F:Flammable;
110-62-3Relevant articles and documents
A novel iron(III) catalysed degradation of aliphatic aldehydes to their lower homologues with implications for lipid peroxidation chemistry
Bigwood,Delve,Read
, p. 776 - 778 (1990)
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Thermolysis of Dioxetanes: Activation Parameters for cis-/trans-3,4-Dialkyl-1,2-dioxetanes
Baumstark, Alfons L.,Dunams, Tambra,Roskamp, Peter C.,Wilson, Catherine E.
, p. 261 - 263 (1983)
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Tungsten Complex Catalyzed Dehydrative Decarboxylation of 2,3-Dihydroxycarboxylic Acids
Yu, Hye Kyung Bae,Schwartz, Jeffrey
, p. 6787 - 6790 (1992)
WOCl4 catalyzes dehydrative decarboxylation of 2,3-dihydrocarboxylic acids to enols, likely via β-lactone intermediates.Classical reagents for conversion of 3-hydroxycarboxylic acids to β-lactones fail with these substrates.
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Bedenbaugh et al.
, p. 4703 (1979)
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Polymeric rhodium-containing catalysts in olefin hydroformylation
Slivinskii,Kolesnichenko
, p. 2449 - 2454 (2004)
The main results obtained by studying hydroformylation of olefins on polymeric rhodium-containing catalysts are reviewed. Different types of N-containing polymeric ligands capable of hydroformylating under conditions of heterogeneous catalysis are considered. Possibilities of using water-soluble polymers containing quaternary ammonium groups are shown. The data on the influence of a polymeric matrix on the catalytic properties of the rhodium catalyst of olefin hydroformylation are presented.
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Fell,B. et al.
, p. 3261 - 3266 (1968)
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Delayed autocatalytic behavior of Mn(II) ions at a critical ratio: The effect of structural isomerism on permanganic oxidation of L-norleucine
Bahrami, Homayoon,Zahedi, Mansour
, p. 1 - 11 (2006)
The kinetics of the permanganic oxidation process of L-norleucine, L-leucine, L-isoleucine, and L-tert-leucine in strong acid medium has been investigated using a spectrophotometric technique. Conclusive evidences have proven autocatalytic activity of Mn(II) for these reactions in strong acid medium analogous to weak acid medium, but in the former, ratio of Mn(II) to amino acid concentration must reach a certain amount for autocatalytic phenomenon to emerge, which we call "critical ratio." This critical ratio depends on the nature of the amino acid employed. Thus considering "delayed autocatalytic behavior" of Mn(II) ions, rate equations satisfying observations for both catalytic and noncatalytic routes have been presented. Kinetic data in a noncatalytic pathway have been fitted to a biparametric equation including inductive, steric, and hyperconjugation correction effects, and it is determined that by shifting the side branch on a carbon chain toward an α-carbon atom (adjacent to amino acid's functional group) and also adding branches to the α-carbon atom, the reaction rate in the noncatalytic pathway decreases. Inductive and steric hindrance factors in amino acid's carbon chain are effective on processes' rate both in catalytic and noncatalytic pathways.
Primary Alcohol Oxidation with N-Iodosuccinimide
Beebe, T. R.,Adkins, R. L.,Bogardus, C. C.,Champney, B.,Hii, P. S.,et al.
, p. 3126 - 3128 (1983)
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Fell,B.,Rupilius,W.
, p. 2721 - 2723 (1969)
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Directed evolution of a pyruvate aldolase to recognize a long chain acyl substrate
Cheriyan, Manoj,Walters, Matthew J.,Kang, Brian D.,Anzaldi, Laura L.,Toone, Eric J.,Fierke, Carol A.
, p. 6447 - 6453 (2011)
The use of biological catalysts for industrial scale synthetic chemistry is highly attractive, given their cost effectiveness, high specificity that obviates the need for protecting group chemistry, and the environmentally benign nature of enzymatic procedures. Here we evolve the naturally occurring 2-keto-3-deoxy-6-phosphogluconate (KDPG) aldolases from Thermatoga maritima and Escherichia coli, into enzymes that recognize a nonfunctionalized electrophilic substrate, 2-keto-4-hydroxyoctonoate (KHO). Using an in vivo selection based on pyruvate auxotrophy, mutations were identified that lower the KM value up to 100-fold in E. coli KDPG aldolase, and that enhance the efficiency of retro-aldol cleavage of KHO by increasing the value of kcat/K M up to 25-fold in T. maritima KDPG aldolase. These data indicate that numerous mutations distal from the active site contribute to enhanced 'uniform binding' of the substrates, which is the first step in the evolution of novel catalytic activity.
Aerosol formation in the cyclohexene-ozone system
Seinfeld,Kalberer,Yu,Cocker,Flagan
, p. 4894 - 4901 (2000)
Atmospheric oxidation of certain VOCs can yield products with low vapor pressure resulting in the partitioning of the products into the aerosol phase, producing secondary organic aerosol. As cyclohexene is known to produce aerosol upon photooxidation, it was used as a model system for the molecular identification of gas- and aerosol-phase products via derivatization and MS detection. Adipic acid, hydroxyglutaric acid, and hydroxyadipic acid were among the compounds identified in the aerosol phase. Pentanal was the predominant product in the gas phase at a molar yield of 17%. Possible explanations for the presence of relatively high vapor pressure compounds in the aerosol phase are presented.
Asymmetric catalysis. Part 127: Enantioselective desymmetrization of 2- n-butyl-4,7-dihydro-1,3-dioxepin with (η6-arene)ruthenium(II) half-sandwich complexes
Brunner, Henri,Prommesberger, Markus
, p. 3231 - 3239 (1998)
(η6-Arene)ruthenium half-sandwich complexes are highly active and stereoselective catalysts in the enantioselective desymmetrization of 2-n- butyl-4,7-dihydro-1,3-dioxepin to give 2-n-butyl-4,5-dihydro-1,3-dioxepin. Enantioselectivities up to 61% ee were achieved. The temperature and solvent dependence of the catalysis as well as the activation of the catalyst were investigated.
Kinetics of the Reversible β-Scission of the Cyclopentyloxy Radical
Beckwith, Athelstan L. J.,Hay, Benjamin P.
, p. 230 - 234 (1989)
The reaction of N-(cyclopentyloxy)pyridine-2-thione (6) with tributylstannane in benzene constitutes a clean experimental system for a kinetic study of the β-scission of the cyclopentyloxy radical (1).Product distributions are reported as a function of tributylstannane concentration over a temperature range of 6-80 deg C.The results are consistent with a mechanism involving a reversible β-scission.Arrhenius parameters for the β-scission of the cyclopentyloxy radical (1) are log A (s-1)=12.55+/-0.41 and Ea=6.26+/-0.54 kcal/mol, while those for the reverse reaction, the 1,5-exo cyclization of the 4-formylbutyl radical (2), are log A (s-1)=10.2+/-0.3 and Ea=6.88+/-0.46 kcal/mol.The observed equilibrium constants and activation parameters are compared with theoretical calculations including group-additivity equilibrium constants and AM1-UHF activation parameters.
Generation of Alkoxyl Radicals from O-Alkyl Benzenesulphenates
Beckwith, Athelstan L.,Hay, Benjamin P.,Williams, Geoffrey M.
, p. 1202 - 1203 (1989)
Representative examples (1, 2, and 3) of primary, secondary, and tertiary alkyl benzenesulphenates, when treated with tributylstannane, generate alkoxy radicals which undergo characteristic β-scission or intramolecular addition reactions; the rate constants of these processes have been determined.
HAPs release from wood drying
Otwell, Lawrence P.,Hittmeier, Michael E.,Hooda, Usha,Yan, Hui,Su, Wei,Banerjee, Sujit
, p. 2280 - 2283 (2000)
Hazardous Air Pollutant (HAP) profiles from drying softwood and hardwood flakes (for the manufacture of oriented strand board) are very similar, indicating that they originate through a common mechanism, the breakdown of wood tissue. Hence, the strategies employed to reduce VOC (volatile organic compound) emissions from hardwood can also be extended to decreasing HAPs from softwood. Drying aspen flakes in the field and in the laboratory gives rise to different VOC species, and direct extension of laboratory data to the field may prove difficult. Formaldehyde emissions from drying fresh aspen flakes are lower than those from stored material; the opposite effect occurs for methanol and the other aldehydes. HAPs evolved from drying pine flakes surge sharply at 5-10% moisture content during drying at 130-160 °C. Emissions of methanol, formaldehyde, pentanal, and hexanal all begin simultaneously, with the release of methanol and formaldehyde being the most sensitive to dryer temperature. Hence, the nature of the VOC mix is partly governed by the dryer temperature. Pine and aspen give rise to similar HAPs profiles during either drying or pressing flakes that are already dried.
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Motoki et al.
, p. 922,924 (1965)
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Tuning Selectivity in Aliphatic C-H Bond Oxidation of N-Alkylamides and Phthalimides Catalyzed by Manganese Complexes
Milan, Michela,Carboni, Giulia,Salamone, Michela,Costas, Miquel,Bietti, Massimo
, p. 5903 - 5911 (2017)
Site selective C-H oxidation of N-alkylamides and phthalimides with aqueous hydrogen peroxide catalyzed by manganese complexes is described. These catalysts are shown to exhibit substantially improved performance in product yields and substrate scope in comparison with their iron counterparts. The nature of the amide and imide group and of the N-alkyl moiety are shown to be effective tools in order to finely tune site selectivity between proximal (adjacent to the nitrogen) and remote C-H bonds on the basis of steric, electronic, and stereoelectronic effects. Moreover, formation of the α-hydroxyalkyl product in good yield and with excellent product chemoselectivity was observed in the reactions of the pivalamide and acetamide derivatives bearing an α-CH2 group, pointing again toward an important role played by stereoelectronic effects and supporting the hypothesis that these oxidations proceed via hydrogen atom transfer (HAT) to a high-valent manganese-oxo species. Good product yields and mass balances are obtained in short reaction times and under mild experimental conditions when relatively low loadings of an electron-rich manganese catalyst are used. The potential utility of these reactions for preparative purposes is highlighted in the site-selective oxidation of the pivalamide and phthalimide derivatives of substrates of pharmaceutical interest.
Modification of rhodium carbonyl catalysts for hydroformylation of 2-butenes by organophosphorus ligands
Kolesnichenko,Markova,Teleshev,Slivinskii
, p. 698 - 700 (1999)
The influence of the nature of the organophosphorus ligand and the P/Rh molar ratio on the catalytic properties of rhodium caibonyl complexes in hydroformylation of 2-butencs was studied. The difference between phosphine and phosphite ligands during the formation of highly selective catalytic complexes was found. It was supposed that a decrease in the selectivity with respect to 2-methylbutanal is due to the isomerization of olefins under conditions of a decrease in the competitive capability of CO for coordination sites (the high P/Rh ratio, a decrease in the total pressure of the synthesis-gas).
Studies on the oxidation of α-amino acids by N-bromo oxidants: Kinetics of the reaction of bromide ion with N-bromoacetamide
Ramachandran,Easwaramoorthy,Malim Maniraj
, p. 545 - 551 (1996)
The rate of oxidation of amino acids (AA) by N-Bromoacetamide (NBA) was studied in aqueous buffered medium at 35°C. The rate of disappearance of (NBA) is catalyzed by the Br- produced from the reduction of NBA. Analysis of the autocatalyzed reaction gives the kinetic data for the oxidation of bromide ion by NBA. The results suggest that the protonated NBA reacts with Br- to form Br2 which rapidly oxidizes amino acids. The rate constant for the reaction between protonated NBA and Br- at 35°C is estimated. 1996 John Wiley & Sons, Inc.
Rapid Identification and Quantification of Linear Olefin Isomers by Online Ozonolysis-Single Photon Ionization Time-of-Flight Mass Spectrometry
Xie, Yuanyuan,Chen, Ping,Hua, Lei,Hou, Keyong,Wang, Yongchao,Wang, Haiyan,Li, Haiyang
, p. 144 - 152 (2016)
The specific locations of the double bonds in linear olefins can facilitate olefin catalytic synthetic reactions to improve the quality of target olefin products. We developed a simple and efficient approach based on single photon ionization time-of-flight mass spectrometry (SPI-TOFMS) combined with online ozonolysis to identify and quantify the linear olefin double bond positional isomers. The online ozonolysis cleaved the olefins at the double bond positions that led to formation of corresponding characteristic aldehydes. The aldehydes were then detected by SPI-TOFMS to achieve unique spectrometric "fingerprints" for each linear olefin to successfully identify the isomeric ones. To accurately quantify the isomeric components in olefin mixtures, an algorithm was proposed to quantify three isomeric olefin mixtures based on characteristic ion intensities and their equivalent ionization coefficients. The relative concentration errors for the olefin components were lower than 2.5% while the total analysis time was less than 2 min. These results demonstrate that the online ozonolysis SPI-TOFMS has the potential for real-time monitoring of catalytic olefin synthetic reactions.
Products of the gas-phase reactions of O3 with alkenes
Atkinson,Tuazon,Aschmann
, p. 1860 - 1866 (1995)
The products of the gas-phase reactions of O3 with 1-pentene, 1-hexene, 1-heptene, 1-octene, 2,3-dimethyl-1-butene, cyclopentene, and 1-methyl-cyclohexene have been investigated at room temperature and 740 Torr total pressure of air in the presence of cyclohexane or n-octane to scavenge OH radicals. Products were identified and quantified by gas chromatography and in situ Fourier transform infrared absorption spectroscopy. The presence of cyclohexene, showed the formation of OH radicals from these O3 reactions. The carbonyl products were identified and quantified. -from Authors
Properties and applications of sodium (5-methyl-2-alkyl-1,3-dioxane-5-yl)-carboxylate synthesized with nanosolid superacid
Yuan, Lin,Jia, Guo Kai,Li, Zhong Yan,Zhang, Min,Yuan, Xian You
, p. 1085 - 1089 (2016)
A series of novel sodium (5-methyl-2-alkyl-1,3-dioxane-5-yl) carboxylate surfactants were synthesized using nanosolid superacid SO2-4 /Fe2O3 as a catalyst and characterized by 1H NMR, IR and elemental analysis. The critical micelle concentration (CMC) of surfactants was determined and the results showed that the CMC values were less than 2.0× 10-3 mol/L. Other relevant surface properties (Krafft point, emulsion stability, foam ability, degradability) were also evaluated. It was suggested that with respect to emulsion formation, foam stability and the range of application temperature, compared with traditional surfactants, the new surfactants could give better results and showed better properties when used as an emulsifier in emulsion polymerization. In addition, the surfactants were stable under neutral and alkaline conditions, and could form solid under acid condition. The solid will generate the original surfactants for reuse with alkali. Sodium (5-methyl-2-alkyl-1,3-dioxane-5-yl) carboxylate is likely to be a new type of 'environmentally friendly' surfactant.
Synthesis of Adipic Acid, 1,6-Hexanediamine, and 1,6-Hexanediol via Double-n-Selective Hydroformylation of 1,3-Butadiene
Mormul, Jaroslaw,Breitenfeld, Jan,Trapp, Oliver,Paciello, Rocco,Schaub, Thomas,Hofmann, Peter
, p. 2802 - 2810 (2016)
A method for the synthesis of the industrially relevant monomers adipic acid, 1,6-hexanediol (HDO), and 1,6-hexanediamine (HMD) via isomerizing hydroformylation of 1,3-butadiene is described. The aldehyde intermediates are protected in situ as acetals to avoid hydrogenation to pentanal. Adipic aldehyde diacetal is obtained in good yields, and the first examples for the conversion toward adipic acid, 1,6-hexanediol, and 1,6-hexanediamine are shown.
Products of the Gas-Phase Reactions of a Series of 1-Alkenes and 1-Methylcyclohexene with the OH Radical in the Presence of NO
Atkinson, Roger,Tuazon, Ernesto C.,Aschmann, Sara M.
, p. 1674 - 1680 (1995)
The products of the gas-phase reactions of the OH radical with 1-pentene, 1-hexene, 1-heptene, 1-octene, 2,3-dimethyl-1-butene, and 1-methylcyclohexene have been investigated in the presence of NO at room temperature and 740 Torr total pressure of air. Products were identified and quantified by gas chromatography and in situ Fourier transform infrared absorption spectroscopy. The carbonyl products identified and their yields were as follows: from 1-pentene, butanal (0.73 +/- 0.09) and HCHO (0.88 +/- 0.11); from 1-hexene, pentanal (0.46 +/- 0.07) and HCHO (0.57 +/- 0.08); from 1-heptene, hexanal (0.30 +/- 0.04) and HCHO (0.49 +/- 0.06); from 1-octene, heptanal (0.21 +/- 0.03) and HCHO (0.39 +/- 0.06); from 2,3-dimethyl-1-butene, acetone (0.27 +/- 0.04), 3-methyl-2-butanone, (0.45 +/- 0.06), and HCHO (0.50 +/- 0.04); and from 1-methylcyclohexene, 5-acetylpentanal (0.31 +/- 0.08). These product yield data suggest that the intermediate β-hydroxyalkoxy radicals undergo isomerization and/or reaction with O2 in competition with decomposition, and the decrease in the carbonyl and HCHO yields with increasing carbon number in the 1-alkenes 1-pentene through 1-octene suggests that isomerization of the intermediate β-hydroxyalkoxy radical is occurring.
Magnetic Polystyrene Nanosphere Immobilized TEMPO: A Readily Prepared, Highly Reactive and Recyclable Polymer Catalyst in the Selective Oxidation of Alcohols
Zheng, Zhi,Wang, Jianli,Zhang, Miao,Xu, Lixin,Ji, Jianbing
, p. 307 - 312 (2013)
The 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) radical immobilized on the magnetic polystyrene nanospheres (MPNs) was used as a recyclable catalyst in the oxidation of various alcohols. The new and simply prepared heterogeneous TEMPO/MPNs exhibits both similar versatility and efficiency to homogeneous TEMPO under basic Montanari conditions. The excellent stability of the MPNs enables the TEMPO/MPNs to be recycled more than 20times without significant leaching of immobilized TEMPO radicals or degradation of Fe3O4 nanoparticles. Moreover, the magnetic response ensures the rapid separation and quantitative recycling of TEMPO/MPNs by simple magnetic decantation.
MANUFACTURING METHOD FOR THE ALDEHYDE BY HYDROFORMYLATION REACTION
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Paragraph 0079-0081; 0083-0084; 0101, (2021/07/13)
A phosphine ligand represented by chemical formula 1. Transition metal catalyst A hydroformylation catalyst composition comprising a solvent and a solvent. Provided is a process for preparing aldehydes by hydroformylation using olefinic compounds and formaldehyde to produce aldehydes.
Method for synthesizing valeraldehyde
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Paragraph 0030; 0032-0052, (2021/03/11)
The invention discloses a method for synthesizing valeraldehyde, which is characterized by comprising the following steps: adding a catalyst and an organic solvent into a reaction kettle, adding n-butene in a closed state, and introducing a mixed gas of CO and H2; heating the reaction kettle for reaction; wherein the catalyst is an N-heterocyclic carbene cobalt complex. Compared with the prior art, the N-heterocyclic carbene cobalt complex can be prepared by using a direct and rapid method, meanwhile, reagents with strong toxicity are not used, and the conditions are mild, so that the N-heterocyclic carbene cobalt complex is a good alternative reaction system of a phosphine ligand catalytic system; the method is simple in synthesis process and low in cost, and has a relatively high industrial application prospect.
