107-87-9Relevant articles and documents
Isobutanol and methanol synthesis on copper catalysts supported on modified magnesium oxide
Xu, Mingting,Gines, Marcelo J. L.,Hilmen, Anne-Mette,Stephens, Brandy L.,Iglesia, Enrique
, p. 130 - 147 (1997)
Alcohols are selectively produced from CO/H2 on K-CuMgCeOx catalysts, but synthesis rates are strongly inhibited by CO2 formed during reaction. Reaction pathways involve methanol synthesis on Cu, chain growth to C2+ alcohols, and metal-base bifunctional coupling of alcohols to form isobutanol. Ethanol reactions on K-Cu0.5Mg5CeOx show that Cu catalyzes both alcohol dehydrogenation and aldol condensation reactions. CeO2 increases Cu dispersion and MgO surface area and K decreases Cu dispersion, but increases the density of basic sites. Reactions of acetaldehyde and 13C-labeled methanol lead to 1-13C-propionaldehyde, a precursor to isobutanol. The density and strength of basic sites were measured using a 12CO2/13CO2 isotopic jump method that probes the number and chemical properties of basic sites available at typical isobutanol synthesis temperatures. K or CeO2 addition to CuMgOx increases the density and strength of basic sites and the rates of base-catalyzed ethanol condensation reactions leading to acetone and n-butyraldehyde. The presence of CO in the He carrier during temperature-programmed surface reactions of ethanol preadsorbed on Cu0.5Mg5CeOx decreases the rate of base-catalyzed condensation reactions of preadsorbed ethanol, possibly due to the poisoning of basic and Cu sites by the CO2 formed from CO via water-gas shift reactions.
An In-Situ Self-regeneration Catalyst for the Production of Renewable Penta-1,3-diene
Feng, Ruilin,Qi, Yanlong,Liu, Shijun,Cui, Long,Dai, Quanquan,Bai, Chenxi
, p. 9495 - 9498 (2021)
Catalyst deactivation is a problem of great concern for many heterogeneous reactions. Here, an urchin-like LaPO4 catalyst was easily developed for pentane-2,3-diol dehydration; it has an impressive ability to restore the activity in situ by itself during the reaction, accounting for its high stability. This facilitates the efficient production of renewable penta-1,3-diene from pentane-2,3-dione via a novel approach, where penta-2,3-diol was obtained as an intermediate in 95 % yield under mild conditions.
Oxidation by a "H2O2-vanadium complex-pyrazine-2-carboxylic acid" reagent 5. Oxidation of lower alkanes with the formation of carbonyl compounds
Shul'pin, G. B.,Drago, R. S.,Gonzalez, M.
, p. 2386 - 2388 (1996)
Lower alkanes (ethane, propane, n-butane, n-pentane) are readily oxidized in acetonitrile solvent by H2O2 with vanadate anion - pyrazine-2-carboxylic acid (PCA), as the catalyst at 75 deg C and pressure of ca. 3 atm to produce predominantly or exclusively ketones (aldehydes).Isobutane is transformed selectively into tert-butyl alcohol.The oxidation of cyclohexane at 26 deg C in acetone or acetic acid is less efficient than in acetonitrile.The reaction does not occur in tert-butyl alcohol.
Catalytic aerobic oxidation of alcohols by Fe(NO3)3-FeBr3
Martín, Sandra E,Suárez, Darío F
, p. 4475 - 4479 (2002)
Selective aerobic oxidation of secondary and benzylic alcohols was efficiently accomplished by the binary catalyst system Fe(NO3)3-FeBr3 under air at room temperature. The oxidation developed in mild conditions and showed
A structure/catalytic activity study of gold(i)-NHC complexes, as well as their recyclability and reusability, in the hydration of alkynes in aqueous medium
Fernández, Gabriela A.,Chopa, Alicia B.,Silbestri, Gustavo F.
, p. 1921 - 1929 (2016)
We conducted a structure/catalytic activity study of water-soluble gold(i) complexes-supporting sulfonated NHC ligands-in the hydration of alkynes in pure water or water nsp;:nsp;methanol (1nsp;:nsp;1), as well as their recyclability. Comparative studies were carried out with the addition of different silver salts. Our results indicate that the bulkier complex is the most effective and that the addition of methanol as co-solvent not only shortens reaction times but also stabilizes the less bulky complexes.
Relative and absolute kinetic studies of 2-butanol and related alcohols with tropospheric Cl atoms
Ballesteros, Bernabe,Garzon, Andres,Jimenez, Elena,Notario, Alberto,Albaladejo, Jose
, p. 1210 - 1218 (2007)
A newly constructed chamber/Fourier transform infrared system was used to determine the relative rate coefficient, ki, for the gas-phase reaction of Cl atoms with 2-butanol (k1), 2-methyl-2-butanol (k 2), 3-methyl-2-butanol (k3), 2,3-dimethyl-2-butanol (k4) and 2-pentanol (k5). Experiments were performed at (298 ± 2) K, in 740 Torr total pressure of synthetic air, and the measured rate coefficients were, in cm3 molecule-1 s -1 units (±2σ): k1 = (1.32 ± 0.14) × 10-10, k2 = (7.0 ± 2.2) × 10 -11, k3 = (1.17 ± 0.14) × 10-10, k4 = (1.03 ± 0.17) × 10-10 and k5 = (2.18 ± 0.36) × 10-10, respectively. Also, all the above rate coefficients (except for 2-pentanol) were investigated as a function of temperature (267-384 K) by pulsed laser photolysis-resonance fluorescence (PLP-RF). The obtained kinetic data were used to derive the Arrhenius expressions: k1(T) = (6.16 ± 0.58) × 10 -11exp[(174 ± 58)/T], k2(T) = (2.48 ± 0.17) × 10-11exp[(328 ± 42)/T], k3(T) = (6.29 ± 0.57) × 10-11exp[(192 ± 56)/T], and k 4(T) = (4.80 ± 0.43) × 10-11exp[(221 ± 56)/T] (in units of cm3 molecule-1 s-1 and ±σ). Results and mechanism are discussed and compared with the reported reactivity with OH radicals. Some atmospheric implications derived from this study are also reported. This journal is the Owner Societies.
A thermodynamic study of the ketoreductase-catalyzed reduction of 2-alkanones in non-aqueous solvents
Tewari, Yadu B.,Schantz, Michele M.,Phinney, Karen W.,Rozzell, J. David
, p. 89 - 96 (2005)
Equilibrium constants K have been measured for the reactions (2-alkanone + 2-propanol = 2-alkanol + acetone), where 2-alkanone = 2-butanone, 2-pentanone, 2-hexanone, 2-heptanone, and 2-octanone and 2-alkanol = 2-butanol, 2-pentanol, 2-hexanol, 2-heptanol, and 2-octanol. The solvents used were n-hexane, toluene, methyl tert-butyl ether (MTBE), and supercritical carbon dioxide SCCO 2 (pressure P - 10.0 MPa). The temperature range was T - (288.15 to 308.27) K. Chiral analysis of the reaction products showed that the enzyme used in this study was stereoselective for the 2-octanone reaction system, i.e. only (S)-(+)-2-octanol was formed. For the reactions involving butanone, pentanone, and hexanone, the products were racemic mixtures of the respective (S)-(+)-2-alkanol and the (R)-(-)-2-alkanol. Chiral analysis showed that for the 2-heptanone reaction system, the 2-alkanol product was a mixture of (S)-(+)-2-heptanol and (R)-(-)-2-heptanol, at the respective mole fractions of 0.95 and 0.05. The equilibrium constant for the reaction system involving 2-butanone carried out in n-hexane was measured at several temperatures. For this reaction, the values for the thermodynamic reaction quantities at T= 298. 15 K are: K= 0.838±0.013; the standard molar Gibbs free energy change ΔrgHm° = (0.44±0.040) kJ · mol-1; the standard molar enthalpy change ΔrgHm° = -(1.2±1.7) kJ mol-1, and the standard molar entropy change ΔrgHm° = -(5.5±5.7) J K-1 mol-1. Interestingly, inspection of the values of the equilibrium constants for these reactions carried out in n-hexane, toluene, MTBE, and SCCO2 shows that these values are comparable and have little dependence on the solvent used to carry out the reaction. The values of the equilibrium constants decrease monotonically with increasing value of the number of carbons Nc and trend towards a limiting value of ≈0.30 for Nc > 8. Published by Elsevier Ltd.
Developing an efficient catalyst for controlled oxidation of small alkanes under ambient conditions
Nagababu, Penumaka,Yu, Steve S.-F.,Maji, Suman,Ramu, Ravirala,Chan, Sunney I.
, p. 930 - 935 (2014)
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.
Product distributions from the OH radical-induced oxidation of n-Pentane and isopentane (2-Methylbutane) in Air
Heimann, Gerald,Warneck, Peter
, p. 677 - 688 (2006)
Hydroxyl radicals, generated by photolysis of H2O2. were reacted with n-pentane and isopentane in air in the absence of nitrogen oxides. The observed product distributions were compared with similar data derived by computer simulations, based on the known reaction mechanisms, to determine relative probabilities for hydrogen abstraction at different sites of the parent compounds and to estimate branching ratios and relative rate coefficients for cross-combination reactions between different peroxy radicals. For n-pentane. the distribution of the pentanols indicates probabilities for hydrogen abstraction, in percent, of q1= 9.1 ± 0.7. q 2 = 56.1 ± 1.8, and q3 = 34.8 ± 1.3. which agree with predictions based on the algorithm proposed by Atkinson. Branching ratios needed to harmonize calculated and observed product distributions are somewhat larger than, although still within the error ranges of. the values found by us previously Comparison between experimental and calculated data confirms the isomerization and decomposition constants recently established for the three pentoxyl radical isomers. The product distribution for isopentane. which is dominated by acetone, acetaldehyde. 2-methyl-butan-2-ol. and 2-methyl-butan-2-hydroperoxide, is in harmony with the predicted oxidation mechanism. Probabilities for hydrogen abstraction from isopentane were estimated to occur to 12% at the primary. 28% at the secondary, and 60% at the tertiary sites, again in agreement with predictions based on the algorithm of Atkinson.
Reactions in the Photocatalytic Conversion of Tertiary Alcohols on Rutile TiO2(110)
Courtois, Carla,Eder, Moritz,Schnabl, Kordula,Walenta, Constantin A.,Tschurl, Martin,Heiz, Ulrich
, p. 14255 - 14259 (2019)
According to textbooks, tertiary alcohols are inert towards oxidation. The photocatalysis of tertiary alcohols under highly defined vacuum conditions on a titania single crystal reveals unexpected and new reactions, which can be described as disproportionation into an alkane and the respective ketone. In contrast to primary and secondary alcohols, in tertiary alcohols the absence of an α-H leads to a C?C-bond cleavage instead of the common abstraction of hydrogen. Surprisingly, bonds to methyl groups are not cleaved when the alcohol exhibits longer alkyl chains in the α-position to the hydroxyl group. The presence of platinum loadings not only increases the reaction rate but also opens up a new reaction channel: the formation of molecular hydrogen and a long-chain alkane resulting from recombination of two alkyl moieties. This work demonstrates that new synthetic routes may become possible by introducing photocatalytic reaction steps in which the co-catalysts may also play a decisive role.
