- Oxidized caesium/nanoporous carbon materials: Solid-base catalysts with highly-dispersed active sites
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By vapor depositing Cs metal on nanoporous carbon materials and then oxidizing, a solid-base catalyst is produced that is quite active for the aldol condensation of acetone to isophorone.
- Stevens, Mark G.,Chen, Denise,Foley, Henry C.
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Read Online
- Rapid, chemoselective and mild oxidation protocol for alcohols and ethers with recyclable N-chloro-N-(phenylsulfonyl)benzenesulfonamide
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Chlorine is the 20th most abundant element on the earth compared to bromine, iodine, and fluorine, a sulfonimide reagent, N-chloro-N-(phenylsulfonyl)benzenesulfonamide (NCBSI) was identified as a mild and selective oxidant. Without activation, the reagent was proved to oxidize primary and secondary alcohols as well as their symmetrical and mixed ethers to corresponding aldehydes and ketones. With recoverable PS-TEMPO catalyst, selective oxidation over chlorination of primary and secondary alcohols and their ethers with electron-donating substituents was achieved. The reagent precursor of NCBSI was recovered quantitatively and can be reused for synthesizing NCBSI.
- Badani, Purav,Chaturbhuj, Ganesh,Ganwir, Prerna,Misal, Balu,Palav, Amey
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supporting information
(2021/06/03)
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- Zwitterion-induced organic-metal hybrid catalysis in aerobic oxidation
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In many metal catalyses, the traditional strategy of removing chloride ions is to add silver salts via anion exchange to obtain highly active catalysts. Herein, we reported an alternative strategy of removing chloride anions from ruthenium trichloride using an organic [P+-N-] zwitterionic compound via multiple hydrogen bond interactions. The resultant organic-metal hybrid catalytic system has successfully been applied to the aerobic oxidation of alcohols, tetrahydroquinolines, and indolines under mild conditions. The performance of zwitterion is far superior to that of many other common Lewis bases or Br?nsted bases. Mechanistic studies revealed that the zwitterion triggers the dissociation of chloride from ruthenium trichloride via nonclassical hydrogen bond interaction. Preliminary studies show that the zwitterion is applicable to catalytic transfer semi-hydrogenation.
- Hu, Rong-Bin,Lam, Ying-Pong,Ng, Wing-Hin,Wong, Chun-Yuen,Yeung, Ying-Yeung
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p. 3498 - 3506
(2021/04/07)
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- Aldol Condensation Versus Superbase-Catalyzed Addition of Ketones to Acetylenes: A Quantum-Chemical and Experimental Study
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The mechanism of aldol condensation of ketones in KOH/DMSO superbasic media has been investigated using the B2PLYP(D2)/6-311+G**//B3LYP/6-31+G? quantum-chemical approach. It is found that the interaction of three ketone molecules resulting in the formation of the cyclohex-2-enone structure [isophorone or 3,5-dicyclohexyl-5-methylspiro(5.5)undec-2-en-1-one] is thermodynamically more favorable than the interaction of two, three, or four molecules of ketone, resulting in the formation of linear products of the condensation. The formation of the condensation products with the isophorone skeleton can significantly hinder the cascade reactions of ketones with acetylenes [to afford 6,8-dioxabicyclo(3.2.1)octanes or acylcyclopentenols] promoted by superbases. In particular, the kinetically more preferable reactions of autovinylation of 2-methyl-3-butyn-2-ol and autocondensation of acetone are the reasons why interaction of acetone with acetylene does not lead to the products of the cascade assemblies. The predominant formation of the products of these side reactions is confirmed experimentally.
- Orel, Vladimir B.,Vitkovskaya, Nadezhda M.,Bobkov, Alexander S.,Semenova, Nadezhda V.,Schmidt, Elena Yu.,Trofimov, Boris A.
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p. 7439 - 7449
(2021/06/21)
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- Base-free oxidation of alcohols enabled by nickel(ii)-catalyzed transfer dehydrogenation
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An efficient nickel(ii)-catalyzed transfer dehydrogenation oxidation of alcohols is reported that relies on cyclohexanone as the formal oxidant and does not require the use of an external base. The synthetic utility of this protocol is demonstratedviathe facile oxidation of structurally complicated natural products.
- Ye, Danfeng,Liu, Zhiyuan,Sessler, Jonathan L.,Lei, Chuanhu
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supporting information
p. 11811 - 11814
(2020/10/13)
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- Nickel-catalyzed deoxygenation of oxiranes: Conversion of epoxides to alkenes
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Deoxygenation of epoxides takes place under the catalysis of nickel in the presence of diethylzinc as a deoxygenation agent to yield alkenes. Epoxides with a wide variety of substitution patterns are deoxygenated in this catalytic system to give terminal, 1,1-disubstituted, 1,2-disubstituted, trisubstituted, and tetrasubstituted alkenes in high yields. Reactions of 1,2-disubstituted epoxides we examined proceeded in an E-stereoselective manner. High compatibility with other functional groups through this transformation was also observed.
- Mori, Takamichi,Takeuchi, Yoshihito,Hojo, Makoto
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supporting information
(2020/01/24)
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- Method for preparing triacetone amine
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An improved method is used for preparing triacetone amine while recycling the by-products. This involves treating the crude product from triacetone amine preparation, which leads to an increase in the content of compounds which react readily with ammonia. This method enables efficient recycling of the by-products formed in the synthesis of triacetone amine.
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Paragraph 0133-0144
(2020/07/05)
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- Transfer-dehydrogenation of secondary alcohols catalyzed by manganese NNN-pincer complexes
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Novel catalytic systems based on pentacarbonylmanganese bromide and stable NNN-pincer ligands are presented for the transfer-dehydrogenation of secondary alcohols to give the corresponding ketones in good to excellent isolated yields. Best results are obtained using di-picolylamine derivatives as ligands and acetone as an inexpensive hydrogen acceptor. Besides high activity for benzylic substrates, aliphatic alcohols, as well as steroid derivatives, are readily oxidized in the presence of the optimal phosphorus-free catalyst.
- Budweg, Svenja,Junge, Kathrin,Beller, Matthias
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supporting information
p. 14143 - 14146
(2019/12/02)
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- Iron–PNP-Pincer-Catalyzed Transfer Dehydrogenation of Secondary Alcohols
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The well-defined iron PNP pincer complex catalyst [Fe(H)(BH4)(CO)(HN{CH2CH2P(iPr)2}2] was used for the catalytic dehydrogenation of secondary alcohols to give the corresponding ketones. Using acetone as inexpensive hydrogen acceptor enables the oxidation with good to excellent yields. DFT computations indicate an outer-sphere mechanism and support the importance of an acceptor to achieve this transformation under milder conditions.
- Budweg, Svenja,Wei, Zhihong,Jiao, Haijun,Junge, Kathrin,Beller, Matthias
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- Copper(II)-Catalyzed Tandem Decarboxylative Michael/Aldol Reactions Leading to the Formation of Functionalized Cyclohexenones
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This work describes the development of a new single-pot copper(II)-catalyzed decarboxylative Michael reaction between β-keto acids and enones, followed by in situ aldolization, which results in highly functionalized chiral and achiral cyclohexenones. The achiral version of this Robinson annulation features a hitherto unprecedented Michael reaction of β-keto acids with sterically hindered β,β′-substituted enones and provides access to all carbon quaternary stereocenter-containing cyclohexenones (11 examples, 43-83% yield). In addition, an asymmetric chiral bis(oxazoline) copper(II)-catalyzed single-pot Robinson annulation has been devised for preparing chiral cyclohexenones, including some products that contain vicinal stereocenters (5 examples, 65-85% yield, 84-94% ee). This latter protocol has been successfully applied to the enantioselective formation of the oxygenated 10-nor-steroid core from readily available starting materials.
- Lee, Jeonghyo,Wang, Sibin,Callahan, Miranda,Nagorny, Pavel
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supporting information
p. 2067 - 2070
(2018/04/16)
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- CATALYTIC OXIDATION OF 3,5,5-TRIMETHYLCYCLOHEXA-3-ENE-1-ONE (?-ISOPHORONE) WITH HYDROGEN PEROXIDE TO AFFORD 2,6,6-TRIMETHYL-2-CYCLOHEXENE-1,4-DIONE (KETO-ISOPHORONE)
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The present invention provides a novel process for producing 2,6,6-trimethyl-2-cyclohexene-1,4-dione (keto-isophorone) by catalytic oxidation of 3,5,5-trimethylcyclohexa-3-ene-1-one (β-isophorone) with hydrogen peroxide as the oxidant. In particular, the novel process includes phase transfer reagent in a biphasic system including an organic phase and an aqueous phase wherein the biphasic system includes 1) a tungsten polyoxyometallate as catalyst and hydrogen peroxide, and/or 2) a mixture of a) a mineral acid, b) hydrogen peroxide, and c) a metal tungstate.
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Page/Page column 0059-0060; 0061-0063; 0064-0066; 0067-0068
(2018/06/15)
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- A preparation method of the isophorone (by machine translation)
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The invention discloses a method for preparing organic catalytic isophorone, to acetone as the starting material, the catalyst organic imidazole system under the catalytic action of quaternary ammonium alkali, acetone generating liquid phase condensation reaction, after distillation of the isophorone. Specifically comprises organic imidazole series quaternary ammonium and alkali and synthesis of synthesis of the isophorone. Organic imidazole series quaternary ammonium strong alkali can be soluble in the reaction medium and as a starting material in the acetone, the reaction can be carried out smoothly. The invention provides a preparation method of the isophorone, synthesizing isophorone, organic catalytic synthesis process, one-way conversion rate is more than 60%, selectivity is greater than 70%. The invention of the preparation method of the isophorone with technology is novel, few steps, mild reaction conditions and the like. (by machine translation)
- -
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Paragraph 0019; 0020-0023
(2017/07/22)
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- Preparation method of isophorone
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The invention discloses a preparation method of organic catalytic isophorone. According to the invention, acetone is used as a starting material. Under the catalytic action of a catalyst organic urotropine quaternary ammonium strong base, acetone is subjected to a liquid-phase condensation reaction; and after distillation, isophorone is obtained. The preparation method specifically contains steps of synthesis of the organic urotropine quaternary ammonium strong base and synthesis of isophorone. The organic urotropine quaternary ammonium strong base can be dissolved in acetone which is used as the reaction medium and starting material to make the reaction to be smoothly carried out. The isophorone preparation method is adopted for synthesis of isophorone. By organic catalytic synthesis, conversion per pass is greater than 50% and selectivity is greater than 60%. The preparation method of isophorone has characteristics of novel technology, less step, mild reaction condition, etc.
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Paragraph 0017-0023
(2017/08/30)
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- Preparation method of isophorone
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The invention discloses a preparation method of organocatalysis isophorone. The preparation method comprises the following steps: taking acetone as an initial raw material, carrying a liquid-phase condensation reaction with the acetone under the catalytic action of catalyst organic pyridine quaternary ammonium strong alkali, and thus obtaining the isophorone through distillation. The preparation method specifically comprises synthesis of the catalyst organic pyridine quaternary ammonium strong alkali and synthesis of the isophorone. The organic pyridine quaternary ammonium strong alkali can be dissolved in the acetone serving as a reaction medium and the initial raw material, so that the reaction can be carried out successfully. By adopting the preparation method of the isophorone provided by the invention, the isophorone is synthesized, the technology adopts organocatalysis synthesis, the conversion per pass is greater than 50%, the selectively is greater than 60%, and the once through yield is greater than 30% The preparation method of the isophorone disclosed by the invention has the characteristics of novel technology, few steps, mild reaction conditions and the like.
- -
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Paragraph 0019; 0021; 0023
(2017/07/21)
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- Visible-light-driven photooxidation of alcohols using surface-doped graphitic carbon nitride
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Carbon-nanodot-doped g-C3N4 is used as a photocatalyst to promote the aerobic oxidation of alcohols and oxyfunctionalisation of activated hydrocarbons. A critical E-factor analysis of the current reaction system reveals its limitations en route to environmentally acceptable oxidation procedures.
- Zhang, Wuyuan,Bariotaki, Anna,Smonou, Ioulia,Hollmann, Frank
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supporting information
p. 2096 - 2100
(2017/07/24)
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- Selective Oxidation of Activated Alcohols by Supported Gold Nanoparticles under an Atmospheric Pressure of O2: Batch and Continuous-Flow Studies
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In the hunt for a simple, mild, and scalable protocol for gold nanoparticle-catalyzed oxidation of benzylic and allylic alcohols under O2, we have used commercially available gold nanoparticles supported on alumina to selectively oxidize a large range of activated alcohols to the corresponding carbonyl compounds in good yields (68–99 %) and with excellent selectivity (ca. 100 %). The true heterogeneous nature of the catalysis by gold was demonstrated, allowing us to further adapt this protocol to continuous-flow reactors by using the tube-in-tube technology, in which higher yields were obtained thanks to an improved oxygenation of the reaction medium.
- Giorgi, Pascal D.,Elizarov, Nelli,Antoniotti, Sylvain
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p. 1830 - 1836
(2017/05/29)
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- Selective Photooxidation Reactions using Water-Soluble Anthraquinone Photocatalysts
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The aerobic organocatalytic oxidation of alcohols was achieved by using water-soluble sodium anthraquinone sulfonate. Under visible-light activation, this catalyst mediated the aerobic oxidation of alcohols to aldehydes and ketones. The photo-oxyfunctionalization of alkanes was also possible under these conditions.
- Zhang, Wuyuan,Gacs, Jen?,Arends, Isabel W. C. E.,Hollmann, Frank
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p. 3821 - 3826
(2017/09/13)
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- Acetone condensation over CaO—SnO2 catalyst
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Aldol condensation of acetone was studied over solid base CaO—SnO2 catalyst in the 300—450 °C temperature range and at 15—75 atm pressure in a fixed-bed reactor. The main products are mesityl oxide and isophorone. The high stability of CaO—SnO2 catalyst performance was observed at pressure of 75 atm giving the acetone conversion of 36—41%. Increase in the temperature and pressure led to a simultaneous raise in acetone conversion. The maximum conversion of 41% was achieved at 400 °C, 75 atm and a flow rate of acetone of 8.1 g h–1 (g catalyst)–1.
- Koklin,Hasyanova,Glukhov,Bogdan
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p. 488 - 490
(2017/09/15)
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- Mesoporous MgO: Synthesis, physico-chemical, and catalytic properties
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Mesoporous MgO was obtained via the hydrothermal synthesis using both ionogenic and non-ionogenic surfactants as structure-directing templates. The materials prepared were characterized by SEM, BET-N2, XRD, and TG-DTA techniques. MgO particles are spherical 20-μm aggregates of primary oxide particles well shaped as rectangular parallelepipeds. Magnesium oxide samples have the specific surface area of 290–400 m2/g and pore sizes of 3.3–4.1 nm. Their mesoporous structure remained unchanged after calcination up to 350°C. Catalytic activity of mesoporous MgO was studied in acetone condensation reaction.
- Maerle,Kasyanov,Moskovskaya,Romanovsky
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p. 1212 - 1216
(2016/06/13)
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- L-Proline and thiourea co-catalyzed condensation of acetone
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Amino acid and primary amine/amide co-catalyzed acetone condensation was investigated. It was found that L-proline had overwhelming catalytic activity over other amino acids as well as the analogues with similar structures. Surprisingly, thiourea, a very cheap and stable chemical, was found to be the favorable co-catalyst. Co-catalyzed by the recyclable L-proline and thiourea, condensation of acetone led to the useful products mesityl oxide (MO), diacetone alcohol (DAA) and isophorone (IP) in the excellent 96.3% total selectivity.
- Xu, Lin,Wang, Fang,Huang, Jiejun,Yang, Chenggen,Yu, Lei,Fan, Yining
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p. 4076 - 4080
(2016/07/06)
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- HYDROLYSIS OF THE RESIDUES OBTAINED IN THE PRODUCTION OF ISOPHORONE TO RECOVER ISOPHORONE AND ACETONE
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A process for preparing isophorone (3,5,5-trimethyl-2-cyclohexen-1-one) is provided wherein distillation vapors from the work-up of product fractions are recycled to earlier stages of operation of the process.
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Paragraph 0033
(2015/02/25)
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- Radical titanocene promoted coupling of epoxides and vinyl sulfones
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A radical coupling reaction of diverse vinyl sulfones and epoxides was mediated by Cp2TiCl (Cp = cyclopentadienyl) to provide a straightforward synthetic pathway to hydroxy sulfones. The reaction was successfully achieved by using either an excess or a catalytic amount of the TiIII reagent. The scope of the reaction was studied for several different functionalized and substituted epoxides and vinyl sulfones.
- Fernndez-Mateos, Alfonso,Encinas-Madrazo, Soledad,Herrero-Teijn, Pablo,Gonzlez, Rosa Rubio
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p. 548 - 555
(2015/01/30)
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- Design and application of the recyclable poly(l-proline-co-piperidine) catalyst for the synthesis of mesityl oxide from acetone
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Unexpectedly, l-proline/piperidine was found to be a better recyclable catalyst system than l-proline or piperidine alone in the condensation of acetone to prepare mesityl oxide (MO), an important intermediate in the chemical industry. Binding the catalyst system onto polymer resin enhanced the MO selectivity and reduced the catalyst loss. The mechanism of the bi-component catalyst system was also studied through control reactions, as well as by dynamic calculations. The MO selectivity could reach 74.4% and its isolated yield could reach 73.9%, based on the consumed acetone. Although the result does not immediately meet the requirement of industrial production, this study provides a novel organocatalyst system, which might offer a potential alternative to traditional inorganic catalysts that can be used under mild and neutral conditions.
- Xu, Lin,Huang, Jiejun,Liu, Yubing,Wang, Yining,Xu, Bolian,Ding, Kehong,Ding, Yuanhua,Xu, Qing,Yu, Lei,Fan, Yining
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p. 42178 - 42185
(2015/05/27)
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- A new peroxo-route for the synthesis of Mg-Zr mixed oxides catalysts: Application in the gas phase acetone self-condensation
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We propose in this manuscript a new peroxo-mediated procedure for preparing magnesia-zirconia mixed oxides, with Mg/Zr molar ratio between 1 and 3, with enhanced distribution of basic sites. The mixed magnesia-zirconia oxides have been prepared from the gelled complex by Pechini-type method. The MgO-ZrO 2 materials have been characterized and used as catalysts for acetone aldol condensation. The proposed preparation method provides a high degree of molecular homogeneity and favours the formation of magnesia-stabilized zirconia phase. Acetone gas-phase self-condensation was carried out over these catalysts as model reaction requiring the presence of basic sites. The condensation yields diacetone alcohol and mesityl oxide as mean C6 products, and phorones, isophorones and mesitylene as C9 products. In comparison to Mg-Zr oxide prepared by co-precipitation, these new materials present better conversions and higher selectivity to linear dimers and trimers (as mesitylene), whereas the selectivity for isophorones is significantly lower.
- Krivtsov, Igor,Faba, Laura,Díaz, Eva,Ordó?ez, Salvador,Avdin, Viacheslav,Khainakov, Sergei,Garcia, Jose R.
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- Chitosan-based Schiff base-metal complexes (Mn, Cu, Co) as heterogeneous, new catalysts for the β-isophorone oxidation
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A new chitosan-based Schiff base was prepared and complexed with manganese, cobalt and copper. These Schiff base metal complexes were used as heterogeneous catalysts for the air oxidation of β-isophorone to ketoisophorone. The obtained complexes were characterized by means of FT-IR,1HNMR spectroscopy, elemental analysis, powder X-ray diffraction, field emission gun scanning electron microscopy, electron spin resonance spectroscopy, ICP-AES and solubility tests. Thermal properties were also investigated using thermal gravimetric analysis. Data obtained by thermal analysis revealed that these complexes showed good thermal stability. The conversion and selectivity of β-isophorone to ketoisophorone for each prepared catalyst was studied using a batch reactor and gas chromatography for product identification and quantification. The results were compared against the homogeneous bis-salicylaldehyde ethylenedi-imine-Mn catalyst. The use of methanol, acetone, methyl isobutyl ketone and n-hexane as solvent and its effect on conversion and selectivity was also investigated. Acetone was found to be a promising solvent for the β-isophorone oxidation. The role of triethyl amine and acetyl acetone in the oxidation reaction has also been investigated.
- Thatte,Rathnam,Pise
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p. 727 - 737
(2014/07/07)
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- Solar photochemical oxidations of benzylic and allylic alcohols using catalytic organo-oxidation with DDQ: Application to lignin models
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Visible light has a dramatic effect on the oxidation of benzylic and allylic alcohols, including those deactivated by electron-withdrawing groups, and β-O-4 lignin models, using catalytic amounts of the organo-oxidant 2,3-dichloro-5,6-dicyano-1,4-benzoquinone. Sodium nitrite or tert-butyl nitrite is used as cocatalyst, and oxygen is employed as the terminal oxidant.
- Walsh, Katie,Sneddon, Helen F.,Moody, Christopher J.
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supporting information
p. 5224 - 5227
(2014/12/11)
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- Solar photochemical oxidation of alcohols using catalytic hydroquinone and copper nanoparticles under oxygen: Oxidative cleavage of lignin models
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Alcohols are converted into to their corresponding carbonyl compounds using catalytic amounts of 1,4-hydroquinone with a copper nanoparticle electron transfer mediator with oxygen as the terminal oxidant in acetone as solvent under visible light irradiation. These conditions employing biorenewable hydroquinone as reagent were developed from initial experiments using stoichiometric amounts of 1,4-benzoquinone as oxidant. A range of benzylic and aliphatic primary and secondary alcohols are oxidized, affording the corresponding aldehydes or ketones in moderate to excellent yields. The methodology is also applicable to the oxidative degradation of lignin model compounds that undergo C-C bond cleavage to give simple aromatic compounds.
- Mitchell, Lorna J.,Moody, Christopher J.
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p. 11091 - 11100
(2015/01/08)
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- Unexpected oxidation of β-isophorone with molecular oxygen promoted by TEMPO
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A novel and efficient protocol for the oxidation of β-isophorone (β-IP) using molecular oxygen without any additives catalyzed by 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) has been established. The generally accepted catalytic mechanism of alcohols by the oxoammonium cation (TEMPO+) derived from TEMPO indeed fails to explain our experimental observations, because a favorable radical-based process is confirmed by electron spin resonance measurements. Our results show that a plateau of the time-dependence curve is observed in the oxidation of β-IP with TEMPO at low temperature, which is quite different from that of N-hydroxyphthalimide (NHPI). The proposed mechanism of this catalytic process is also compared with that of NHPI. The theoretically characterized reaction pathways show that unlike the phthalimide N-oxyl radical, TEMPO promotes the oxidation via its interaction with the active intermediate hydroperoxide (ROOH) rather than its initial interaction with β-IP, and byproduct water also assists the α-H atom transfer from ROOH to TEMPO. In addition to the intensive oxidation of alcohols catalyzed by TEMPO, the present study widens its specific applications in the active C-H bonds of hydrocarbons, and also provides new insights into its promoted metal-free oxidation. This journal is the Partner Organisations 2014.
- Jia, Lu,Chen, Kexian,Wang, Congmin,Yao, Jia,Chen, Zhirong,Li, Haoran
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p. 15590 - 15596
(2014/05/06)
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- Photocatalytic degradation of water taste and odour compounds in the presence of polyoxometalates and TiO2: Intermediates and degradation pathways
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Geosmin (GSM) and 2-methylisoborneol (MIB) are produced by several species of cyanobacteria and actinomycetes. These compounds can taint water and fish causing undesirable taste and odours. Studies have shown that GSM/MIB are resistant in standard water treatments. Polyoxometalates (POM) are efficient photocatalysts in the degradation and mineralization of a great variety of organic pollutants, presenting similar behaviour with the widely published titanium dioxide (TiO2). Photocatalytic degradation of GSM and MIB under UV-A light in the presence of a characteristic POM photocatalyst, SiW 12O404-, in aqueous solution has been studied and compared with the photodegradation by TiO2 suspensions. GSM and MIB are effectively degraded in the presence of both photocatalysts. Addition of OH radical scavengers (KBr and tertiary butyl alcohol, TBA) retards the photodegradation rates of both compounds, suggesting that photodegradation mechanism takes place via OH radicals. Intermediates identified using GC-MS in the case of GSM and MIB, are mainly identical in the presence of both photocatalysts, also suggesting a common reaction mechanism. Possible photocatalytic degradation pathway for both GSM and MIB is proposed.
- Fotiou, Theodora,Triantis, Theodoros M.,Kaloudis, Triantafyllos,Papaconstantinou, Elias,Hiskia, Anastasia
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- Acetone condensation over sulfated zirconia catalysts
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The aldol condensation reaction over sulfated zirconia led to the production of diacetone alcohol, which was further dehydrated forming mesityl oxide. The sulfated zirconia was obtained from zirconium acetate ethane sulfonate as a single source precursor. Oxides were obtained by calcinations of the precursors at 550-650 C, while the self-condensation reaction of acetone was carried out at 150 C. The precursor and the produced oxides were characterized using various characterization techniques. The precursors were synthesized with different acetate to ethane sulfonate ratio, ranging from 1 to 3. The major products obtained from the condensation reaction over the resulted oxide were mesityl oxide, mesitylene isophorone, naphthalene, and pentamers. The selectivity of mesityl oxide was approximately 100 % at the initial time-on-stream.
- Al-Hazmi, Mohammed H.,Choi, Yongman,Apblett, Allen W.
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p. 705 - 716
(2013/07/26)
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- Selective aerobic oxidation of allylic and benzylic alcohols catalyzed by N-hydroxyindole and copper(I) chloride
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In the presence of copper(I) chloride, tert-butyl 1-hydroxy-2-methyl-6- trifluoromethyl-1H-indole-3-carboxylate acted as a catalyst for the chemoselective aerobic oxidation of allylic and benzylic alcohols. A variety of primary and secondary allylic and benzylic alcohols were oxidized into the corresponding α,β-unsaturated carbonyl compounds in good yields without affecting non-allylic alcohols.
- Shen, Shu-Su,Kartika, Vita,Tan, Ying Shan,Webster, Richard D.,Narasaka, Koichi
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experimental part
p. 986 - 990
(2012/03/12)
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- Pincer and diamine Ru and Os diphosphane complexes as efficient catalysts for the dehydrogenation of alcohols to ketones
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The ruthenium and osmium complexes [MCl2(diphosphane)(L)] (M=Ru, Os; L=bidentate amino ligand) and [MCl(CNN)(dppb)] (CNN=pincer ligand; dppb=1,4-bis- (diphenylphosphino)butane), containing the N-H moiety, have been found to catalyze the acceptorless dehydrogenation of alcohols in tBuOH and in the presence of KOtBu. The compounds trans-[MCl2(dppf)(en)] (M=Ru 7, Os 13; dppf=1,1′-bis(diphenylphosphino)ferrocene; en=ethylenediamine) display very high activity and different substrates, including cyclic and linear alcohols, are efficiently oxidized to ketones by using 0.8-0.04mol% of catalyst. The effect of the base and the comparison of the catalytic activity of the Ru versus Os complexes are reported. The ruthenium complex 7 generally leads to a faster conversion into ketones with respect to the osmium complex 13, which displays better activity in the dehydrogenation of 5-en-3β-hydroxy steroids. The synthesis of new Ru and Os complexes [MCl2(PP)(L)] (PP=dppb, dppf; L=(±)-trans-1,2-diaminocyclohexane, 2-(aminomethyl) pyridine, and 2-aminoethanol) of trans and cis configuration is also reported. Alcohol breakdown: Ruthenium and osmium phosphane complexes containing nitrogen ligands with the N-H functionality efficiently catalyze the acceptorless dehydrogenation of alcohols. With [MCl2(dppf)(en)] (M=Ru, Os; dppf=1,1′-bis(diphenylphosphino)ferrocene; en=ethylenediamine) in the presence of KOtBu several alcohols have been converted into ketones (see scheme), including sterols for which Os displays a better activity than Ru. Copyright
- Baratta, Walter,Bossi, Gianluca,Putignano, Elisabetta,Rigo, Pierluigi
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experimental part
p. 3474 - 3481
(2011/05/02)
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- SBA-15-functionalized TEMPO confined ionic liquid: An efficient catalyst system for transition-metal-free aerobic oxidation of alcohols with improved selectivity
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A novel SBA-15-functionalized TEMPO confined ionic liquid [BMIm]Br was found to be a highly efficient and recyclable catalyst system for the transition-metal-free aerobic oxidation of a wide range of structurally diverse alcohols. Thanks to the strong physical confinement of the ionic liquid inside the mesochannels of SBA-15-supported TEMPO, the resulting solid catalyst showed improved selectivity in the aerobic oxidation of allylic alcohols. The catalyst can be recovered and re-used for at least 11 reaction runs without significant loss of either activity or confined IL.
- Karimi, Babak,Badreh, Ebrahim
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supporting information; experimental part
p. 4194 - 4198
(2011/06/25)
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- COMPOSITION CONTAINING A COMPOUND CAPABLE OF ESTABLISHING HYDROGEN BONDS, AND COSMETIC TREATMENT PROCESS
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Composition containing, in a cosmetically or dermatologically acceptable medium, a compound that may be obtained by reaction between: an oil bearing at least one nucleophilic and/or electrophilic reactive function, anda junction group capable of establishing hydrogen bonds with one or more partner junction groups, the junction group bearing at least one reactive function capable of reacting with the reactive function borne by the oil, and also comprising at least one unit of formula (I) or (II):
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- Rapid and selective catalytic oxidation of secondary alcohols at room temperature by using (N-Heterocyclic Carbene)-Ni0 systems
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The selective, anaerobic catalytic oxidation of secondary alcohols at room temperature by using an in situ (N-heterocyclic carbene)-Ni0 system is presented. The use of non-anhydrous, non-degassed 2,4-dichlorotoluene as both the oxidant and the solvent allows for very short reaction times and very high yields. In addition, a well-defined (N-heterocyclic carbene)-Ni0 complex was synthesized and applied to these oxidation reactions.
- Berini, Christophe,Winkelmann, Ole H.,Otten, Jennifer,Vicic, David A.,Navarro, Oscar
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supporting information; experimental part
p. 6857 - 6860
(2010/08/03)
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- Synthesis of methyl acetoacetate from acetone and dimethyl carbonate with alkali-promoted MgO catalysts
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The synthesis of methyl acetoacetate (MAA) by methoxycarbonylation of acetone with dimethyl carbonate (DMC) was carried out in the presence of MgO and alkali-promoted MgO catalysts. From among Li, Na, K, and Cs, potassium was found to be the most effective promoter to improve the activity of MgO. The effect of K/MgO with variable content of K was also investigated, and the individual catalysts were characterised by the XRD, BET, SEM, CO2-TPD, and in situ CO2 IR techniques. The results showed that the addition of a small amount of K (1.97 mass %) could promote MAA formation, but a higher K loading caused a decrease in the yield of MAA, which might result from particle agglomeration and the presence of stable potassium carbonates. In situ FTIR experiments of co-adsorbed reactants indicated that the reaction probably proceeded via abstraction of Hα from acetone by base sites.
- Wu, Dudu,Chen, Zhi
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experimental part
p. 758 - 766
(2011/11/29)
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- Cr, Zr-incorporated hydrotalcites and their application in the synthesis of isophorone
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Cr3+ and Zr4+ cation-incorporated hydrotalcites (HTs) were prepared by coprecipitation method. Corresponding mixed oxide were obtained by the thermal decomposition of HTs at 773 K for 8 h and applied in the synthesis of isophorone (IP) from acetone. From the characteristic results, both Cr3+ and Zr4+ were introduced into the lattice of hydrotalcite producing the more disordered HT structures. Compared with Mg-Al mixed oxide, Cr and Zr modified mixed oxide demonstrated more amount of basic sites and stronger base strength, which were responsible for the improvement of catalytic activity. As a result, both of the modified mixed oxide exhibited IP selectivity of more than 70% under atmospheric pressure.
- Liu, Yanxia,Sun, Kunpeng,Ma, Haowen,Xu, Xianlun,Wang, Xiaolai
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experimental part
p. 880 - 883
(2010/11/04)
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- Titanocene-promoted intermolecular couplings of epoxides with nitriles. An easy access to β-hydroxyketones
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(Chemical Equation Presented) Radical couplings of epoxides and nitriles mediated by Cp2TiCl provide a diastereoselective route to the synthesis of β-hydroxyketones. The conditions of this "aldol- like" reaction are mild enough to avoid the dehydration of the β-hydroxyketone. The scope of the coupling reaction with functionalized and tetrasubstituted epoxides has been studied. The radical character of the coupling reactions is demonstrated.
- Fernandez-Mateos,Encinas Madrazo,Herrero Teijon,Rubio Gonzalez
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supporting information; experimental part
p. 3913 - 3918
(2009/10/20)
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- Heteropoly acid-based supported ionic liquid-phase catalyst for the selective oxidation of alcohols
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A supported ionic liquid strategy has been applied for the immobilization of a heteropolyacid, molybdovanadophosphoric acid, onto ionic liquid-modified mesoporous silica SBA-15. The immobilized catalyst demonstrated high activity in the aerobic oxidation of primary and secondary alcohols to aldehydes and ketones, respectively. No overoxidation of the primary alcohols to carboxylic acids was observed. Secondary alcohols were chemoselectively oxidized to ketones in the presence of primary alcohol, hetero atom, and allyl groups. This catalyst could be recycled five times without obvious loss of activity.
- Bordoloi, Ankur,Sahoo, Suman,Lefebvre,Halligudi
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experimental part
p. 232 - 239
(2009/03/11)
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- Development of an amphiphilic resin-dispersion of nanopalladium catalyst: Design, preparation, and its use in aquacatalytic hydrodechlorination and aerobic oxidation
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An amphiphilic polystyrene-poly(ethylene glycol) (PS-PEG) resin-dispersion of nanoparticles of palladium was designed and prepared with a view toward use for catalysis in water. The amphiphilic PSPEG resin-dispersion of nanoparticles of palladium exhibited high catalytic performance in the hydrodechlorination of chloroarenes under aqueous conditions. The amphiphilic resin-supported nanopalladium particle also catalyzed alcohol oxidation, which is one of the most fundamental and important yet immature processes in organic chemistry, in water under an atmospheric pressure of oxygen gas to form aldehydes, ketones, and carboxylic acids.
- Uozumi, Yasuhiro,Nakao, Ryu,Rhee, Hakjune
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p. 420 - 427
(2008/02/06)
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- An efficient deprotection of dithioacetals to carbonyls using Oxone-KBr in aqueous acetonitrile
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A simple and efficient method has been developed for the chemoselective dethioacetalization of dithioacetals to aldehydes and ketones using Oxone-KBr in aqueous acetonitrile at room temperature.
- Desai,Pore,Tamhankar,Jadhav,Wadgaonkar
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p. 8559 - 8561
(2007/10/03)
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- Oppenauer-type oxidation of secondary alcohols catalyzed by homogeneous water-soluble complexes
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The catalytic system composed of [Ir(COD)Cl]2, 2,2′-biquinoline-4,4′-dicarboxylic acid dipotassium salt (BQC), and sodium carbonate is highly efficient for the selective oxidation of benzylic, 1-heteroaromatic, aliphatic, and allylic secondary alcohols using catalyst:substrate ratios ranging from 0.4% to 2.5%. Sterically hindered allylic alcohols undergo selectively good conversions to the corresponding enones, while unhindered ones are completely isomerized to saturated ketones. Mercury tests indicate that the catalytic process is likely homogeneous. The mechanism proposed for this Oppenauer-type oxidation including the isomerization process is based on iridium-alkoxide species.
- Ajjou, Abdelaziz Nait,Pinet, Jean-Louis
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p. 702 - 710
(2007/10/03)
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- Reductive ring-opening reaction of 2,3-epoxy-1,4-butanediones with SbCl3-Bu4NI in the presence of Na2S 2O3·5H2O
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1,4-Disubstituted 2,3-epoxy-1,4-butanediones were converted to 1,4-disubstituted 2-hydroxy-1,4-butanediones with SbCl3-Bu 4NI in the presence of Na2S2O 3-5H2O. The ring opening of terminal epoxides can also be accomplished to afford the corresponding haloalcohol with SbCl3 and tetrabutylammonium halides, Bu4NX (X = Cl, Br, I) under the same reaction conditions. Copyright Taylor & Francis, Inc.
- Sayama, Shinsei
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p. 2115 - 2124
(2007/10/03)
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- Combination of two catalytic sites in a novel nanocrystalline TiO 2-iron tetrasulfophthalocyanine material provides better catalytic properties
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Mesoporous titania nanocrystals containing iron tetrasulfophthalocyanine (FePcS) have been synthesised by a one-pot hydrolytic process from a modified Ti alkoxide; the novel hybrid catalyst was efficient in heterogeneous oxidation of 2,3,6-trimethylphenol and β-isophorone suggesting a cooperative effect between TiO2 and FePcS catalytic sites. The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2005.
- Beyrhouty, Mirvat,Sorokin, Alexander B.,Daniele, Stephane,Hubert-Pfalzgraf, Liliane G.
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p. 1245 - 1248
(2007/10/03)
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- Bis(4,5-dimethoxy-2-nitrophenyl)ethylene glycol: A new and efficient photolabile protecting group for aldehydes and ketones
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Synthesis of a new photolabile protecting group, bis(4,5-dimethoxy-2- nitrophenyl)ethylene glycol (4) from 4,5-dimethoxy-2-nitrobenzyl alcohol in three steps in good yields is described. The acetals and ketals of 4 are stable against acidic and basic reaction conditions and are cleaved smoothly on irradiation at 350 and 400 nm with regeneration of carbonyl compounds in high yields and efficiency.
- Kantevari, Srinivas,Narasimhaji, Ch. Venkata,Mereyala, Hari Babu
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p. 5849 - 5854
(2007/10/03)
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- Selective oxidations of allylic alcohols using vanadyl and cobalt(II) alkyl phosphonate modified silicas
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A range of allylic alcohols can be selectively oxidised to either the corresponding epoxide or the enone in good yields using catalytic quantities of vanadyl or cobalt(II) alkyl phosphonate modified silicas, CoEPS3 and VOEPS3 and tert-butyl hydroperoxide.
- Jurado-Gonzalez, Magdalena,Sullivan, Alice C.,Wilson, John R.H.
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p. 4465 - 4468
(2007/10/03)
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- IMPROVED NEUTRALIZATION OF ISOPHORONE NITRILE SYNTHESIS PRODUCTS
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The invention relates to a method for producing 3-cyano-3,5,5- trimethylcyclohexanone (isophorone nitrile) by reacting isophorone with hydrogen cyanide in the presence of a base as a catalyst. A special sulfonic acid or a special carboxylic acid is added to the resulting raw isophorone nitrile product which is then distilled. The invention further relates to the use of a special sulfonic acid or a special carboxylic acid as a neutralizing agent prior to distilling a raw isophorone nitrile product which is obtained by reacting isophorone with hydrogen cyanide in the presence of a base as a catalyst in order to prevent precipitations during neutralization of the base used as a catalyst with an acid.
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- Chemoselective oxidation of alcohols to aldehydes and ketones by iodosobenzene/(salen) chromium complex
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Various benzylic and allylic alcohols were selectively oxidized to their corresponding aldehydes and ketones by a new Cr(III)(salen) complex I as the catalyst and PhIO as terminal oxidant. The oxidation requires relatively shorter reaction time and produces excellent yields.
- Kim, Sung Soo,Kim, Dong Won
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p. 1391 - 1394
(2007/10/03)
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- Solvent-free oxidation of alcohols by t-butyl hydroperoxide catalyzed by water-soluble copper complex
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The catalytic system composed of CuCl2 and 2,2'-biquinoline-4,4'-dicarboxylic acid dipotassium salt (BQC), was found to be highly efficient for the selective oxidation of secondary benzylic, allylic and propargylic alcohols to the corresponding ketones, with aqueous t-butyl hydroperoxide under phase-transfer catalysis conditions. The catalytic system is stable and can be recycled and reused several times without loss of activity.
- Ferguson, Gabriel,Ajjou, Abdelaziz Nait
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p. 9139 - 9142
(2007/10/03)
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- Catalytic oxidation of alcohols in water under atmospheric oxygen by use of an amphiphilic resin-dispersion of a nanopalladium catalyst
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A step closer to the ideal oxidation of alcohols: Catalytic oxidation of alcohols in water under atmospheric oxygen was achieved by use of an amphiphilic resindispersion of a nanopalladium catalyst (see scheme). This system combines high catalytic activity owing to the large surface area of the nanoparticles and water-based reactivity provided by the amphiphilicity of the polystyrene - poly(ethylene glycol) matrix.
- Uozumi, Yasuhiro,Nakao, Ryu
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p. 194 - 197
(2007/10/03)
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- TEMPO-Catalyzed Aerobic Oxidation of Alcohols to Aldehydes and Ketones in Ionic Liquid [bmim][PF6]
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(matrix presented) A simple and mild TEMPO-CuCl catalyzed aerobic oxidation of primary and secondary alcohols to the corresoponding aldehydes and ketones in ionic liquid [bmim][PF6] with no trace of overoxidation to carboxylic acids has been developed. The product can be isolated by a simple extraction with organic solvent, and the ionic liquid can be recycled or reused.
- Ansari, Imtiaz A.,Gree, Rene
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p. 1507 - 1509
(2007/10/03)
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