G. N. Menchikova

Direct catalytic oxidation of lower alkanes in ionic liquid media

Immobilization of rhodium (palladium)-copper-chloride catalytic systems in ionic liquids as high-boiling-point solvents affects the distribution of propane oxidation products: the acetone yield increases and the yield of alcohols decreases. Propane is oxidized to acetone, bypassing the isopropanol formation step. Methane is oxidized under more severe conditions than propane, giving methyl trifluoroacetate as the main product. Mechanisms of action of the catalytic systems based on rhodium and palladium are close to each other and likely include oxo or peroxo complexes as intermediates.

Oxidative functionalization of methane in the presence of a homogeneous rhodium-copper-chloride catalytic system: Transformation of acetic and propionic acids as solvent components

The oxidative functionalization of methane (O2, CO, 95°C, RhIII/CuI, II/Cl− catalytic system) was studied in an aqueous acetic or propionic acid medium. It was shown that oxidative decarbonylation of carboxylic acids takes place along with methanol and methyl carboxylate formation.

Oxidative decarbonylation of acetic and propionic acids: Unexpected H/D exchange of propionic acid with a solvent

A problem facing chemists engaged in study of bio� mass treatment—how to eliminate a carboxyl group from lipid fatty acids—can be solved by means of acid decarbonylation and subsequent alcohol dehydration (1). In the present work, we demonstrated for the first time that rhodiumcatalyzed joint oxidation of car� boxylic acids and CO under mild conditions 1 leads to the oxidative decarbonylation of acetic and propionic acids to methanol (methyl acetate) and ethanol (ethyl propionate), respectively. We also observed an unusual substitution of deuterium for a hydrogen atom in the alkyl radical of the molecules of the products of oxida� tive decarbonylation of propionic acid. The oxidation of СН4 in the Rh III /Cu I,II /Cl - sys� tem in a CF 3 COOH solution leads to the formation of methanol (or trifluoromethyl acetate) and formic acid (2, 3). The change of the solvent for aqueous acetic acid (both with and without adding sulfuric acid

The Oxidation of Carbon Monoxide as an Integrated Part of the Coupled Alkane Oxidation Process: Gas-Phase Oxidation over Supported Metal-Complex Catalysts

Heterogeneous rhodium–copper chloride catalysts for gas-phase oxidation processes were prepared via the cold impregnation of γ-Al2O3 with aqueous RhCl3 and CuCl2 solutions. Heptafluorobutyric or pentafluorobenzoic acids were additionally deposited onto these catalysts to simulate the action of homogeneous rhodium–copper chloride catalytic systems in the coupled alkane–carbon monoxide oxidation reaction. The catalysts were studied in the reactions of carbon monoxide oxidation and coupled propane–CO oxidation with dioxygen by diffuse reflectance IR Fourier transform spectroscopy (DRIFTS) and electron paramagnetic resonance (EPR). The obtained data indicate the probable transfer of electrons between rhodium and copper compounds.

Oxidation of carbon monoxide catalyzed by Pd(α,α-bipy)Cl 2 —CuCl 2 —C 3 F 7 COOH/γ-Al 2 O 3 : oscillations in the flow reactor

аInstitute of Structural Macrokinetics and Materials Science, Russian Academy of Sciences, 8 ul. Akad. Osipyana,142432 Chernogolovka, Moscow Region, Russian Federation. Fax: +7 (496) 524 6222. E mail: echep@ism.ac.ru bN. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky prosp., 119991 Moscow, Russian Federation. Fax: +7 (499) 135 5328. E mail: ot@ioc.ac.ru cInstitute of Problems of Chemical Physics, Russian Academy of Sciences, 1 prosp. Akad. Semenova,142432 Chernogolovka, Moscow Region, Russian Federation. Fax: +7 (495) 993 5707. E mail: kulav@icp.ac.ru

The effect of the conditions of the photocatalytic carbonylation of pentane catalyzed by the Rh2Cl2(CO)4-PMe3 system on the yield of C6-aldehyde

The yield of C6-aldehyde in the photocatalytic system Rh2Cl2(CO)4-PMe3 passes through a maximum as the CO pressure and PMe3 concentration increase. The increase in the yield of aldehydes with increasing CO pressure is related to the increase in the carbonylation rate and to the retardation of the photodecomposition of the aldehydes. The rate of the photocatalytic carbonylation of pentane in this system is 20 times higher than in the presence of RhCl(PMe3)2(CO).