120-92-3Relevant articles and documents
Efficient conversion of furfural into cyclopentanone over high performing and stable Cu/ZrO2 catalysts
Zhang, Yifeng,Fan, Guoli,Yang, Lan,Li, Feng
, p. 117 - 126 (2018)
Currently, biomass transformation to produce high value-added chemicals and liquid biofuels is attracting more and more interest by the virtue of its importance in the sustainable development of human society. Herein, we reported the conversion of furfural (FFA) into cyclopentanone (CPO) in water over high performing and stable Cu/ZrO2 catalysts prepared by our developed one-pot reduction-oxidation method. It was demonstrated that surface structures and catalytic performances of catalysts could be delicately adjusted by varying the calcination temperatures for catalyst precursors. Especially, an appropriate calcination temperature of 500 °C could significantly enhance the interactions between surface Cu species and the ZrO2 support, thus greatly facilitating the formation of Cu+-O-Zr-like structure at the metal-support interface, and the resulting Cu/ZrO2 catalyst showed a superior catalytic performance with a high CPO yield of 91.3% under mild reaction conditions (i.e. a low hydrogen pressure of 1.5 MPa and 150 °C) to other metal oxides supported copper catalysts prepared by the conventional impregnation. It was revealed that in addition to surface acidic sites, surface Cu+/(Cu°+Cu+) ratio also played a key role in promoting the formation of CPO in the present Cu/ZrO2 catalytic system.
Catalytic Oxidation of Cyclopentene by O2 over Pd(II)-SBA-15 Complexes
Yue, Lumin,Wang, Zhenwei,Bao, Lele,Fu, Wei,Xu, Li,Li, Jun,Lu, Guanzhong
, p. 2269 - 2278 (2017)
Abstract: Novel catalysts with Pd(II)-picolinamide complexes anchored into the channels of mesoporous material SBA-15 were prepared for chemical transformation of cyclopentene, and characterized in details. Spectra of 29Si NMR, 13C NMR and XPS revealed the organic ligands were grafted into the SBA-15 and Pd(II) complexes formed. Spacial diversity of the complexes, especially distances from –C=O to N on pyridyl cycles, may influence electronic distribution of conjugated system and further the catalytic activity. With the help of the newly synthesized catalytic materials, a new heterogeneous oxidation system was developed for selective catalytic transformation of cyclopentene to cyclopentanone with molecular oxygen as the sole oxidant. Analytic results of the reaction mixtures indicated that all catalysts exhibited high activity, while the cat.1 and cat.2 with 2-pyridinecarbonyl or 3-pyridinecarbonyl on the ligands gave better yields of cyclopentanone. 96.2% conversion of cyclopentene and 76.3% yied of cyclopentanone were achieved over the catalyst cat.2 under the conditions of 0.7?MPa O2, 323?K and 6?h reaction. In addition, the catalysts were also appealing for easy separation and recyclable property. Graphical Abstract: [Figure not available: see fulltext.] A new heterogeneous reaction system was developed for the catalytic oxidation of cyclopentene to cyclopentanone by molecular oxygen over novel catalysts. The synthesized catalysts are comprised of Pd(II)-picolinamide complexes anchored into the channels of SBA-15. The new system was efficient for the mentioned reaction, and the catalysts were reusable.
PREPARATION OF KETONES BY A NOVEL DECARBALKOXYLATION OF β-KETO ESTERS: STEREOELECTRONIC ASSISTANCE TO C-C BOND FISSION
Aneja, R.,Hollis, W. M.,Davies A. P.,Eaton, G.
, p. 4641 - 4644 (1983)
Reaction of β-keto esters with the sodium derivative of propane-1,2-diol in an excess of anhydrous propane-1,2-diol causes facile decarboxylation to ketones in excellent yields.
Trinuclear triangular copper(II) clusters - Synthesis, electrochemical studies and catalytic peroxidative oxidation of cycloalkanes
Di Nicola, Corrado,Garau, Federica,Karabach, Yauhen Y.,Martins, Luisa M. D. R. S.,Monari, Magda,Pandolfo, Luciano,Pettinari, Claudio,Pombeiro, Armando J. L.
, p. 666 - 676 (2009)
The reactions of CuII carboxylates (valerate, 2-methylbutyrate, hexanoate, heptanoate) with pyrazole (Hpz) in EtOH or EtOH/water solutions easily afford the triangular trinuclear copper derivatives [Cu 3(μ3-OH)(μ-pz)3(RCOO)2(L) x] [R = CH3(CH2)3, L = H 2O, x = 1 for 5; R = CH3CH2CH(CH3), L = EtOH, x = 2 for 6; R = CH3(CH2)4, L = EtOH, x = 1 for 7; R = CH3(CH2)5, L = EtOH, x = 1 for 8] as it has been previously found for R = H, L = Hpz, x = 2, (1); R = CH3, L = Hpz, x = 1, (2); R = CH3CH2, L = EtOH, x = 1, (3) and [Cu3(μ3-OH)(μ-pz) 3-(CH3(CH2)2COO)2(MeOH) (H2O)], (4). The trinuclear structure common to 5-8 has been assigned on the basis of magnetic susceptibility studies, ESI MS, IR and UV/Vis spectroscopy as well as 1H NMR measurements. The room temp. magnetic susceptibilities of 5-8 almost correspond to the presence of a single unpaired electron for each trinuclear unit. The IR spectra exhibit signals due to the bridging μ3-OH in accordance with what was observed in the spectra of 1-4. Solid-state and MeOH solution UV/Vis spectra show the same features previously reported for 1-4 and 1H NMR spectra of 1-8 show almost identical low field signals that can be assigned to pz- hydrogens. A detailed investigation of the supramolecular structures of 1 and 4 and the single-crystal X-ray study of the polymeric paddlewheel Cu(2-methylbutyrate) 2, A, are also reported. Electrochemical experiments show that in 1-8 the CuII ions can be reduced, in distinct steps, to CuI and Cu0. All the complexes act as catalysts or catalyst precursors for the efficient peroxidative oxidation, by aqueous hydrogen peroxide in acetonitrile and at room temp., of cycloalkanes RH (cyclohexane and cyclopentane) to the corresponding cyclic alcohols and ketones, with overall yields of up to 34% and TONs up to 42. Radical pathways involving the formation of alkyl hydroperoxides (ROOH) are involved. Wiley-VCH Verlag GmbH & Co. KGaA, 2009.
Synthesis of Unsaturated Spiroacetals, Cyclopentanone Derivatives, in the Presence of Natural Aluminosilicate Modified with Zirconium Cations
Abbasov,Alimardanov, Kh. M.,Abbaszade,Guseinova,Azimli
, p. 603 - 607 (2019)
Abstract: Conditions for the condensation of cyclopentanone and n-valeric aldehyde to 2-pentylidenecyclopentanone in the presence of an alcoholic solution of piperidine have been developed. The isomerization of the latter in a continuous-flow system over γ-Al2O3 yields 2-pentylcyclopent-2-en-1-one. The condensation of the obtained unsaturated ketones with ethane-1,2-diol in the presence of a heterogeneous catalyst, a natural aluminosilicate (perlite) modified with zirconyl sulfate, has been studied. The optimum conditions for the preparation of the corresponding unsaturated spiroacetals have been found. The synthesized compounds can be used as synthetic fragrances for different purposes.
Kinetics and mechanisms of the thermal decomposition of 2-methyl-1,3-dioxolane, 2,2-dimethyl-1,3-dioxolane, and cyclopentanone ethylene ketal in the gas phase. Combined experimental and DFT study
Rosas, Felix,Lezama, Jesus,Mora, Jose R.,Maldonado, Alexis,Chuchani, Gabriel,Cordova, Tania
, p. 9228 - 9237,10 (2012)
The kinetics of the gas-phase thermal decomposition of 2-methyl-1,3- dioxolane, 2,2-dimethyl-1,3-dioxolane, and cyclopentanone ethylene ketal were determined in a static system and the reaction vessel deactivated with allyl bromide. The decomposition reactions, in the presence of the free radical suppressor propene, are homogeneous, are unimolecular, and follow first-order law kinetics. The products of these reactions are acetaldehyde and the corresponding ketone. The working temperature range was 459-490 °C, and the pressure range was 46-113 Torr. The rate coefficients are given by the following Arrhenius equations: for 2-methyl-1,3-dioxolane, log k = (13.61 ± 0.12) - (242.1 ± 1.0)(2.303RT)-1, r = 0.9997; for 2,2-dimethyl-1,3-dioxolane, log k = (14.16 ± 0.14) - (253.7 ± 2.0)(2.303RT)-1, r = 0.9998; for cyclopentanone ethylene ketal, log k = (14.16 ± 0.14) - (253.7 ± 2.0)(2.303RT)-1, r = 0.9998. Electronic structure calculations using DFT methods B3LYP and MPW1PW91 with 6-31G(d,p), and 6-31++G(d,p) basis sets suggest that the decomposition of these substrates takes place through a stepwise mechanism. The rate-determining step proceeds through a concerted nonsynchronous four-centered cyclic transition state, and the elongation of the C-OCH3 bond in the direction C αδ+...OCH3δ- is predominant. The intermediate products of these decompositions are unstable, at the working temperatures, decomposing rapidly through a concerted cyclic six-centered cyclic transition state type of mechanism.
Regeneration of aldehydes and ketones from oximes using bis(trimethylsilyl)chromate
Lee,Kwak,Hwang
, p. 2425 - 2429 (1992)
Bis(trimethylsilyl) chromate transforms oximes of not only ketones but also aldehydes and 1,2-diketones to the corresponding carbonyl compounds, in high yields.
Catalytic oxidation of cycloalkanes by porphyrin cobalt(II) through efficient utilization of oxidation intermediates
Shen, Hai M.,Wang, Xiong,Guo, A. Bing,Zhang, Long,She, Yuan B.
, p. 1166 - 1173 (2020)
The catalytic oxidation of cycloalkanes using molecular oxygen employing porphyrin cobalt(II) as catalyst was enhanced through use of cycloalkyl hydroperoxides, which are the primary intermediates in oxidation of cycloalkanes, as additional oxidants to further oxidize cycloalkanes in the presence of porphyrin copper(II), especially for cyclohexane, for which the selectivity was enhanced from 88.6 to 97.2% to the KA oil; at the same time, the conversion of cyclohexane was enhanced from 3.88 to 4.41%. The enhanced efficiency and selectivity were mainly attributed to the avoided autoxidation of cycloalkanes and efficient utilization of oxidation intermediate cycloalkyl hydroperoxides as additional oxidants instead of conventional thermal decomposition. In addition to cyclohexane, the protocol presented in this research is also very applicable in the oxidation of other cycloalkanes such as cyclooctane, cycloheptane and cyclopentane, and can serve as a applicable and efficient strategy to boost the conversion and selectivity simultaneously in oxidation of alkanes. This work also is a very important reference for the extensive application of metalloporphyrins in catalysis chemistry.
Mild homogeneous oxidation and hydrocarboxylation of cycloalkanes catalyzed by novel dicopper(II) aminoalcohol-driven cores
Fernandes, Tiago A.,André, Vania,Kirillov, Alexander M.,Kirillova, Marina V.
, p. 357 - 367 (2017)
N-benzylethanolamine (Hbea) and triisopropanolamine (H3tipa) were applied as unexplored aminoalcohol N,O-building blocks for the self-assembly generation of two novel dicopper(II) compounds, [Cu2(μ-bea)2(Hbea)2](NO3)2 (1) and [Cu2(H3tipa)2(μ-pma)]·7H2O (2) {H4pma = pyromellitic acid}. These were isolated as stable and aqua-soluble microcrystalline products and were fully characterized by IR spectroscopy, ESI–MS(±), and single-crystal X-ray diffraction, the latter revealing distinct Cu2 cores containing the five-coordinate copper(II) centers with the {CuN2O3} or {CuNO4} environments. Compounds 1 and 2 were used as homogeneous catalysts for the mild oxidation of C5–C8 cycloalkanes to give the corresponding cyclic alcohols and ketones in up to 23% overall yields based on cycloalkane. The reactions proceed in aqueous acetonitrile medium at 50 °C using H2O2 as an oxidant. The effects of different reaction conditions were studied, including the type and loading of catalyst, amount and kind of acid promoter, and water concentration. Despite the fact that different acids (HNO3, H2SO4, HCl, or CF3COOH) promote the oxidation of alkanes, the reaction is exceptionally fast in the presence of a catalytic amount of HCl, resulting in the TOF values of up to 430 h?1. Although water typically strongly inhibits alkane oxidations due to the reduction of H2O2 concentration and lowering of the alkane solubility, in the systems comprising 1 and 2 we observed a significant growth (up to 5-fold) of an initial reaction rate in the cyclohexane oxidation on increasing the amount of H2O in the reaction mixture. The bond-, regio- and stereo-selectivity parameters were investigated in oxidation of different linear, branched, and cyclic alkane substrates. Both compounds 1 and 2 also catalyze the hydrocarboxylation of C5–C8 cycloalkanes, by CO, K2S2O8, and H2O in a water/acetonitrile medium at 60 °C, to give the corresponding cycloalkanecarboxylic acids in up to 38% yields based on cycloalkanes.
Highly dispersed Co and Ni nanoparticles encapsulated in N-doped carbon nanotubes as efficient catalysts for the reduction of unsaturated oxygen compounds in aqueous phase
Gong, Wanbing,Chen, Chun,Zhang, Haimin,Wang, Guozhong,Zhao, Huijun
, p. 5506 - 5514 (2018)
N-Doped carbon nanotube-encapsulated metal nanoparticles are of great interest in heterogeneous catalysis owing to their improved mass transfer ability and superior stability. Herein, a facile one-pot pyrolysis approach using melamine as the carbon and nitrogen source was developed to fabricate metal nanoparticles embedded in bamboo-like N-doped carbon nanotubes (named as Co@NCNTs-600-800 and Ni@NCNTs-600-800). The optimized Co@NCNTs-600-800 catalyst exhibited outstanding activity in furfural (FAL) selective hydrogenation to furfuryl alcohol (FOL) or cyclopentanone (CPO) in aqueous media. High yields of FOL (100%) and CPO (75.3%) were achieved at 80 °C and 140 °C, respectively. Besides, this cobalt catalyst showed very good stability and recyclability during the reaction. The synergistic effect between metallic cobalt and N-doped carbon nanotubes was systematically investigated. In addition, the as-prepared Ni@NCNTs-600-800 catalyst also exhibited remarkable activity. Under optimal conditions (100 °C and 4 MPa H2 pressure), a maximum tetrahydrofurfuryl alcohol (THFOL) yield (99.5%) was obtained in the aqueous-phase hydrogenation of FAL. The research thus highlights new perspectives for non-noble metal-based N-doped carbon nanotube catalysts for biomass transformation.
