- Synthesis, characterization, DFT studies, and immobilization of cobalt(II) complex with N,N′,N″-tris(2-pyrimidinyl)dimethylentriamine on modified iron oxide as oxidation catalyst
-
[Co3(PDMT)Cl6] complex, in which PDMT is N,N′,N″-tris(2-pyrimidinyl)dimethylentriamine was prepared in cyclohexanol under hydrothermal condition. At first, the crystal structure of PDMT was solved based on the Rietveld method by using laboratory X-ray powder diffraction data. The molecular geometry of the ligand and complex were optimized by B3LYP method. In order to heterogenize the prepared complex, it was immobilized on the modified Fe3O4 nanoparticles with (3-aminopropyl)trimethoxysilane (APTMS). The prepared compound designated as Fe3O4SiO2-2APTMS[Co3(PDMT)Cl6] was found to successfully catalyze the epoxidation of cyclooctene, styrene, cyclohexene, trans-stilbene as well as oxidation of fluorene, diphenylmethane, ethylbenzene, adamantane, cyclohexane, cyclooctane and norbornene with TBHP as oxidant with 25-100% conversions and 18-100% selectivities. Ligand, complex and Fe3O4SiO2-2APTMS[Co3(PDMT)Cl6] were characterized by FT-IR, TEM, XRD, Mass, UV-Vis, DSC-TGA, NMR, GC and GC-Mass techniques.
- Sharbatdaran, Masoomeh,Farzaneh, Faezeh,Larijani, Majid Mojtahedzadeh,Salimi, Alireza,Ghiasi, Mina,Ghandi, Mehdi
-
p. 264 - 275
(2016/06/09)
-
- From DNA to catalysis: A thymine-acetate ligated non-heme iron(III) catalyst for oxidative activation of aliphatic C-H bonds
-
A non-heme, iron(iii)/THA(thymine-1-acetate) catalyst together with H2O2 as an oxidant is efficient in oxidative C-H activation of alkanes. Although having a higher preference for tertiary C-H bonds, the catalyst also oxidizes aliphatic secondary C-H bonds into carbonyl compounds with good to excellent conversions. Based on the site selectivity of the catalyst and our mechanistic studies the reaction proceeds via an Fe-oxo species without long lived carbon centered radicals.
- Al-Hunaiti, Afnan,R?is?nen, Minn?,Repo, Timo
-
p. 2043 - 2046
(2016/02/05)
-
- Doped graphene as a metal-free carbocatalyst for the selective aerobic oxidation of benzylic hydrocarbons, cyclooctane and styrene
-
Nitrogen (N)-, boron (B)-, and boron,nitrogen (B,N)-doped graphene (G) act as carbocatalysts, promoting the aerobic oxidation of the benzylic positions of aromatic hydrocarbons and cyclooctane to the corresponding alcohol/ketone mixture with more than 90 % selectivity. The most active material was the co-doped (B,N)G, which, in the absence of solvent and with a substrate/(B,N)G ratio of 200, achieved 50 % tetralin conversion in 24 h with a alcohol/ketone selectivity of 80 %. An FT-Raman spectroscopic study of a sample of (B,N)G heated at 100 °C in the presence of oxygen revealed new bands that disappeared upon evacuation and that have been attributed to hydroperoxide-like species formed on the G sheet based on the isotopic shift of the peak from 819 to 779 cm-1 when 18O2 was used as the oxidizing reagent. Furthermore, (B)G and (N)G exhibited high catalytic activity in the aerobic oxidation of styrene to benzaldehyde (BA) in 4 h. However, the product distribution changed over time and after 10 h a significant percentage of styrene oxide (SO) was observed under the same conditions. The use of doped G as catalyst appears to offer broad scope for the aerobic oxidation of benzylic compounds and styrene, for which low catalyst loading, mild reaction temperatures, and no additional solvents are required. Oxidation at graphene: Boron- and nitrogen-doped graphenes are excellent catalysts for promoting the oxidation of benzylic hydrocarbons, cyclooctane, and styrene with molecular oxygen at 0.5 wt % under atmospheric pressure and solvent-free conditions (see figure). Copyright
- Dhakshinamoorthy, Amarajothi,Primo, Ana,Concepcion, Patricia,Alvaro, Mercedes,Garcia, Hermenegildo
-
p. 7547 - 7554
(2013/07/11)
-
- The Mechanism of Product Formation in the Oxidation of 1,2-Cyclooctanediol to Suberic Acid
-
It was shown that the catalytic oxidation of 1,2-cyclooctanediol with hydrogen peroxide to suberic acid is an irreversible process comprising consecutive reactions. The reactivity of the reactant diol and the intermediate products 2-hydroxycyclooctanone and 1,2-cyclooctanedione was compared. To substantiate the consecutive character of product formation, the results of a kinetic study on the molecular geometry of functional alicyclic compounds involved in the process were used. A possible mechanism was proposed for the conversion of products at individual stages of the process of manufacturing suberic acid from 1,2-cyclooctanediol.
- Antonova,Il'in,Kunitskii,Artem'eva,Chabutkina
-
p. 419 - 423
(2007/10/03)
-
- Scope, kinetics, and mechanistic aspects of aerobic oxidations catalyzed by ruthenium supported on alumina
-
The Ru/Al2O3 catalyst was prepared by modification of the preparation of Ru(OH)3·nH2O. The present Ru/Al 2O3 catalyst has high catalytic activities for the oxidations of activated, nonactivated, and heterocyclic alcohols, diols, and amines at 1 atm of molecular oxygen. Furthermore, the catalyst could be reused seven times without a loss of catalytic activity and selectivity for the oxidation of benzyl alcohol. A catalytic reaction mechanism involving a ruthenium alcoholate species and β-hydride elimination from the alcoholate has been proposed. The reaction rate has a first-order dependence on the amount of catalyst, a fractional order on the concentration of benzyl alcohol, and a zero order on the pressure of molecular oxygen. These results and kinetic isotope effects indicate that β-elimination from the ruthenium alcoholate species is a rate-determining step.
- Yamaguchi, Kazuya,Mizuno, Noritaka
-
p. 4353 - 4361
(2007/10/03)
-
- Aerobic Oxidation of Vicinal Diols Catalyzed by an Anderson-Type Polyoxometalate, [IMo6O24]5-
-
An Anderson-type polyoxometalate, [IVIIMo6O24]5-, has been used as a catalyst for the aerobic oxidation at 80°C of vicinal diols (glycols). This is the first report on the use of such a polyoxometalate as an oxi
- Khenkin, Alexander M.,Neumann, Ronny
-
p. 1017 - 1021
(2007/10/03)
-
- Oxidation of 1,2-cyclooctanediol with hydrogen peroxide to suberic acid
-
The salient and specific features of 1,2-cyclooctanediol oxidation with hydrogen peroxide to suberic acid in the presence of various catalytic systems were studied. The oxidation of 1,2-cyclooctanediol with such a mild and environmentally friendly oxidizing agent as hydrogen peroxide was shown to yield high-purity suberic acid containing no admixtures of dicarboxylic acids with a smaller number of carbon atoms by carrying out the reaction in a heterogeneous system with a hydrocarbon solvent for the diol.
- Chabutkina,Antonova,Artem'eva,Danilova,Mashina
-
p. 285 - 290
(2007/10/03)
-
- Efficient oxidation of alcohols to carbonyl compounds with molecular oxygen catalyzed by N-hydroxyphthalimide combined with a Co species
-
Highly efficient catalytic oxidation of alcohols with molecular oxygen by N-hydroxyphthalimide (NHPI) combined with a Co species was developed. The oxidation of 2-octanol in the presence of catalytic amounts of NHPI and Co(OAc)2 under atmospheric dioxygen in AcOEt at 70 °C gave 2-octanone in 93% yield. The oxidation was significantly enhanced by adding a small amount of benzoic acid to proceed smoothly even at room temperature. Primary alcohols were oxidized by NHPI in the absence of any metal catalyst to form the corresponding carboxylic acids in good yields. In the oxidation of terminal vic-diols such as 1,2-butanediol, carbon-carbon bond cleavage was induced to give one carbon less carboxylic acids such as propionic acid, while internal vic-diols were selectively oxidized to 1,2-diketones.
- Iwahama, Takahiro,Yoshino, Yasushi,Keitoku, Takashi,Sakaguchi, Satoshi,Ishii, Yasutaka
-
p. 6502 - 6507
(2007/10/03)
-
- Aerobic oxidation of alcohols to carbonyl compounds catalyzed by N-hydroxyphthalimide (NHPI) combined with Co(acac)3
-
Aerobic oxidation of various alcohols has been accomplished by using a new catalytic system. N-hydroxyphthalimide (NHPI) combined with Co(acac)3. The oxidation of alcohols by NHPI was found to be markedly enhanced by adding a slight amount of Co(acac)3 (0.05 equiv. to NHPI). Thus, secondary alcohols and vic-diols which are difficult to be oxidized by NHPI alone were smoothly oxidized with molecular oxygen (1 atm) to the corresponding carbonyl compounds under relatively mild conditions (65 ~ 75 °C).
- Iwahama, Takahiro,Sakaguchi, Satoshi,Nishiyama, Yutaka,Ishii, Yasutaka
-
p. 6923 - 6926
(2007/10/02)
-
- A direct conversion of vic-diols into 1,2-diketones with aqueous hydrogen peroxide catalyzed by peroxotungstophosphate (PCWP)
-
α-Hydroxy ketones and vic-diols were successfully oxidized to the corresponding diketones with acqueous hydrogen peroxide in the presence of a catalytic amount of peroxotungstophosphate (PCWP). This method provides a straightforward route of 1,2-diketones which are difficult to prepare by conventional oxidation of vic-diols.
- Iwahama, Takahiro,Sakaguchi, Satoshi,Nishiyama, Yutaka,Ishii, Yasutaka
-
p. 1523 - 1526
(2007/10/02)
-
- Conversion of Ketals to Ketones by Nitrogen Dioxide in the Presence of Silica Gel
-
Nitrogen dioxide transforms ketals to ketones in the presence of silica gel under neutral, anhydrous and mild conditions.
- Nishiguchi, Takeshi,Ohosima, Tatsuya,Nishida, Akiko,Fujisaki, Shizuo
-
p. 1121 - 1122
(2007/10/02)
-
- Oxidation of Vicinal Diols to α-Dicarbonyl Compounds by Trifluoroacetic Anhydride "Activated" Dimethyl Sulfoxide
-
Trifluoroacetic anhydride "activated" dimethyl sulfoxide is an effective oxidant for the conversion of vicinal diols into the corresponding α-dicarbonyl compounds or products derived therefrom.Unlike the Swern oxidant, the title reagent system gives good yields of products derived from halogenated substrates.The method has permitted syntheses of previously inaccessible compounds including tropolones, a ?-homo-o-benzoquinone, and a "hyperreactive" α-keto aldehyde.
- Amon, Catherine M.,Banwell, Martin G.,Gravatt, G.Lance
-
p. 4851 - 4855
(2007/10/02)
-