96-41-3Relevant academic research and scientific papers
Ruthenium(II) Complexes with New Tridentate Ligands containing P, N, O Donor Atoms: Highly Efficient Catalysts for Transfer Hydrogenation of Ketones by Propan-2-ol
Yang, Hong,Alvarez, Marie,Lugan, Noel,Mathieu, Rene
, p. 1721 - 1722 (1995)
The complexes in which L is a tridentate ligand with P, N and O donor atoms are very efficient catalysts for the transfer hydrogenation of cyclic ketones and acetophenone (turnover -1) in basic media; when L is optically active, no significant e.e. is observed.
Thermodynamic properties, conformational composition, and phase transitions of cyclopentanol
Kabo, G. J.,Diky, V.V.,Kozyro, A. A.,Krasulin, A. P.,Sevruk, V. M.
, p. 953 - 968 (1995)
Thermodynamic properties of cyclopentanol were studied.The molar heat capacity of c-C5H9OH(cr and l) in the temperature range T = 5.4 K to 303.0 K was measured by vacuum adiabatic calorimetry.Three solid-to-solid transitions were found: at T = 176 K with ΔtrsHm = (57 +/- 5) J*mol-1; at T = 202.6 K with ΔtrsHm = (3366 +/- 14) J*mol-1, and at T = 234 K with ΔtrsHm = (55 +/- 6) J*mol-1.The fusion temperature of c-C5H9OH is 255.6 K, and ΔfusHm = (1227 +/- 5) J*mol-1.Basic thermodynamic functions at T = 298.15 K in the liquid state are Cs,m = (182.48 +/- 0.73) J*K-1*mol-1, Sm = (204.14 +/- 0.90) J*K-1*mol-1, and Φm = (96.98 +/- 0.40) J*K-1*mol-1.The enthalpy of vaporization was measured with a heat-conducting microcalorimeter: ΔvapHm(298.15 K) = (57.05 +/- 0.65) kJ*mol-1.Using these and literature data, the standard molar entropy of c-C5H9OH(g) was determined: S0m(g, 340 K) = (362.9 +/- 2.4) J*K-1*mol-1.Conformational analysis was made by the molecular-mechanics method, and statistical calculations of standard molar thermodynamic functions in the ideal-gas state were carried out on the basis of molecular parameters and conformational properties.The calculated entropy value at T = 340 K was put into agreement with the experimental one by adjusting the pseudorotational moment of inertia.The standard molar entropy and molar heat capacity of c-C5H9OH in the ideal-gas state at T = 298.15 K are 347.91 J*K-1*mol-1 and 105.43 J*K-1*mol-1, respectively.Thermodynamic analysis of phase transitions in the condensed state was made.It was shown that pseudorotation in the plastic crystal state of c-C5H9OH is significantly hindered.Thermodynamic quantities allowed us to propose the absence of a non-equilibrium mixture of conformers at T -> 0.An anomalously low entropy difference between liquid and rigid crystal of cyclopentanol in comparison with other cyclopentane derivatives shows a relatively high ordering in the liquid.
Catalytic hydroprocessing of furfural to cyclopentanol over Ni/CNTs catalysts: Model reaction for upgrading of bio-oil
Zhou, Minghao,Zhu, Hongyan,Niu, Lei,Xiao, Guomin,Xiao, Rui
, p. 235 - 241 (2014)
A series of nickel-based catalysts with HNO3- pretreated CNTs as support (x% Ni/CNTs, x represents the Ni loading amount) were synthesized using impregnation method, which were successfully applied for the upgrading of model compound (furfural) in bio-oil. Effects of nickel loading amount, reaction temperature, reaction time and hydrogen pressure on conversion of furfural as well as selectivity for cyclopentanol were investigated systematically. The conversion of furfural over 30 wt% Ni/CNTs was up to 96.5 % with a yield of 83.6 % toward cyclopentanol, when the reaction was carried out at 140 °C with a initial H2 pressure of 5.0 MPa. The features of the Ni/ CNTs catalysts were investigated via XRD, XPS, TEM. Springer Science+Business Media New York 2013.
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.
Primary Alcohols via Nickel Pentacarboxycyclopentadienyl Diamide Catalyzed Hydrosilylation of Terminal Epoxides
Lambert, Tristan H.,Steiniger, Keri A.
supporting information, p. 8013 - 8017 (2021/10/25)
The efficient and regioselective hydrosilylation of epoxides co-catalyzed by a pentacarboxycyclopentadienyl (PCCP) diamide nickel complex and Lewis acid is reported. This method allows for the reductive opening of terminal, monosubstituted epoxides to form unbranched, primary alcohols. A range of substrates including both terminal and nonterminal epoxides are shown to work, and a mechanistic rationale is provided. This work represents the first use of a PCCP derivative as a ligand for transition-metal catalysis.
Selective Aerobic Oxidation of Secondary C (sp3)-H Bonds with NHPI/CAN Catalytic System
Wang, Lingyao,Zhang, Yuanbin,Yuan, Haoran,Du, Renfeng,Yao, Jia,Li, Haoran
, p. 1663 - 1669 (2020/10/21)
Abstract: The direct aerobic oxidation of secondarty C(sp3)-H bonds was achieved in the presence of N-hydroxyphthalimide (NHPI) and cerium ammonium nitrate (CAN) under mild conditions. Various benzylic methylenes could be oxidized to carbonyl compounds in satisfied selectivity while saturated cyclic alkanes could be further oxidized to the corresponding lactones with the catalytic system. Remarkably, 25% of isochroman was converted to corresponding ketone with a selectivity of 96%. The reaction was initiated by hydrogen atom abstraction from NHPI by cerium and nitrates under oxygen atmosphere to form PINO radicals. 2,2,6,6-Tetramethylpiperidine-1-oxyl (TEMPO) addition experiments showed that the oxidation proceeded via a complex radical chain mechanism and an ion pathway. Graphic Abstract: [Figure not available: see fulltext.]
Nature of polymeric condensates during furfural rearrangement to cyclopentanone and cyclopentanol over Cu-based catalysts
Cai, Xichen,Li, Cuiqing,Li, Dongsheng,Li, Zhanqiao,Song, Yongji,Tian, Ziyou,Wang, Hong,Zhang, Chen,Zhang, Wei
, p. 22767 - 22777 (2021/12/24)
Catalyst deactivation and carbon loss are frequently encountered problems in furfural conversion in the aqueous phase. Although several mechanisms were proposed, an in-depth experimental study on the spent catalysts and condensates formed on catalyst surfaces is essential for the development of catalysts with high resistance to condensation. A series of Cu catalysts with various alkali or alkaline earth metal additives was synthesized and tested for furfural conversion to cyclopentanone and cyclopentanol. The addition of alkali or alkaline earth metals significantly inhibited the condensate formation, likely due to the stabilization effect of the important carbocation intermediate. Characterization techniques including FT-IR, XRD, thermogravimetric analysis, and pyrolysis GC-MS were used to analyze the spent catalysts. The results revealed that the condensates formed on the catalyst surface were highly conjugated polymers resulting from the polymerization of furfuryl alcohol. The conclusions of this research are applicable to other furfural hydroconversions in the aqueous phase in acidic or neutral environments. This journal is
Hydrogenolysis of Furfuryl Alcohol to 1,2-Pentanediol Over Supported Ruthenium Catalysts
Yamaguchi, Aritomo,Murakami, Yuka,Imura, Tomohiro,Wakita, Kazuaki
, p. 731 - 736 (2021/06/12)
Hydrogenolysis of the furan rings of furfural and furfuryl alcohol, which can be obtained from biomass, has attracted attention as a method for obtaining valuable chemicals such as 1,2-pentanediol. In this study, we examined the hydrogenolysis of furfuryl alcohol to 1,2-pentanediol over Pd/C, Pt/C, Rh/C, and various supported Ru catalysts in several solvents. In particular, we investigated the effects of combinations of solvents and supports on the reaction outcome. Of all the tested combinations, Ru/MgO in water gave the best selectivity for 1,2-pentanediol: with this catalyst, 42 % selectivity for 1,2-pentanediol was achieved upon hydrogenolysis of furfuryl alcohol for 1 h at 463 K. In contrast, reaction in water in the presence of Ru/Al2O3 afforded cyclopentanone and cyclopentanol by means of hydrogenation and rearrangement reactions.
Selective tandem hydrogenation and rearrangement of furfural to cyclopentanone over CuNi bimetallic catalyst in water
Gao, Jin,Liu, Xin,Luo, Yang,Ma, Hong,Sun, Yuxia,Xu, Jie,Zhang, Meiyun,Zhang, Shujing
, p. 2216 - 2224 (2021/09/20)
Tandem catalysis for the hydrogenation rearrangement of furfural (FA) provides an attractive solution for manufacturing cyclopentanone (CPO) from renewable biomass resources. The CuNi/Al-MCM-41 catalyst was synthesized and afforded excellent catalytic performance with 99.0% conversion and 97.7% selectivity to CPO in a near-neutral solution under 2.0 MPa H2 at 160 °C for 5 h, much higher than those on other molecular sieve supports including MCM-41, SBA-15, HY, and ZSM-5. A small amount of Al highly dispersed in MCM-41 plays an anchoring role and ensures the formation of highly dispersed CuNi bimetallic nanoparticles (NPs). The remarkably improved catalytic performance may be attributed to the bimetallic synergistic and charge transfer effects. In addition, the initial FA concentration and the aqueous system pH required precise control to minimize polymerization and achieve high selectivity of CPO. Fourier transform infrared spectroscopy and mass spectra results indicated that polymerization was sensitive to pH values. Under acidic conditions, FA and intermediate furfuryl alcohol polymerize, while the intermediate 4-hydroxy-2-cyclopentenone mainly polymerizes under alkaline conditions, blocking the cascade of multiple reactions. Therefore, near-neutral conditions are most suitable for minimizing the impact of polymerization. This study provides a useful solution for the current universal problems of polymerization side reactions and low carbon balance for biomass conversion.
Biomimetic ketone reduction by disulfide radical anion
Barata-Vallejo, Sebastian,Bobrowski, Krzysztof,Chatgilialoglu, Chryssostomos,Ferreri, Carla,Marciniak, Bronislaw,Skotnicki, Konrad
, (2021/09/13)
The conversion of ribonucleosides to 2′-deoxyribonucleosides is catalyzed by ribonucleoside reductase enzymes in nature. One of the key steps in this complex radical mechanism is the reduction of the 3′-ketodeoxynucleotide by a pair of cysteine residues, providing the electrons via a disulfide radical anion (RSSR??) in the active site of the enzyme. In the present study, the bioinspired conversion of ketones to corresponding alcohols was achieved by the intermediacy of disulfide radical anion of cysteine (CysSSCys)?? in water. High concentration of cysteine and pH 10.6 are necessary for high-yielding reactions. The photoinitiated radical chain reaction includes the one-electron reduction of carbonyl moiety by disulfide radical anion, protonation of the resulting ketyl radical anion by water, and H-atom abstraction from CysSH. The (CysSSCys)?? transient species generated by ionizing radiation in aqueous solutions allowed the measurement of kinetic data with ketones by pulse radiolysis. By measuring the rate of the decay of (CysSSCys)?? at λmax = 420 nm at various concentrations of ketones, we found the rate constants of three cyclic ketones to be in the range of 104–105 M?1s?1 at ~22?C.
