
, p. 1189 - 1193 (2015)
This report presents a novel strategy that facilitates delivery of multiple, specific payloads of Pt(IV) prodrugs using a well-defined supramolecular system. This delivery system comprises a hexanuclear Pt(II) cage that can host four Pt(IV) prodrug guest molecules. Relying on host-guest interactions between adamantyl units tethered to the Pt(IV) molecules and the cage, four prodrugs could be encapsulated within one cage. This host-guest complex, exhibiting a diameter of about 3 nm, has been characterized by detailed NMR spectroscopic measurements. Owing to the high positive charge, this nanostructure exhibits high cellular uptake. Upon entering cells and reacting with biological reductants such as ascorbic acid, the host-guest complex releases cisplatin, which leads to cell cycle arrest and apoptosis. The fully assembled complex displays cytotoxicity comparable to that of cisplatin against a panel of human cancer cell lines, whereas the cage or the Pt(IV) guest alone exhibit lower cytotoxicity. These findings indicate the potential of utilising well-defined supramolecular constructs for the delivery of prodrug molecules.
Glutaric and Succinic Acids in the Cobalt Acetate Catalyzed Oxidation of Cyclohexane with Oxygen
Schulz, Johann G. D.,Onopchenko, Anatoli
, p. 3716 - 3719 (1980)
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Toyama,Tsuchiya
, p. 751 (1936)
The effect of Br- and alkali in enhancing the oxidation of furfural to maleic acid with hydrogen peroxide
Yang, Tao,Li, Wenzhi,Ogunbiyi, Ajibola T.
, (2021)
This study was focused on investigating a novel catalytic system for the selective conversion of furfural to maleic acid (MA) in an aqueous system with hydrogen peroxide as an oxidant. A series of experiments that study the impacts of catalyst species, furfural concentration, catalyst dosage, reaction temperature, residue time, hydrogen peroxide concentration, excess water content, and solvent types on the oxidation of furfural to MA was carried out. The results showed that the co-existence of Br- and alkali sites might play a vital role in furfural oxidation, which could improve the MA yield remarkably. Under 90 °C for 3 h, 72.4 % MA yield was obtained with KOH and KBr as co-catalyst in an aqueous phase. Moreover, a possible reaction pathway of furfural oxidation was proposed on the basis of our reaction system.
Photoelectroreduction of Building-Block Chemicals
Chen, Fengjiao,Cui, Wei,Zhang, Jie,Wang, Yeyun,Zhou, Junhua,Hu, Yongpan,Li, Yanguang,Lee, Shuit-Tong
, p. 7181 - 7185 (2017)
Conventional photoelectrochemical cells utilize solar energy to drive the chemical conversion of water or CO2 into useful chemical fuels. Such processes are confronted with general challenges, including the low intrinsic activities and inconvenient storage and transportation of their gaseous products. A photoelectrochemical approach is proposed to drive the reductive production of industrial building-block chemicals and demonstrate that succinic acid and glyoxylic acid can be readily synthesized on Si nanowire array photocathodes free of any cocatalyst and at room temperature. These photocathodes exhibit a positive onset potential, large saturation photocurrent density, high reaction selectivity, and excellent operation durability. They capitalize on the large photovoltage generated from the semiconductor/electrolyte junction to partially offset the required external bias, and thereby make this photoelectrosynthetic approach significantly more sustainable compared to traditional electrosynthesis.
Unusual conversion of 5-hydroxy-2(5H)-furanone in aqueous solution
Poskonin,Badovskaya
, p. 594 - 597 (2003)
The conversion of 5-hydroxy-2(5H)-furanone into succinic acid in aqueous solution has been detected experimentally for the first time, indicating the possibility of forming and hydrolyzing its previously unknown tautomeric forms. The accelerating effect of increased pH values and temperature on the reaction has been established. A scheme is proposed to form succinic acid from 5-hydroxy-2(5H)-furanone.
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Ince
, p. 155 (1895)
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Selective oxidation of furfural in a bi-phasic system with homogeneous acid catalyst
Li, Xiaodan,Lan, Xiaocheng,Wang, Tiefeng
, p. 97 - 104 (2016)
The selective catalytic oxidation of furfural to 2(5H)-furanone, succinic acid (SA) and maleic acid (MA) was studied. Under optimized conditions, furfural was oxidized to 2(5H)-furanone with a yield of 60–62% in an aqueous/organic bi-phasic system using 1,2-dichloroethane or ethyl acetate as the solvent and formic acid as the catalyst, while the total yield of SA and MA was 15–20%. Compared with other homogeneous and heterogeneous acid catalysts, formic acid gave a much higher selectivity to 2(5H)-furanone because it reacted with hydrogen peroxide to generate performic acid that had a strong oxidizing nature and good solubility in both the aqueous and organic phases. The solvent had a significant influence on the product distribution. A simplified reaction network was established to quantitatively analyze the solvent effect based on the reaction rate constants. In the homogeneous system, the yield of 2(5H)-furanone decreased while the yield of SA increased with an increasing dielectric constant of the solvent. The formic acid/furfural molar ratio, reaction temperature and furfural concentration were optimized for the selective oxidation of furfural to 2(5H)-furanone in the bi-phasic reaction system.
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Sakurai
, p. 8,10 (1937)
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Wieland,Mothes
, p. 149,152 Anm. 1, 153, 157 (1924)
Fichter,Buess
, p. 704 (1935)
Catalytic oxidation of furan and hydrofuran compounds. 4. Oxidation of furfural by hydrogen peroxide in the presence of sodium molybdate
Grunskaya,Badovskaya,Poskonin,Yakuba
, p. 775 - 780 (1998)
The oxidation of furfural by an aqueous solution of hydrogen peroxide in the presence of sodium molybdate was studied for the first time. Its final products are 2(5H)-furanone and also tartaric, malic, and succinic acids. The process takes place through the formation of peroxide and carbonyl compounds. Kinetic curves for the consumption of the reagents and the accumulation of the reaction products were obtained. In direction oxidation in this system differs substantially from the previously studied reactions of furfural with an aqueous solution of hydrogen peroxide without a catalyst and in the presence of selenium and vanadium compounds. 1999 Kluwer Academic/Plenum Publishers.
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Fischer,Roedig,Rauch
, (1942)
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Levulinic acid upgrade to succinic acid with hydrogen peroxide
Carnevali, Davide,Rigamonti, Marco G.,Tabanelli, Tommaso,Patience, Gregory S.,Cavani, Fabrizio
, p. 98 - 104 (2018)
Levulinic acid is produced from the acidic aqueous degradation of 5-hydroxymethylfurfural, with potential applications in bio-value added chemicals synthesis. Here, we report for the first time, the Baeyer-Villiger oxidation of levulinic acid to succinic acid, with hydrogen peroxide and tungstic acid at mild conditions and without any organic solvent. We investigated the effects of time, amount of reagent-to-catalyst molar ratio and H2O2-to-levulinic acid molar ratio. The maximum succinic acid selectivity was 75% with a levulinic acid conversion as high as 48%, after 6 h at 90 °C. We propose a reaction mechanism based on results obtained from the reactivity of the intermediates. The catalyst interacts with the substrate, forming a cyclic species that enhances the formation of succinic acid versus 3-hydroxypropanoic acid.
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Ruggli,Maeder
, (1944)
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Schmid,Maschka
, p. 235,238 (1949)
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Acree,Jacobson,Haller
, p. 449 (1945)
HPLC studies on the organic subset of the oscillatory BZ reaction. 2. Two different types of malonyl radicals in the Ce4+-malonic acid reaction
Sirimungkala, Atchara,Foersterling, Horst-Dieter,Noszticzius, Zoltan
, p. 3051 - 3055 (1996)
Applying combined HPLC and NMR techniques, it was found that, besides the already known 1,1,2,2-ethanetetracarboxylic acid (ETA), monomalonyl malonate (MAMA) is also a product of the Ce4+-malonic acid reaction. This is indirect evidence that two different types of organic radicals are formed in the reaction: the alkyl and the carboxylato malonyl radicals. While ETA is a recombination product of two alkyl radicals, MAMA is formed in the recombination of one alkyl and one carboxylato radical.
Anodic Oxidation of Cyclohexanone on Lead Dioxide Electrode in Aqueous Sulfuric Acid Solution
Kunai, Atsutaka,Hatoh, Kazuhito,Hirano, Yoshinobu,Harada, Junji,Sasaki, Kazuo
, p. 1717 - 1722 (1985)
The electrolytic behavior of cyclohexanone was examined by potentiometry with rotating disk electrode as well as by product analyses.The reaction was activation controlled and the reaction orders were first with respect to cyclohexanone and zero for proton.Cyclohexanone reacted by approximately 6 electrons to give adipic acid mainly which accumulated proportionally to the electricity consumed.Changes in temperature, proton concentration, and current denisty resulted in only minor effects on the reaction.In neutral solution, however, the oxidation was suppressed and oxygen evolution dominated.Other electrode materials such as Pt, graphite, RuO2, and PtO2 were inactive.The chemical oxidation with PbO2 itself did not occur.From these facts, reaction mechanism was discussed.
SELECTIVE ANODIC OXIDATION OF TETRAHYDROFURAN
Wermeckes, Bernd,Beck, Fritz,Schulz, Harry
, p. 577 - 583 (1987)
The anodic oxidation of tetragydrofuran in acid aqueous electrolytes has been investigated in detail.Selective oxidation to 2-hydroxy tetrahydrofuran has been found to proceed.Under optimum conditions (smooth platinum, high current densities, 200 - 400 mA/cm2, 1 - 6 M THF, 1 M H2SO4, 35 deg C, quasi divided cells), the product was obtained in batch type laboratory scale (60percent of 2 F/mol conversion) with 70percent current efficiency and 95percent selectivity.Only traces of butyrolactone and succinic acid, the dominating products in the case of PbO2 anodes, were found.Oxygen is the main side product.
An efficient method for the catalytic aerobic oxidation of cycloalkanes using 3,4,5,6-Tetrafluoro-N-Hydroxyphthalimide (F4-NHPI)
Guha, Samar K.,Ishii, Yasutaka
, p. 327 - 335 (2021/12/13)
N-Hydroxyphthalimide (NHPI) is known to be an effective catalyst for the oxidation of hydrocarbons. The catalytic activity of NHPI derivatives is generally increased by introducing an electron-withdrawing group on the benzene ring. In a previous report, two NHPI derivatives containing fluorinated alkyl chain were prepared and their catalytic activity was investigated in the oxidation of cycloalkanes. It was found that the fluorinated NHPI derivatives showed better yields for the oxidation reaction. As a continuation of our work with fluorinated NHPI derivatives, our next aim was to investigate the catalytic activity of the NHPI derivatives by introducing fluorine atoms in the benzene ring of NHPI. In the present research, 3,4,5,6-Tetrafluoro-N-Hydroxyphthalimide (F4-NHPI) is prepared and its catalytic activity has been investigated in the oxidation of two different cycloalkanes for the first time. It has been found that F4-NHPI showed higher catalytic efficiency compared with that of the parent NHPI catalyst in the present reactions. The presence of a fluorinated solvent and an additive was also found to accelerate the oxidation.
Labile Photo-Induced Free Radical in α-Ketoglutaric Acid: a Universal Endogenous Polarizing Agent for In Vivo Hyperpolarized 13C Magnetic Resonance
Brindle, Kevin M.,Cheng, Tian,Comment, Arnaud,Gaunt, Adam P.,Hesse, Friederike,Lewis, Jennifer S.,Marco-Rius, Irene
supporting information, (2021/12/09)
Hyperpolarized (HP) 13C magnetic resonance enables non-invasive probing of metabolism in vivo. To date, only 13C-molecules hyperpolarized with persistent trityl radicals have been injected in humans. We show here that the free radical photo-induced in alpha-ketoglutaric acid (α-KG) can be used to hyperpolarize photo-inactive 13C-molecules such as [1-13C]lactate. α-KG is an endogenous molecule with an exceptionally high radical yield under photo-irradiation, up to 50 %, and its breakdown product, succinic acid, is also endogenous. This radical precursor therefore exhibits an excellent safety profile for translation to human studies. The labile nature of the radical means that no filtration is required prior to injection while also offering the opportunity to extend the 13C relaxation time in frozen HP 13C-molecules for storage and transport. The potential for in vivo metabolic studies is demonstrated in the rat liver following the injection of a physiological dose of HP [1-13C]lactate.
Oxidation of cyclohexanone and/or cyclohexanol catalyzed by Dawson-type polyoxometalates using hydrogen peroxide
Dermeche, Leila,Idrissou, Yasmina,Mazari, Tassadit,Moudjahed, Mohammed,Rabia, Cherifa
, (2022/03/07)
The oxidation of cyclohexanone, cyclohexanol or cyclohexanone/cyclohexanol mixture using as catalyst, Dawson-type polyoxometalates (POMs) of formula, α- and β-K6P2W18O62, α-K6P2Mo6W12O62 and α1-K7P2Mo5VW12O62 and hydrogen peroxide, carried out at 90 °C with a reaction time of 20 h, led to a high number of mono- and di-acids which were identified by GC-MS. Levulinic, 6-hydroxyhexanoic, adipic, glutaric and succinic acids, major products were evaluated by HPLC. Regardless of the substrate nature, all POMs exhibited high catalytic activity with 94–99% of conversion, whereas the formation of the different products is sensitively related to both the composition and symmetry of the POMs and the substrate nature. The main products are adipic acid in the presence of α-K6P2Mo6W12O62 and α1-K7P2Mo5VW12O62, levulinic acid in the presence of α1-K7P2Mo5VW12O62 and β-K6P2W18O62 and 6-hydroxyhexanoic acid in the presence of α- and β-K6P2W18O62. Graphical abstract: High catalytic activity was observed with?α- and?β-K6P2W18O62, α-K6P2Mo6W12O62 and α1-K7P2Mo5VW12O62 Dawson-type for the oxidation of cyclohexanone, cyclohexanol or cyclohexanone/cyclohexanol mixture, in the hydrogen peroxide presence, to several oxygenated products. Adipic, levulinic and 6-hydroxyhexanoic acids are the main products. The peroxo- species formed in situ could be the active sites.[Figure not available: see fulltext.]
