- One-pot synthesis of a hierarchical microporous-mesoporous phosphotungstic acid-HKUST-1 catalyst and its application in the selective oxidation of cyclopentene to glutaraldehyde
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A hierarchical microporous-mesoporous metal-organic framework of HKUST-1(Cu)-encapsulated phosphotungstic acid (HPW) material, referred to as HPWs@Meso-HKUST-1, is prepared by a one-pot synthesis method using cetyltrimethylammonium bromide as the supramolecular template. The addition of HPWs to the synthesis mixture of hierarchical porous HKUST-1 results in the direct encapsulation of HPWs inside the mesopores of the HKUST-1 structure, with a homogeneous distribution over the HKUST-1 crystals, which is confirmed by XRD, FT-IR, N2 adsorption, UV-Vis DRS, and TEM. FT-IR-CO adsorption experiments indicated that additional Lewis acid sites were present in the HPWs@Meso-HKUST-1 sample. The novel heterogeneous catalyst demonstrates excellent catalytic performance for the selective oxidation of cyclopentene (CPE) to glutaraldehyde (GA) using tert-butyl hydroperoxide and acetonitrile (MeCN) as the oxidant and solvent, respectively. The high activity of the catalyst is attributed to the mesostructure of the catalyst and the nature and appropriate abundance of the HPWs - being highly dispersed with the addition of Lewis sites. After a reaction for 36 h, the 30% wt% HPWs@Meso-HKUST-1 catalyst exhibits a CPE conversion of 92.5% and a high GA yield of 73%. Furthermore, the HPWs@Meso-HKUST-1 material is sufficiently stable to prevent the leaching of HPWs, and behaves as a true heterogeneous catalyst that can be repeatedly recycled without sustaining a loss of activity and selectivity in the selective oxidation of CPE.
- Yang, Xinli,Qiao, Liming,Dai, Weilin
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- Selective oxidation of cyclopentene to glutaraldehyde by H2O2over Nb-SBA-15
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A series of niobium-containing mesoporous materials Nb-SBA-15 have been prepared by a sonication-impregnation and hydrothermal process. The dispersion and structural properties of the niobium-containing species were systematically characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, inductively coupled plasma mass spectrometry, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, temperature programmed desorption and N2 adsorption-desorption. Their catalytic performance was evaluated for the selective oxidation of cyclopentene (CPE) to glutaraldehyde (GA). The novel Nb-based catalyst exhibited high activity with a CPE conversion of 87.3% and GA yield of 62% under favourable conditions. No significant deterioration of the catalyst performance was found in the cycle test, indicating the stability of the catalyst. The new Nb-SBA-15 catalyst displayed good catalytic performance both in ethanol and tert-butyl alcohol, which made the catalytic reaction system more flexible for future application. In addition, in situ infrared spectroscopy was adopted to monitor the reaction process. A mechanism of CPE oxidation to GA was proposed tentatively according to our experiment and some reports in the literature. This journal is
- Han, Qi,Li, Jun,Qi, Yingmeng,Wu, Li
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- Oxidation of Cyclopentene with Hydrogen Peroxide Catalyzed by 12-Heteropoly Acids
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12-Heteropoly acids exhibited high performance for selective oxidation of cyclopentene to glutaraldehyde with hydrogen peroxide.Especially, heteropoly acids with mixed addenda atoms of Mo and W, H3PMo(12-x)WxO40 (x= 1-9, showed excellent results.
- Furukawa, Hiroshi,Nakamura, Teiji,Inagaki, Hiroyuki,Nishikawa, Eiichiro,Imai, Chihiro,Misono, Makoto
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- Novel economic and green approach to the synthesis of highly active W-MCM41 catalyst in oxidative cleavage of cyclopentene
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A highly active and perfectly structured W-MCM41 catalyst for the oxidative cleavage of cyclopentene to glutaraldehyde was synthesized through a novel economic and green synthetic method by using Na2SiO3 as the Si source and CH3COOC2H5 as the hydrolyzer.
- Dai, Wei-Lin,Chen, Hao,Cao, Yong,Li, Hexing,Xie, Songhai,Fan, Kangnian
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- Enantioselective Rauhut-Currier reactions promoted by protected cysteine
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We report highly enantioselective examples of the Rauhut-Currier cycloisomerization reaction (the "vinylogous Morita-Baylis-Hillman reaction"). The reaction is highly practical and is catalyzed by a commercially available derivative of the proteinogenic amino acid cysteine. Reactions are conducted in the presence of potassium tert-butoxide and a critical concentration of water in bulk acetonitrile. A mechanistic model is advanced that may account for reaction selectivity that is predicated on organizational chelation of K ion in the product-determining step in which the Cys derivative undergoes elimination. Copyright
- Aroyan, Carrie E.,Miller, Scott J.
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- Oxidation of cyclopentene by H2O2 to glutaraldehyde over the WO3/SiO2 catalyst
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A novel WO3/SiO2 was designed for the catalytic oxidation of cyclopentene by H2O2 to glutaraldehyde In comparison with those homogeneous catalysts, it seems more suitable for the industrial process owing to the high yield of glutaraldehyde and easy separation of the present catalyst from reaction products.
- Jin, Ronghua,Xia, Xin,Xue, Di,Deng, Jing-Fa
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- Pd-Ce nanoparticles supported on functional Fe-MIL-101-NH2: An efficient catalyst for selective glycerol oxidation
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Metal organic framework Fe-MIL-101-NH2 was prepared at different reaction time. The morphology of the Fe-MIL-101-NH2 slightly changed following a longer reaction time; the crystal structure remained. Neocuproine ligand coordinating palladium complex has demonstrated high activity in selective glycerol oxidation towards 1,3-dihydroxyacetone (DHA). Neocuproine ligand was attached to MOF Fe-MIL-101-NH2 by forming an amide (CO[sbnd]NH) bond in this work. The functional Fe-MIL-101-NH2 was used as catalyst supports to hold palladium and cerium nanoparticles. The resulting composite of the Pd-Ce/Fe-MIL-101[sbnd]N[dbnd]CHNeocuproine was found to be a high efficient catalyst in the selective oxidation conversion of glycerol to dihydroxyacetone in comparison with catalysts Pd/Fe-MIL-101[sbnd]N[dbnd]CHNeocuproine and Pt-Bi/C. The catalysts and products were analyzed by FT-IR, XRD, SEM, TEM and 1H, 13C NMR spectroscopy. In addition, the supported catalyst is recyclable with sustainable activity.
- Li, Xinhang,Tjiptoputro, Adrian Kaizen,Ding, Jun,Xue, Jun Min,Zhu, Yinghuai
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- Atmospheric chemistry of bifunctional cycloalkyl nitrates
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Reported here are some aspects of the atmospheric chemistry of the cycloalkyl nitrates trans-2-hydroxy-cyclopentyl-1-nitrate (HCPN), 2-oxo-cyclohexyl-1-nitrate (OCHN) and trans-1-methyl-cyclohexyl-1,2-dinitrate (MCHDN). Their UV absorption spectra have been measured and rate coefficients for their reaction with OH radicals have been determined at 302 K in 1000 mbar of synthetic air. The tropospheric lifetimes of the cycloalkyl nitrates have been estimated from calculations of their photolysis frequencies and first-order OH-radical loss rates. HCPN will not photolyse under atmospheric conditions and for OCHN and MCHDN 24 h globally-averaged photolysis lifetimes of 1.6 and 7.7 days, respectively, have been estimated. The globally-averaged 24 h lifetimes due to reaction with OH radicals are approximately 4 days for both HCHN and OCHN and 8 days for MCHDN. Therefore, for OCHN and MCHDN both photolysis and reaction with OH radicals will be significant atmospheric sinks. For HCHN wet deposition may also be important due to the increased solubility of this compound.
- Waengberg,Barnes,Becker
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- Synthesis, x-ray crystallography, and computational analysis of 1-azafenestranes
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The tandem [4+2]/[3+2] cycloaddition of nitroalkenes has been employed in the synthesis of 1-azafenestranes, molecules of theoretical interest because of planarizing distortion of their central carbon atoms. The synthesis of c,c,c,c-[5.5.5.5]-1-azafenestrane was completed in good yield from a substituted nitrocyclopentene, and its borane adduct was analyzed through X-ray crystallography, which showed a moderate distortion from ideal tetrahedral geometry. The syntheses of two members of the [4.5.5.5] family of 1-azafenestranes are also reported, including one with a trans fusion at a bicyclic ring junction which brings about considerable planarization of one of the central angles (16.8° deviation from tetrahedral geometry). While investigating the [4.5.5.5]-1-azafenestranes, a novel dyotropic rearrangement that converts nitroso acetals into tetracyclic aminals was discovered. Through conformational analysis, a means to prevent this molecular reorganization was formulated and realized experimentally with the use of a bulky vinyl ether in the key [4+2] cycloaddition reaction. Finally, DFT calculations on relative strain energy for the 1-azafenestranes, as well as their predicted central angles, are disclosed.
- Denmark, Scott E.,Montgomery, Justin I.,Kramps, Laurenz A.
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- Preparation of Heterogeneous Mesoporous Silica-Supported 12-Tungstophosphoric Acid Catalyst and Its Catalytic Performance for Cyclopentene Oxidation
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Keggin-structured 12-tungstophosphoric acids were immobilized onto the surface of amine-modified mesoporous sieve SBA-15 as onium salts. All the catalyst materials were characterized by X-ray diffraction, N2 physisorption, Fourier transform infrared spectroscopy, thermal gravimetric analysis, and X-ray photoelectron spectroscopy for their structural integrity and physicochemical properties. Characterization of the catalysts confirmed an ordered hexagonal mesostructure for SBA-15 and that the Keggin structure of the heteropolyanions on the amine-modified SBA-15 was preserved. The catalytic activities of the catalysts were evaluated for the liquid-phase oxidation of cyclopentene with 50% hydrogen peroxide as the oxidant in tert-butanol. A 100% conversion of cyclopentene and an 81% selectivity for glutaraldehyde were obtained and these were higher than that for the catalysts prepared by direct impregnation. The stability and reusability of the catalysts were studied and the catalysts could be reused at least five times, which indicates their excellent reusability. The influence of reaction temperature and reaction time was also investigated. In addition, a reaction mechanism was proposed.
- Yuan, Chengyuan,Chen, Jing
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- A novel green process for the synthesis of glutaraldehyde by WS 2@HMS material with aqueous H2O2
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A novel and green route is reported for the selective oxidation of cyclopentene oxide to glutaraldehyde by using aqueous H2O2 as the oxidant and WS2@hexagonal mesoporous silica (WS2@HMS) material as the catalyst, which shows a very large surface area, high efficiency, excellent selectivity and outstanding reusability.
- Zhu, Quanjing,Chu, Xiaofeng,Zhang, Zhaoyan,Dai, Wei-Lin,Fan, Kangnian
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- Highly efficient oxidation of cyclopentene catalyzed by magnetically recoverable Ca–Co ferrite spinels with high solvent selectivity
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The calcium doped CoFe2O4 spinels CaxCo1?xFe2O4 (x = 0, 0.1, 0.3, 0.5 and 0.7) were prepared by simple sol–gel auto-combustion method. The samples were characterized by X-ray diffractometry, Raman spectrometry, scanning and transmission electron microscopy, N2-physisorption and inductive coupled plasma-atomic emission spectroscopy. The samples have shown prominent activities in oxidation of cyclopentene using 30% hydrogen peroxide as oxidant. When compared to the pristine CoFe2O4, the Ca-doped ones were more efficient having a conversion ranging from 72.1% to 100% and a H2O2 utilization efficiency range of 80.0–84.7%. When the calcium content was 0.3 and above, the cyclopentene was quantitatively converted to cyclopentenone at 60 °C for 8 h reaction. More interestingly, the catalyst has shown great solvent selectivity with respect to the product distribution. Finally, the catalyst can be easily separated magnetically for reuse and no obvious loss of activity was observed after five consecutive runs.
- Bo, Lili,Hu, Yusen,Zhang, Zhixia,Balanay, Mannix,Fan, Haiyan,Tong, Jinhui
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- Selective oxidation of cyclopentene to glutaraldehyde by H2O2 over the WO3/SiO2 catalyst
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A novel WO3/SiO2 was prepared by incipient wetness impregnation of the SiO2 support synthesized by the xerogel method with the W-containing salt solution. The as-prepared WO3/SiO2 catalyst exhibited a very high yield of glutaraldehyde in the liquid phase cyclopentene oxidation by aqueous H2O2 and the leach of WO3 species during the reaction could be neglected. As a heterogeneous catalyst, it seems more suitable for the industrial process than those homogeneous catalysts owing to its easy separation from reaction products, which makes it possible to use the catalyst repetitively. According to the XRD patterns, the WO3 was present in amorphous state due to its high dispersion on the SiO2 support. These amorphous WO3 species were proved to be the active sites since the crystallization at high temperature caused a considerable deactivation. The lifetime of the catalyst was measured and its regeneration method was proposed. Effects of various factors on the catalytic behaviors, such as the WO3 loading, the calcination temperature, and the reaction media, were also investigated and discussed based on the characterizations of BET, XRD, DSC, TEM, EXAFS, and Raman spectra.
- Jin, Ronghua,Li, Hexing,Deng, Jing-Fa
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- Method for catalyzing catalytic oxidation reaction of cyclopentene by vacancy silicon-tungsten heteropolyacid salt catalyst
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The invention relates to a method for catalyzing a catalytic oxidation reaction of cyclopentene by utilizing a vacancy silicon-tungsten heteropolyacid salt catalyst. The invention aims to provide a process method for preparing glutaraldehyde and 1, 2-cyclopentanediol by carrying out catalytic oxidation on cyclopentene by using a two-vacancy silicon-tungsten heteropolyacid salt catalyst, which is small in environmental pollution, high in catalytic activity, high in yield and easy in recycling of the catalyst. According to the technical scheme, the method comprises the following steps of: (1) weighing cyclopentene, a heteropolyacid catalyst and 30% hydrogen peroxide according to a reaction molar ratio of 1: (0.0002-0.0020): (0.5-4.0), adding a quantitative reaction solvent, mixing well, controlling the temperature range to be 30-55 DEG C, reacting for 0.5-8 hours, and stirring until the reaction is finished; (2) carrying out a rectification process on a mixture generated by the reaction to obtain glutaraldehyde and 1, 2-cyclopentanediol; and (3) carrying out reduced pressure distillation on the reaction liquid to remove the solvent, and filtering, washing, vacuum-drying, collecting and recycling the vacancy silicon-tungsten heteropolyacid catalyst.
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Paragraph 0046-0100; 0100-0122
(2021/11/06)
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- Understanding the mechanism of N coordination on framework Ti of Ti-BEA zeolite and its promoting effect on alkene epoxidation reaction
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The function of ammonium salts on the epoxidation performance over Ti-BEA zeolite was investigated in detail. Experiments of alkene epoxidation, side reactions of epoxide and decomposition of H2O2 with or without ammonium salts were designed, and the UV-Vis spectroscopy was employed to analyze the structure of Ti-hydroperoxo species. It is revealed that the ammonia (or amines) dissociated from the ammonium salt would chelate with the linear Ti-η1(OOH) species and form a bridged Ti-η2(OOH)-R species, which is more stable, more weaker in epoxide adsorption and acidity as well. Therefore, side reactions and H2O2 decomposition would be suppressed, and both alkene conversion and epoxide selectivity would be promoted simultaneously. On the other hand, the excessive NH3?H2O (NH3/Ti>1) or NaOH bond with the Ti-η2(OOH)-R species and generate salt-like Ti-η2(OO)-M+ species, resulting in the deactivation of Ti active center. While for ammonium salts, e.g. NH4Cl, the limited dissociation degree along with the acidic environment help the Ti active center to maintain in highly active. In short, this work provides a practical Ti active center tuning method for Ti-BEA zeolite, as well as a thorough understanding of its Ti-hydroperoxo species.
- Liang, Xiaohang,Liu, Dan,Luo, Yibin,Peng, Xinxin,Shu, Xingtian,Xia, Changjiu
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- Novel method for synthesizing dialdehyde compound
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The invention provides a method for synthesizing a dialdehyde compound, and an acetal represented by the structural formula (I) and a Grignard reagent represented by the structural formula (II) are subjected to a coupling reaction and then hydrolyzed to obtain the dialdehyde compound, wherein the structural formula (I) and the structural formula (II) are described in the specification. The method has the advantages of high reaction activity, the reaction can be carried out even under the condition of room temperature, the reaction completed time is short, almost no other by-products are generated, no catalyst is required to be used, the reaction yield is high, and the reaction speed is fast. Moreover, the product purity is high, the dialdehyde compound with the purity of about 98% can be obtained after concentration, and no complex purification process is required.
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Paragraph 0072; 0074; 0076
(2020/07/23)
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- PROCESS FOR PRODUCING DIALDEHYDE
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PROBLEM TO BE SOLVED: To provide a process for producing dialdehyde in high yield. SOLUTION: Provided is a process for producing a dialdehyde, comprising the step of reacting a cyclic alkene with an oxidizing agent in the presence of a catalyst having mononuclear ruthenium immobilized on a catalyst carrier. SELECTED DRAWING: None COPYRIGHT: (C)2020,JPOandINPIT
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Paragraph 0025; 0027
(2020/05/16)
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- Reductive Electrochemical Activation of Molecular Oxygen Catalyzed by an Iron-Tungstate Oxide Capsule: Reactivity Studies Consistent with Compound i Type Oxidants
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The reductive activation of molecular oxygen catalyzed by iron-based enzymes toward its use as an oxygen donor is paradigmatic for oxygen transfer reactions in nature. Mechanistic studies on these enzymes and related biomimetic coordination compounds designed to form reactive intermediates, almost invariably using various "shunt" pathways, have shown that high-valent Fe(V)=O and the formally isoelectronic Fe(IV) =O porphyrin cation radical intermediates are often thought to be the active species in alkane and arene hydroxylation and alkene epoxidation reactions. Although this four decade long research effort has yielded a massive amount of spectroscopic data, reactivity studies, and a detailed, but still incomplete, mechanistic understanding, the actual reductive activation of molecular oxygen coupled with efficient catalytic transformations has rarely been experimentally studied. Recently, we found that a completely inorganic iron-tungsten oxide capsule with a keplerate structure, noted as {Fe30W72}, is an effective electrocatalyst for the cathodic activation of molecular oxygen in water leading to the oxidation of light alkanes and alkenes. The present report deals with extensive reactivity studies of these {Fe30W72} electrocatalytic reactions showing (1) arene hydroxylation including kinetic isotope effects and migration of the ipso substituent to the adjacent carbon atom ("NIH shift"); (2) a high kinetic isotope effect for alkyl C - H bond activation; (3) dealkylation of alkylamines and alkylsulfides; (4) desaturation reactions; (5) retention of stereochemistry in cis-alkene epoxidation; and (6) unusual regioselectivity in the oxidation of cyclic and acyclic ketones, alcohols, and carboxylic acids where reactivity is not correlated to the bond disassociation energy; the regioselectivity obtained is attributable to polar effects and/or entropic contributions. Collectively these results also support the conclusion that the active intermediate species formed in the catalytic cycle is consistent with a compound I type oxidant. The activity of {Fe30W72} in cathodic aerobic oxidation reactions shows it to be an inorganic functional analogue of iron-based monooxygenases.
- Bugnola, Marco,Shen, Kaiji,Haviv, Eynat,Neumann, Ronny
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p. 4227 - 4237
(2020/05/05)
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- Controlling the Morphology and Titanium Coordination States of TS-1 Zeolites by Crystal Growth Modifier
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Developing an effective strategy to synthesize perfect titanosilicate TS-1 zeolite crystals with desirable morphologies, enriched isolated framework Ti species, and thus enhanced catalytic oxidation properties is a pervasive challenge in zeolite crystal engineering. We here used an amino acid l-carnitine as a crystal growth modifier and ethanol as a cosolvent to regulate the morphologies and the Ti coordination states of TS-1 zeolites. During the hydrothermal crystallization process, the introduced l-carnitine can not only tailor the anisotropic growth rates of zeolite crystals but also induce the formation of uniformly distributed framework Ti species through building a suitable chemical interaction with the Ti precursor species. Condition optimizations could afford the generation of perfect hexagonal plate TS-1 crystals and elongated platelet TS-1 crystals enriched in tetrahedral framework Ti sites (TiO4) or mononuclear octahedrally coordinated Ti species (TiO6). Both samples showed significant improvement in catalytic activity for the H2O2-mediated epoxidation of alkenes. In particular, the elongated platelet TS-1 enriched in "TiO6"species afforded the highest activity in 1-hexene epoxidation, with a turnover frequency (TOF) of up to 131 h-1, which is approximately twice as high as that of the conventional TS-1 zeolite (TOF: 65 h-1) and even higher than those of the literature-reported TiO6-containting TS-1 catalysts derived from the hydrothermal post-treatment of TS-1 zeolites. This work demonstrates that the morphologies and the titanium coordination states of TS-1 zeolites can be effectively tuned by directly introducing suitable crystal growth modifiers, thus providing new opportunities for developing highly efficient titanosilicate zeolite catalysts for important catalytic applications.
- Chang, Xinyu,Chen, Ziyi,Hu, Dianwen,Jia, Mingjun,Li, Yingying,Song, Xiaojing,Yang, Xiaotong,Yu, Jihong,Zhang, Hao,Zhang, Peng,Zhang, Qiang,Zhang, Tianjun
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supporting information
p. 13201 - 13210
(2020/10/02)
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- Visible-light mediated C-C bond cleavage of 1,2-diols to carbonyls by cerium-photocatalysis
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We describe a photocatalytic method for the cleavage of vicinal diols to aldehydes and ketones. The reaction is catalyzed by blue light and a cerium-catalyst and the scope includes aryl as well as alkyl substituted diols. The simple protocol which works under air and at room temperature enables the valorization of abundant diols.
- Schwarz, Johanna,K?nig, Burkhard
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supporting information
p. 486 - 488
(2019/01/10)
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- Efficient Vanadium-Catalyzed Aerobic C?C Bond Oxidative Cleavage of Vicinal Diols
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The aerobic oxidative C?C bond cleavage of vicinal diols catalyzed by vanadium amino triphenolates is described. Our results show that C?C bond cleavage can be performed in different solvents, under an air or oxygen atmosphere, with a large variety of glycols (cyclic or linear, with aromatic or aliphatic substituents) affording the corresponding carbonyl derivatives with high chemoselectivity. Reactions can be performed with as little as 10 ppm of catalyst reaching TON up to 81,000 and TOFs of up to 4150 h?1. A reaction mechanism, rationalized by density functional theory calculations, is also proposed. (Figure presented.).
- Amadio, Emanuele,González-Fabra, Joan,Carraro, Davide,Denis, William,Gjoka, Blerina,Zonta, Cristiano,Bartik, Kristin,Cavani, Fabrizio,Solmi, Stefania,Bo, Carles,Licini, Giulia
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supporting information
p. 3286 - 3296
(2018/05/30)
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- Method for preparing glutaraldehyde through organic-inorganic heteropolyacid salt catalyzed oxidation of cyclopentene
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The invention relates to a method for preparing glutaraldehyde, and concretely relates to a new method for preparing glutaraldehyde through organic-inorganic heteropolyacid salt catalyzed oxidation ofcyclopentene. The method is characterized in that [C6H5CH2N(CH3)2(CH2)3SO3H]Ti0.5PW4O16 is used as a catalyst, acetone is used as a solvent, a molar ratio of the cyclopentene to the catalyst is 30:1,a molar ratio of the cyclopentene to hydrogen peroxide (30wt% H2O2) is 1:1.5, the volume of the solvent is 56 times that of the cyclopentene, a reaction is carried out at 35 DEG C for 3 h, the yieldof the glutaraldehyde is 70%, and the catalyst can be repeatedly used after being filtered, washed and dried. The method solves the problem of difficulty in separation of the catalyst and the productin homogeneous catalysis and overcomes the disadvantages of slow reaction rate and easy loss of active component in heterogeneous catalysis during the catalyzed cyclopentene oxidation for preparing the glutaraldehyde, and the has the advantages of environmental protection, simplicity in treatment, and great theoretic meaning and industrial values.
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Paragraph 0021; 0025; 0026; 0027-0034
(2018/03/28)
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- Mesoporous silica as phase transfer agent in the biphasic oxidative cleavage of alkenes using triazole complexes of ruthenium as catalyst precursors
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The oxidative cleavage of alkenes was performed using ruthenium triazole -arene complexes immobilized on mesoporous silica materials. These silica-organometallic hybrid materials were found to show enhanced activity when compared to conventional homogeneous systems even when operating at a relatively low catalyst loading. The enhanced catalytic performance of these heterogeneous systems can be attributed to the mesoporous silica acting as a phase transfer agent in the biphasic catalyst system.
- Leckie, Laura,Mapolie, Selwyn F.
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- Preparation method and application of brphinsted acidic ionic liquid using periodate as anion as well as method for preparing alpha,omega-dialdehyde
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The invention relates to the field of fine chemical industry, and concretely provides an application of brphinsted acidic ionic liquid using periodate as an anion as well as a preparation method thereof. The invention provides a method for preparing alpha,omega-dialdehyde. The method comprises the following steps: in a condition of a solution, cycloolefin and/or alkylene oxide and an oxidizing agent are contacted, transparent liquid with white deposition is obtained, transparent liquid and white deposition are obtained by separation, wherein the oxidizing agent is brphinsted acidic ionic liquid using periodate as the anion. The brphinsted acidic ionic liquid using periodate as the anion can be used as an oxidizing agent for carrying out an oxidation reaction is provided for the first time, and the method has the advantages of simple and easily operated process, green and environmental protection, cleaning, and repeated recovery and utilization of the oxidizing agent.
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Paragraph 0134; 0135
(2017/05/12)
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- Method for continuously producing glutaraldehyde
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The invention discloses a method for continuously producing glutaraldehyde and belongs to the field of fine chemical intermediate chemical engineering and technologies. Water, 2-methoxy-3,4-dihydropyran and a sodium dihydrogen phosphate saturated solution continuously enter a tanks-in-series reactor and are hydrolyzed at certain temperature to obtain an aqueous solution of glutaraldehyde and methyl alcohol, hydrolysate enters a continuous rectifying tower, methyl alcohol is generated on a tower top, and a qualified glutaraldehyde aqueous solution is generated by a tower bottom. The method has the advantages of being high in production efficiency, stable in process and very suitable for being used in large-scale production devices.
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Paragraph 0011; 0012; 0013; 0014; 0015; 0016
(2017/02/28)
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- A glutaraldehyde last of the ten Heavenly Stems armor bromine ammonium solution preparation method (by machine translation)
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The invention discloses a glutaraldehyde last of the ten Heavenly Stems armor bromine ammonium solution preparation method, the product belongs to the field of disinfectants; the present invention is to air, pentanediol, aluminum trioxide carrier silver, pharmaceutical agent, de-ionized water, concentration is 10% of the last of the ten Heavenly Stems armor bromine ammonium solution as raw material, in order to oxygen generator, liquid phase reaction tank, liquid ingredient tank, double-head liquid quantitative filling machine for apparatus producing glutaraldehyde last of the ten Heavenly Stems armor bromine ammonium solution, the product is a broad spectrum, high-efficiency, non-irritating, non-corrosive disinfectant, can quickly kill of a variety of viral, bacterial, fungal, parasite, mycoplasma and other pathogenic microorganism, product is characterized in that the wide range of application, to water quality requirements, in hard water can still play a role. (by machine translation)
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Paragraph 0012; 0013
(2017/06/09)
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- Discovery of a highly potent anti-inflammatory epoxyisoprostane-derived lactone
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Epoxyisoprostanes EI (1) and EC (2) are effective inhibitors of the secretion of proinflammatory cytokines IL-6 and IL-12. In detailed studies toward the investigation of the molecular mode of action of these structures, a highly potent lactone (3) derived from 1 was identified. The known isoprostanoids 1 and 2 are most likely precursors of 3, the product of facile intramolecular reaction between the epoxide with the carboxylic acid in 2.
- Egger, Julian,Bretscher, Peter,Freigang, Stefan,Kopf, Manfred,Carreira, Erick M.
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supporting information
p. 17382 - 17385
(2015/02/19)
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- Pd(II)-catalyzed deprotection of acetals and ketals containing acid sensitive functional groups
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The pincer complex [Pd(C1,O1,N1-L)(NCMe)] ClO4 (L = monoanionic ligand resulting from deprotonation of the acetyl group of the dimethyl monoketal of 2,6-diacetylpyridine) is used for the high-yield and selective catalytic hydrolysis of aliphatic, aromatic, cyclic, and acyclic dimethyl-acetals, -ketals, and dioxolanes, even in the presence of large substituents. Other protecting groups, such as THP or TBDMS, or very acid-sensitive alcohols were not affected. The catalyst is easily prepared in high yield from Pd(AcO)2 and 2,6-diacetylpyridinium perchlorate stable to air and moisture, easily and fully recoverable and reusable.
- Juliá-Hernández, Francisco,Arcas, Aurelia,Vicente, José
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p. 1141 - 1144
(2014/02/14)
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- Characterization of a new enzyme oxidizing ω-amino group of aminocarboxyric acid, aminoalcohols and amines from Phialemonium sp. AIU 274
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A new enzyme exhibiting oxidase activity for ω-aminocarboxylic acids, ω-aminoalcohols, monoamines and diamines was found from a newly isolated fungal strain, Phialemonium sp. AIU 274. The enzyme also oxidized aromatic amines, but not l- and d-amino acids. The Vmax/Km value for hexylamine was higher than those for 6-aminoalcohol and 6-aminhexanoic acid in the aliphatic C6 substrates. In the aliphatic amines, the higher Vmax/Km values were obtained by the longer carbon chain amines. Thus, the enzyme catalyzed oxidative deamination of the ω-amino group in a wide variety of the ω-amino compounds and preferred medium- and long-chain substrates. The oxidase with such broad substrate specificity was first reported here. The enzyme contained copper, and the enzyme activity was strongly inhibited by isoniazid, iproniazid and semicarbazide, but not by clorgyline and pargyline. The enzyme was composed of two identical subunits of 75 kDa.
- Isobe, Kimiyasu,Sasaki, Tomoko,Aigami, Yuusuke,Yamada, Miwa,Kishino, Shigenobu,Ogawa, Jun
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- Synthesis and Biological Evaluation of Tricyclic Guanidine Analogues of Batzelladine K for Antimalarial, Antileishmanial, Antibacterial, Antifungal, and Anti-HIV Activities
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Fifty analogues of batzelladine K were synthesized and evaluated for in vitro antimalarial (Plasmodium falciparum), antileishmanial (Leishmania donovani), antimicrobial (panel of bacteria and fungi), antiviral (HIV-1) activities. Analogues 14h and 20l exhibited potential antimalarial activity against chloroquine-sensitive D6 strain with IC50 1.25 and 0.88μm and chloroquine-resistant W2 strain with IC50 1.64 and 1.07μm, respectively. Analogues 12c and 14c having nonyl substitution showed the most potent antileishmanial activity with IC50 2.39 and 2.78μm and IC90 11.27 and 12.76μm, respectively. Three analogues 12c, 14c, and 14i were the most active against various pathogenic bacteria and fungi with IC503.02μm and MIC/MBC/MFC 6μm. Analogue 20l having pentyl and methyl substituents on tricycle showed promising activities against all pathogens. However, none was found active against HIV-1. Our study demonstrated that the tricyclic guanidine compounds provide new structural class for broad spectrum activity. Fifty analogues of tricyclic guanidine derivative of batzelladine K were synthesized and tested for antimalarial, antileishmanial, antimicrobial, antifungal and anti-HIV activities. We have identified several active analogues.
- Ahmed, Nafees,Brahmbhatt, Keyur G.,Khan, Shabana I.,Jacob, Melissa,Tekwani, Babu L.,Sabde, Sudeep,Mitra, Debashis,Singh, Inder P.,Khan, Ikhlas A.,Bhutani, Kamlesh K.
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p. 491 - 498
(2013/05/21)
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- Oxidative deamination of amines using sodium nitrite
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A novel synthetic utility of sodium nitrite for oxidative deamination is described. Aromatic and aliphatic amines compounds were successfully converted into the corresponding carbonyl compounds in the presence of sodium nitrite, potassium iodide, and molecular oxygen under reflux conditions. The method is applicable for both primary and secondary amines for moderate to good yields of corresponding carbonyl compounds. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications to view the free supplemental file.
- Chaudhari, Hemchandra K.,Telvekar, Vikas N.
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p. 1155 - 1160
(2013/03/29)
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- RHO KINASE INHIBITORS
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The present invention relates to compounds of formula I and pharmaceutically acceptable salts thereof, wherein R1, R2, R3 and X are as defined herein. The invention also relates to pharmaceutical compositions comprising these compounds, methods of using these compounds in the treatment of various diseases and disorders, processes for preparing these compounds and intermediates useful in these processes.
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Page/Page column 70-71
(2012/05/05)
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- Nicotinium dichromate (= 3-carboxypyridinium dichromate; NDC) as an efficient reagent for the oxidative deamination of amines and aminophosphonates
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A new method for the efficient synthesis of aldehydes, ketones, and oxophosphonates from various types of amines (primary and secondary) and aminophosphonates via oxidative deamination by nicotinium dichromate (= 3-carboxypyridinium dichromate; NDC) is described.
- Sobhani, Sara,Aryanejad, Sima,Maleki, Mahdi Faal
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experimental part
p. 613 - 617
(2012/05/20)
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- Vanadium phosphorus oxide modified by silver doping: A highly effective catalyst for allylic oxidation of cycloolefins
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Allylic oxidation of cycloolefins was carried out over Ag-VPO catalyst using tert-butyl hydroperoxide (TBHP) as oxidant in argon atmosphere, under our reaction conditions, attack of the activated C-H bonds was preferred instead of the epoxidation of C=C bond and corresponding α, β-enones were obtained as the main products. It is a high yielding, safe and eco-friendly method.
- Liu, Junhua,Wang, Fang,Ma, Zhenmao,Lin, Jun,Gu, Zhenggui
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experimental part
p. 103 - 107
(2012/03/09)
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- MODIFICATION OF ALLERGENS
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The invention relates to a process for modifying allergens to enhance their suitability in immunotherapy. The invention further relates to the modified allergens and pharmaceutical compositions thereof, as well as to their use in immunotherapy.
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- An expedient procedure for the oxidative cleavage of olefinic bonds with PhI(OAc)2, NMO, and Catalytic OsO4
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(Figure Presented) PhI(OAc)2 In the presence of OsO4 (cat.) and 2,6-lutidine cleaves oleflnlc bonds to yield the corresponding carbonyl compounds, albeit, In some cases, with a-hydroxy ketones as byproduct. A more practical and clean protocol to effect oxidative cleavage of olefinic bonds involves NMO, OsO4 (cat.), 2,6-lutidine, and PhI(OAc) 2.
- Nicolaou,Adsool, Vikrant A.,Hale, Christopher R. H.
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supporting information; experimental part
p. 1552 - 1555
(2010/06/16)
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- Oxidative deamination of α-aminophosphonates and amines by zinc dichromate trihydrate (ZnCr2O73H2O) under solvent-free conditions at room temperature
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A novel method for the rapid and efficient conversion of a variety of -aminophosphonates to α-ketophosphonates using ZnCr2O 73H2O via oxidative deamination under solvent-free conditions at room temperature is described. This method is also applicable to the rapid and highly selective oxidation of various types of ordinary amines (primary and secondary) to aldehydes and ketones in good to high yields. Georg Thieme Verlag Stuttgart New York.
- Sobhani, Sara,Maleki, Mahdi Faal
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experimental part
p. 383 - 386
(2010/04/05)
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- An improved protocol for the oxidative cleavage of alkynes, alkenes, and diols with recyclable Ru/C
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Efficient synthesis of carboxylic acids from alkynes; aldehydes from alkenes and diols employing Ru/C-based recyclable catalytic system is reported with good to excellent yields. Georg Thieme Verlag Stuttgart.
- Vijay Kumar,Prakash Reddy,Sridhar,Srinivas,Rama Rao
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experimental part
p. 739 - 742
(2009/07/18)
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- PREPARATION OF GLUTARALDEHYDE
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Provided is a process for the preparation of glutaraldehyde. The process comprises reacting an alkoxydihydropyran with water in the presence of an acidic catalyst. The alcohol by-product distilled from the reaction mixture is subjected to a heterogeneous catalyst that is located external to the distillation column used for distilling the alcohol, thereby increasing glutaraldehyde yield and decreasing the level of alkoxydihydropyran contamination in the alcohol.
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Page/Page column 3-4
(2009/12/28)
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- A highly stereoselective organocatalytic tandem aminoxylation/aza-Michael reaction for the synthesis of tetrahydro-1,2-oxazines
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(Chemical Equation Presented) A facile stereoselective synthesis of multifunctionalized tetrahydro-1,2-oxazines (THOs) has been achieved by the organocatalyzed asymmetric tandem α-aminoxylation/aza-Michael reaction for the C-O/C -N bond formations in moderate to good yields with excellent diastereo- (>99:1 dr) and enantioselectivities (92% to >99% ee).
- Zhu, Di,Lu, Min,Chua, Pei Juan,Tan, Bin,Wang, Fei,Yang, Xinhao,Zhong, Guofu
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supporting information; experimental part
p. 4585 - 4588
(2009/05/13)
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- Proline-mediated enantioselective construction of tetrahydropyridines via a cascade Mannich-type/intramolecular cyclization reaction
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A highly diastereo- and enantioselective synthesis of 2,3-disubstituted tetrahydropyridines was accomplished via a proline-mediated cascade Mannich-type/intramolecular cyclization reaction from preformed N-PMP (p-methoxyphenyl) aldimines and inexpensive aqueous tetrahydro-2H-pyran-2,6- diol.
- Han, Rong-Gang,Wang, Yao,Li, Yu-Ye,Xu, Peng-Fei
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body text
p. 1474 - 1478
(2009/07/18)
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- Oxidative cleavage of alkenes catalyzed by a water/organic soluble manganese porphyrin complex
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Tetrakis(4-hydroxyphenyl)porphyrin [TPP-(OH)4] was modified with poly(ethylene glycol) chain as four side arms, such that this compound is soluble in both organic and water solutions. Complexation of this porphyrin with manganese metal ions resulted in the formation of MnCl-TPP-(PEO750)4. This complex proved to be an excellent catalyst for the oxidative cleavage of C{double bond, long}C bonds, yielding the corresponding carbonyl compounds with sodium periodate as an oxidant. Mechanistic pathway for this cleavage is discussed.
- Liu, Shiuh-Tzung,Reddy, K. Venugopal,Lai, Rung-Yi
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p. 1821 - 1825
(2007/10/03)
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- Activated iodosylbenzene monomer as an ozone equivalent: Oxidative cleavage of carbon-carbon double bonds in the presence of water
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Reported here for the first time are the developments of an efficient method for oxidative cleavage of carbon-carbon double bonds yielding carbonyl compounds by using aryl-λ3-iodanes, which involve a combination of iodosylbenzene and HBF4 in the presence of water. The method serves as a safety alternative to ozonolysis. The oxidative cleavage of olefins probably involves the hitherto unknown direct vicinal dihydroxylations of double bonds with aryl-λ3-iodanes and the subsequent oxidative glycol fissions. Cyclic (cyclopentenes, cyclohexenes, etc.) and acyclic olefins are cleaved smoothly under our conditions. In the reaction of electron-deficient styrenes such as m-nitrostyrene, intermediate formation of the corresponding epoxide was detected. A variety of aryloxiranes also undergo an oxidative cleavage of the epoxide rings under our conditions, and aromatic aldehydes were obtained in good yields. Copyright
- Miyamoto, Kazunori,Tada, Norihiro,Ochiai, Masahito
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p. 2772 - 2773
(2007/10/03)
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- Alkene cis-dihydroxylation by [(Me3tacn)(CF3CO 2)RuVIO2]CIO4 (Me3tacn = 1,4,7-trimethyl-1,4,7-triazacyclononane): Structural characterization of [3 + 2] cycloadducts and kinetic studies
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cis-Dioxoruthenium(VI) complex [(Me3tacn)(CF3CO 2)RuVIO2]CIO4 (1, Me3tacn = 1,4,7-trimethyl-1,4,7-triazacyclononane) reacted with alkenes in aqueous tert-butyl alcohol to afford cis-1,2-diols in excellent yields under ambient conditions. When the reactions of 1 with alkenes were conducted in acetonitrile, oxidative C=C cleavage reaction prevailed giving carbonyl products in >90% yields without any cis-diol formation. The alkene cis-dihydroxylation and C=C cleavage reactions proceed via the formation of a [3 + 2] cycloadduct between 1 and alkenes, analogous to the related reactions with alkynes [Che et al. J. Am. Chem. Soc. 2000, 122, 11380], With cyclooctene and trans-β-methylstyrene as substrates, the Ru(III) cycloadducts [(Me3tacn)(CF 3CO2)RuIIIO(H)CH(CH2) 6HCO]CIO4 (4a) and [(Me3tacn)(CF 3CO2)RuIIIO(H)-PhCHCH(CH3)O]CIO 4 (4b) were isolated and structurally characterized by X-ray crystal analyses. The kinetics of the reactions of 1 with a series of p-substituted styrenes has been studied in acetonitrile by stopped-flow spectrophotometry. The second-order rate constants varied by 14-fold despite an overall span of 1.3 V for the one-electron oxidation potentials of alkenes. Secondary kinetic isotope effect (KIE) was observed for the oxidation of β-d2-styrene (kH/kD = 0.83 ± 0.04) and α-deuteriostyrene (kH/kD = 0.96 ± 0.03), which, together with the stereoselectivity of cis-alkene oxidation by 1, is in favor of a concerted mechanism.
- Yip, Wing-Ping,Yu, Wing-Yiu,Zhu, Nianyong,Che, Chi-Ming
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p. 14239 - 14249
(2007/10/03)
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- ETHER COMPOUNDS AND COMPOSITIONS FOR CHOLESTEROL MANAGEMENT AND RELATED USES
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The present invention relates to novel ether compounds, compositions comprising ether compounds, and methods useful for treating and preventing cardiovascular diseases, dyslipidemias, dysproteinemias, and glucose metabolism disorders comprising administering a composition comprising an ether compound. The compounds, compositions, and methods of the invention are also useful for treating and preventing Alzheimer's Disease, Syndrome X, peroxisome proliferator activated receptor-related disorders, septicemia, thrombotic disorders, obesity, pancreatitis, hypertension, renal disease, cancer, inflammation, and impotence. In certain embodiments, the compounds, compositions, and methods of the invention are useful in combination therapy with other therapeutics, such as hypocholesterolemic and hypoglycemic agents.
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Page/Page column 252
(2010/02/13)
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- Automated system for coating the human body: virtual motion
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In a system for coating human skin, a chemical composition, such as a cosmetic or medical formulation, is uniformly coated over the entire body or selected parts of the body of the person being coated. The system includes atomization of the coating composition, containment of the atomized spray, and residual recovery which together yield a novel method for applying chemical compositions.
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- Bromonitrothienyldioxanes
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The invention relates to novel 5-bromo-5-nitro-2-thienyl-1,3-dioxanes of the formula (I) in which R1, R2 and R3 are as defined in the description are highly suitable for use as biocides for protecting plants and industrial materials.
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- 3-NITROISOXAZOLES AND THEIR USE IN THE PROTECTION OF MATERIALS
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The 3-nitroisoxazoles of the formula (I) in which R1 and R2 are each as defined in the description, some of which are known, are highly suitable for use as biocides for protecting industrial materials.
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- Thiazines and thiazoles as agents for protecting materials
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The novel and known thiazines and thiazoles of the formula (I) in which R1, R2 and n are as defined in the description, are highly suitable for use as biocides for protecting industrial materials.
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- O-aryl dithiazole dioxides
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The invention relates to new O-aryldithiazole dioxides, to two processes for their preparation, and to their use as pesticides in crop protection and in the protection of materials.
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- Products of the gas-phase reaction of O3 with cyclohexene
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In the troposphere, alkenes react with OH radicals, NO3 radicals, and O3, with the O3 reactions often being an important transformation process during both daytime and nighttime. The reactions of O3 with alkenes lead to the production of OH radicals, often in high yield, and these reactions also lead to the formation of secondary organic aerosol. Products of the gas-phase reactions of O3 with cyclohexane and cyclohexene-d10 were studied in the presence of OH radical scavengers by gas. Cyclohexane and cyclohexene-d12 were used as OH radicals. In the cyclohexene reaction in the presence of sufficient cyclohexane to scavenge >95% of the OH radicals formed, 1.47 × 1014 molecule/cu cm of O3 consumed 1.62 × 1014 molecule/cu cm of cyclohexene, with a 3.5% yield of HC(O)OH which increased to 4.5% after 17 min. Addition of butanal to the reactant mixtures resulted in changes in the post-reaction API-MS spectra. Adipaldehyde could be formed from reaction of the thermalized Criegee intermediate (presumably the anti-intermediate) with water vapor. OH (or OD) radical formation yields were also measured from the reactions of O3 with propylene (40 ± 6%).
- Aschmann, Sara M.,Tuazon, Ernesto C.,Arey, Janet,Atkinson, Roger
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p. 2247 - 2255
(2007/10/03)
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- Polymer-supported tertiary amine in organic synthesis: A useful reagent in the conversion of alkenes to carbonyl compounds via the corresponding ozonides
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Polymer-supported tertiary amine 6 is useful to workup the ozonolytic reaction of alkenes. The corresponding carbonyl products can be isolated in excellent yields by simple filtration. For some substituted alkenes, carboxylic acids were formed as the major products and can be isolated from the polymeric resin by washing with 1M HCl followed by extraction with organic solvent. In all cases, simply washing with aqueous NaOH can regenerate the polymeric amine 6. The reactivity of the regenerated polymeric amine is as effective as that of the freshly prepared one.
- Hon, Yung-Son,Wu, Kun-Chan
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p. 493 - 498
(2007/10/03)
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- Catalytic aerobic oxidation of diols under photo-irradiation: Highly efficient synthesis of lactols
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Aerobic oxidation of 1, n- and 1,ω-diols with (ON)Ru(salen) 1 as the catalyst was found to give the corresponding lactols in almost quantitative yields. Furthermore, in the oxidation of 2,2-dimethylalkane-1,ω-diols, less sterically hindered ω-alcohols were found to be preferentially oxidized when (ON)Ru(salen) 6 was used as the catalyst. n-Decanol was preferentially oxidized in the presence of 2,2-dimethylpropanol also by using 6 as the catalyst.
- Miyata, Atsushi,Furukawa, Mizuki,Irie, Ryo,Katsuki, Tsutomu
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p. 3481 - 3484
(2007/10/03)
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- Method for hydrogenating carbonyl compounds
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A process for the catalytic hydrogenation of a carbonyl compound or of a mixture of two or more carbonyl compounds in the presence of a catalyst which comprises an inorganic support containing TiO2, and as active component copper or a mixture of copper and at least one of the metals selected from the group of zinc, aluminum, cerium, a noble metal and a group VIII metal, wherein the copper surface area does not exceed 10 m2/g.
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