- The kinetics of the reaction between cyclopentene and aqueous hydrogen peroxide under phase-transfer catalysis
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The kinetics of the reaction between cyclopentene and an aqueous solution of hydrogen peroxide under phase-transfer catalysis conditions has been studied. The activation energies of the successive stages of cyclopentene epoxidation to 1,2-epoxycyclopentane and the hydration of the resulting epoxide to 1,2-cyclopentanediol have been found, and the orders of the reactions with respect to the reactants have been determined. A mathematical model of the process that adequately describes the available experimental data in the entire range of reactant concentrations has been proposed.
- Meshechkina,Mel'Nik,Rybina,Srednev,Moskvichev, Yu. A.,Shevchuk
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Read Online
- Oxidative cleavage of cycloalkenes using hydrogen peroxide and a tungsten-based catalyst: Towards a complete mechanistic investigation
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The identification of the intermediates and by-products produced during the oxidative cleavage of cycloalkenes in the presence of H2O2 and a tungsten-based catalyst for the production of dicarboxylic acids has been carried out under various experimental conditions. On the basis of this mechanistic investigation and previous studies from the literature, a complete reaction scheme for the formation of the reaction products and by-products is proposed. In this hypothetical mechanism, the production of a hydroperoxyalcohol intermediate accounts for the two pathways proposed by Noyori and Venturello for the formation of the targeted dicarboxylic acid. In addition, Baeyer-Villiger oxidation of the mono-aldehyde intermediate allows explaining the formation of short chain diacids observed as by-products during the reaction. Hence, the proposed mechanism constitutes a real tool for scientists looking for a better understanding and those heading to set up environmentally friendly conditions for the oxidative cleavage of cycloalkenes.
- Cousin, Tony,Chatel, Gregory,Andrioletti, Bruno,Draye, Micheline
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p. 235 - 242
(2021/01/11)
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- Tandem Lewis acid catalysis for the conversion of alkenes to 1,2-diols in the confined space of bifunctional TiSn-Beta zeolite
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The generation of multifunctional isolated active sites in zeolite supports is an attractive method for integrating multistep sequential reactions into a single-pass tandem catalytic reaction. In this study, bifunctional TiSn-Beta zeolite was prepared by a simple and scalable post-synthesis approach, and it was utilized as an efficient heterogeneous catalyst for the tandem conversion of alkenes to 1,2-diols. The isolated Ti and Sn Lewis acid sites within the TiSn-Beta zeolite can efficiently integrate alkene epoxidation and epoxide hydration in tandem in a zeolite microreactor to achieve one-step conversion of alkenes to 1,2-diols with a high selectivity of >90%. Zeolite confinement effects result in high tandem rates of alkene epoxidation and epoxide hydration as well as high selectivity toward the desired product. Further, the novel method demonstrated herein can be employed to other tandem catalytic reactions for sustainable chemical production.
- Lei, Qifeng,Wang, Chang,Dai, Weili,Wu, Guangjun,Guan, Naijia,Hunger, Michael,Li, Landong
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p. 1176 - 1184
(2021/02/16)
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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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- 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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- Catalyst Systems Based on a Metal Halide and a Quaternary Ammonium Salt in the 1,2-Epoxycyclopentane Carboxylation Reaction
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Abstract: Results of a study of 1,2-epoxycyclopentane carboxylation to cyclopentene carbonate (CPC) in the presence of various catalyst systems have been described. It has been found that the reaction occurs most efficiently in the presence of cobalt (nickel) chloride (bromide) hydrate and a quaternary ammonium salt (TEAB, TBAB). It has been recommended that CPC should be synthesized under a CO2 pressure of no less than 3.5 MPa at a temperature of 140–150°С without any solvent or in the medium of a solvent, such as target CPC, DMF, or N-MP, at a 1,2-epoxycyclopentane weight fraction in the feed mixture of no less than 25%. These conditions provide the formation of CPC with a selectivity of 97–99% and almost complete epoxide conversion within 2–4 h. It has been shown that the developed catalyst system can be recycled.
- Taranenko, G. Yu.,Rybina,Srednev,Meshechkina,Tarasov
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- Method for synthesizing o-glycol compounds by virtue of bifunctional characteristic catalyst
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The invention belongs to the technical field of organic chemical synthesis and particularly relates to a method for synthesizing o-glycol compounds by virtue of a bifunctional characteristic catalyst.The o-glycol compounds are prepared from olefin and an oxidizing agent through reaction under the effect of the bifunctional characteristic catalyst, wherein the bifunctional characteristic catalystcontains the following components in percentage by mass: 25%-75% of a titanium silicalite molecular sieve, 20%-70% of nano-silicon dioxide and 5%-10% of heteropolyacid. The method provided by the invention has the beneficial effects that a process for synthesizing o-glycol by virtue of a traditional two-step method is simplified; the catalyst can still remain good catalytic performance under a long-period operation condition in the method, the raw material conversion rate is high, and the yields of the o-glycol compounds are high; and the olefin raw material conversion rate is 80.2%-94.6%, andthe selectivity of o-glycol generated through reaction is 85.7%-96.3%.
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Paragraph 0034-0035; 0036-0037; 0039-0045
(2018/04/26)
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- Method for synthesizing vicinal diol compound by virtue of one-step process
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The invention belongs to the technical field of organic chemical synthesis, and in particular relates to a method for synthesizing a vicinal diol compound by virtue of a one-step process. The vicinaldiol compound is obtained by carrying out reaction on olefin and an oxidizing agent in presence of a bifunctional catalyst, wherein the bifunctional catalyst comprises 25-75% of titanium silicalite molecular sieves, 20-70% of nano alumina and 3-8% of boric oxide in percentage by mass with the titanium silicalite molecular sieves, nano alumina and boric oxide as the benchmarks. The method for synthesizing the vicinal diol compound has the advantages that the traditional two-step vicinal diol synthesis technology is simplified; in the synthetic method, a catalyst still maintains good catalytic performance under long-period operation condition, raw material conversion rate is high, and yield of the vicinal diol compound is high; and olefin raw material conversion rate is 80.2-94.6%, and vicinal diol reaction generation selectivity is 85.7-96.3%.
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Paragraph 0032-0041
(2018/04/26)
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- Method for preparing vicinal diol compound through ring-opening reaction
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The present invention discloses a method for preparing a vicinal diol compound through a ring-opening reaction. The method takes a hydrocarbons epoxide as a raw material and takes an anion exchange resin as a catalyst. The vicinal diol compound is prepared by using a fixed bed continuous hydrolysis reaction technology. The anion exchange resin is a halogen-substituted macroporous polystyrene-divinyl benzene quaternary ammonium salt type anion exchange resin. The synthesis method is simple, the catalyst can be used many times, the raw material conversion rate is high, and the yield of the vicinal diol compound is high.
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Paragraph 0015; 0031; 0033; 0036
(2017/03/28)
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- Method of using anion exchange resin as catalyst to synthesize vicinal diol compound
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The invention discloses a method of using anion exchange resin as a catalyst to synthesize a vicinal diol compound. The method includes: using hydrocarbon epoxide as a raw material and the anion exchange resin as the catalyst; adopting a fixed bed continuous hydrolysis reaction process to obtain the vicinal diol compound, wherein the anion exchange resin is halogen substituted macroporous polystyrene-divinyl benzene quaternary ammonium salt type anion exchange resin. The method is simple, the catalyst can be utilized repeatedly, the raw material is high in conversion rate, and the vicinal diol compound is high in yield.
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Paragraph 0027; 0029; 0030; 0036
(2017/07/06)
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- Synthetic method for o-glycol compounds
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The invention discloses a synthetic method for o-glycol compounds. The method prepares the o-glycol compounds by using a fixed-bed continuous hydrolysis reaction process with hydrocarbon epoxides as raw materials and anion exchange resin as a catalyst, wherein the anion exchange resin is halogen-p-substituted macroporous polystyrene-divinyl benzene quaternary phosphonium salt anion exchange resin. The synthetic method is simple; the catalyst can be repeatedly used a plurality of times; the conversion rate of the raw materials is high; and the yield of the o-glycol compounds is high.
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Paragraph 0026-0027; 0029-0036
(2017/08/28)
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- Method for synthesizing ortho-diol compound by using macroporous anion exchange resin as catalyst
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The invention discloses a method for synthesizing an ortho-diol compound by using macroporous anion exchange resin as a catalyst. According to the method, hydrocarbon epoxide is used as a raw material, the anion exchange resin is used as the catalyst, and a fixed bed continuous hydrolysis reaction technology is adopted for preparing the ortho-diol compound; the anion exchange resin is halogen ortho-substituted macroporous polystyrene-divinyl benzene quaternary phosphonium salt type anion exchange resin. The synthesis method is simple, the catalyst can be used repeatedly, the conversion rate of the raw material is high, and the yield of the ortho-diol compound is high.
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Paragraph 0024; 0025; 0026; 0028; 0029; 0030-0035
(2017/05/27)
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- Method for synthesizing vicinal diol compound which takes hydrocarbon epoxide as raw material
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The present invention discloses a method for preparing a vicinal diol compound which takes a hydrocarbon epoxide as a raw material. The method takes the hydrocarbon epoxide as the raw material and takes an anion exchange resin as a catalyst. The vicinal diol compound is prepared by using a fixed bed continuous hydrolysis reaction technology. The anion exchange resin is a halogen-substituted macroporous polystyrene-divinyl benzene quaternary ammonium salt type anion exchange resin. The synthesis method is simple, the catalyst can be used many times, the raw material conversion rate is high, and the yield of the vicinal diol compound is high.
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Paragraph 0027-0028; 0032; 0037
(2017/08/03)
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- A 1,2-pentanediol preparation method
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The invention discloses a preparation method of 1,2-cyclopentanediol. The preparation method comprises the following steps: 1) oxidizing reaction, namely adding a certain amount of raw materials, namely cyclopentene, a catalyst, a cocatalyst and hydrogen peroxide to a reaction system, reacting at 35-45 DEG C for 4-6 hours, so as to obtain an oxidative product cyclopentene oxide of cyclopentene; 2) hydrolysis reaction, adding a certain amount of deionized water to the oxidative product cyclopentene oxide, carrying out hydrolysis reaction at 70-90 DEG C for 80-110 hours based on a solid proton acid as the catalyst; and 3) product separation, namely distilling the mixture obtained after hydrolysis reaction at reduced pressure to obtain the product 1,2-cyclopentanediol. According to the preparation method of the 1,2-cyclopentanediol, hydrogen peroxide is adopted as an oxidant; Fu-Cu main catalyst and KCl cocatalyst are adopted to catalyze; the oxidant is easily available and low in cost; the water generated by reaction does not pollute the environment; the catalyst is easily available, low in cost, small in toxicity, high in activity, and strong in stability; the product is high in yield; and the production process is simple and easy to operate.
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Paragraph 0020; 0021; 0023; 0024
(2017/02/09)
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- SPIROHYDANTOIN COMPOUNDS AND THEIR USE AS SELECTIVE ANDROGEN RECEPTOR MODULATORS
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The present invention relates to a compound of formula (1-1 ) in free form or in pharmaceutically acceptable salt form in which the substituents are as defined in the specification; to its preparation, to its use as a medicament and to medicaments comprising it. The present invention further provides a combination of pharmacologically active agents and a pharmaceutical composition.
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Page/Page column 56
(2013/09/12)
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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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p. 1744 - 1747
(2013/03/14)
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- Efficiency of phase-transfer catalysis in cyclopentene epoxidation with hydrogen peroxide
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The effect of the structure and amount of the phase-transfer catalyst (quaternary ammonium salts) and the solvent effect on cyclopentene oxidation with an aqueous hydrogen peroxide solution in the liquid-liquid two-phase system was studied. The phase-tran
- Meshechkina,Mel'Nik,Rybina,Srednev,Shevchuk
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scheme or table
p. 661 - 665
(2012/08/08)
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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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p. 1191 - 1198
(2016/04/10)
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- Mild organic ammonium tribromide-mediated regioselective ring opening of epoxides with alcohols, water, acetic anhydride, and amines under solvent-free reaction conditions
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Organic ammonium tribromide (OATB), N-methylpyrrolidine-2-one hydrotribromide (MPHT) was found to be an efficient catalyst for the regioselective ring opening of epoxides with various nucleophiles under solvent free conditions. This procedure occurs under neutral and mild reaction conditions with out adding any additive and afforded high yields of products.
- Singhal, Sweety,Jain, Suman L.,Sain, Bir
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experimental part
p. 1829 - 1837
(2011/06/19)
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- Novel polymer-supported ruthenium and iron complexes that catalyze the conversion of epoxides into diols or diol mono-ethers: Clean and recyclable catalysts
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Polymer-supported metal (Fe or Ru) complexes for epoxide ring opening reactions were successfully prepared by anchoring the bis(2-picolyl)amine ligand onto the polymer poly(chloromethylstyrene-co-divinylbenzene) (PCD); the catalysts showed heterogeneous catalytic activity and easy recyclability in the ring opening reactions of various epoxide substrates with methanol or H 2O at room temperature under mild and neutral conditions. The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.
- Lee, Sun Hwa,Lee, Eun Yong,Yoo, Dong-Woo,Hong, Sung Jin,Lee, Jung Hwan,Kwak, Han,Lee, Young Min,Kim, Jinheung,Kim, Cheal,Lee, Jin-Kyu
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p. 1579 - 1582
(2008/03/14)
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- Catalytic asymmetric dihydroxylation of olefins using polysulfone-based novel microencapsulated osmium tetroxide
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A polysulfone based novel polymer-supported osmium catalyst has been developed. The catalyst was prepared from commercially available polysulfone, based on a microencapsulation technique and was employed in the asymmetric dihydroxylation of various olefins using (DHQD)2PHAL as the chiral ligand and NMO as the co-oxidant in H2O-acetone-CH3CN (1:1:1). The catalyst was recovered by simple filtration and was reused to obtain excellent yields with good enantioselectivity up to five times.
- Malla Reddy,Srinivasulu,Venkat Reddy,Narasimhulu,Venkateswarlu
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p. 5285 - 5288
(2007/10/03)
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- Reaction-controlled phase-transfer catalytic oxidative cleavage of cyclopentene to glutaraldehyde over peroxy-niobic acid
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The oxidative cleavage of cyclopentene to glutaraldehyde with aqueous H2O2 was performed over a peroxy-niobic acid catalyst with high yield (72%) and complete conversion of cyclopentene under mild reaction conditions. Peroxy-niobic acid has been shown as a "reaction-controlled phase-transfer" catalyst, which has the advantages of both homogeneous and heterogeneous catalysts.
- Chen, Hao,Dai, Wei-Lin,Jiang, An-Ren,Deng, Jing-Fa
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p. 220 - 221
(2007/10/03)
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- DERMATOLOGICAL COMPOSITIONS AND METHODS
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Disclosed are methods and compositions for regulating the melanin content of mammalian melanocytes; regulating pigmentation in mammalian skin, hair, wool or fur; treating or preventing various skin and proliferative disorders; by administration of various compounds, including alcohols, diols and/or triols and their analogues.
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- Treatment of neurodegenerative diseases
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Disclosed are methods for increasing the differentiation of mammalian neuronal cells for purposes of treating neurodegenerative diseases or nerve damage by administration of various compounds including alcohols, diols and/or triols and their analogues.
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- Treatment of diseases mediated by the nitric oxide/cGMP/protein kinase G pathway
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Disclosed are methods and compositions for stimulating cellular nitric oxide (NO) synthesis, cyclic guanosine monophosphate levels (cGMP), and protein kinase G (PKG) activity for purposes of treating diseases mediated by deficiencies in the NO/cGMP/PKG signal transduction pathway, by administration of various compounds including alcohols, diols and/or triols and their analogues.
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- Kinetics and mechanism of the catalytic oxidation of cyclopentene to glutaraldehyde with aqueous hydrogen peroxide
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Kinetics and mechanism of the catalytic oxidation of cyclopentene to glutaraldehyde by aqueous hydrogen peroxide have been studied. In tungstic acid-t-butanol system, cyclopentene is first oxidized to cyclopentene oxide almost quantitatively, which is then transferred into an intermediate. The intermediate, which is separated and identified as β-hydroxycyclopentylhydroperoxide, can easily change into glutaraldehyde during purification. The study shows that during the formation of the intermediate two by-products are also formed. These three reactions are found to be of first-order parallel reactions. The effects of temperature and concentration of tungstic acid, hydrogen peroxide, water and t-butanol on the reaction rates have been studied. A suitable mechanism for the reaction has been proposed.
- Dai, Weilin,Huang, Xiaojun,Chen, Haiying,Deng, Jingfa
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p. 583 - 589
(2007/10/03)
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- Addition of Acyl and Sulfonyl Hypohalites Generated from N-Halogeno Amides to Alkenes: Synthesis of trans-vic-Halogeno Esters and their Conversion to cis-1,2-Diols
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N-Iodo- and N-bromo-p-nitrobenzamide have been shown to react with various organic acids to form the respective acyl or sulfonyl hypoiodites or hypobromites.These readily add to double bonds under mild conditions to yield trans-vic-halogeno esters.The ste
- Goosen, Andre,Hoffman, Eric,Taljaard, Benjamin
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- A new process for preparing dialdehydes by catalytic oxidation of cyclic olefins with aqueous hydrogen peroxide
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Dialdehydes were prepared by the reaction between cyclic olefins and aqueous hydrogen peroxide catalyzed by tungstic acid. Glutaraldehyde and adipaldehyde were synthesized by this method with good yield. Several different conditions were tested.
- Deng,Xu,Chen,Jiang
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p. 3503 - 3514
(2007/10/02)
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- Permanganate Ion Oxidations. 19. Hexadecyltrimethylammonium Permanganate Oxidation of Cycloalkenes
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The kinetics of hexadecyltrimethylammonium permanganate (cetyltrimethylammonium permanganate, CTAP) oxidation of cycloalkenes in dichloromethane have been studied.The relative rates of oxidation versus 13C NMR chemical shifts, vertical ionization potentials, and strain energies are discussed.A comparison of the relative rate of permanganate ion oxidation with the relative rates of addition of other reagents to carbon-carbon double bonds suggests that it may act as a 1,3-dipole.
- Freeman, Fillmore,Kappos, John C.
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p. 2730 - 2734
(2007/10/02)
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- Oxidative Cleavage of Olefins into Carboxylic Acids with Hydrogen Peroxide by Tungstic Acid
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A facile conversion of olefins into carboxylic acids could be achieved by using aqueous hydrogen peroxide (35percent-H2O2) in the presence of catalytic amounts of tungstic acid (5 wtpercent).The oxidation was markedly influenced by the acidity of the reaction medium, and it was found to proceed favorably under a weak acidic condition (pH 4-5).
- Oguchi, Takahito,Ura, Toshikazu,Ishii, Yasutaka,Ogawa, Masaya
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p. 857 - 860
(2007/10/02)
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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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p. 877 - 880
(2007/10/02)
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- Hydroboration. 57. Hydroboration with 9-Borabicyclononane of Alkenes Containing Representative Functional Groups
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The hydroboration of alkenes containing representative functional groups was examined with 9-borabicyclononane (9-BBN) in order to extend the hydroboration reaction for the preparation of functionally substituted organoboranes.Terminal alkenes containing a remote functional group are hydroborated with a remarkable regioselectivity (>=98percent terminal), producing the corresponding stable organoboranes. 9-BBN hydroborates the allylic derivatives so as to place boron essentially on the terminal carbon atom (>=97percent).The directive effect is further enhanced (>=99percent) in the case of β-methylallyl derivatives.The hydroboration of crotyl derivatives attaches boron predominantly at the 2-position, followed by an elimination-rehydroboration sequence.However, crotyl alcohol can be protected against elimination as the tert-butyl or tetrahydropyranyl ethers.The hydroboration-oxidation of ethyl crotonate involves a series of elimination, hydroboration, and condensation processes.In the vinyl, crotyl, and isobutenyl systems, the mesomeric effect of the substituent favors the placement of boron at the β-position, while the inductive effect favors the α-position, with the former effect predominating in most cases.Acyclic β-substituted organoboranes undergo rapid elimination.Nonpolar solvents and lower reaction temperatures decrease the rate of elimination.However, those derived from cyclic vinyl derivatives are relatively stable under neutral conditions, undergoing facile elimination in the presence of a base.
- Brown, Herbert C.,Chen, Jackson C.
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p. 3978 - 3988
(2007/10/02)
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