HOMOGENEOUS HYDROGENATION OF KETONES TO ALCOHOLS WITH RUTHENIUM COMPLEX CATALYSTS

Sanchez-Delgado, R.A.,Ochoa, O.L. De

, p. 427 - 434 (1980)

A number of ruthenium triphenylphosphine complexes catalyse the reduction of ketones to their corresponding alcohols in the presence of water.The most convenient catalyst precursors are carbonyl containing complexes which do not promote decarbonylation of the substrate.The hydrogenation of acetone with hydridochlorocarbonyltris(triphenylphosphine)ruthenium is first order with respect to the substrate concentration, the catalyst concentration, the hydrogen pressure and the water concentration.Turnover numbers up to 15,000 have been achieved with this catalyst.Other ketones are also reduced by RuHCl(CO)(PPh3)3 and the rate of the reaction is dependent on the nature of the substrate.

Nucleophilic substitution in radicals derived from isopropyl chloride

Kosobutskii

, p. 1050 - 1052 (2003)

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Kinetics of an Associative Ligand-Exchange Process: Alcohol Exchange with Arsenate(V) Triesters

Baer, Carl D.,Edwards, John O.,Kaus, Malcolm J.,Richmond, Thomas G.,Rieger, Philip H.

, p. 5793 - 5798 (1980)

The rate of alcohol exchange with trialkyl arsenates has been studied by three techniques.Exchange of the straight-chain alcohols (ethyl, n-propyl, n-butyl, and n-pentyl) was studied in acetonitrile solution by using proton NMR line broadening.Activation enthalpies and entropies were found in the ranges 1 to 6kJ mol-1 and -204 and -226 J mol-1 K-1, respectively.The reactions are subject to acid catalysis for which slightly higher ΔH and less negative ΔS values were found.Methyl exchange, studied by the same technique, is about one powere of ten faster.Isopropyl exchange, about three powers of ten slower, was studied in acetonitrile and dichloromethane solutions by deuterium labeling, using proton NMR.The interchange reaction of benzyl alcohol with triisopropyl arsenate in acetonitrile or dichloromethane was followed by spectrophotometry.Hydrogen bonding between alcohol and ester (which complicates order determination) was observed when reactants were at concentrations greater than about 10-2 M.The strongly associative mechanism is discussed.

Hydrodeoxygenation of glycerol into propanols over a Ni/WO3–TiO2 catalyst

Greish, Alexander A.,Finashina, Elena D.,Tkachenko, Olga P.,Nikul'shin, Pavel A.,Ershov, Mikhail A.,Kustov, Leonid M.

, p. 119 - 120 (2020)

Hydrodeoxygenation of glycerol in a flow reactor over a bifunctional Ni/WO3–TiO2 catalyst at 240–255 °C and hydrogen pressure of 3 MPa affords propan-1-ol and propan-2-ol in total yield of 94%.

Electrode Potential of a Dispersed Raney Nickel Electrode during Acetone Hydrogenation: Influence of the Solution and Reaction Kinetics

Pardillos-Guindet, J.,Vidal, S.,Court, J.,Fouilloux, P.

, p. 12 - 20 (1995)

The hydrogenation of acetone was investigated in basic aquueous solutions with undoped and chromium-doped catalysts.The reaction was carried out under pressure in an autoclave equipped with a reference electrode.The consumption of hydrogen and the electrode potential were measured during the course of the reaction.A mathematical model was applied which fits the experimental kinetic data well.It allows the computation of the rate constant and the absorption equilibrium constants.The kinetics obey a Langmuir-Hinshelwood mechanism with competitive adsorption.The metallic catalyst particles behave like a dispersed electrode and an electrochemical double layers is formed at their surface.In the presence of hydrogen alone, the metal potential obeys the Nernst law for the hydrogen electrode.During acetone hydrogenation, the double layer is modified and the measured potential goes to the positive region for several tens of millivolts, depending on whether the catalyst is doped or not.In all cases an experimental correlation was found between this experimental potential rise and the reaction rate.

CATALYTIC AND STOICHIOMETRIC REDUCTION OF KETONES AND ALDEHYDES BY THE HYDRIDOTETRACARBONYL FERRATE ANION

Marko, Laszlo,Radhi, Mazin A.,Otvos, Irma

, p. 369 - 376 (1981)

Acetone is catalytically reduced to isopropyl alcohol by carbon monoxide and water in the presence of iron carbonyls and triethylamine at 100 deg C and 100 bar.Use of NaOH in place of triethylamine gives a much less efficient catalyst system.The Et3NH*HFe(CO)4 system also catalyses the reduction of n-butyraldehyde to n-butyl alcohol at room temperature in a fast stoichiometric reaction, whereas NaHFe(CO)4 is inactive under the same conditions.The Et3NH+ cation is necessary for the transfer of a proton to the carbonyl group, while the HFe(CO)4- anion carries out nucleophilic attack on carbonyl group and supplies the hydride ion.

Catalytic reduction of acetophenone with transition metal systems containing chiral bis(oxazolines)

Gómez, Montserrat,Jansat, Susanna,Muller, Guillermo,Bonnet, Michel C,Breuzard, Jérémy A.J,Lemaire, Marc

, p. 186 - 195 (2002)

The catalytic behaviour of several Ru, Rh and Ir systems containing bis(oxazoline) ligands (1-6) has been tested in the asymmetric reduction of acetophenone (7) to give 1-phenylethanol (8) by hydrogenation (Ir systems), transfer hydrogenation (Ir and Ru s

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Osburn,Werkman

, p. 417 (1935)

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Engineered alkane-hydroxylating cytochrome P450BM3 exhibiting nativelike catalytic properties

Fasan, Rudi,Chen, Mike M.,Crook, Nathan C.,Arnold, Frances H.

, p. 8414 - 8418 (2007)

(Figure Presented) Divide, evolve, and conquer: A domain-based strategy (see scheme) was used to engineer high catalytic and coupling efficiency for propane hydroxylation in a multidomain cytochrome P450 enzyme. The engineered enzymes exhibit high total activities in whole-cell bioconversions of propane to propanol under mild conditions, using air as oxidant.

Synthesis of uniform titanium and 1:1 strontium-titanium carboxyhydrosols by controlled hydrolysis of alkoxymetal carboxylate precursors

Riman,Landham,Bowen

, p. 821 - 826 (1989)

Uniform inorganic carboxhydrosols containing titanium or strontium and titanium cations were precipitated from isopropyl alcohol solutions by the controlled hydrolysis of metal alkoxycarboxylate precursors. The hydrolysis of various triisopropoxytitanium carboxylate compounds yielded the capability to control particle size. Spherical particles of carboxyhydrosols were prepared in mean sizes from 0.4 to 2.9 μm. Controlled hydrolysis of quintaisopropoxystrontium titanium octanoate resulted in slightly agglomerated, uniform 1-μm spheres in a solvent medium in which controlled precipitation of uniform powders was not previously possible. Conversion of the hydrous oxide carboxylate precipitate to the oxide via calcination or hydrothermal treatment was possible.

Propane reacts with O2 and H2 on gold supported TS-1 to form oxygenates with high selectivity

Bravo-Suarez,Bando,Akita,Fujitani,Fuhrer,Oyama

, p. 3272 - 3274 (2008)

Gold nanoparticles supported on a microporous titanosilicate (TS-1) were found to be highly selective (95%) towards the formation of acetone and isopropanol from propane, O2, and H2 at moderate temperatures (443 K). The Royal Society of Chemistry.

Hydrogenation of acetone on technetium catalysts

Rimar,Pirogova

, p. 398 - 401 (1998)

The catalytic properties of supported mono-and bimetallic catalysts of the Tc/support, M/support, and M-Tc/support types (M = Pt, Pd, Rh, Ru, Ni, Re, Co; supports are γ-Al2O3, MgO, SiO2) were investigated in the acetone hydrogenation. The main products of this reaction are isopropyl alcohol and propane. The catalytic activity in the acetone hydrogenation of the metals studied decreases in the consequence Pt > Tc ≈ Rh > Pd > Ru > Ni ≈ Re > Co (with γ-Al2O3 as the support). The influence of support nature on the catalytic activity was investigated for the Rh-Tc system as an example. A nonadditive increase in the catalytic activity of Rh-Tc/γ-Al203 in comparison with monometallic catalysts was found. The state of the surface of the catalysts was characterized by the UV-VIS diffuse reflectance spectra.

EFFECT OF ISOTOPE SUBSTITUTION ON THE MAGNITUDE OF NONEQUILIBRIUM NUCLEAR POLARIZATION IN PHOTOLYSIS OF ACETONE IN METHANOL

Skakovskii, E. D.,Tychinskaya, L. Yu.,Rykov, S. V.,Yankelevich, A. Z.

, p. 2456 - 2459 (1989)

Polarization of nuclei in both the products of the reactions and in the CHD2OD proton without polarization in the CH3OH protons is observed in irradiation of a solution of acetone in CD3OD in the presence of CHD2OD and CH3OH.Polarization of the protons of the products is strongly dependent on the temperature of the solution and arises in radical pairs; polarization of the proton of partially deuterated methyl alcohol is due to a mechanism of optical nuclear polarization.It was hypothesized that the isotope effect is due to a difference in proton and electron relaxation and to a difference in the rates of cross-relaxation transitions.

Dubey, R. K.,Singh, A.,Mehrotra, R. C.

, p. 169 - 176 (1988)

Ruthenium carbonyl carboxylate complexes with nitrogen-containing ligands III. Catalytic activity in hydrogenation

Frediani, Piero,Bianchi, Mario,Salvini, Antonella,Guarducci, Roberto,Carluccio, Luciano C.,Piacenti, Franco

, p. 187 - 198 (1995)

Several mononuclear and dinuclear ruthenium carbonyl acetate complexes containing bipyridine or phenanthroline have been tested as catalysts in the hydrogenation of alkenes, alkynes and ketones.They are active in polar solvents and in water and the nitrogen-containing ligands are unaltered at the end of the hydrogenation.Keywords: Ruthenium; Carbonyl complexes; N-donors; Hydrogenation; Catalysis; Homogeneous

The role played by acid and basic centers in the activity of biomimetic catalysts of the catalase, peroxidase, and monooxidase reactions

Magerramov,Nagieva

, p. 1895 - 1900 (2010)

The acid-basic centers of heterogeneous carriers of catalase, peroxidase, and monooxigenase biomimetics, in particular, iron protoporphyrin deposited on active or neutral aluminum magnesium silicate, were studied. The catalytic activity of biomimetics was stabilized, which allowed us not only to synthesize fairly effective biomimetics but also to clarify certain details of the mechanism of their action and perform a comparative analysis of the functioning of biomimetics and the corresponding enzymes.

A Cross-Correlation Mechanism for the Formation of Spin Polarization

Tsentalovich, Yu. P.,Frantsev, A. A.,Doktorov, A. B.,Yurkovskaya, A. V.,Sagdeev, R. Z.

, p. 8900 - 8908 (1993)

Photolysis of acetone in the presence of various hydrogen donors and of 3-hydroxy-3-methyl-2-butanone involves the formation of propan-2-olyl radicals which show both electron and nuclear spin polarization.The electron polarization of the radicals leads to additional nuclear polarization of the reaction products.Transfer of electron to nuclear polarization can occur by cross-relaxation and cross-correlation.The latter is descibed in detail.Experimentally, the mechanisms leads to a formation of net nuclear polarization for symmetrical radical pairs as well as an unusual kinetic behavior of multiplet effects.

Brunelli, M.,Perego, G.,Lugli, G.,Mazzei, A.

, (1979)

Time-Dependent Self-Assembly of Copper(II) Coordination Polymers and Tetranuclear Rings: Catalysts for Oxidative Functionalization of Saturated Hydrocarbons

Costa, Ines F. M.,Kirillova, Marina V.,André, Vania,Fernandes, Tiago A.,Kirillov, Alexander M.

supporting information, p. 14491 - 14503 (2021/07/19)

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.

Hydrogen-Catalyzed Acid Transformation for the Hydration of Alkenes and Epoxy Alkanes over Co-N Frustrated Lewis Pair Surfaces

Deng, Qiang,Deng, Shuguang,Gao, Ruijie,Li, Xiang,Tsang, Shik Chi Edman,Wang, Jun,Zeng, Zheling,Zou, Ji-Jun

, p. 21294 - 21301 (2021/12/17)

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.