- 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
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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.
- Yang, Hong,Alvarez, Marie,Lugan, Noel,Mathieu, Rene
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- Thermodynamic properties, conformational composition, and phase transitions of cyclopentanol
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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.
- Kabo, G. J.,Diky, V.V.,Kozyro, A. A.,Krasulin, A. P.,Sevruk, V. M.
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- Catalytic hydroprocessing of furfural to cyclopentanol over Ni/CNTs catalysts: Model reaction for upgrading of bio-oil
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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.
- Zhou, Minghao,Zhu, Hongyan,Niu, Lei,Xiao, Guomin,Xiao, Rui
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- An efficient method for the catalytic aerobic oxidation of cycloalkanes using 3,4,5,6-Tetrafluoro-N-Hydroxyphthalimide (F4-NHPI)
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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.
- Guha, Samar K.,Ishii, Yasutaka
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p. 327 - 335
(2021/12/13)
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- Chromium-Catalyzed Production of Diols From Olefins
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Processes for converting an olefin reactant into a diol compound are disclosed, and these processes include the steps of contacting the olefin reactant and a supported chromium catalyst comprising chromium in a hexavalent oxidation state to reduce at least a portion of the supported chromium catalyst to form a reduced chromium catalyst, and hydrolyzing the reduced chromium catalyst to form a reaction product comprising the diol compound. While being contacted, the olefin reactant and the supported chromium catalyst can be irradiated with a light beam at a wavelength in the UV-visible spectrum. Optionally, these processes can further comprise a step of calcining at least a portion of the reduced chromium catalyst to regenerate the supported chromium catalyst.
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Paragraph 0111
(2021/03/19)
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- Time-Dependent Self-Assembly of Copper(II) Coordination Polymers and Tetranuclear Rings: Catalysts for Oxidative Functionalization of Saturated Hydrocarbons
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This study describes a time-dependent self-assembly generation of new copper(II) coordination compounds from an aqueous-medium reaction mixture composed of copper(II) nitrate, H3bes biobuffer (N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid), ammonium hydroxide, and benzenecarboxylic acid, namely, 4-methoxybenzoic (Hfmba) or 4-chlorobenzoic (Hfcba) acid. Two products were isolated from each reaction, namely, 1D coordination polymers [Cu3(μ3-OH)2(μ-fmba)2(fmba)2(H2O)2]n (1) or [Cu2(μ-OH)2(μ-fcba)2]n (2) and discrete tetracopper(II) rings [Cu4(μ-Hbes)3(μ-H2bes)(μ-fmba)]·2H2O (3) or [Cu4(μ-Hbes)3(μ-H2bes)(μ-fcba)]·4H2O (4), respectively. These four compounds were obtained as microcrystalline air-stable solids and characterized by standard methods, including the single-crystal X-ray diffraction. The structures of 1 and 2 feature distinct types of metal-organic chains driven by the μ3- or μ-OH- ligands along with the μ-benzenecarboxylate linkers. The structures of 3 and 4 disclose the chairlike Cu4 rings assembled from four μ-bridging and chelating aminoalcoholate ligands along with μ-benzenecarboxylate moieties playing a core-stabilizing role. Catalytic activity of 1-4 was investigated in two model reactions, namely, (a) the mild oxidation of saturated hydrocarbons with hydrogen peroxide to form alcohols and ketones and (b) the mild carboxylation of alkanes with carbon monoxide, water, and peroxodisulfate to generate carboxylic acids. Cyclohexane and propane were used as model cyclic and gaseous alkanes, while the substrate scope also included cyclopentane, cycloheptane, and cyclooctane. Different reaction parameters were investigated, including an effect of the acid cocatalyst and various selectivity parameters. The obtained total product yields (up to 34% based on C3H8 or up to 47% based on C6H12) in the carboxylation of propane and cyclohexane are remarkable taking into account an inertness of these saturated hydrocarbons and low reaction temperatures (50-60 °C). Apart from notable catalytic activity, this study showcases a novel time-dependent synthetic strategy for the self-assembly of two different Cu(II) compounds from the same reaction mixture.
- Costa, Ines F. M.,Kirillova, Marina V.,André, Vania,Fernandes, Tiago A.,Kirillov, Alexander M.
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supporting information
p. 14491 - 14503
(2021/07/19)
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- Three metal centers (Co _AOMARKENCODEAMPX0AOA) Cu _AOMARKENCODEAMPX0AOA Method using Zn) 2D MOFs/ultraviolet light to catalyze oxidation of cycloalkane
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The invention relates to a three-metal center (Co _AOMARKENCODEAMPX0AOA). Cu _AOMARKENCODEAMPX0AOA The method comprises Zn) 2D MOFs/ultraviolet light catalytic oxidation of cycloalkane to synthesize cycloalkyl alcohol and cycloalkanone, and belongs to the field of industrial catalysis and fine organic synthesis. To the application method, metalloporphyrin three-metal center (Co _AOMARKENCODEAMPX0AOA) is used. Cu _AOMARKENCODEAMPX0AOA Zn) 2D MOFs dispersed in cycloalkane, wherein metalloporphyrin three-metal center (Co _AOMARKENCODEAMPX0AOA) Cu _AOMARKENCODEAMPX0AOA Zn) 2D MOFs mass is 0.01% - 20%, g / mol of the substance of the cycloalkane, and the reaction system is sealed. An oxidant is introduced, the ultraviolet lamp is a light source, and the reaction liquid of the stirring reaction 2.0-24 . 0h. is subjected to post-treatment to obtain the product cycloalkyl alcohol and cycloalkyl ketone. The method provided by the invention has the advantages of low reaction temperature, mild reaction conditions, high reaction efficiency, high selectivity of cycloalkyl alcohol and cycloalkyl ketone, less byproducts and small environmental impact. The invention provides a high efficiency. Available, safe cycloalkanes selectively catalyze the oxidative synthesis of cycloalkyl alcohols and cycloalkyl ketones.
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Paragraph 0028; 0075-0076
(2021/11/06)
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- Cyclopentadiene fuels
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A method for making cyclopentadiene fuels comprising producing cyclopent-2-en-1-one or a mixture of cyclopent-2-en-1-one from a bio-based source. The cyclopent-2-en-1-one or the mixture of cyclopent-2-en-1-one is hydrogenated, thereby forming cyclopent-2-en-1-ol or a mixture of cyclopent-2-en-1-ol. The cyclopent-2-en-1-ol or the mixture of cyclopent-2-en-1-ol is dehydrated with a dehydrating agent, thereby forming cyclopentadiene or a mixture of cyclopentadiene. The cyclopentadiene or mixture of cyclopentadiene is converted to dicyclopentadiene or dihydrodicyclopentadiene. The dicyclopentadiene or dihydrodicyclopentadiene is hydrogenated, thereby forming tetrahydrodicyclopentadiene. The tetrahydrodicyclopentadiene is isomerized, thereby forming exo-tetrahydrodicyclopentadiene.
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Page/Page column 6-7
(2021/08/04)
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- Primary Alcohols via Nickel Pentacarboxycyclopentadienyl Diamide Catalyzed Hydrosilylation of Terminal Epoxides
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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.
- Lambert, Tristan H.,Steiniger, Keri A.
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p. 8013 - 8017
(2021/10/25)
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- Hydrogen-Catalyzed Acid Transformation for the Hydration of Alkenes and Epoxy Alkanes over Co-N Frustrated Lewis Pair Surfaces
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Hydrogen (H2) is widely used as a reductant for many hydrogenation reactions; however, it has not been recognized as a catalyst for the acid transformation of active sites on solid surface. Here, we report the H2-promoted hydration of alkenes (such as styrenes and cyclic alkenes) and epoxy alkanes over single-atom Co-dispersed nitrogen-doped carbon (Co-NC) via a transformation mechanism of acid-base sites. Specifically, the specific catalytic activity and selectivity of Co-NC are superior to those of classical solid acids (acidic zeolites and resins) per micromole of acid, whereas the hydration catalysis does not take place under a nitrogen atmosphere. Detailed investigations indicate that H2 can be heterolyzed on the Co-N bond to form Hδ-Co-N-Hδ+ and then be converted into OHδ-Co-N-Hδ+ accompanied by H2 generation via a H2O-mediated path, which significantly reduces the activation energy for hydration reactions. This work not only provides a novel catalytic method for hydration reactions but also removes the conceptual barriers between hydrogenation and acid catalysis.
- Deng, Qiang,Deng, Shuguang,Gao, Ruijie,Li, Xiang,Tsang, Shik Chi Edman,Wang, Jun,Zeng, Zheling,Zou, Ji-Jun
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p. 21294 - 21301
(2021/12/17)
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- Cu6- And Cu8-Cage Sil- And Germsesquioxanes: Synthetic and Structural Features, Oxidative Rearrangements, and Catalytic Activity
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This study reports intriguing features in the self-assembly of cage copper(II) silsesquioxanes in the presence of air. Despite the wide variation of solvates used, a series of prismatic hexanuclear Cu6 cages (1-5) were assembled under mild conditions. In turn, syntheses at higher temperatures are accompanied by side reactions, leading to the oxidation of solvates (methanol, 1-butanol, and tetrahydrofuran). The oxidized solvent derivatives then specifically participate in the formation of copper silsesquioxane cages, allowing the isolation of several unusual Cu8-based (6 and 7) and Cu6-based (8) complexes. When 1,4-dioxane was applied as a reaction medium, deep rearrangements occurred (with a total elimination of silsesquioxane ligands), causing the formation of mononuclear copper(II) compounds bearing oxidized dioxane fragments (9 and 11) or a formate-driven 1D coordination polymer (10). Finally, a "directed"self-assembly of sil- and germsesquioxanes from copper acetate (or formate) resulted in the corresponding acetate (or formate) containing Cu6 cages (12 and 13) that were isolated in high yields. The structures of all of the products 1-13 were established by single-crystal X-ray diffraction, mainly based on the use of synchrotron radiation. Moreover, the catalytic activity of compounds 12 and 13 was evaluated toward the mild homogeneous oxidation of C5-C8 cycloalkanes with hydrogen peroxide to form a mixture of the corresponding cyclic alcohols and ketones.
- Astakhov, Grigorii S.,Levitsky, Mikhail M.,Zubavichus, Yan V.,Khrustalev, Victor N.,Titov, Aleksei A.,Dorovatovskii, Pavel V.,Smol'Yakov, Alexander F.,Shubina, Elena S.,Kirillova, Marina V.,Kirillov, Alexander M.,Bilyachenko, Alexey N.
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p. 8062 - 8074
(2021/05/26)
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- Bioinspired Heterobimetallic Photocatalyst (RuIIchrom-FeIIIcat) for Visible-Light-Driven C-H Oxidation of Organic Substrates via Dioxygen Activation
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We report a bioinspired heterobimetallic photocatalyst RuIIchrom-FeIIIcat and its relevant applications toward visible-light-driven C-H bond oxidation of a series of hydrocarbons using O2 as the O-atom source. The RuII center absorbs visible light near 460 nm and triggers a cascade of electrons to FeIII to afford a catalytically active high-valent FeIV═O species. The in situ formed FeIV═O has been employed for several high-impact oxidation reactions in the presence of triethanolamine (TEOA) as the sacrificial electron donor.
- Goswami, Tapas,Kumar, Arun,Kumar, Sushil,Le Poul, Nicolas,Nautiyal, Divyanshu,Singh, Siddhant,Thetiot, Franck
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supporting information
p. 16059 - 16064
(2021/11/13)
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- Interfacial effect of Pd supported on mesoporous oxide for catalytic furfural hydrogenation
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Highly dispersed Pd is loaded onto different types of mesoporous oxide supports to investigate the synergetic metal-support effect in catalytic furfural (FAL) hydrogenation. Ordered mesoporous Co3O4, MnO2, NiO, CeO2, and Fe2O3 are prepared by the nanocasting and the supported Pd on mesoporous oxide catalysts are obtained by the chemical reduction method. It is revealed that mesoporous oxides play an important role on Pd dispersion as well as the redox behavior of Pd, which determines the final FAL conversion. Among the catalysts used, Pd/Co3O4 shows the highest conversion in FAL hydrogenation and distinct product selectivity toward 2-methylfuran (MF). While FAL is converted via two distinct pathways to produce either furfuryl alcohol (FA) via aldehyde hydrogenation or MF via hydrogenolysis, MF as a secondary product is derived from FA via the hydrogenolysis of C–O over the Pd/Co3O4 catalyst. It is revealed that FAL is hydrogenated to FA preferentially on the Pd surface; then the secondary hydrogenolysis to MF from FA is further promoted at the interface between Pd and Co3O4. We confirm that the reaction pathway over Pd/Co3O4 is totally different from other catalysts such as Pd/MnO2, which produces FA dominantly. The characteristics of the mesoporous oxides influence the Pd-oxide interfaces, which determine the activity and selectivity in FAL hydrogenation.
- Lee, Hojeong,Nguyen-Huy, Chinh,Jeong Jang, Eun,Lee, Jihyeon,Yang, Euiseob,Lee, Man Sig,Kwak, Ja Hun,An, Kwangjin
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p. 291 - 300
(2020/03/05)
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- Nitrogen-Doped Carbon Composites with Ordered Macropores and Hollow Walls
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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.
- Chen, Jianmin,Chen, Liyu,Fang, Ruiqi,Li, Yingwei,Qin, Ze,Wang, Yajing,Yang, Xianfeng,Yao, Wen
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supporting information
p. 23729 - 23734
(2021/10/04)
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- Biomimetic ketone reduction by disulfide radical anion
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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.
- Barata-Vallejo, Sebastian,Bobrowski, Krzysztof,Chatgilialoglu, Chryssostomos,Ferreri, Carla,Marciniak, Bronislaw,Skotnicki, Konrad
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- Efficient oxidation of cycloalkanes with simultaneously increased conversion and selectivity using O2 catalyzed by metalloporphyrins and boosted by Zn(AcO)2: A practical strategy to inhibit the formation of aliphatic diacids
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The direct sources of aliphatic acids in cycloalkanes oxidation were investigated, and a strategy to suppress the formation of aliphatic acids was adopted through enhancing the catalytic transformation of oxidation intermediates cycloalkyl hydroperoxides to cycloalkanols by Zn(II) and delaying the emergence of cycloalkanones. Benefitted from the delayed formation of cycloalkanones and suppressed non-selective thermal decomposition of cycloalkyl hydroperoxides, the conversion of cycloalkanes and selectivity towards cycloalkanols and cycloalkanones were increased simultaneously with satisfying tolerance to both of metalloporphyrins and substrates. For cyclohexane, the selectivity towards KA-oil was increased from 80.1% to 96.9% meanwhile the conversion was increased from 3.83 % to 6.53 %, a very competitive conversion level with higher selectivity compared with current industrial process. This protocol is not only a valuable strategy to overcome the problems of low conversion and low selectivity lying in front of current cyclohexane oxidation in industry, but also an important reference to other alkanes oxidation.
- Shen, Hai-Min,Wang, Xiong,Ning, Lei,Guo, A-Bing,Deng, Jin-Hui,She, Yuan-Bin
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- Manganese-catalyzed homogeneous hydrogenation of ketones and conjugate reduction of α,β-unsaturated carboxylic acid derivatives: A chemoselective, robust, and phosphine-free in situ-protocol
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We communicate a user-friendly and glove-box-free catalytic protocol for the manganese-catalyzed hydrogenation of ketones and conjugated C[dbnd]C[sbnd]bonds of esters and nitriles. The respective catalyst is readily assembled in situ from the privileged [Mn(CO)5Br] precursor and cheap 2-picolylamine. The catalytic transformations were performed in the presence of t-BuOK whereby the corresponding hydrogenation products were obtained in good to excellent yields. The described system offers a brisk and atom-efficient access to both secondary alcohols and saturated esters avoiding the use of oxygen-sensitive and expensive phosphine-based ligands.
- Topf, Christoph,Vielhaber, Thomas
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- Ruthenium-p-cymene Complex Side-Wall Covalently Bonded to Carbon Nanotubes as Efficient Hybrid Transfer Hydrogenation Catalyst
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A half-sandwich ruthenium-p-cymene organometallic complex has been immobilized at Single Walled Carbon Nanotubes (SWNT) sidewalls through a stepwise covalent chemistry protocol. The introduction of amino groups by means of diazonium-chemistry protocols leads the grafting at the outer walls of the nanotubes. This hybrid material is active in the transfer hydrogenation of ketones to yield alcohols, using as hydrogen source 2-propanol. SWNT?NH2?Ru presents a broad scope, performing the reaction under aerobic conditions and can be recycled over 9 consecutive reaction runs without losing activity or leaching ruthenium out. Comparison of the activity with related homogeneous catalysts reveals an improved performance due to the covalent bond between the metal and the material, achieving turnover frequencies as high as 192774 h?1.
- Blanco, Matías,Cembellín, Sara,Agnoli, Stefano,Alemán, José
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p. 5156 - 5165
(2021/11/05)
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- Synthesis, crystal and structural characterization, Hirshfeld surface analysis and DFT calculations of three symmetrical and asymmetrical phosphonium salts
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Three stable phosphonium salts of 1,4-butanediylebis(triphenylphosphonium) dibromide I, butane-4?bromo-1-(triphenylphosphonium) bromide II and 1,3-propanediylbis(triphenylphosphonium) tetrahydroborate III were synthesized and structurally characterized. Single crystal X-ray diffraction analysis, spectroscopic methods and thermal analysis methods were used for the characterization of titled compounds. Crystallographic data showed that compound I crystallized in the triclinic crystal system with Pī space group and compound II crystallized in the monoclinic crystal system with P21/c space group. The crystal packing structures of I and II were stabilized by various intermolecular interactions, especially of C–H···π contacts. The molecular Hirshfeld surface analysis and 2D fingerprint revealed that the C···H contacts have 24.3% and 18.4% contributions in the crystal packings of compounds I and II, respectively. In addition, the H···Br (28.5%) contact has a considerable contribution to the crystal architecture of compound II. Theoretical studies were performed by DFT method to investigate the structural properties of the titled compounds. The isotopic ratio of boron in tetrahydroborate anion of compound III calculated by 1H NMR spectroscopy. The isotopic ratio for 10B/11B was 19.099 / 80.900%. Reduction of some carbonyl compounds to corresponding alcohols was performed by compound III and the optimum conditions were determined.
- Delaram, Behnaz,Gholizadeh, Mostafa,Makari, Faezeh,Nokhbeh, Seyed Reza,Salimi, Alireza
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- Synthesis of new rhodium(III) complex by benzylic C[sbnd]S bond cleavage of thioether containing NNS donor Schiff base ligand: Investigation of catalytic activity towards transfer hydrogenation of ketones
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A new rhodium(III)-triphenylphosphine mixed ligand complex, [Rh(PPh3)(L)Cl2] (1) is synthesized by benzylic C[sbnd]S bond cleavage of L-CH2Ph ligand (where, L-CH2Ph = 2-(benzylthio)-N-(pyridin-2-ylmethylene)aniline). The complex is thoroughly characterized by several spectroscopic techniques. Geometry of the complex is confirmed by single crystal X-ray crystallography. Electronic structure, redox properties, absorption and emission properties of the complex were studied. DFT and TDDFT calculations were carried out to interpret the electronic structure and absorption properties of the complex respectively. The synthesized Rh(III) complex was tested as catalyst towards transfer hydrogenation reaction of ketones in iPrOH and an excellent catalytic conversion was observed under mild conditions.
- Biswas, Sujan,Das, Akash,Kumar Manna, Chandan,Kumar Mondal, Tapan,Naskar, Rahul
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- Pincerlike molybdenum complex and preparation method thereof, catalytic composition and application thereof, and alcohol preparation method
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The invention discloses a clamp-type molybdenum complex, a preparation method, a corresponding catalyst composition and application. The method comprises the steps: obtaining 9 molybdenum complexes with different structures through coordination reaction of 2-(substituent ethyl)-(5, 6, 7, 8-tetrahydroquinolyl) amine and a corresponding carbonyl molybdenum metal precursor; and catalyzing a ketone compound transfer hydrogenation reaction through a molybdenum complex to generate 40 alcohol compounds. The preparation method of the molybdenum complex is simple, high in yield and good in stability. For a transfer hydrogenation reaction of ketone, the molybdenum-based catalytic system has high catalytic activity and small molybdenum loading capacity, is used for production of aromatic and aliphatic alcohols, and has the advantages of simple method, small environmental pollution and high yield.
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Paragraph 0134-0140
(2021/08/11)
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- Chemoselective and Site-Selective Reductions Catalyzed by a Supramolecular Host and a Pyridine-Borane Cofactor
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Supramolecular catalysts emulate the mechanism of enzymes to achieve large rate accelerations and precise selectivity under mild and aqueous conditions. While significant strides have been made in the supramolecular host-promoted synthesis of small molecules, applications of this reactivity to chemoselective and site-selective modification of complex biomolecules remain virtually unexplored. We report here a supramolecular system where coencapsulation of pyridine-borane with a variety of molecules including enones, ketones, aldehydes, oximes, hydrazones, and imines effects efficient reductions under basic aqueous conditions. Upon subjecting unprotected lysine to the host-mediated reductive amination conditions, we observed excellent ?-selectivity, indicating that differential guest binding within the same molecule is possible without sacrificing reactivity. Inspired by the post-translational modification of complex biomolecules by enzymatic systems, we then applied this supramolecular reaction to the site-selective labeling of a single lysine residue in an 11-amino acid peptide chain and human insulin.
- Morimoto, Mariko,Cao, Wendy,Bergman, Robert G.,Raymond, Kenneth N.,Toste, F. Dean
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supporting information
p. 2108 - 2114
(2021/02/06)
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- CHEMICAL COMPOUNDS
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The present disclosure describes novel compounds, or their pharmaceutically acceptable salts, pharmaceutical compositions containing them, and their medical uses. Compounds of the disclosure have activity as dual modulators of Janus kinase (JAK), alone, or in combination with one or more of an additional mechanism, including a tyrosine kinase, such as TrkA or Syk, and PDE4, and are useful in the in the treatment or control of inflammation, auto-immune diseases, cancer, and other disorders and indications where modulation of JAK would be desirable. Also described herein are methods of treating inflammation, auto-immune diseases, cancer, and other conditions susceptible to inhibition of JAK and PDE4 by administering a compound herein described.
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Paragraph 0530-0531
(2021/01/23)
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- Selective aqueous-phase hydrogenation of furfural to cyclopentanol over Ni-based catalysts prepared from Ni-MOF composite
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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.
- Chen, Changzhou,Jiang, Jianchun,Li, Jing,Ren, Jurong,Wu, Dichao,Xia, Haihong,Zhou, Minghao
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- Selective Aerobic Oxidation of Secondary C (sp3)-H Bonds with NHPI/CAN Catalytic System
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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.]
- Wang, Lingyao,Zhang, Yuanbin,Yuan, Haoran,Du, Renfeng,Yao, Jia,Li, Haoran
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p. 1663 - 1669
(2020/10/21)
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- Adsorption Configuration-Determined Selective Hydrogenative Ring Opening and Ring Rearrangement of Furfural over Metal Phosphate
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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.
- Tong, Zhikun,Li, Xiang,Dong, Jingyu,Gao, Rui,Deng, Qiang,Wang, Jun,Zeng, Zheling,Zou, Ji-Jun,Deng, Shuguang
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- Nature of polymeric condensates during furfural rearrangement to cyclopentanone and cyclopentanol over Cu-based catalysts
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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
- Cai, Xichen,Li, Cuiqing,Li, Dongsheng,Li, Zhanqiao,Song, Yongji,Tian, Ziyou,Wang, Hong,Zhang, Chen,Zhang, Wei
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p. 22767 - 22777
(2021/12/24)
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- Hydrogenolysis of Furfuryl Alcohol to 1,2-Pentanediol Over Supported Ruthenium Catalysts
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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.
- Yamaguchi, Aritomo,Murakami, Yuka,Imura, Tomohiro,Wakita, Kazuaki
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p. 731 - 736
(2021/06/12)
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- Selective tandem hydrogenation and rearrangement of furfural to cyclopentanone over CuNi bimetallic catalyst in water
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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.
- Gao, Jin,Liu, Xin,Luo, Yang,Ma, Hong,Sun, Yuxia,Xu, Jie,Zhang, Meiyun,Zhang, Shujing
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p. 2216 - 2224
(2021/09/20)
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- Catalytic hydrogenation of furfural to tetrahydrofurfuryl alcohol using competitive nickel catalysts supported on mesoporous clays
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Nickel catalysts supported on mesoporous clays with different acid properties, such as montmorillonite MK-10, Al-pillared montmorillonite, mesoporous Na-saponite and mesoporous H-saponite, were prepared, characterized and tested for the hydrogenation of furfural to tetrahydrofurfuryl alcohol (THFA). Clays were also modified introducing basicity through magnesium oxide in different amounts. Catalysts with higher acidity or low amounts of metallic centres favoured deactivation and/or selectivity to the non-desired products. Interestingly, the addition of MgO both neutralized the acidity of the montmorillonite supports and improved the hydrogenation of the furanic ring, resulting in higher selectivity to THFA. The best catalyst was the one prepared with montmorillonite MK-10 covered by 30 wt% of magnesium oxide and with 8.8 % of the Ni metal phase achieving total conversion and total selectivity to THFA. The activity of this catalyst was maintained after several reuses.
- Sunyol,English Owen,González,Salagre,Cesteros
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- Supramolecular bimetallic vanadium(V) complex driven by hydrogen bonding and O???O chalcogen bonding interaction: Oxidation of cyclohexane and its application toward C[sbnd]H bond activation
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Vanadium(V) complex was synthesized in good yield and characterized by FT-IR, UV–Visible and NMR spectroscopy. The structure of the complex was confirmed by single X-ray crystallography. X-ray structural analysis the complex featuring O???O chalcogen bonding interaction and other short interaction. The O???O intermolecular interactions distance is 2.794 ?. Clearly, the O???O intermolecular distance in the O-linked complex is less than the sum of van der Waals atomic radii of oxygen 3.00 ? (rvdW (O) = 1.50 ?). Oxidations of cyclohexane to cyclohexanol were also carried out, using the synthetic complex as a catalyst. The catalytic studies were carried out successfully using m-chloroperbenzoic acid as oxidant at 100 °C, under solvents free conditions. The catalytic protocols are very simple and the catalyst can be recovered without any lost in products formation in the next consecutive cycle.
- Clovis, Ndege Simisi,Kurbah, Sunshine Dominic
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- Catalytic oxidation of cycloalkanes by porphyrin cobalt(II) through efficient utilization of oxidation intermediates
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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.
- Shen, Hai M.,Wang, Xiong,Guo, A. Bing,Zhang, Long,She, Yuan B.
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p. 1166 - 1173
(2020/09/17)
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- Erbium-Catalyzed Regioselective Isomerization-Cobalt-Catalyzed Transfer Hydrogenation Sequence for the Synthesis of Anti-Markovnikov Alcohols from Epoxides under Mild Conditions
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Herein, we report an efficient isomerization-transfer hydrogenation reaction sequence based on a cobalt pincer catalyst (1 mol %), which allows the synthesis of a series of anti-Markovnikov alcohols from terminal and internal epoxides under mild reaction conditions (≤55 °C, 8 h) at low catalyst loading. The reaction proceeds by Lewis acid (3 mol % Er(OTf)3)-catalyzed epoxide isomerization and subsequent cobalt-catalyzed transfer hydrogenation using ammonia borane as the hydrogen source. The general applicability of this methodology is highlighted by the synthesis of 43 alcohols from epoxides. A variety of terminal (23 examples) and 1,2-disubstituted internal epoxides (14 examples) bearing different functional groups are converted to the desired anti-Markovnikov alcohols in excellent selectivity and yields of up to 98%. For selected examples, it is shown that the reaction can be performed on a preparative scale up to 50 mmol. Notably, the isomerization step proceeds via the most stable carbocation. Thus, the regiochemistry is controlled by stereoelectronic effects. As a result, in some cases, rearrangement of the carbon framework is observed when tri-and tetra-substituted epoxides (6 examples) are converted. A variety of functional groups are tolerated under the reaction conditions even though aldehydes and ketones are also reduced to the respective alcohols under the reaction conditions. Mechanistic studies and control experiments were used to investigate the role of the Lewis acid in the reaction. Besides acting as the catalyst for the epoxide isomerization, the Lewis acid was found to facilitate the dehydrogenation of the hydrogen donor, which enhances the rate of the transfer hydrogenation step. These experiments additionally indicate the direct transfer of hydrogen from the amine borane in the reduction step.
- Liu, Xin,Longwitz, Lars,Spiegelberg, Brian,T?njes, Jan,Beweries, Torsten,Werner, Thomas
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p. 13659 - 13667
(2020/11/30)
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- Effect of pretreatment conditions on acidity and dehydration activity of CeO2-MeOx catalysts
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A series of MeOx-modified CeO2 (CeO2-MnOx, CeO2-ZnO, CeO2-MgO, CeO2-CaO, and CeO2-Na2O) catalysts were prepared by the impregnation of CeO2 with corresponding metal nitrates. Acidity and oxidation state of cerium were investigated on both oxidized and reduced catalysts by employing Fourier Transform Infrared spectroscopy (FTIR) on adsorbed pyridine and in situ H2-Temperature Programmed Reduction/X-ray Absorption Spectroscopy (H2-TPR/XAS) techniques, respectively. Metal oxide addition tended to alter both type and number of acid sites on ceria. EXAFS data showed a significant difference in NCe-O between unmodified and CeO2-MeOx, suggesting that added MeOx interferes with vacancy formation on ceria during reduction. In comparison with air-pretreated samples, H2-pretreated ones under similar conversion of 1,5 pentanediol exhibited a higher selectivity towards linear alcohols. Alcohol conversion found to correlate with total acidity (i.e., Br?nsted and Lewis). CeO2 benefited from the addition of alkali (Na) or alkaline earth metals (Mg, Ca) by producing unsaturated alcohols.
- Cronauer, Donald C.,Góra-Marek, Kinga,Garcia, Richard,Gnanamani, Muthu Kumaran,Jacobs, Gary,Kropf, A. Jeremy,Marshall, Christopher L.
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- A gradient reduction strategy to produce defects-rich nano-twin Cu particles for targeting activation of carbon-carbon or carbon-oxygen in furfural conversion
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Complexity of chemical linkages (C-C/C-H/C-O, C=C/C=O, or C-O-H/C-O-C) in biomass-derived molecules makes the selective activation of targeted bonds much more challenging, expecting well-defined catalysts and definite catalytically-active sites. This work demonstrates an effective gradient reduction strategy to control the definite structure of catalytically-active sites, affording defects-rich nano-twin Cu particles. This strategy just involves the reduction (calcination under H2) of CuII-containing layered double hydroxides (LDHs) simply with controlling the reduction gradient (interval time) of CuII species in two chemical micro-environments (CuII-O-CuII and CuII-O-MII/III/IV (M ≠ Cu)) in the brucite-like layer of LDHs. The nano-twin Cu particles efficiently promote the target activation of C-O and C=C in the conversion of furfural to cyclopentanone (CPO). With ~100% furfural conversion, the defects-rich nano-twin Cu particles afford a CPO selectivity of 92%, 50% higher than regular spherical Cu particles. The multi-stepped defect sites, originating from the planar defects, play a decisive role in promoting the CPO selectivity by facilitating the hydro-deoxygenation to C-O of 4-hydroxycyclopentenone (HCP) and hydrogenation to C=C of HCP or cyclopentenone.
- An, Zhe,Guo, Shaowei,He, Jing,Ma, Xiaodan,Shu, Xin,Song, Hongyan,Xiang, Xu,Zhang, Jian,Zhu, Yanru
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- Hydrogenation of Furfural to Cyclopentanone under Mild Conditions by a Structure-Optimized Ni?NiO/TiO2 Heterojunction Catalyst
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The catalytic conversion of biomass-derived furfural (FFA) into cyclopentanone (CPO) in aqueous solution is an important pathway to obtain sustainable resources. However, the conversion and selectivity under mild conditions are still unsatisfactory. In this study, a catalyst consisting of Ni?NiO heterojunction supported on TiO2 with optimized composition of anatase and rutile (Ni?NiO/TiO2-Re450) is prepared by pyrolysis at 450 °C. With Ni?NiO/TiO2-Re450, as catalyst, complete conversion of FFA and 87.4 % yield of CPO are achieved under mild reaction conditions (1 MPa, 140 °C, 6 h). 95.4 % FFA conversion is retained up to the fifth run, indicating the high stability of the catalyst. Multiple characterizations, control experiments, and theoretical calculations demonstrate that the good catalytic performance of Ni?NiO/TiO2-Re450 can be attributed to a synergistic effect of the Ni?NiO heterojunction and the TiO2 support. This low-cost catalyst may expedite the catalytic upgrading and practical application of biomass-derived chemicals.
- Chen, Shuo,Qian, Ting-Ting,Ling, Li-Li,Zhang, Wenhua,Gong, Bing-Bing,Jiang, Hong
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p. 5507 - 5515
(2020/09/01)
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- Efficient catalytic transfer hydrogenation reactions of carbonyl compounds by Ni(II)-diphosphine complexes
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The catalytic transfer hydrogenation reactions of a series of aromatic and aliphatic carbonyl compounds were investigated using divalent Ni(II)-diphosphine complexes, [L2NiCl2] (where L2 = 1,1-bis(diphenylphosphino)methane (dppm), 1,2-bis(diphenylphosphino)ethane (dppe), 1,3-bis(diphenylphosphino)propane (dppp), 1,1-bis(diphenylphosphino)ferrocene (dppf), and N-butyl-N-(diphenylphosphino)-1,1-diphenylphosphinamine (dppba)). This is a single-step reaction in the presence of potassium hydroxide and isopropyl alcohol to afford the corresponding alcohols. This protocol tolerates other sensitive functional groups like olefinic double bonds and also achieves high chemoselectivity. All the reactions were monitored by GC and GC–MS. The plausible mechanism is also discussed. The method reported in the present article is simple, cost-effective, and provides excellent conversions. Nickel-diphosphine complexes appear as a potential alternative to expensive transition metal complexes.
- Venkatesh, Sadhana,Panicker, Rakesh R.,Lenin Kumar, Verdhi,Pavankumar,Viswanath, Nukala,Singh, Shangrila,Desikan, Rajagopal,Sivaramakrishna, Akella
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p. 2963 - 2977
(2020/11/03)
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- Synthesis and characterization of silica-coated magnetite nanoparticles modified with bis(pyrazolyl) triazine ruthenium(II) complex and the application of these nanoparticles as a highly efficient catalyst for the hydrogen transfer reduction of ketones
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We present a facile and efficient method for modifying the surface of silica-coated Fe3O4 magnetic nanoparticles (MNPs) with bis(pyrazolyl) triazine ruthenium(II) complex [MNPs@BPT–Ru (II)]. Field emission-scanning electron microscopy, thermogravimetric/derivative thermogravimetry analysis, X-ray powder diffraction, Fourier-transform infrared spectroscopy, vibrating sample magnetometry, and energy-dispersive X-ray spectrometry analyses were employed for characterizing the structure of these nanoparticles. MNPs@BPT–Ru(II) nanoparticles proved to be a magnetic, reusable, and heterogeneous catalyst for the hydrogen transfer reduction of ketone derivatives. In addition, highly pure products were obtained with excellent yields in relatively short times in the presence of this catalyst. A comparison of this catalyst with those previously used for the hydrogen transfer reactions proved the uniqueness of MNPs@BPT–Ru(II) nanoparticle which is due to its inherent magnetic properties and large surface area. The presented method also had other advantages such as simple reaction conditions, eco-friendliness, high recovery ability, easy work-up, and low cost.
- Mobinikhaledi, Akbar,Moghanian, Hassan,Ajerloo, Bahram,Dousti, Fatemeh
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- One-pot biosynthesis of 1,6-hexanediol from cyclohexane by: De novo designed cascade biocatalysis
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1,6-Hexanediol (HDO) is an important precursor in the polymer industry. The current industrial route to produce HDO involves energy intensive and hazardous multistage (four-pot-four-step) chemical reactions using cyclohexane (CH) as the starting material, which leads to serious environmental problems. Here, we report the development of a biocatalytic cascade process for the biotransformation of CH to HDO under mild conditions in a one-pot-one-step manner. This cascade biocatalysis operates by using a microbial consortium composed of three E. coli cell modules, each containing the necessary enzymes. The cell modules with assigned functions were engineered in parallel, followed by combination to construct E. coli consortia for use in biotransformations. The engineered E. coli consortia, which contained the corresponding cell modules, efficiently converted not only CH or cyclohexanol to HDO, but also other cycloalkanes or cycloalkanols to related dihydric alcohols. In conclusion, the newly developed biocatalytic process provides a promising alternative to the current industrial process for manufacturing HDO and related dihydric alcohols. This journal is
- Kang, Lixin,Li, Aitao,Li, Qian,Li, Renjie,Wang, Fei,Yu, Xiaojuan,Zhang, Zhongwei,Zhao, Jing
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p. 7476 - 7483
(2020/11/23)
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- Conversion of Furfural Derivatives to 1,4-Pentanediol and Cyclopentanol in Aqueous Medium Catalyzed by trans-[(2,9-Dipyridyl-1,10-phenanthroline)(CH3CN)2Ru](OTf)2
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The complex trans-[(2,9-dipyridyl-1,10-phenanthroline)(CH3CN)2Ru](OTf)2 was synthesized and tested as a homogeneous hydrodeoxygenation catalyst for the conversion of biomass-derived furfuryl alcohol and furfuryl acetate to 1,4-pentanediol (as the primary target compound) and cyclopentanol (formed by the competing Piancatelli rearrangement) in aqueous reaction medium at elevated temperature (150-200 °C) and hydrogen pressure (800 psi = 5.12 MPa). Catalytic reactions using furfuryl alcohol as a substrate were limited by the formation of solid resins with the product yields showing a strong negative correlation with increasing substrate concentration and maximum yields of 1,4-pentanediol and cyclopentanol being 23 and 41%, respectively. A two-level full factorial design of experiments study with four independent input variables (temp., time, [cat.], [substrate]) and a center point was carried out for the conversion of furfuryl acetate, showing good reproducibility between replicates and no humin formation. This enabled a full statistical analysis of the input variable impact on product distribution and yield. The maximum yields of 1,4-pentanediol and cyclopentanol using furfuryl acetate as a substrate are 68 and 35%, respectively. The decreased self-reactivity of furfuryl acetate versus furfuryl alcohol dramatically increases the yields of target products but still shows a strong negative correlation of the yield of the desired products with increasing substrate concentration.
- Banz Chung, Elise M.-J.,Da Cunha, Igor Tadeu,Magee, Megan,Moore, Cameron M.,Schlaf, Marcel,Soltanipanah, Parnian,Stones, Maryanne K.,Sullivan, Ryan J.,Sutton, Andrew D.,Umphrey, Gary J.
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p. 2667 - 2683
(2020/03/11)
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- Method for catalytic oxidation of cycloalkane by confinement porphyrin Co (II)
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The invention relates to a method for catalytic oxidation of cycloalkane by confinement porphyrin Co (II). The method comprises the following steps: dispersing confinement cobalt porphyrin (II) in cycloalkane, sealing the reaction system, heating to 100-130 DEG C while stirring, introducing oxygen to 0.2-3.0 MPa, keeping the set temperature and oxygen pressure, stirring to react for 3.0-24.0 h, and carrying out post-treatment on a reaction solution to obtain products naphthenic alcohol and naphthenic ketone. The method achieves high selectivity of naphthenic alcohol and naphthenic ketone, andeffectively inhibits the generation of aliphatic diacid. The aliphatic diacid is low in selectivity, so that the continuity of the cycloalkane oxidation process and the separation of the products arefacilitated; the method has the potential of solving the problem that naphthenic alcohol and naphthenic ketone are easily and deeply oxidized to generate aliphatic diacid in the industrial cycloalkanecatalytic oxidation process; and the method is a novel efficient and feasible method for selective catalytic oxidation of cycloalkane.
- -
-
Paragraph 0067; 0068
(2020/05/01)
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- Confinement porphyrin Co (II), and preparation method and application thereof
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Confinement porphyrin Co (II). A preparation method includes: under acidic condition, performing condensation on aromatic aldehyde and pyrrole in equal molar ratio to obtain a phenylporphyrin compound, and carrying out metallization in a chloroform-methanol solution to obtain porphyrin Cu (II), performing bromination and demetalization by perchloric acid to obtain confinement porphyrin, performingstirring reflux on the confinement porphyrin in a methanol solution for 12.0-24.0 h to obtain confinement porphyrin Co (II). An application includes: dissolving the confinement porphyrin Co (II) in naphthenic hydrocarbon and sealing the reaction system, stirring and heating the reaction system to 100-130 DEG C and feeding oxygen to 0.2-3.0 MPa; maintaining the set temperature and oxygen pressureand performing a stirring reaction for 3.0-24.0 h; performing after treatment on the reaction liquid to prepare the product. In the invention, generation of fatty diacid is effectively inhibited, andcontinuity of a naphthenic hydrocarbon oxidization process and product separation is facilitated. The invention has the potential of solving the problem that naphthene alcohols and naphthene ketones are liable to undergo deep oxidization and form the fatty diacid in an industrial naphthenic hydrocarbon catalytic oxidation process.
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Paragraph 0099-0100
(2020/04/17)
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- Method for synergistically catalyzing and oxidizing cycloparaffin through confined metalloporphyrin cobalt (II)/Cu (II) salt
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The invention discloses a method for synergistically catalyzing and oxidizing cycloparaffin through confined metalloporphyrin cobalt (II)/Cu (II) salt. The preparation method comprises the following steps: dispersing confined metalloporphyrin cobalt (II) (0.001%-5%, g/mol) and Cu (II) salt (0.01%-10%, mol/mol) into cycloparaffin; and sealing the reaction system, heating the temperature to 90-150 DEG C while stirring, introducing an oxidant, keeping the set temperature and pressure, carrying out stirring and reacting for 2.0-24.0 hours, and carrying out after-treatment on the reaction solutionto obtain the products cycloalkyl alcohol and cycloalkyl ketone. The method disclosed by the invention has the advantages of high cycloalkyl alcohol and cycloalkyl ketone selectivity, low reaction temperature, few byproducts, small environmental influence and the like. In addition, the content of cycloalkyl hydroperoxide is low, and the safety coefficient is high. The invention provides an efficient, feasible and safe method for synthesizing cycloalkyl alcohol and cycloalkyl ketone through selective catalytic oxidation of cycloparaffin.
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Paragraph 0041-0042
(2020/12/10)
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- Ruthenium Trichloride Catalyst in Water: Ru Colloids versus Ru Dimer Characterization Investigations
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An easy-to-prepare ruthenium catalyst obtained from ruthenium(III) trichloride in water demonstrates efficient performances in the oxidation of several cycloalkanes with high selectivity toward the ketone. In this work, several physicochemical techniques were used to demonstrate the real nature of the ruthenium salt still unknown in water and to define the active species for this Csp3-H bond functionalization. From transmission electron microscopy analyses corroborated by SAXS analyses, spherical nanoobjects were observed with an average diameter of 1.75 nm, thus being in favor of the formation of reduced species. However, further investigations, based on X-ray scattering and absorption analyses, showed no evidence of the presence of a metallic Ru-Ru bond, proof of zerovalent nanoparticles, but the existence of Ru-O and Ru-Cl bonds, and thus the formation of a water-soluble complex. The EXAFS (extended X-ray absorption fine structure) spectra revealed the presence of an oxygen-bridged diruthenium complex [Ru(OH)xCl3-x]2(μ-O) with a high oxidation state in agreement with catalytic results. This study constitutes a significant advance to determine the true nature of the RuCl3·3H2O salt in water and proves once again the invasive nature of the electron beam in microscopy experiments, routinely used in nanochemistry.
- Lebedeva, Anastasia,Albuquerque, Brunno L.,Domingos, Josiel B.,Lamonier, Jean-Fran?ois,Giraudon, Jean-Marc,Lecante, Pierre,Denicourt-Nowicki, Audrey,Roucoux, Alain
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p. 4141 - 4151
(2019/03/26)
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- Interconverting Lanthanum Hydride and Borohydride Catalysts for C=O Reduction and C?O Bond Cleavage
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The high catalytic reactivity of homoleptic tris(alkyl) lanthanum La{C(SiHMe2)3}3 is highlighted by C?O bond cleavage in the hydroboration of esters and epoxides at room temperature. The catalytic hydroboration tolerates functionality typically susceptible to insertion, reduction, or cleavage reactions. Turnover numbers (TON) up to 10 000 are observed for aliphatic esters. Lanthanum hydrides, generated by reactions with pinacolborane, are competent for reduction of ketones but are inert toward esters. Instead, catalytic reduction of esters requires activation of the lanthanum hydride by pinacolborane.
- Patnaik, Smita,Sadow, Aaron D.
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p. 2505 - 2509
(2019/02/01)
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- Consecutive addition esterification and hydrolysis of cyclic olefins catalyzed by multi-SO3H functionalized multi heteropolyanion-based ionic hybrids undersolvent-free conditions
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An efficient protocol for the synthesis of cycloalkyl carboxylates and alcohols from cyclic olefins is described. The cyclic olefins were converted to corresponding target molecules under solvent-free conditions catalyzed by two novel multi-SO3H functionalized multi heteropolyanion-based ionic hybrids through one-pot consecutive addition esterification and hydrolysis reactions. This approach has several advantages, including high yield, simple workup and simple purification.
- Zheng, Guocai,Li, Xinzhong
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p. 933 - 941
(2019/03/17)
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- Mild C-H functionalization of alkanes catalyzed by bioinspired copper(ii) cores
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Three new copper(ii) coordination compounds formulated as [Cu(H1.5bdea)2](hba)·2H2O (1), [Cu2(μ-Hbdea)2(aca)2]·4H2O (2), and [Cu2(μ-Hbdea)2(μ-bdca)]n (3) were generated by aqueous medium self-assembly synthesis from Cu(NO3)2, N-butyldiethanolamine (H2bdea) as a main N,O-chelating building block and different carboxylic acids [4-hydroxybenzoic (Hhba), 9-anthracenecarboxylic (Haca), or 4,4′-biphenyldicarboxylic (H2bdca) acid] as supporting carboxylate ligands. The structures of products range from discrete mono- (1) or dicopper(ii) (2) cores to a 1D coordination polymer (3), and widen a family of copper(ii) coordination compounds derived from H2bdea. The obtained compounds were applied as bioinspired homogeneous catalysts for the mild C-H functionalization of saturated hydrocarbons (cyclic and linear C5-C8 alkanes). Two model catalytic reactions were explored, namely the oxidation of hydrocarbons with H2O2 to a mixture of alcohols and ketones, and the carboxylation of alkanes with CO/S2O82- to carboxylic acids. Both processes proceed under mild conditions with a high efficiency and the effects of different parameters (e.g., reaction time and presence of acid promoter, amount of catalyst and solvent composition, substrate scope and selectivity features) were studied and discussed in detail. In particular, an interesting promoting effect of water was unveiled in the oxidation of cyclohexane that is especially remarkable in the reaction catalyzed by 3, thus allowing a potential use of diluted, in situ generated solutions of hydrogen peroxide. Moreover, the obtained values of product yields (up to 41% based on alkane substrate) are very high when dealing with the C-H functionalization of saturated hydrocarbons and the mild conditions of these catalytic reactions (50-60 °C, H2O/CH3CN medium). This study thus contributes to an important field of alkane functionalization and provides a notable example of new Cu-based catalytic systems that can be easily generated by self-assembly from simple and low-cost chemicals.
- Kirillova, Marina V.,Fernandes, Tiago A.,André, Vania,Kirillov, Alexander M.
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supporting information
p. 7706 - 7714
(2019/08/30)
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- Solvent-Tailored Pd3P0.95 nano catalyst for amide-nitrile inter-conversion, the hydration of nitriles and transfer hydrogenation of the CO bond
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For the first time, a one pot thermolysis of [Pd(PPh3)2Cl2] prepared by reacting Ph3P with PdCl2 in a 2:1 molar ratio in MeOH at 280 °C in a trioctylphosphine (TOP) and oleylamine(OA)-octadecane(ODE) mixture (1:1) was used to prepare quantum dots (QDs; size ~2-3 nm) and nanoparticles (NPs; size ~13-14 nm), respectively, of composition Pd3P0.95. TEM, SEM-EDX, powder-XRD and XPS (for QDs only) were used to authenticate the two nanophases. 31P{1H}NMR experiments performed to monitor the progress of thermolysis reactions revealed that the phosphorus present in the Pd3P0.95 QDs had come from TOP, whereas in Pd3P0.95 NPs, its source is triphenylphosphine. The nature of the solvent did not affect the chemical composition of the nano-phase but controlled its size. Probably, solvent dependent, unique, single source precursors (SSPs) of palladium were generated in situ, and controlled the size. The catalytic activity of both Pd3P0.95 QDs and NPs was explored. The QDs were found to be efficient as a catalyst for the amide-nitrile interconversion at room temperature (yield up to 92% in 4 h), hydration of nitriles and transfer hydrogenation (TH) of carbonyl compounds with yields up to 96% in 3-4 h. The yields and reaction rates of amide-nitrile inter-conversion and TH when catalyzed by Pd3P0.95 QDs were found to be higher compared to the ones observed with the Pd/C catalyst. The binding energy of Pd(3d) in the X-ray photoelectron spectrum (XPS) of Pd3P0.95 indicated an electron transfer from the metal to phosphorus, resulting in electron deficient palladium, which facilitates the coordination of a substrate to Pd and drives the reaction. The reusability of Pd3P0.95 QDs for the interconversion was found to be up to 4-Times, while for the transfer hydrogenation of carbonyl compounds it was up to 6-Times, but with a diminished yield. Pd3P0.95 NPs were found to be less active (yield up to 36% in optimized reaction conditions) in comparison to Pd3P0.95 QDs. The mercury poisoning test suggested that the catalysis predominantly proceeded heterogeneously on the surface of the QDs. The PXRD and XPS results did not suggest a significant variation in the phase of QDs after the third catalytic cycle. The bleeding of Pd during catalysis (determined by flame AAS) and the agglomeration of QDs as supported by the SEM-EDX and TEM results are probably responsible for the reduction in the catalytic activity of QDs after reusing three times.
- Sharma, Alpesh K.,Joshi, Hemant,Bhaskar, Renu,Singh, Ajai K.
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supporting information
p. 10962 - 10970
(2019/07/31)
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- Transfer hydrogenation of ketones catalyzed by 2,6‐bis(triazinyl)pyridine ruthenium complexes: The influence of alkyl arms
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The transfer hydrogenation of ketones catalyzed by transition metal complexes has attracted much attention. A series of ruthenium(II) complexes bearing 2,6-bis(5,6-dialkyl-1,2,4-triazin-3-yl)pyridine ligands (R-BTPs) were synthesized and characterized by NMR analysis and X-ray diffraction. These ruthenium(II) complexes were applied in the transfer hydrogenation of ketones. Their different catalytic activity were attributed to the alkyl arms on the 2,6-bis(5,6-dialkyl-1,2,4-triazin-3-yl)pyridine. As the length of the alkyl arms rising, the catalytic activities of the complex catalysts decreased. By means of 0.4 mol % catalyst RuCl2(PPh3)(3-methylbutyl-BTP) in refluxing 2-propanol, a variety of ketones were reduced to their corresponding alcohols with >95% conversion over a period of 3 h.
- Wang, Liandi,Liu, Tingting
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supporting information
(2019/08/12)
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- Catalytic hydrogenation of aldehydes and ketones using cinchona–bipyridyl-based palladium catalyst
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Understanding the need for simple, robust and low effluents, in chemical processes, we have developed an elegant protocol for the catalytic reduction of aldehydes and ketones to corresponding alcohols which are used in synthetic fragrance applications using cinchona alkaloid-derived palladium catalyst. This system holds good for very low catalyst loading surfaces with the formation of fewer impurities and negligible decomposition under moderate pressure. The conversions and yields range from moderate to good (60–80%).
- Chidambaram, Ramasamy R.,Sadhasivam, Velu,Mariyappan, Mathappan,Siva, Ayyanar
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p. 373 - 384
(2019/01/28)
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- Manganese(I)-Catalyzed Transfer Hydrogenation and Acceptorless Dehydrogenative Condensation: Promotional Influence of the Uncoordinated N-Heterocycle
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The four bidentate manganese(I) complexes [(C5H4N-C5H3N-OH)Mn(CO)3Br] (1), [(C9H6N-C5H3N-OH)Mn(CO)3Br] (2), [(C8H5N2-C5H3N-OH)Mn(CO)3Br] (3), and [(C8H5N2-C5H3N-OCH3)Mn(CO)3Br] (4) were synthesized. These complexes were tested as catalysts for the transfer hydrogenation of ketones, and 3 showed the highest activity. The reactions proceeded well with 0.5 mol % of catalyst loading and 20 mol % of t-BuOK at 85 °C for 24 h. Furthermore, 3 was also used as a catalyst for the synthesis of primary alcohols via transfer hydrogenation of aldehydes and the synthesis of 1,2-disubstituted benzimidazoles and quinolines via acceptorless dehydrogenative condensations.
- Zhang, Chong,Hu, Bowen,Chen, Dafa,Xia, Haiping
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p. 3218 - 3226
(2019/09/13)
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- Method for (II) preparing/cycloalkanol and cycloalkanone by synergetic (II) catalysis of molecular oxygen-selective oxidation of cycloalkane by using cobalt salt, namely, zinc salt of zinc salt (by machine translation)
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In a stainless steel (II) high /(II) pressure reaction kettle with a polytetrafluoroethylene inner container, the cobalt salt is stirred and heated at room temperature to give an oxidant oxygen (II); a set temperature (II) and an oxygen pressure stirring reaction are kept; and the reaction (II) mixture/is (II) stirred and reduced to generate a peroxide, namely cycloalkanol and cycloalkanone (II)/(II). The catalyst has the advantages of cheap and easily available catalyst, low synthesis cost, high selectivity, effective inhibition of generation of aliphatic diacid, low selectivity of aliphatic diacid, and facilitation of serialization of the naphthenic acid process and separation of products. (by machine translation)
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Paragraph 0101-0102
(2019/12/08)
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- A Nanospherical Mesoporous Ruthenium-Containing Polymer as a Guaiacol Hydrogenation Catalyst
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Abstract: A hybrid catalyst is synthesized using ruthenium nanoparticles deposited on a nanospherical mesoporous polymer. Catalytic properties are studied in guaiacol hydrogenation at a temperature of 200–250°С and a hydrogen pressure of 5.0 MPa. Effect of solvent and catalytic additives on the reaction is investigated. It is shown that the synthesized catalyst exhibits the highest activity in guaiacol hydrodeoxygenation in the two-phase system water/n-dodecane and when the reaction is carried out in the presence of scandium triflate.
- Boronoev,Shakirov,Ignat’eva,Maximov,Karakhanov
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p. 1300 - 1306
(2020/01/02)
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