- Individual stereoisomers of verbenol and verbenone express bioactive features
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Naturally occurring terpene core compounds have been used extensively in both pharmaceutical and cosmetic industry. However, since chirality of these compounds has profound influence on the level of their bioactivity, the aim of the present study was to a
- Ivanov, Marija,Kovalenko, Vitaly,Svirid, Anastasia,Kosti?, Marina,Petrovi?, Jovana,Stojkovi?, Dejan
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- Selective Allylic Oxidation of Terpenic Olefins Using Co-Ag Supported on SiO2 as a Novel, Efficient, and Recyclable Catalyst
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Co-Ag supported on the SiO2 catalyst was synthesized by the sol-gel method and characterized using XRD, FT-IR, TG-DTG, BET, CV, and SEM/EDX analysis. The catalytic performance of the resulting catalyst was examined by the oxidation of mono and sesquiterpenic olefins using hydrogen peroxide and tert-butyl peroxide as oxidant agents. Various parameters such as catalyst amount, temperature, and solvents have been studied. The Co-Ag supported on the SiO2 catalyst showed a high activity, selectivity, and recyclability for the selected oxidation reaction.
- Aberkouks, Abderrazak,Mekkaoui, Ayoub Abdelkader,Ait Ali, Mustapha,El Firdoussi, Larbi,El Houssame, Soufiane
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- Stereospecific synthesis of S-(?)-trans-verbenol and its antipode by inversion of sterically hindered alcohols
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S-(?)-trans-Verbenol (1) and its antipode, R-(+)-trans-verbenol (1′) have been confirmed as the critical pheromone components of bark beetles. Synthesis of these two active secondary alcohols (1 and 1′) from commercially available starting materials S-α-pinene and R-α-pinene was reported. The key steps were mainly depended on the effective SN2 stereo-inversion of the hydroxy group of sterically hindered alcohols (3 and 3′), using Mitsunobu reaction or hydrolysis of mesylate ester, alternatively. Our results provide a new and stereo-selectivity way to obtain optically active insect pheromones.
- Fang, Jia-Xing,Kong, Xiang-Bo,Liu, Fu,Zhang, Su-Fang,Zhang, Zhen
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- Cis-dioxidomolybdenum(VI) complexes with chiral tetradentate Schiff bases: Synthesis, spectroscopic characterization and catalytic activity in sulfoxidation and epoxidation
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New chiral mononuclear cis-dioxidomolybdenum(VI) complexes, MoO2L1-MoO2L7, have been synthesized by the reaction of MoO2(acac)2 with tetradentate Schiff bases derived from various substitut
- Karman, Marta,Romanowski, Grzegorz
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- Oxy-functionalization of olefins with neat and heterogenized binuclear V(IV)O and Fe(II)complexes: Effect of steric hindrance on product selectivity and output in homogeneous and heterogeneous phase
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Neat {[VO(sal2bz)]2; [Fe(sal2bz)(H2O)2]2·2H2O} and zeolite-Y immobilized {[VO(sal2bz)]2-Y; [Fe(sal2bz)(H2O)2]2-Y} binuclear complexes have been prepared and characterized by spectroscopic techniques (IR, UV–vis), elemental analyses (CHN, ICP-OES), thermal study (TGA), scanning electron micrograph (SEM), adsorption study (BET)and X-ray diffraction (XRD)patterns. Neat (homogeneous)and immobilized (heterogeneous)complexes were employed as catalysts in the oxidation of olefins, namely, cyclohexene, limonene and α-pinene in the presence of 30% hydrogen peroxide. 100% conversion of cyclohexene and α-pinene was obtained while limonene was oxidized up to 90%. Homogeneous catalysts showed highly selective result as neat [VO(sal2bz)]2 complex has provided 87% cyclohexane-1,2-diol and neat [Fe(sal2bz)(H2O)2]2·2H2O complex has provided 79% verbenone in oxidation of cyclohexene and α-pinene, respectively. We have observed that due to steric hindrance, formation of olefinic oxidation products increases on moving from α-pinene to limonene and limonene to cyclohexene. Additionally. recovered heterogeneous catalysts showed intact results up to two consecutive runs. Probable catalytic mechanism has been proposed for oxidation of cyclohexene.
- Parmar, Digvijaysinh K.,Butani, Pinal M.,Thumar, Niraj J.,Jasani, Pinal M.,Padaliya, Ravi V.,Sandhiya, Paba R.,Nakum, Haresh D.,Khan, Md. Nasim,Makwana, Dipak
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- A Cu-Doped ZIF-8 metal organic framework as a heterogeneous solid catalyst for aerobic oxidation of benzylic hydrocarbons
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Mixed-metal metal organic frameworks have received considerable attention in recent years and it has been shown that the activity of the parent metal organic framework (MOF) is often enhanced upon doping with external metal ions within the framework. In this context, Cu2+ ions with different loadings were incorporated within the ZIF-8 framework to obtain a series of Cu-doped ZIF-8 materials and their activity was examined in the aerobic oxidation of hydrocarbons. The as-synthesized Cu-doped solids were characterized by powder X-ray diffraction (XRD), ultraviolet diffuse reflectance spectroscopy (UV-DRS), scanning electron microscopy (SEM), Fourier Transform infrared (FT-IR), electron paramagnetic resonance (EPR) and inductively coupled plasma (ICP) analysis. The experimental results revealed that the activity of Cu-doped ZIF-8 is much higher than that of the parent ZIF-8 in all the tested substrates at 120 °C. Furthermore, the activity of the Cu-doped ZIF-8 with the highest Cu loading was eight fold higher than that of the parent ZIF-8 in the aerobic oxidation of cyclooctane (1) at 120 °C with more than 80% selectivity to the corresponding cyclooctanol/cyclooctanone (ol/one) mixture. Cu-doped ZIF-8 was reused two times with no significant drop in its activity under identical conditions. Furthermore, comparison of the two times reused solid with that of the fresh solid by powder XRD and SEM analysis revealed identical structural integrity and morphology, respectively during the oxidation reactions.
- Nagarjun, Nagarathinam,Dhakshinamoorthy, Amarajothi
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p. 18702 - 18712
(2019/12/09)
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- Green and simple preparation method for synthesizing (-)-trans-verbenol and enantiomer (+)-trans-verbenol thereof
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The invention provides a green and simple preparation method for synthesizing (-)-trans-verbenol and enantiomer (+)-trans-verbenol thereof. The method is characterized by comprising the following steps: using (-)-cis-verbenol and (+)-cis-verbenol, utilizing a Mitsunobu reaction, and performing hydroxyl configuration inversion so as torespectively obtain the (-)-trans-verbenol and (+)-trans-verbenol, wherein the yield of the (-)-trans-verbenol is 81%, and the yield of the (+)-trans-verbenol is 80%. The synthetic method in the invention comprises novel, effective and environment-friendly steps and procedures. Compared with the conventional trans-verbenol synthesis method, the method disclosed by the invention avoids use of lead tetraacetate (an oxidizing agent) and benzene toxic solvents. The raw trans-verbenol can be prepared by alpha-pinene oxidation, and the (-)-trans-verbenol and (+)-trans-verbenol can be used for controlling bark beetles in China.
- -
-
Paragraph 0024; 0025; 0026
(2019/09/13)
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- Cobalt-Catalyzed Hydroboration of Alkenes, Aldehydes, and Ketones
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An operationally convenient and general method for hydroboration of alkenes, aldehydes, and ketones employing Co(acac)3 as a precatalyst is reported. The hydroboration of alkenes in the presence of HBpin, PPh3, and NaOtBu affords good to excellent yields with high Markovnikov selectivity with up to 97:3 branched/linear selectivity. Moreover, Co(acac)3 could be used effectively to hydroborate aldehydes and ketones in the absence of additives under mild reaction conditions. Inter- and intramolecular chemoselective reduction of the aldehyde group took place over the ketone functional group.
- Tamang, Sem Raj,Bedi, Deepika,Shafiei-Haghighi, Sara,Smith, Cecilia R.,Crawford, Christian,Findlater, Michael
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p. 6695 - 6700
(2018/11/21)
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- Zeolite Y encaged Ru(III) and Fe(III) complexes for oxidation of styrene, cyclohexene, limonene, and α-pinene: An eye-catching impact of H2SO4 on product selectivity
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A novel Ru(III) and Fe(III) complexes of ligands 1 and/or 2 {where 1 = 2,2'-((1E,1'E)-((azanediylbis(ethane-2,1-diyl))bis(azanylylidene))bis(methanylylidene))diphenol and 2 = 2,2'-((1E,1'E)-((azanediylbis(ethane-2,1-diyl))bis(azanylylidene))bis(methanylylidene)) bis(4-nitrophenol)} have been synthesized as ‘neat’ and zeolite Y encapsulated complexes. These catalysts are characterized by various analytical tools such as FTIR, UV–vis, elemental analysis, ICP-AES, molar conductivity, 1H- and 13C NMR, TGA, SEM, AAS, BET, magnetic susceptibility and powder XRD to endorse the complex formation, absence of peripheral redundant ligands and complexes, conservation of zeolite Y morphology and crystallinity, and the encapsulation of complexes without devastation in the zeolite Y framework. Out of these synthesized catalysts, 5Y is found to be a potent candidate for styrene (Conv. 76.1%, TOF: 2130 h?1), cyclohexene (Conv. 84.4%, TOF: 2351 h?1), limonene (Conv. 81.6%, TOF: 2273 h?1), and α-pinene (Conv. 72.6%, TOF: 2023 h?1) oxidation with high selectivity of respective allylic products excluding the styrene oxidation, which undergoes epoxidation only. The addition of H2SO4 in an identical reaction catalyzed by 5Y not only surge the conversion up to 100% in a short time span with high TOF but also increase the selectivity of respective epoxidation products. This switchover in the selectivities could be credited to the presence of H2SO4 that facilitates the heterolytic [sbnd]O[sbnd]O[sbnd] bond cleavage of metal hydroperoxide and stimulates the epoxidation over allylic oxidation. Furthermore, the results establish that the heterogeneous systems are effortlessly recovered and reused without ample drop in the activity and selectivity.
- Godhani, Dinesh R.,Nakum, Haresh D.,Parmar, Digvijaysinh K.,Mehta, Jignasu P.,Desai, Nisheeth C.
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p. 223 - 237
(2016/12/09)
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- Catalytic Activity of Crystallographically Characterized Organic–Inorganic Hybrid Containing 1,5-Di-amino-pentane Tetrachloro Manganate with Perovskite Type Structure
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Abstract: Layered 2D organic–inorganic hybrid perovskite (OIHS) of the diammonium series, 1,5 di-aminepentane tetrachloro mangenate ([NH3–(CH2)5–NH3] MnCl4) was prepared by slow evaporation and reducing temperature method and characterized by single crystal X-ray diffraction analysis. Its structure consists of organic cation, [NH3(CH2)5NH3]+2 extended in a zigzag fashion and inorganic anion, [MnCl6]?2 where Mn2+ is coordinated by six Cl? ion in octahedral fashion. The organic and inorganic segments are alternately stacked along c-axis where inorganic layer is extended through corner-shared octahedra sandwiched by the di-aminopentane molecules. The layers (organic and inorganic) were connected to each other through N–HCl hydrogen bonds and van-der Waals interaction to build cation–anion–cation cohesion. The hybrid crystal had orthorhombic non-centrosymetric system having I212121 space group with unit cell parameters a = 7.1742(3) ?, b = 7.3817(3) ?, c = 23.9650(10) ?, V = 1269.13 ?3 and Z = 4. The hybrid exhibited excellent catalytic activity towards sulphide and alkene oxidation using aqueous H2O2 as an oxidant. Graphical Abstract: OIHS of the diammonium series [NH3–(CH2)5–NH3] MnCl4; 1,5 di-aminepentane tetrachloro mangenate were prepared by slow evaporation and temperature decrease method, characterized by single crystal X-ray diffraction. This complex exhibits excellent catalytic activity towards sulphide oxidation and alkene oxidation using aqueous H2O2 as an oxidant. [Figure not available: see fulltext.].
- Mondal, Paramita,Abdel-Aal, Seham Kamal,Das, Debasis,Islam, Sk Manirul
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p. 2332 - 2339
(2017/08/22)
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- Cis-dioxo-Mo(VI) salophen complex supported on Fe3O4@SiO2 nanoparticles as an efficient magnetically separable and reusable nanocatalyst for selective epoxidation of olefins
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In this work, paramagnetic Fe3O4/SiO2 nanoparticles were synthesized, characterized and functionalized with dioxo-Mo(VI) tetradentate Schiff base complex and characterized using IR spectroscopy, X-ray powder diffraction spectroscopy, scanning electron microscopy, transmission electron microscopy, vibrating sample magnetometry, diffuse reflectance spectroscopy and atomic absorption spectroscopy. Catalyst was used for the selective epoxidation of cyclooctene, cyclohexene, styrene, indene, α-pinene, 1-hepten, 1-octene, 1-dodecen and trans-stilbene using tert-butyl hydroperoxide as oxidant in 1,2-dichloroethane. This catalyst is efficient for oxidation of cyclooctene with a 100% selectivity for epoxidation with 100% conversion in 1?h. After the reaction, the magnetic nanocatalyst was easily separated by simply applying an external magnetic field and was used at least five successive times without significant decrease in conversion.[Figure not available: see fulltext.].
- Bezaatpour, Abolfazl,Khatami, Sahar,Nejati, Kamellia
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p. 2105 - 2115
(2017/09/13)
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- Kinetic study of α-pinene allylic oxidation over FePcCl16-NH2-SiO2 catalyst
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The kinetic of α-pinene oxidation over an iron hexadecachlorinated phthalocyanine immobilized on modified silica (FePcCl16-NH2-SiO2) with t-butyl hydroperoxide (TBHP) as oxidant is proposed. Reaction rates were calculated by the initial reaction rate method from the data obtained in a batch reactor, and compared with kinetic expressions proposed from mechanisms based on Langmuir Hinshelwood Hougen Watson (LHHW) and power-rate law models. The kinetic parameters were estimated from the experimental data by optimization using the Genetic Algorithm. A kinetic expression based on LHHW model with the adsorption of α-pinene, TBHP and the main reaction products (verbenone, α-pinene epoxide and verbenol) on the surface of the catalyst predicted the experimental data with good accuracy (R2?=?0.986). The apparent activation energy of α-pinene allylic oxidation over FePcCl16-NH2-SiO2/TBHP was 40.08?kJ/mol. α-Pinene conversion of 83.7% was obtained after 23?h with a selectivity to verbenone of 23%. Under the reaction conditions leaching of the active species was not observed; however, the effect of radicals in the bulk liquid phase was demonstrated, confirming that the reaction involves a combination of both heterogeneous and homogeneous pathways. The catalyst can be used at least in seven cycles without loss of α-pinene conversion nor verbenone selectivity.
- Becerra, Jaime-Andrés,González, Lina-María,Villa, Aída-Luz
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- Biologically Inspired and Magnetically Recoverable Copper Porphyrinic Catalysts: A Greener Approach for Oxidation of Hydrocarbons with Molecular Oxygen
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An efficient synthetic method for magnetically recoverable hybrid copper porphyrinic nanomaterials is reported. These functionalized magnetic materials prove to be efficient bioinspired oxidation catalysts of olefins and thiols, using molecular oxygen as oxidant, in total absence of reductants and solvents, with the highest TON (turnover number) yet achieved for this reaction (≈200 000). A comparative study between homogeneous and heterogeneous oxidation of cyclohexene is discussed, revealing the heterogeneous system to be the most promising concerning stability and reusability of the catalysts. The full characterization of the magnetic hybrid porphyrinic nanomaterials, by transmission electron microscopy, flame atomic absorption spectrometry, thermogravimetry, N2 sorption, and infrared spectroscopy, is also described.
- Henriques, César A.,Fernandes, Auguste,Rossi, Liane M.,Ribeiro, M. Filipa,Calvete, Mário J. F.,Pereira, Mariette M.
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p. 3359 - 3368
(2016/06/06)
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- Monoterpene hydroxylation with an artificial self-sufficient P450 utilizing a P450SMO reductase domain for the electron transfer
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Cytochrome P450SMO from Rhodococcus sp. ECU0066 is a natural self-sufficient P450 monooxygenase, consisting of a heme domain, a flavin-reductase domain containing FMN and NADPH binding sites, and a [Fe2S2] ferredoxin domain. P450cam catalyzes the hydroxylation of camphor to 5-exo-hydroxycamphor. The variant P450cam (Y96F/V247L) was reported for the oxidation of monoterpene by protein engineering. In this work, we constructed an artificial self-sufficient P450-type monoterpene hydroxylase by connecting the P450SMO reductase domain and the P450cam (Y96F/V247L) domain together with a linker region (G4S)4. The resultant chimeric P450 enzyme could catalyze the hydroxylation of (-)-limonene and α-pinene as well as camphor, which were all inactive for the natural fusion protein P450SMO. Co-expression of the fused P450 with a glucose dehydrogenase (GDH) improved the (-)-limonene conversion as sufficient NADPH was regenerated in the system with glucose as a cosubstrate. This work illustrated that P450SMO reductase might act as an electron donor partner of P450s and might be used for fusion with heterogeneous P450 domains to elucidate the catalytic function of other unknown P450s.
- Luan, Zheng-Jiao,Yin, Yue-Cai,Li, Ai-Tao,Yu, Hui-Lei,Xu, Jian-He
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- Selectively catalytic epoxidation of α-pinene with dry air over the composite catalysts of Co-MOR(L) with Schiff-base ligands
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Twelve bi-/tridentate Schiff-base ligands (L1-L12) have been designed, synthesized and coordinated with ion-exchanged Co-MOR (Mordenite) forming a series of Co-MOR(L) composite catalysts, for which various analyzes and characterizations are conducted. Selectively catalytic epoxidation of α-pinene with dry air over Co-MOR(L) catalysts has been carried out, where uses TBHP in small amounts as the initiator. Among these Co-MOR(L) catalysts, Co-MOR(L8) exhibits the best activity for the titled reaction to obtain 85.8 mol% conversion and 90.8% selectivity of epoxide. Some factors such as the structure of ligands, the oxidants, the solvents, the catalyst amount, the reaction temperature and time play important roles in controlling the epoxidation. The recyclable stability of the Co-MOR(L8) catalyst is confirmed. The studies on the electrochemical behaviors of Co species in Co-MOR(L8) reveal the importance of reversible change between Co oxidation states for the epoxidation.
- Lu,Lei,Wei,Ma,Zhang,Hu,Zhou,Xia
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- Synthesis and analgesic activity of stereoisomers of 2-(3(4)-hydroxy-4(3)-methoxyphenyl)-4,7-dimethyl-3,4,4a,5,8,8a-hexahydro-2H-chromene-4,8-diols
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2-(3(4)-Hydroxy-4(3)-methoxyphenyl)-4,7-dimethyl-3,4,4a,5,8,8a-hexahydro-2H-chromene-4,8-diols were found recently to possess high analgesic activity and low acute toxicity. Stereoisomers of these compounds with high optical purity were synthesized from (+)- and (-)-α-pinenes for the first time in this work. The structure of (4S)-4b isomer was confirmed by the XRD data. Studies of analgesic activity of the resulting products demonstrated that neither the absolute configuration nor cis- or trans-arrangement of vicinal oxygen atoms plays a significant role in manifestation of analgesic effect by these isomers, while only (4S)-4b isomer, but not (4R)-4b demonstrated the analgesic effect.
- Pavlova, Alla,Mikhalchenko, Oksana,Rogachev, Artem,Il'Ina, Irina,Korchagina, Dina,Gatilov, Yuriy,Tolstikova, Tat'Yana,Volcho, Konstantin,Salakhutdinov, Nariman
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p. 3821 - 3830
(2015/10/06)
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- Biomass toward fine chemical products: Oxidation of α-pinene over sieves nanostructured modified with vanadium
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Vanadium-containing molecular sieves (V-M(x)) were synthetized and applied as heterogeneous catalysts for the liquid phase oxidation of α-pinene with hydrogen peroxide at 70°C. It has been found that the vanadium content in V-M(x) materials affected the conversion of α-pinene and product distribution. The turnover numbers increased strongly with the decreasing of V content probably caused by a high V dispersion. The major products were verbenone, trans-sobrerol and campholenic aldehyde. The acid-base properties of V-M(x) affected the distribution of products formed via the isomerization of α-pinene oxide over Lewis acid sites to campholenic aldehyde while Br?nsted acid sites brought about the formation of 1,2 pinanediol and trans-sobrerol by hydrolysis and by the opening of oxirane ring. The increase in V content in V-M(x) led to the increase in campholenic aldehyde, 1,2 pinanediol, trans- sobrerol and over oxidation products. Moreover, the effect of several solvents on the reaction oxidation was studied. The results showed that the highest α-pinene conversions are obtained in the following order: acetonitrile > ethanol > isoamyl alcohol > methyl ethyl ketone. Thus, using aprotic solvents, the catalytic activity was increased and the formation of alkyl glycol ethers as by-product was not observed.
- Cánepa, Analía L.,Chanquía, Corina M.,Vaschetti, Virginia M.,Eimer, Griselda A.,Casuscelli, Sandra G.
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-
- Hydrocarbon oxidation over Fe- and Cr-containing metal-organic frameworks MIL-100 and MIL-101-a comparative study
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Catalytic properties of Fe- and Cr-based metal-organic frameworks (MOFs) MIL-100 and MIL-101 have been assessed in two liquid-phase reactions: solvent-free allylic oxidation of alkenes (cyclohexene, α- and β-pinenes) with molecular oxygen and oxidation of anthracene (AN) with tert-butyl hydroperoxide (TBHP). In the oxidation of alkenes, the product selectivity strongly depends on the nature of metal (Fe or Cr) but, for the same metal, only slightly differs for the MIL-100 and MIL-101 structures. The Fe-containing MOFs afford the formation of unsaturated alcohols while Cr-based MOFs give mainly unsaturated ketones. Both Cr-MIL-100 and Cr-MIL-101 favor decomposition of cyclohexenyl hydroperoxide to produce 2-cyclohexen-1-one with 67-69% selectivity. Stability toward destruction reduced in the order Cr-MIL-101, Cr-MIL-100 > Fe-MIL-100 > Fe-MIL-101. In the oxidation of anthracene over both Cr-MOFs and Fe-MIL-101, the selectivity toward 9,10-anthraquinone (AQ) attained 100% at 92-100% AN conversion. The turnover frequency (TOF) decreased in the order Cr-MIL-101 > Fe-MIL-101 > Cr-MIL-100 > Fe-MIL-100. Cr-MIL-101 revealed superior catalytic performance in terms of AN conversion, AQ selectivity and TOF. Nearly quantitative yield of AQ was obtained after 1.5 h at 100 °C in chlorobenzene as solvent. No leaching of active metal occurred under optimal reaction conditions and the MOFs could be recycled several times without deterioration of the catalytic properties.
- Kholdeeva, Oxana A.,Skobelev, Igor Y.,Ivanchikova, Irina D.,Kovalenko, Konstantin A.,Fedin, Vladimir P.,Sorokin, Alexander B.
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- Epoxidation of mixed bi-olefins with air over nanosized Co 3O4 assisted by ultrasonic waves
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Nanosized Co3O4 prepared by a simple method is considerably active in the ultrasonic waves assisted epoxidation of mixed bi-olefins with dry air. Both conversions and selectivities are distinctly promoted with α-methylstyrene and α-pinene mixed in the molar ratio of 1:1, as compared to α-methylstyrene or to α-pinene alone. When other alkenes are mixed with cyclooctene at 1:5 (molar ratio), different effects are observed. The mixture of styrene and cyclooctene shows almost the same increase in activity as the mixture of α-methylstyrene and α-pinene. While isophorone could assist the epoxidation of cyclooctene, by itself it could not be oxidized by molecular oxygen under the present conditions. When indene is mixed with cyclooctene, its conversion increases; however, the reactivity of cyclooctene decreases notably. UV-vis spectral analysis shows that these observations may be due to the intermolecular electron transfer which is very important for the enhancement of reactivities of bi-olefinic molecules.
- Lei,Lu,Zhang,Wei,Zhou,Xia
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p. 709 - 716
(2013/07/27)
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- Solvent-free allylic oxidation of alkenes with O2 mediated by Fe- and Cr-MIL-101
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Catalytic properties of Fe-MIL-101 and Cr-MIL-101 metal-organic frameworks in the solvent-free oxidation of cyclohexene and α-pinene with molecular oxygen have been explored. Both catalysts allow alkene oxidation under mild conditions (1 bar O2, 40-60°C) and afford allylic oxidation products. The nature of catalysis and the product distribution strongly depend on the nature of the transition metal. Cr-MIL-101 behaves as truly heterogeneous catalyst to give predominantly α,β-unsaturated ketones. Catalysis over Fe-MIL-101 has true heterogeneous nature only at 40°C, producing mainly 2-cyclohexene-1-ol. At 50-60°C, iron leaching into solution occurs, leading to cyclohexenyl hydroperoxide as the major product. Under optimal conditions, both catalysts can be reused several times without suffering a loss of the catalytic properties. Rate-retarding and rate-accelerating effects of inhibitors and initiators, respectively, indicate radical chain mechanism. Different pathways for transformation of hydroperoxide have been suggested to rationalize the observed differences in the reaction selectivities over Cr- and Fe-MIL-101.
- Skobelev, Igor Y.,Sorokin, Alexander B.,Kovalenko, Konstantin A.,Fedin, Vladimir P.,Kholdeeva, Oxana A.
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- Vanadium-containing nickel phosphate molecular sieves as catalysts for α-pinene oxidation with molecular oxygen: A study of the effect of vanadium content on activity and selectivity
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Vanadium-containing nickel phosphate molecular sieves (V-VSB-5) were applied as heterogeneous catalysts for the liquid phase oxidation of α-pinene with molecular oxygen at 60 °C. It has been found that the vanadium content in V-VSB-5 materials affects the
- Timofeeva, M. N.,Panchenko, V. N.,Prosvirin, I. P.,Hasan, Zubair,Jhung, Sung Hwa
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p. 328 - 334,7
(2020/07/30)
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- A recyclable polymer anchored copper(II) catalyst for oxidation reaction of olefins and alcohols with tert-butylhydroperoxide in aqueous medium
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A new reusable polymer anchored Cu(II) complex was synthesized which can acts as an efficient heterogeneous catalyst for oxidation of olefins and alcohols with tert-butylhydroperoxide (TBHP) in aqueous medium. The present catalyst well oxidized styrene and other olefins to their allylic products and alcohols were converted to their corresponding aldehydes in good-to-moderate yields. This catalyst can be easily recovered by filtration and recycled without significant loss of its catalytic performances.
- Islam,Roy, Anupam Singha,Mondal, Paramita,Paul, Sumantra,Salam, Noor
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p. 170 - 176
(2012/10/30)
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- [PZnMo2W9O39]5- immobilized on ionic liquid-modified silica as a heterogeneous catalyst for epoxidation of olefins with hydrogen peroxide
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The epoxidation of alkenes with hydrogen peroxide catalyzed by [PZnMo 2W9O39]5-, ZnPOM, supported on ionic liquid-modified silica, Im-SiO2, is reported. The immobilized catalyst, [ZnPOM@Im-SiO2] was characterized by elemental analysis, X-ray diffraction (XRD), scanning electron microscopy (SEM), FT-IR and UV-Vis spectroscopic methods. This new synthesized hybrid catalyst was applied for efficient epoxidation of various olefins with aqueous H2O2 in acetonitrile under reflux conditions. This solid catalyst can be easily recovered by simple filtration and reused several times without significant loss of its catalytic activity.
- Hajian, Robabeh,Tangestaninejad, Shahram,Moghadam, Majid,Mirkhani, Valiollah,Khosropour, Ahmad Reza
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p. 975 - 979
(2013/02/22)
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- Lanthanide replacement in organic synthesis: Luche-type reduction of α,β-unsaturated ketones in the presence of calcium triflate
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Development of a calcium-mediated regioselective 1,2-reduction of challenging α,β-unsaturated ketones, such as 2-cyclopententone, is reported. The corresponding allylic alcohols are obtained in very good regioselectivities using Ca(OTf)2 and NaBH4. Furthermore, we have shown that our method can stereoselectively reduce aziridinyl ketones.
- Forkel, Nina V.,Henderson, David A.,Fuchter, Matthew J.
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supporting information; experimental part
p. 2129 - 2132
(2012/09/08)
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- Enzymatic allylic oxidations with a lyophilisate of the edible fungus Pleurotus sapidus
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Allylic oxidations belong to the most attractive synthetic transformations because they convert readily available and cheap starting materials into value-added products. In this study, we describe oxidative conversions of terpenoids and a number of related cycloalkenes with a lyophilisate of the edible fungus Pleurotus sapidus. The biocatalytic protocol is simple and the biocatalyst is readily available. The conversions of various cycloalkenes proceed cleanly in most cases to the corresponding enones. The substrate scope is remarkable and includes a number of mono- and sequiterpenes, functionalized terpenoids as well as simple cyclohexenes and benzylic substrates. Enzymatic allylic oxidations by Pleurotus sapidus are thus an excellent non-toxic alternative to metal-mediated oxidation procedures in academic labs and for industrial application in food technology, cosmetics or pharmaceutical research. The Royal Society of Chemistry 2012.
- Rickert, Aljona,Krombach, Verena,Hamers, Oliver,Zorn, Holger,Maison, Wolfgang
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experimental part
p. 639 - 644
(2012/04/23)
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- Selective photosensitized oxidation and its catalytic regulation of monoterpene with molecular oxygen in different reaction media
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The photo-catalytic oxidation of α-pinene, β-pinene and limonene with molecular oxygen sensitized by tetrachlorotetraiodo-fluorescein sodium salt (RB) has been studied in different reaction media under green light irradiation. Simple and efficient photosensitized oxidation equipment was employed successfully to improve the efficiency of the photosensitized reaction. The results indicate that the photosensitized oxidation products can be directly obtained without after-treatment by reductive reagent. Furthermore, it was found that the product distributions are remarkably affected by reaction media, and that N,N-dimethylformamide (DMF) can regulate the selectivity to products. In particular, the good selectivity (85%) to the main product (myrtenal) and the excellent conversion (99%) were obtained in the absence of any other catalysts when DMF was used as reaction solvent in the photosensitized oxidation of β-pinene. Moreover, the possible photosensitized oxidation reaction mechanism in different media was suggested in the present work.
- You, Kuiyi,Yin, Dulin,Mao, Liqiu,Liu, Pingle,Luo, He'An
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experimental part
p. 321 - 325
(2011/10/13)
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- Cobalt(III)-oxo cubane clusters as catalysts for oxidation of organic substrates
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Transition metal coordination complexes play a vital role as catalysts in the oxidation of organic substrates including renewable chemicals in an economically viable and environmentally friendly way. Here we highlight the preparation, characterization and application of oxo-cubane complexes of cobalt(III) as oxidation catalysts using air and water as oxidants. Cobalt(III)-oxo complexes of the type Co4O4(O 2CR)4L4 have been prepared by a general method and these have been characterized by analytical, spectroscopic, electrochemical and crystallographic methods. These soluble complexes have shown promising utility as catalysts in the aerobic oxidation of side chains of alkylaromatic hydrocarbon compounds. Oxidation of neat ethylbenzene has shown very high conversion and selectivity for acetophenone formation. On the other hand, oxidation of p-xylene has been found to yield both p-toluic acid and terephthalic acid. It is also possible to oxidize p-xylene in an aqueous medium under moderate applied O2 pressure. Selective epoxidation of α-pinene with air as the oxidant also takes place with the cobalt(III)-based homogeneous catalysts. Indian Academy of Sciences.
- Das, Birinchi Kumar,Chakrabarty, Rajesh
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experimental part
p. 163 - 173
(2012/03/26)
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- Synthesis, characterization, and catalytic activity of a polymer-supported copper(II) complex with a thiosemicarbazone ligand
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A thiosemicarbazone Cu(II) complex anchored to a polystyrene framework has been synthesized and characterized by analytical and spectroscopic techniques. The complex was found to be a highly active catalyst for the oxidation of various organic substrates including alkenes and alcohols using H 2O2 as oxidant. The reaction conditions were optimized with respect to temperature, solvent, oxidant, catalyst amount, and substrate to peroxide ratio. The heterogeneous catalyst was reused five times without significant loss of activity. A comparison between the catalytic activities of this polymer-supported Cu(II) complex and its homogeneous analogue was carried out.
- Islam, Manirul,Hossain, Dildar,Mondal, Paramita,Tuhina, Kazi,Roy, Anupam Singha,Mondal, Sanchita,Mobarak, Manir
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experimental part
p. 223 - 230
(2012/04/17)
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- Antiviral activity of 3-methyl-6-(prop-l-en-2-yl)cyclohex-3-ene-l,2-diol and its derivatives against influenza A(HlNl)2009 virus
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A number of new derivatives of monoterpenoid with a para-menthane framework 3-methyl-6-(prop-1-en-2- yl)cyclohex-3-ene-1,2-diol (-)-3 were synthesized. The antiviral activity of (-)-3 and its derivatives against the pandemic influenza virus A/California/07/09 (H1N1)v was studied in vitro. Compound (-)-3 was found to be active against this virus (selectivity index 7.5); for mononicotinate (+)-6 the selectivity index was 17. The absolute configuration of compound 6 was shown to be critical for its antiviral activity.
- Ardashov, Oleg V.,Zarubaev, Vladimir V.,Shtro, Anna A.,Korchagina, Dina V.,Volcho, Konstantin P.,Salakhutdinov, Nariman F.,Kiselev, Oleg I.
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scheme or table
p. 375 - 380
(2012/06/01)
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- Olefin epoxidation with tert-BuOOH catalyzed by vanadium polyoxometalate immobilized on ionic liquid-modified MCM-41
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Preparation and characterization of vanadium-containing polyphosphomolybdates supported on ionic liquid-modified MCM-41, MCM-41-Im, are reported. The catalyst, [PVMo@MCM- 41-Im], was characterized by elemental analysis, X-ray diffraction, scanning electron microscopy and also FT-IR, and UV-Vis spectroscopic methods. This heterogeneous catalytic system was applied for efficient epoxidation of various olefins in the presence of tert-BuOOH in 1,2-dichloroethane under reflux. The catalyst can be reused several times without apparent loss of its catalytic performance.
- Hajian, Robabeh,Tangestaninejad, Shahram,Moghadam, Majid,Mirkhani, Valiollah,Mohammadpoor-Baltork, Iraj,Khosropour, Ahmad Reza
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scheme or table
p. 4134 - 4144
(2012/03/26)
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- Synthesis, catalytic oxidation and antimicrobial activity of copper(II) Schiff base complex
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A new polymer supported Cu(II) Schiff base complex was synthesized. The solid complex was characterized by Fourier transform infrared spectroscopy (FT-IR), UV-vis diffuse reflectance spectroscopy (DRS), thermogravimetric analysis (TGA) and scanning electron microscope (SEM). Its homogeneous analogue was also prepared. The catalytic performances of the copper complex in oxidation reactions were evaluated for both homogeneous and heterogeneous systems. The copper(II) complex was found to be efficient catalyst for the oxidation of alkenes, alkanes and aromatic alcohols in the presence of hydrogen peroxide as oxidant at room temperature. The catalytic investigation revealed that the solid complex performs better than the homogeneous one as an oxidation catalyst. The solids containing the immobilized complex can be recovered from the reaction medium and reused almost five times, maintaining good catalytic activity. Furthermore, the in vitro toxicity of the ligand and complex was tested against the growth of bacterial species, viz., Staphylococcus aureus and Escherichia coli.
- Islam,Roy, Anupam Singha,Mondal, Paramita,Mubarak, Manir,Mondal, Sanchita,Hossain, Dildar,Banerjee, Satabdi,Santra
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experimental part
p. 106 - 114
(2011/05/12)
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- Highly potent activity of (1R,2R,6S)-3-methyl-6-(prop-1-en-2-yl)cyclohex-3- ene-1,2-diol in animal models of parkinson's disease
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(1R,2R,6S)-3-Methyl-6-(prop-1-en-2-yl)cyclohex-3-ene-1,2-diol 1 possesses potent antiparkinsonian activity in both MPTP and haloperidol animal models. The use of compound 1 resulted in nearly full recovery of the locomotor and exploratory activities and was as effective as the comparator agent (levodopa). All eight stereoisomers of compound 1 have been synthesized and the influence of the absolute configuration on the antiparkinsonian activity of compound 1 was shown.
- Ardashov, Oleg V.,Pavlova, Alla V.,Il'ina, Irina V.,Morozova, Ekaterina A.,Korchagina, Dina V.,Karpova, Elena V.,Volcho, Konstantin P.,Tolstikova, Tat'yana G.,Salakhutdinov, Nariman F.
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supporting information; experimental part
p. 3866 - 3874
(2011/08/07)
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- Solvent-free chromium catalyzed aerobic oxidation of biomass-based alkenes as a route to valuable fragrance compounds
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Chromium containing mesoporous molecular sieves MCM-41 were shown to be an efficient heterogeneous catalyst for the liquid-phase aerobic oxidation of various monoterpenic alkenes under mild solvent-free conditions. The material was prepared through a direct hydrothermal method and characterized by ICP-AES, N2 adsorption-desorption, TEM, XRD, SAXS, and H2-TPR techniques. Characterizations suggest that chromium introduced in MCM-41 is essentially incorporated in the silica framework, with no extraframework chromium oxides being detected. Various oxygenated monoterpenoids important for the flavor and fragrance industry were obtained with high combined selectivities (75-92%) at 30-40% substrate conversions. The oxidation of β-pinene led almost exclusively to allylic mono-oxygenated derivatives, whereas limonene and α-pinene gave both epoxides and allylic oxidation products. The catalyst undergoes no metal leaching and can be easily recovered and re-used. A silica-included chromium catalyst prepared through a conventional sol-gel method showed activity comparable with that of Cr-MCM-41; however, selectivity was much lower.
- Robles-Dutenhefner, Patricia A.,Brand?o, Bruno B.N.S.,De Sousa, Líniker F.,Gusevskaya, Elena V.
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experimental part
p. 172 - 178
(2012/02/05)
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- H2O2 based α-pinene oxidation over Ti-MCM-41. A kinetic study
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α-Pinene oxidation with hydrogen peroxide using Ti-MCM-41, prepared by hydrothermal synthesis, with a Ti content of 1.12 wt.% was studied. The major products of reaction observed were: verbenone, verbenol and campholenic aldehyde which are used in the pha
- Cánepa, Analía L.,Herrero, Eduardo R.,Crivello, Mónica E.,Eimer, Griselda A.,Casuscelli, Sandra G.
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experimental part
p. 1 - 7
(2011/10/09)
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- Selective oxidation of olefins catalyzed by polymer-anchored nickel(II) complex in water medium
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Selective oxidation of olefins has been carried out in water medium with tert-butylhydroperoxide (TBHP, 70% aqueous) as an oxidant using polymer-anchored Ni(II) complex as a catalyst. Several parameters were varied to optimize the reaction conditions. Under the optimized reaction conditions olefins gave selectively allylic oxidation products. The present polymer anchored Ni(II) complex can be recycled five times without any appreciable loss in catalytic activity.
- Islam, Manirul,Hossain, Dildar,Mondal, Paramita,Roy, Anupam Singha,Mondal, Sanchita,Mobarak, Manir
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scheme or table
p. 3765 - 3770
(2011/09/21)
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- Silica supported Ru(salophen)Cl: An efficient and robust heterogeneous catalyst for epoxidation of alkenes with sodium periodate
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In the present work, heterogenization of Ru(salophen)Cl via its axial ligation to silica-bound imidazole, SiIm, is reported. The heterogeneous catalyst, [Ru(salophen)Cl-SiIm], was characterized by elemental analysis, SEM, TEM, FT-IR and diffuse reflectance UV-Vis spectroscopic techniques. The catalyst, which is not soluble in water and common organic solvents, was used for efficient epoxidation of cyclic and linear alkenes with NaIO4 under agitation with magnetic stirring. This new heterogenized catalyst is of high stability and reusability in the oxidation reactions. The effect of reaction parameters such as solvent and oxidant in the epoxidation of cis-cyclooctene were also investigated.
- Hatefi, Mehdi,Moghadam, Majid,Mirkhani, Valiollah,Sheikhshoaei, Iran
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experimental part
p. 2953 - 2958
(2011/01/07)
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- Mechanism of the aerobic oxidation of α-Pinene
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A combined experimental and theoretical approach is used to study the thermal autoxidation of α-pinene. Four different types of peroxyl radicals are generated; the verbenyl peroxyl radical being the most abundant one. The peroxyl radicals propagate a long
- Neuenschwander, Ulrich,Guignard, Florian,Hermans, Ive
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experimental part
p. 75 - 84
(2011/02/21)
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- Heterogeneous selective oxidation catalysts based on coordination polymer MIL-101 and transition metal-substituted polyoxometalates
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Titanium- and cobalt-monosubstituted Keggin heteropolyanions, [PW11CoO39]5- and [PW11TiO40]5-, were electrostatically bound to the chromium terephthalate polymer matrix MIL-101. The MIL-supported polyoxometalate (POM) catalysts were characterized by elemental analysis, XRD, N2 adsorption, and FT-IR-spectroscopy. The catalytic performance of both MIL-101 and the novel composite materials M-POM/MIL-101 was assessed in the oxidation of three representative alkenes-α-pinene, caryophyllene, and cyclohexene-using molecular oxygen and aqueous hydrogen peroxide as oxidants. Ti-POM/MIL-101 demonstrated fairly good catalytic activity and selectivity in α-pinene allylic oxidation and caryophyllene epoxidation with hydrogen peroxide, whereas Co-POM/MIL-101 catalyzed α-pinene allylic oxidation by molecular oxygen. Both composite materials are stable to POM leaching, behave as true heterogeneous catalysts, and can be used repeatedly without sustaining a loss of activity and selectivity in oxidations with O2 and H2O2, provided that rather mild reaction conditions (T 2O2] 0.2 M) are used with the latter oxidant.
- Maksimchuk,Timofeeva,Melgunov,Shmakov,Chesalov,Dybtsev,Fedin,Kholdeeva
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experimental part
p. 315 - 323
(2009/02/05)
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- Cobalt- and manganese-substituted ferrites as efficient single-site heterogeneous catalysts for aerobic oxidation of monoterpenic alkenes under solvent-free conditions
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Cobalt- and manganese-substituted ferrites were used as heterogeneous catalysts for liquid-phase aerobic oxidation of various monoterpenic alkenes. The materials were prepared by co-precipitation and characterized by Moessbauer spectroscopy, powder X-ray diffractometry, magnetization measurements, and elemental analysis. The results show that isomorphic substitution of iron in the ferrite crystalline structure occurred preferentially at octahedral positions and strongly affected its catalytic properties in the oxidation of monoterpenes. Various valuable oxygenated monoterpenic compounds were obtained with high combined selectivities (75-95%) at ca. 40% substrate conversions. Oxidations of β-pinene and 3-carene led almost exclusively to allylic mono-oxygenated derivatives, whereas limonene and α-pinene gave both epoxides and allylic products. The use of inexpensive catalyst and oxidant, solvent-free conditions, and high final product concentrations (ca. 40 wt%) are significant practical advantages of this environmentally friendly process. The catalysts undergo no metal leaching and can be easily recovered by the application of an external magnet and reused.
- Menini, Luciano,Pereira, Marcio C.,Parreira, Luciana A.,Fabris, Jose D.,Gusevskaya, Elena V.
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p. 355 - 364
(2008/09/18)
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- Aerobic oxidations of α-pinene over cobalt-substituted polyoxometalate supported on amino-modified mesoporous silicates
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Co-containing polyoxometalate [Bu4N]4H[PW11Co(H2O)O39] (Co-POM) was supported on various NH2-modified mesoporous silicate matrixes (SBA-15, MCF, and SiO2-xerogel). The catalysts
- Maksimchuk,Melgunov,Chesalov,Mrowiec-Bialon,Jarzebski,Kholdeeva
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p. 241 - 248
(2008/02/13)
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- Formation of trans-verbenol and verbenone from α-pinene catalysed by immobilised Picea abies cells
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Both enantiomers and the raceinate of α-pinene were transformed by Picea abies cells immobilised on alginate. The main products were cis- and trans-verbenol, the later being further transformed to verbenone. The enantiomeric purity of each product more or less corresponded to that of the substrate. Transformation by free cells was faster than that by the immobilised cells. The ratio of products differed to some extent between the transformation by tree and immobilised cells.
- Vanek, Tomas,Halik, Jan,Vankova, Radmila,Valterova, Irena
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p. 321 - 325
(2007/10/03)
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- Homogeneous and polymer-supported catalysts in the oxidation of α-pinene with oxygen
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The catalytic activities of nitrogen-containing cobalt complexes, polymer (AN-251 anion exchanger)-supported cobalt complex, and a polymer-salt composition containing molybdenum salt and nonionogenic water-soluble polymers were compared in the oxidation o
- Men'shikov,Sennikov,Romanova,Sycheva,Ostroushko
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p. 790 - 794
(2007/10/03)
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- Transformation of α-pinene using Picea abies suspension culture
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α-Pinene, both as the pure enantiomers and as the racemate, was transformed mainly to trans-verbenol by treatment with a Picea abies suspension cell culture. These reactions were followed by a slow transformation of the verbenol to verbenone, which was not transformed further. trans-Pinocarveol, myrtenol, cis-verbenol, and α-terpineol were byproducts of intermediate abundance. When subjected to the action of the suspension culture, cis-verbenol was not only transformed to verbenone but also isomerized to trans-verbenol. The transformation of α-pinene was fast, and the products were detected within one minute. The absolute configuration of the major products corresponded to that of the starting α-pinene enantiomer.
- Lindmark-Henriksson, Marica,Isaksson, Dan,Sjoedin, Kristina,Hoegberg, Hans-Erik,Vanek, Tomas,Valterova, Irena
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p. 337 - 343
(2007/10/03)
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- Co(II) catalysed oxidation of α-pinene by molecular oxygen. Part 2
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This paper reports studies of factors affecting air oxidation of (-)-α-pinene catalysed by Co(II)-pyridine complexes without a concomitant co-oxidant. Observations are presented about the nature and amount of the catalyst, reaction temperature, oxygen flow and solvent vs. non-solvent conditions. In addition, attention has been paid to the influence of added base or acid, and identification of side products. (C) 2000 Elsevier Science Ltd.
- Lajunen, Marja K.,Maunula, Tatja,Koskinen, Ari M.P.
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p. 8167 - 8171
(2007/10/03)
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- New catalysts for the aerobic selective oxidation of hydrocarbons: Mn(III)- and Co(III)-containing molecular sieves for the epoxidation of alkenes
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Co(III) or Mn(III) ions that replace some 4 atom% of Al(III) sites in microporous aluminophosphate number 36 (AlPO-36) function as catalytically active centres for the production from benzaldehyde of acylperoxy radicals: these, in turn, in dry air (30 bar) convert cyclohexene, pinene, limonene and styrene to their corresponding epoxides and diols.
- Raja, Robert,Sankar, Gopinathan,Thomas, John Meurig
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p. 829 - 830
(2007/10/03)
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- Photocatalytic Activation of Oxygen by Iron(III) Porphyrins
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Photochemical charge transfer excitation of tetraphenyl(porphyrinato)iron(III) complexes yields tetraphenyl-(porphyrinato)iron(II) which is able to coordinate molecular oxygen under formation of oxo-[tetraphenyl(porphyrinato)]-iron(IV). Based on this photochemical reaction pathway photocatalytic oxygenation of α-pinene and other alkenes can be initiated. Iron(III) complexes of tetramesitylporphyrin, tetrakis-(pentafluorophenyl)porphyrin, octa-β-bromo-tetrakis-(pentafluorophenyl)porphyrin, and octa-β-chloro-tetrakis-(pentafluorophenyl)porphyrin were investigated photochemically with the aim to improve the low photochemical efficiency of tetraphenyl(porphyrinato)iron(III). The influence of substituents on the porphyrin ligand on the photochemical behavior of the corresponding iron(III) complexes is measured mainly by means of temperature dependent UV/Vis spectroscopy. Both, the yield of oxygenation products formed photocatalytically with α-pinene and the product distribution (allylic alcohols versus epoxide) depend on the design of the porphyrin ligands coordinated with iron(III).
- Hennig, Horst,Luppa, Doritt
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p. 757 - 767
(2007/10/03)
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- Comparative autoxidation of 3-Carene and α-Pinene: Factors governing regioselective hydrogen abstraction reactions
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Autoxidation reactions of 3-Carene 1 and α-Pinene 2 were performed using various homogeneous catalysts. Different product and regio- selectivities were observed. The factors that promote hydrogen abstraction (HA) reactions in both molecules are discussed, and it is proposed that the difference in the product selectivities is due to the lack of 'cyclic activation' in 2. Oxidation of 1 produced mainly 3-carene-5-one 3, while 2 yielded 2,3-epoxypinane 6 as the major product.
- Rothenberg, Gadi,Yatziv, Yael,Sasson, Yoel
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p. 593 - 598
(2007/10/03)
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- Photocatalytic Oxygenation of Selected Cycloalkenes in Aqueous Solutions Induced by Water-Soluble Metal Porphyrin Complexes
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Water-soluble manganese(III) as well as iron(III) porphyrinates are introduced as light-sensitive precursor compounds for the photocatalytic activation of dioxygen in aqueous solutions.It is shown that in the presence of α-pinene (4) and the further cycloalkenes 11-13 photocatalytic oxygenation reactions occur.The dependence of the selectivity of the oxygen transfer to the olefin on both the presence of water and the variation of the substrate-to-catalyst ratio is discussed.The catalyst may be conveniently separated from the substrates/products by using aqueous solvent systems. - Key Words: Photooxygenation / Dioxygen activation / Metallporphyrins / Epoxidation
- Hennig, Horst,Behling, Joerdis,Meusinger, Reinhard,Weber, Lutz
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p. 229 - 234
(2007/10/02)
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- Photokatalytische Oxygenierung von Cycloalkenen mit Mangan(III) Tetraarylporphyrin-Komplexen
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The catalytic oxygenation of cyclohexene, 1-methylcyclohexene, α-pinene, 1,5-dimethylcycloocta-1,5-diene, and cis,trans-cyclodeca-1,5-diene with (tetraarylporphyrinato)manganese(III) complexes in the presence of molecular oxygen and visible light is reported.The photocatalytic reaction results in the formation of epoxides and allylic oxygenation products due to allylic hydrogen abstraction.
- Weber, L.,Behling, J.,Haufe, G.,Hennig, H.
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p. 265 - 268
(2007/10/02)
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