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.]
Selective aqueous-phase hydrogenation of furfural to cyclopentanol over Ni-based catalysts prepared from Ni-MOF composite
Chen, Changzhou,Jiang, Jianchun,Li, Jing,Ren, Jurong,Wu, Dichao,Xia, Haihong,Zhou, Minghao
, (2021/10/01)
Metal-organic frameworks (MOFs) as an emerging class of porous materials exhibit some unique advantages, including controllable composition, a large surface area, high porosity, and so on. In this work, the spherical NiMo bimetal catalysts supported on porous carbon matrix were prepared using a simple wet impregnation method and studied for selective hydrogenation of furfural (FFA). Three different catalysts were investigated including Ni/C-Mo-BTC, Ni/C-Mo-DHTA and Ni/C-Mo-PTA. Of the catalysts studied the Ni/C-Mo-BTC catalyst could achieve the highest selectivity of CPL (up to 90%) under moderate reaction conditions (140 °C, 2 MPa, 2 h) in aqueous medium. In addition, other Ni-based catalysts (Ni/C-Fe, Ni/C-Zn, Ni/C-Cu, Ni/C-Ce) were also investigated to achieve yields of 20–70% under the same reaction conditions. The influence of temperature, H2 pressure, time and solvent were investigated for the best performing catalyst. Based on the optimal reaction condition, various of furfural derivatives could also be effectively transferred to produce corresponding products. The detailed physicochemical characterization was carried out by means of XRD, SEM, TEM, XPS, NH3-TPD and Raman analysis. In the end, the optimal Ni/C-Mo0.4 catalyst could be recycled magnetically and efficiently applied in the next run for five consecutive recycling tests in the FFA hydrogenation to CPL. The results suggested Ni/C-Mo0.4 catalyst occurred to increasingly favor the formation of Ni-Mo alloys and suggested a metallic active site in FFA hydrogenation with the addition of element Mo. Mechanism study indicated that water was a key factor contributing to the formation of different desired products, which was responsible for the arrangement of furan compound.
Adsorption Configuration-Determined Selective Hydrogenative Ring Opening and Ring Rearrangement of Furfural over Metal Phosphate
Tong, Zhikun,Li, Xiang,Dong, Jingyu,Gao, Rui,Deng, Qiang,Wang, Jun,Zeng, Zheling,Zou, Ji-Jun,Deng, Shuguang
, (2021/05/27)
Developing an economic catalyst to upgrade furfural to alcohols (such as linear alcohol and cyclopentanol) is highly significant for fine chemical synthesis and biomass utilization. Here, a class of metal phosphate nanoparticles (such as CoP, Co2P, and Ni2P) with different metal compositions and topological structures is synthesized. The acidity and hydrogen activation ability were well adjusted according to the types. An 80.2% yield of 1,2,5-pentanetriol was reported for the first time via a hydrogenative ring-opening route over CoP, whereas Ni2P shows a high catalytic efficiency for cyclopentanol with a 62.8% yield via a hydrogenative ring-rearrangement route. Based on the catalytic performance of Pd/C and the result of attenuated total reflectance-infrared spectroscopy, the route difference is derived from the adsorption configuration of furfural on the catalyst. After loading on the insert support, the metal phosphate/support catalysts show high activity and stability during the recycling experiments. This work provides an effective strategy to regulate the reaction path through an adsorption mechanism and shows the precise synergistic effect of hydrogenation and acid catalysis.
Nitrogen-Doped Carbon Composites with Ordered Macropores and Hollow Walls
Chen, Jianmin,Chen, Liyu,Fang, Ruiqi,Li, Yingwei,Qin, Ze,Wang, Yajing,Yang, Xianfeng,Yao, Wen
supporting information, p. 23729 - 23734 (2021/10/04)
Metal-organic frameworks provide versatile templates for the fabrication of various metal/carbon materials, but most of the derived composites possess only microspores, limiting the accessibility of embedded active sites. Herein, we report the construction of cobalt/nitrogen-doped carbon composites with a three-dimensional (3D) ordered macroporous and hollow-wall structure (H-3DOM-Co/NC) using a single-crystal ordered macropore (SOM)-ZIF-8@ZIF-67 as precursor. During the pyrolysis, the interconnected macroporous structure of SOM-ZIF-8@ZIF-67 is mostly preserved, whereas the pore wall achieves a solid-to-hollow transformation with Co nanoparticles formed in the hollow walls. The 3D-ordered macroporous carbon skeleton may effectively promote long-range mass transfer and the hollow wall can facilitate local accessibility of active sites. This unique structure can greatly boost its catalytic activity in the selective hydrogenation of biomass-derived furfural to cyclopentanol, much superior to its counterparts without this well-designed hierarchically porous structure.
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.
