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Corresponding Carbonyl Compounds (corresponding + carbonyl_compound)
Selected AbstractsFacile and Selective Oxidation of Benzylic Alcohols to Their Corresponding Carbonyl Compounds with Sodium Nitrate in the Presence of Broensted Acidic Ionic Liquids.CHEMINFORM, Issue 34 2007Abdol R. Hajipour Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Mechanism of Hydride Abstraction by Cyclopentadienone-Ligated Carbonylmetal Complexes (M = Ru, Fe)EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 2 2009Megan K. Thorson Abstract Cyclopentadienone-ligated ruthenium complexes, such as Shvo's catalyst, are known to oxidize reversibly alcohols to the corresponding carbonyl compounds. The mechanism of this reaction has been the subject of some controversy, but it is generally believed to proceed through concerted transfer of proton and hydride, respectively, to the cyclopentadienone ligand and the ruthenium center. In this paper we further study the hydride transfer process as an example of a coordinatively directed hydride abstraction by adding quantitative understanding to some features of this mechanism that are not well understood. We find that an oxidant as weak as acetone can be used to re-oxidize the intermediate ruthenium hydride without catalyst re-oxidation becoming rate-limiting. Furthermore, C,H cleavage is a significantly electrophilic event, as demonstrated by a Hammett reaction parameter of , = ,0.89. We then describe how the application of our mechanistic insights obtained from the study have enabled us to extend the ligand-directed hydride abstraction strategy to include a rare example of an iron(0) oxidation catalyst.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] Cloning, expression and characterization of a gene encoding nitroalkane-oxidizing enzyme from Streptomyces ansochromogenesFEBS JOURNAL, Issue 24 2002Jihui Zhang A nitroalkane-oxidizing enzyme gene (naoA) was cloned from a genomic DNA library of Streptomyces ansochromogenes 7100. The deduced protein (NaoA) of this gene contains 363 amino acids and has high similarity to several nitroalkane-oxidizing enzymes from various micro-organisms. The naoA gene was subcloned into an expression vector pET23b and overexpressed in Escherichia coli BL21(DE3). The protein was then purified, and its characteristics were studied. Experimental results showed that NaoA can convert 1-nitropropane, 2-nitropropane and nitroethane into the corresponding carbonyl compounds. The optimal pH and temperature for NaoA was found to be pH 7,8 and 48,56 °C, respectively. The Km of NaoA for nitroethane is ,,26.8 mm. NADH and nitro blue tetrazolium are strong inhibitors of NaoA, and thiol compounds and superoxide dismutase partially inhibit the enzyme activity. Therefore, superoxide may be an essential intermediate in the oxidation of nitroalkane by NaoA. [source] TEMPO- tert -Butyl Nitrite: An Efficient Catalytic System for Aerobic Oxidation of AlcoholsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 1-2 2009Xijun He Abstract A metal-free catalytic system consisting of 2,2,6,6-tetramethylpiperidine N -oxyl (TEMPO) and tert -butyl nitrite has been developed to activate molecular oxygen for the aerobic oxidation of alcohols. A variety of active and non-active alcohols were oxidized to their corresponding carbonyl compounds in high selectivity and yields. [source] Size-Dependent Catalytic Activity of Supported Palladium Nanoparticles for Aerobic Oxidation of AlcoholsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 3 2008Jing Chen Abstract Silica-alumina (SiO2 -Al2O3)-supported palladium catalysts prepared by adsorption of the tetrachloropalladate anion (PdCl42,) followed by calcination and reduction with either hexanol or hydrogen were studied for the aerobic oxidation of alcohols. The mean size of the Pd particles over the SiO2 -Al2O3 support was found to depend on the Si/Al ratio, and a decrease in the Si/Al ratio resulted in a decrease in the mean size of the Pd nanoparticles. By changing the Si/Al ratio, we obtained supported Pd nanoparticles with mean sizes ranging from 2.2 to 10,nm. The interaction between the Pd precursor and the support was proposed to play a key role in tuning the mean size of the Pd nanoparticles. The Pd/SiO2 -Al2O3 catalyst with an appropriate mean size of Pd particles could catalyze the aerobic oxidation of various alcohols to the corresponding carbonyl compounds, and this catalyst was particularly efficient for the solvent-free conversion of benzyl alcohol. The intrinsic turnover frequency per surface Pd atom depended significantly on the mean size of Pd particles and showed a maximum at a medium mean size (3.6,4.3,nm), revealing that the aerobic oxidation of benzyl alcohol catalyzed by the supported Pd nanoparticles was structure-sensitive. [source] Aerobic, Chemoselective Oxidation of Alcohols to Carbonyl Compounds Catalyzed by a DABCO-Copper Complex under Mild ConditionsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 14-15 2007Sreedevi Mannam Abstract A DABCO-copper(I) chloride complex (5 mol,%) together with TEMPO (5 mol,%) in nitromethane as solvent has been used as an efficient catalytic system for the selective oxidation of benzylic and allylic alcohols into the corresponding carbonyl compounds at room temperature where molecular oxygen acts as an ultimate, stoichiometric oxidant and water is the only by-product. The solid-state structure determination of the DABCO-copper complex shows that the copper is in the +II oxidation state with trigonal bipyramidal geometry and exists in a linear polymeric structure due to strong hydrogen bonding. [source] Chemoselective Oxidation of Alcohols by a H2O2,Pt Black System under Organic Solvent- and Halide-Free ConditionsCHEMISTRY - AN ASIAN JOURNAL, Issue 8-9 2008Yoshihiro Kon Dr. Abstract Environmentally benign oxidation of allylic alcohols by platinum black catalyst with aqueous hydrogen peroxide to give the corresponding ,,,-unsaturated carbonyl compounds in high yield is presented. Reactions are carried out under organic solvent- and halide-free conditions. The platinum black catalyst is commercially available and is found to be reusable at least seven times before significant loss of catalytic activity. The operation is very simple, even in a hectogram-scale synthesis, and gives corresponding carbonyl compounds in over 90,% yield. The effective oxidation of benzyl and secondary alcohols are also described. [source] | ||||||||||