- Vanadium(V)-Induced Oxidative Cross-Coupling of Various Boron and Silyl Enolates
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Intermolecular oxidative cross-coupling of two different enolates is one of the most useful reactions to synthesize unsymmetrical 1,4-dicarbonyl compounds. In this study, the oxovanadium(V)-induced intermolecular oxidative cross-coupling of enolates afforded unsymmetrical 1,4-dicarbonyl compounds. Various boron and silyl enolates underwent the formation of ketone–ester, ester–ketone, ester–ester, amide–ketone and amide–ester coupling products. These results clearly show the versatility of the present oxidative cross-coupling protocol.
- Amaya, Toru,Osafune, Yuma,Maegawa, Yusuke,Hirao, Toshikazu
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- Deactivation of Supported Nickel-Based Hydrogenation Catalysts with Sulfide Ions
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Abstract: Kinetics of the liquid-phase hydrogenation of a multiple carbon bond is studied in an aqueous medium on supported nickel catalysts at different hydrogen pressures in the system under conditions of partly controlled deactivation of the active surface sites with sulfide ions. The pattern of deactivation of the active surface sites of Ni/SiO2 catalysts containing different amounts of the active metal on the surface with sulfide ions in water is determined. The resistance of the studied catalysts to deactivation during the reduction of diethyl maleate (DM) and propen-2-ol-1 is determined experimentally. It is shown that the catalyst is more resistant to deactivation during the hydrogenation of propen-2-ol-1; this finding is attributed to the steric factor. It is found that the hydrogen pressure in the system does not affect the deactivation pattern. Excessive pressure slightly alters the deactivation resistance of the catalyst during the hydrogenation of propen-2-ol-1. It is shown experimentally that the catalytic properties of nickel in liquid-phase hydrogenation reactions can be controlled by introducing small amounts of a catalytic poison into the system at high hydrogen pressures.
- Prozorov,Afineevskii,Knyazev,Sukhachev, Ya. P.,Sukhacheva
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- Photocatalytic Reaction of Diazo Compounds with Aldehydes
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Photocatalytic reactions of diazoacetates with aldehydes led to α-alkylated carbonyl compounds instead of the expected cyclopropane derivatives. The reaction requires a dual catalytic system – photocatalysis merged with enamine-iminium catalysis. NMR, EPR, UV/Vis, and ESI-MS analyses provided sufficient data to corroborate the proposed radical mechanism – enamine catalysis merged with photocatalysis. (Figure presented.).
- Rybicka-Jasińska,Ciszewski,Gryko
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- Electrocatalytic Hydrogenation of Diethyl Fumarate. A Simple System Development.
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Diethyl fumarate was chosen as a model in search for better conditions to achieve selective electrocatalytic hydrogenation. In addition to carbon felt, several catalytic cathode surfaces have been examined, including Fe, Pt, Ni, Pb, Al, Cu, Zn, and stainless steel. Other variables like current density (58 to 285 mA.dm2), supporting electrolyte (NaCl, KBr, NaBr, NaI, NaF), solution pH* (3.0 to 9.0) and co-solvent (CH3CN, t-BuOH, MeOH and THF) were tried. The majority of the reactions were carried out at constant current in an undivided cell fitted with the chosen working electrode and DSA (RuO2/TiO2) as the auxiliary electrode, in H2O/co-solvent (4:1). The best results for hydrogenation (84 percent chemical yield) were obtained using Fe as cathode, a current density of 175 mA.dm2, in H2O/CH3CN (4:1) at pH* 5.5. NaBr and KBr are also useful electrolytes for hydrogenation. pH* variation does not seem to affect product ratio. THF as co-solvent and NaF as supporting electrolyte should be avoided, as well as carbon felt and Ni as electrodes.
- Silva, Jose Ginaldo da,Goulart, Marilia O. F.,Navarro, Marcelo
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- Ultrasound-assisted electrochemical reduction of emulsions in aqueous media
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The electrochemical reduction of diethylmaleate, diethylfumarate and diethylacetylene dicarboxylate in the form of microscopic droplets generated by applying power ultrasound to aqueous electrolyte media allows a clean hydrogenation of the carbon-carbon double/triple bond whilst providing a novel and versatile methodology for electrochemistry of insoluble materials in aqueous environments.
- Marken, Frank,Compton, Richard G.,Bull, Steven D.,Davies, Stephen G.
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- Synthesis of a sulfated-group-riched carbonaceous catalyst and its application in the esterification of succinic acid and fructose dehydration to form HMF
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A novel sulfated-group-riched sulfonated carbonaceous catalyst with high acidic strength and adjustable ratio of acidic groups was designed in the paper, where glucose and benzyl chloride were hydrothermally carbonized first followed by sulfonation treatment. Various physicochemical techniques were used to characterize the catalyst such as IR, 13C MAS NMR and XPS spectra, NH3-TPD, XRD patterns and TG curve. Then, it was applied in the esterification of succinic acid and fructose dehydration to form HMF. Compared to commercial Amberlyst-15 catalyst, such carbonaceous solid acid exhibited excellent catalytic activity and thermal stability, which was attributed to its higher amount of sulfonic acid group.
- Liu, Huihui,Peng, Qian,Ren, Jiawen,Shi, Bianfang,Wang, Yanqin
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- Trimethylsilylketene dialkylacetals in organic synthesis: Reactions with alkyldiazoacetates
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The reaction of trimethylsilylketene dialkylacetals with alkyldiazoacetates in the presence of Cu(acac)2 or Rh2(OAc)4 results in the formation of alkyl-2,2-dialkoxy-3-trimethylsilylcyclopropane-1-carboxylates 3-8. The cycloaddition proceeds stereoselectively, giving exclusively one of two possible diastereomers. Compounds 4 and 6 are transformed by reaction with LiAlH4 to cyclopropylmethanols 9 and 10 in high yields. All compounds have been characterized by elemental analyses, 1H, 13C NMR and IR spectroscopy.
- Zaitseva, Galina S.,Novikova, Ol'ga P.,Grigoriev, Evgeny V.,Kisin, Alexander V.,Avtomonov, Evgeni V.,Lorberth, Joerg
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- Vicinal alkylation-carboxymethylation of electron-poor alkenes by radical-chain reactions with O-alkyl O-silyl ketene acetals and their [3+2] annulation by reaction with O-cyclopropylcarbinyl O-silyl ketene acetals
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O-Silyl ketene acetals of the type H2C=C(OR)OSiMe 2But, in which R is a tertiary or secondary alkyl group, react with electron-poor alkenes to bring about vicinal alkylation- carboxymethylation of the latter. When R is a cyclopropyldimethylcarbinyl group such reactions take a more complex course involving ring opening of the cyclopropylcarbinyl radical and lead ultimately to [3+2] annulation of the alkene.
- Cai, Yudong,Roberts, Brian P.
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- A Synthetic Bilayer Membrane Functionalised with Hydrophobic Vitamin B12 as an Artificial Glutamate Mutase
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Heptapropyl cobyrinate perchlorate catalysed the conversion of diethyl β-methylaspartate into diethyl glutamate in single-compartment vesicles in the presence of vanadium trichloride as a co-catalyst under aerobic irradiation conditions.
- Murakami, Yukito,Hisaeda, Yoshio,Ohno, Teruhisa
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- Synthesis and antiischemic activity of dicarboxylic nitroxyalkylamides and nitroxyalkylimides
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A number of dicarboxylic N-(2-nitroxyalkyl)amides and N-(2-nitroxyalkyl)imides were synthesized and their antiischemic activity was studied. The ratio of the areas of necrotic and ischemic zones was used as a criterion for evaluation of antiischemic activity. The maximum values were close to antiischemic activity of Nicorandil, with acute toxicity of compounds synthesized being considerably lower.
- Fedorov,Bogdanov,Fadeev,Lagodzinskaya
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- Synthesis of 1,4-diketones: reaction of α-bromo ketones with tetrakis(dimethylamino)ethylene (TDAE)
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1,4-Diketones were prepared by the reaction of α-bromo ketones with tetrakis(dimethylamino)ethylene (TDAE) in moderate to good yields. Similarly, α-bromo esters were reductively coupled using TDAE to give the 1,4-diesters in moderate yields.
- Nishiyama, Yutaka,Kobayashi, Akihiro
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- Rieke zinc as a reducing agent for common organic functional groups
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The ability of Rieke zinc to reduce common organic functional groups has been studied. Nitrobenzene, conjugated aldehydes, arylacetylenes, and phenylpropiolates are readily reduced under mild conditions. Benzonitrile, alkylacetylenes, ketones, unconjugated aldehydes, and alkenes are not reduced.
- Kroemer, Jeremy,Kirkpatrick, Chris,Maricle, Brian,Gawrych, Rick,Mosher, Michael D.,Kaufman, Don
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- Oxidation of cyclohexanone and/or cyclohexanol catalyzed by Dawson-type polyoxometalates using hydrogen peroxide
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The oxidation of cyclohexanone, cyclohexanol or cyclohexanone/cyclohexanol mixture using as catalyst, Dawson-type polyoxometalates (POMs) of formula, α- and β-K6P2W18O62, α-K6P2Mo6W12O62 and α1-K7P2Mo5VW12O62 and hydrogen peroxide, carried out at 90 °C with a reaction time of 20 h, led to a high number of mono- and di-acids which were identified by GC-MS. Levulinic, 6-hydroxyhexanoic, adipic, glutaric and succinic acids, major products were evaluated by HPLC. Regardless of the substrate nature, all POMs exhibited high catalytic activity with 94–99% of conversion, whereas the formation of the different products is sensitively related to both the composition and symmetry of the POMs and the substrate nature. The main products are adipic acid in the presence of α-K6P2Mo6W12O62 and α1-K7P2Mo5VW12O62, levulinic acid in the presence of α1-K7P2Mo5VW12O62 and β-K6P2W18O62 and 6-hydroxyhexanoic acid in the presence of α- and β-K6P2W18O62. Graphical abstract: High catalytic activity was observed with?α- and?β-K6P2W18O62, α-K6P2Mo6W12O62 and α1-K7P2Mo5VW12O62 Dawson-type for the oxidation of cyclohexanone, cyclohexanol or cyclohexanone/cyclohexanol mixture, in the hydrogen peroxide presence, to several oxygenated products. Adipic, levulinic and 6-hydroxyhexanoic acids are the main products. The peroxo- species formed in situ could be the active sites.[Figure not available: see fulltext.]
- Dermeche, Leila,Idrissou, Yasmina,Mazari, Tassadit,Moudjahed, Mohammed,Rabia, Cherifa
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- Metal-free reduction of unsaturated carbonyls, quinones, and pyridinium salts with tetrahydroxydiboron/water
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A series of unsaturated carbonyls, quinones, and pyridinium salts have been effectively reduced to the corresponding saturated carbonyls, dihydroxybenzenes, and hydropyridines in moderate to high yields with tetrahydroxydiboron/water as a mild, convenient, and metal-free reduction system. Deuterium-labeling experiments have revealed this protocol to be an exclusive transfer hydrogenation process from water. This journal is
- Li, Tiejun,Peng, Henian,Tang, Wenjun,Tian, Duanshuai,Xu, Guangqing,Yang, He
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p. 4327 - 4337
(2021/05/31)
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- Poly(methylhydrosiloxane) as a reductant in the catalytic base-free Wittig reaction
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Herein, we report a catalytic, base-free Wittig reaction forming highly functionalized alkenes with PMHS as a terminal reductant and butylacetate as a green solvent. Poly(methylhydrosiloxane) (PMHS) is a non-toxic, enviromentally friendly, inexpensive and easy to handle reductant. However, the inherent low reactivity hampers its applicability in catalytic reactions, such as P(iii)/P(v) redox cycling reactions. Most of these catalytic systems include highly active aryl silanes to facilitate phosphane oxide reduction and are not compatible with PMHS or similar more sustainable terminal reductants. The herein reported catalyst system which is based on a methyl-substituted phosphetane operates at low catalyst loadings without additional co-catalysts and allowes the use of PMHS as terminal reductant. A wide variety of functional groups was tolerated and 25 different alkenes were synthesized in yields up to 96% with excellent stereoselectivity. Mechanistic studies revealed the formation of water from silanol condensation as the main pathway of siloxane formation.
- Longwitz, Lars,T?njes, Jan,Werner, Thomas
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supporting information
p. 4852 - 4857
(2021/07/12)
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- Zeolite Y from kaolin clay of Kachchh, India: Synthesis, characterization and catalytic application
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Kaolin clay obtained from Kachchh, Gujarat was used as alumina and silica source to synthesize zeolite Y by hydrothermal method. The synthesis route comprised of the following steps: sulfuric acid treatment at 110 ?°C (4 ?h) for impurity removal followed by calcination at 600 ?°C for 4 ?h, thermal activation of kaolin into metakaolin by NaOH fusion at 850 ?°C (8 ?h); aging of reaction mixtures at 50 ?°C (24 ?h); crystallization (24 ?h) followed by washing and drying. The synthesized zeolite Y was examined by multiple characterization techniques which revealed a pore volume of 0.22 ?cm3/g with pore size of 2.89 ?nm having essential surface area of 320 ?m2/g, indicating a porous material having majority of micropores and remaining mesopores. The zeolite exhibited good catalytic activity for succinic acid esterification using ethanol to produce monoethyl and diethyl succinate. The conversion of SA (72%) and yield (60%) of valuable diester indicated good conversion rate and selectivity at moderate reaction conditions. Detailed structural comparison with zeolite Y synthesized using standard chemical route is also carried out. This work demonstrated an effective way of preparing environmentally benign porous zeolite Y having high surface area and pore volume that can be useful for catalytic applications.
- Gandhi, Dolly,Bandyopadhyay, Rajib,Soni, Bhavna
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- Biomass-derived dibasic acids to diesters with inorganic ligand-supported catalyst: synthesis, optimization, characterization
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Several attempts have been made to obtain aliphatic dicarboxylic diesters from esterification reaction to develop the biomass-derived platform molecules and green manufacturing processes. In this paper, Na3(H2O)6[AlMo6O18(OH)6], an Anderson-type polyoxometalate, firstly, was reported as a catalyst for diester synthesis from dicarboxylic acid to diester which showed an well productivity and selectivity characterized by 1H and 13C. Response surface methodology (RSM) integrated with the desirability function approach was used to determine the best operative conditions, and the optimal reaction parameters for maximum dipropyl succinate yield (77 ± 2.5%) were identified as 1.19?mol.% catalyst loading, 4.9:1 propanol/succinic acid ratio, 113?°C, and 9.6?h. Three batches of tests were carried for catalyst recycling with 78–75% yield even after 6 cycles of esterification. In addition, the substrate carbon chain was increased for investigation of substrate scope achieving satisfactory results and all products were characterized by 1H and 13C nuclear magnetic resonance spectroscopy.
- Chen, Zhe,Han, Sheng,Lu, Deli,Xu, Yumeng
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- One-pot production of diethyl maleate via catalytic conversion of raw lignocellulosic biomass
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The conversion of lignocellulose into a value-added chemical with high selectivity is of great significance but is a big challenge due to the structural diversities of biomass components. Here, we have reported an efficient approach for the one-step conversion of raw lignocellulose into diethyl maleate by the polyoxometalate ionic liquid [BSmim]CuPW12O40 in ethanol under mild conditions. The results reveal that all of the fractions in biomass, i.e., cellulose, lignin and hemicellulose, were simultaneously converted into diethyl maleate (DEM), achieving a 329.6 mg g-1 yield and 70.3% selectivity from corn stalk. Importantly, the performance of the ionic liquid catalyst [BSmim]CuPW12O40 was nearly twice that of CuHPW12O40, which can be attributed to the lower incorporation of the Cu2+ site in [BSmim]CuPW12O40. Hence, this process opens a promising route for producing bio-based bulk chemicals from raw lignocellulose without any pretreatment.
- Cai, Zhenping,Chen, Rujia,Jiang, Lilong,Li, Fukun,Li, Xuehui,Long, Jinxing,Zhang, Hao
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supporting information
p. 10116 - 10122
(2021/12/24)
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- Electrochemical Tandem Olefination and Hydrogenation Reaction with Ammonia
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An electrochemical Horner-Wadsworth-Emmons/hydrogenation tandem reaction was achieved using ammonia as electron and proton donors. The reaction could give two-carbon-elongated ester and nitrile from aldehyde or ketones directly. This reaction could proceed with a catalytic amount of base or even without a base. The ammonia provides both the electron and proton for this tandem reaction and enables the catalyst-free hydrogenation of an α,β-unsaturated HWE intermediate. More than 40 examples were reported, and functional groups, including heterocycles and hydroxyl, were tolerated.
- Zhang, Xiaofeng,Jiang, Runze,Cheng, Xu
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p. 16016 - 16025
(2021/08/24)
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- Reactions of Alkyl 2-(Bromozinc)acylates with N-Chloro- and N-Bromodiethylamines
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Abstract: The reaction of alkyl 2-(bromozinc)acylates, obtained from ethyl bromoacetate (or butyl 2-bromobutanoate, or butyl 2-bromo-2-methylpropanoate) under the action of zinc, with N-chloro- or N-bromodiethylamine in tetrahydrofuran at 20–25°C under ar
- Zaynashev, A. T.,Zorin, А. V.,Zorin, V. V.
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p. 602 - 605
(2021/06/02)
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- Reduction of Activated Alkenes by PIII/PV Redox Cycling Catalysis
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The carbon–carbon double bond of unsaturated carbonyl compounds was readily reduced by using a phosphetane oxide catalyst in the presence of a simple organosilane as the terminal reductant and water as the hydrogen source. Quantitative hydrogenation was observed when 1.0 mol % of a methyl-substituted phosphetane oxide was employed as the catalyst. The procedure is highly selective towards activated double bonds, tolerating a variety of functional groups that are usually prone to reduction. In total, 25 alkenes and two alkynes were hydrogenated to the corresponding alkanes in excellent yields of up to 99 %. Notably, less active poly(methylhydrosiloxane) could also be utilized as the terminal reductant. Mechanistic investigations revealed the phosphane as the catalyst resting state and a protonation/deprotonation sequence as the crucial step in the catalytic cycle.
- Longwitz, Lars,Werner, Thomas
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supporting information
p. 2760 - 2763
(2020/02/05)
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- The Synthesis of Chiral Allyl Carbamates via Merger of Photoredox and Nickel Catalysis
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A mild, and versatile, organophotoredox/Ni-mediated protocol was developed for the direct preparation of diverse, enantioenriched allyl carbamates. The reported approach represents a significant departure from classical step-by-step synthesis of allyl carbamates. This dual photoredox/Ni based strategy offers unrivalled capacity for convergent unification of readily available alkyl halides and chiral carbamates derived from 1-bromo-alken-3-ols with high chemoselectivity and efficiency. The reported photoredox/Ni catalyzed cross-coupling reaction is not limited to carbamates, but also to other O-derivatives such as esters, ethers, acetals, carbonates or silyl ethers. To demonstrate the utility of the reported protocol, the resulting allyl carbamates were transformed into functionalized non-racemic allylamines through a sigmatropic rearrangement reaction in enantiospecific manner. This approach allowed for synthesis of enantiomeric allylamines by a simple control of the geometry of a double bond of allyl carbamates. (Figure presented.).
- Garbacz, Mateusz,Stecko, Sebastian
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supporting information
p. 3213 - 3222
(2020/07/06)
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- Method for preparing disuccinate
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The invention relates to a method for preparing disuccinate. The method comprises the step of subjecting glucose, fructose, cellobiose and microcrystalline cellulose, which serve as raw materials, toa catalyzed selective oxidation process in a manner of taking molecular oxygen as an oxygen supply, thereby obtaining the disuccinate. According to the method, the raw materials employed can be obtained from biomass resources such as starch, cellulose and wastes of agriculture and forestry, the catalyst composition is simple, the reaction conditions are mild, and the selectivity of the target product disuccinate is high, so that the method has an important application prospect.
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Paragraph 0019-0020; 0024
(2019/01/07)
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- BIOFUELS PRODUCTION FROM BIO-DERIVED CARBOXYLIC-ACID ESTERS
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A process for producing biofuels compounds directly from carboxylic acid esters recovered from a fermentation system is described. The process involves taking a fermentation broth that has been reduced to a dry powder containing free organic acids; reacting the carboxylic acid in the powder with an alcohol solvent under a CO2-containing atmosphere in substantial absence of any other acid catalyst at a reaction temperature and pressure that corresponds to supercritical, critical or near critical conditions for at least one of the alcohol or CO2 to synthesize an ester, then subjecting the ester to either hydrogenolysis or hydrogenation to form a biofuel.
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Paragraph 0053; 0056
(2017/04/11)
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- Method of selectively catalytically oxidizing biomass-based furan compound
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The invention discloses a method of selectively catalytically oxidizing a biomass-based furan compound. The method comprises the following step of: by taking a heteropolyacid functional ionic liquid as a catalyst and an alcohol solution as a reaction medium, obtaining dicarboxylic acid or dicarboxylate in the conditions that the reaction temperature is 100-150 DEG C, the reaction time is 1-3h and the oxygen pressure is 0.5-1.0MPa, wherein over 62.35% of difumarate selectivity is obtained. The single chemical yield and selectivity for oxidizing preparation of a biomass-based furan derivative are far higher than those of the prior art. The method has the remarkable advantage that an ionic liquid catalyst can be recovered and recycled by simply adjusting the temperature. The method disclosed by the invention is mild in reaction condition, green and safe in process and simple to operate, and can realize intermittent and continuous production.
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Paragraph 0090-0093
(2017/07/19)
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- N-Hydroxy sulfonamides as new sulfenylating agents for the functionalization of aromatic compounds
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An unprecedented use of N-hydroxy sulfonamides as sulfenylating agents has been established. In the presence of catalytic amounts of iodine and N-hydroxysuccinimide, N-hydroxy sulfonamides participated in sulfenylation with indoles, 7-azaindole, N-methyl pyrrole, and 2-naphthol to afford structurally diverse thioethers in moderate to excellent yields with very high regioselectivity.
- Wang, Fu-Xiang,Zhou, Shao-Da,Wang, Chengming,Tian, Shi-Kai
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supporting information
p. 5284 - 5288
(2017/07/10)
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- Valuable new platform chemicals obtained by valorisation of a model succinic acid and bio-succinic acid with an ionic liquid and high-pressure carbon dioxide
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The potential application of biomass and catalysts is crucial to form a bridge between the emerging bio-based industry and the current process technology. Using this approach to succinic acid, a biomass derived acid, might lead to new routes for derivative production, opening its transition to the industrial scale. A considerable number of succinic acid-based products were obtained in this work in advanced, one-pot processes executed in a green solvent, supercritical carbon dioxide. Ionic liquids, which present an alternative to volatile and flammable solvents, allowed for a subsequent transformation of carbohydrate rich renewable feedstock by a simple reaction in alternative media. Reactions give a possibility of conversion of a cheap lignocellulosic biomass to succinic acid-based products, such as ethanol having a potential application in biorefinery, as well as to pyrrolidine-2,5-diones, representing antibiotics and to succinic acid esters, valuable platform chemicals. Mechanistic analysis of the formation of reaction products was successfully developed. The valorisation of a model succinic acid was compared with the valorisation of a bioderived succinic acid under identical reaction conditions and the results are discussed. The palladium catalyst nanoparticles formed seem to be stabilised by ionic liquids allowing for five successive cycles with efficient conversion and selectivity in the hydrogenation of bio-succinic acid. The presented valorisation of a biomass derived carboxylic acid is an excellent starting point for derivative production.
- Silva, Daniel,Bogel-Lukasik, Ewa
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p. 4048 - 4060
(2017/09/07)
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- Palladium–Bis(carbene) Catalysts for the Bisalkoxycarbonylation of Olefins to Succinic Diesters
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A series of Pd-bis(NHC) (NHC = N-heterocyclic carbene) complexes possessing various anions and substituents were used in the bisalkoxycarbonylation of olefins (α-olefins and ethylene) to afford industrially useful succinic diesters in modest to good yields. The influence of different ligands and counteranions of the Pd complexes on their catalytic activity was assessed, and it was found that dimeric Pd–bis(NHC)Br was the best catalyst for the bisalkoxycarbonylation reactions. The structure of dimeric Pd–bis(NHC)Br was confirmed by X-ray crystallographic analysis.
- Cho, Yu Jin,Lim, Yu Na,Yoon, Woojin,Yun, Hoseop,Jang, Hye-Young
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supporting information
p. 1139 - 1142
(2017/03/08)
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- Hydrogen Gas-Mediated Deoxydehydration/Hydrogenation of Sugar Acids: Catalytic Conversion of Glucarates to Adipates
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The development of a system for the operationally simple, scalable conversion of polyhydroxylated biomass into industrially relevant feedstock chemicals is described. This system includes a bimetallic Pd/Re catalyst in combination with hydrogen gas as a terminal reductant and enables the high-yielding reduction of sugar acids. This procedure has been applied to the synthesis of adipate esters, precursors for the production of Nylon-6,6, in excellent yield from biomass-derived sources.
- Larson, Reed T.,Samant, Andrew,Chen, Jianbin,Lee, Woojin,Bohn, Martin A.,Ohlmann, Dominik M.,Zuend, Stephan J.,Toste, F. Dean
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supporting information
p. 14001 - 14004
(2017/10/17)
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- REDUCTION METHOD USING WATER AS PROTON SOURCE BY MEANS OF N-HETEROCYCLIC CARBENE
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PROBLEM TO BE SOLVED: To provide a reduction method using water as a proton source by means of N-heterocyclic carbene, in which the N-heterocyclic carbene is used actively as a reaction accelerator to realize a hydrogenation reaction by using water as the proton source. SOLUTION: A solution, which is obtained by mixing: a reaction substrate shown at an upper stage of the following formulae; a precursor of the triazole-based N-heterocyclic carbene (NHC) shown at a lower stage; water; and 1,2-dimethoxyethane being a solvent, is reacted at 100°C or higher temperature for 2 hours or more while making the solution to pass through a microwave reaction unit and the reacted solution is subjected to reduced-pressure distillation to obtain a hydrogenated product. The formulae: (EWG1-EWG4 are each an ester group, a cyano group, a ketone group, an amido group or an imido group;R1-R5 are each a 1-20C aliphatic group, a 3-12C alicyclic group or 6-30C aromatic group) SELECTED DRAWING: None COPYRIGHT: (C)2016,JPO&INPIT
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Paragraph 0014; 0015; 0019
(2016/10/10)
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- Reduced graphene oxide supported nickel-palladium alloy nanoparticles as a superior catalyst for the hydrogenation of alkenes and alkynes under ambient conditions
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Addressed herein is the superior catalytic performance of reduced graphene oxide supported Ni30Pd70 alloy nanoparticles (rGO-Ni30Pd70) for the direct hydrogenation of alkenes and alkynes to alkanes, which surpasses the commercial Pd/C catalyst both in activity and stability. A variety of cyclic or aromatic alkenes and alkynes (a total of 17 examples) were rapidly reduced to the corresponding alkanes with high yields (>99%) via the presented direct hydrogenation protocol under ambient conditions. Compared to the commercially available Pd/C (10 wt%) catalyst, the rGO-Ni30Pd70 catalyst provided higher yields in shorter reaction times under the optimized conditions. Moreover, the rGO-Ni30Pd70 catalysts were more stable and durable than the commercial Pd/C catalysts by preserving their initial activity after five consecutive runs in the hydrogenation reactions.
- ?etinkaya, Yasin,Metin, ?nder,Balci, Metin
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p. 28538 - 28542
(2016/04/08)
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- A Luminescent Zirconium(IV) Complex as a Molecular Photosensitizer for Visible Light Photoredox Catalysis
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Titanium and zirconium complexes carrying two 2,6-bis(pyrrolyl)pyridine ligands have been synthesized and characterized. The neutral complexes Ti(MePDP)2 and Zr(MePDP)2 (MePDP = 2,6-bis(5-methyl-3-phenyl-1H-pyrrol-2-yl)pyridine) show intense ligand-to-metal charge-transfer bands in the visible region and undergo multiple reversible redox events under highly reducing conditions. Zr(MePDP)2 exhibits photoluminescent behavior and its excited state can be quenched by mild reductants to generate a powerful electron transfer reagent with a ground state potential of -2.16 V vs Fc+/0. This reactivity was utilized to facilitate dehalogenation reactions, the reduction of electron-poor olefins, and the reductive coupling of benzyl bromide via photoredox catalysis. In these reactions, the earth-abundant metal complex Zr(MePDP)2 acts as a substitute for the precious metal photosensitizer [Ru(bpy)3]2+.
- Zhang, Yu,Petersen, Jeffrey L.,Milsmann, Carsten
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p. 13115 - 13118
(2016/10/25)
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- Electroreductive hydrogenation of activated olefins using the concept of site isolation
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Electroreductive hydrogenation of activated olefins was investigated using the concept of site isolation. It was shown by electrochemical measurements as well as preparative electrolyses that the use of silica gel-supported sulfonic acid (Si-SO3H) promotes the protonation step in electroreductive hydrogenation of activated olefins without electroreductive destruction at the cathode. On the basis of the concept of site isolation, electroreductive hydrogenation of several activated olefins was successfully carried out to provide the corresponding hydrogenation products in high yields.
- Tomida, Shinsuke,Tsuda, Ryohei,Furukawa, Shiho,Saito, Marie,Tajima, Toshiki
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- A levulinic acid and levulinate catalytic oxidation process for the conversion of
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The invention relates to a method for catalytic oxidation conversion of levulinic acid and levulinic acid ester. The method adopts air or oxygen as the oxidant, and a bivalent manganese compound and nitric acid, nitrate or nitrous acid, nitrite are employed as a composite catalyst to catalyze levulinic acid or levulinic acid ester liquid phase selective oxidation and esterification reaction under mild conditions, thus obtaining succinic acid diester. The method has the characteristics of high catalytic oxidation efficiency and mild reaction condition, the bivalent manganese compound and nitric acid, nitrate or nitrous acid, nitrite involved in the composite catalyst are cheap and easily available, and the product is easy to separate and purify, so that the method has very good practicability and broad application prospects.
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Paragraph 0025
(2017/03/08)
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- A kind of preparation method of succinic acid diester
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Disclosed is a method for preparing succinic acid diester, in which levulinic acid or levulinate esters are used as raw materials, molecular oxygen is used as oxygen source, and succinic acid diester is produced by catalytic selective oxidation and esterification reaction. The levulinic acid or levulinate esters used as raw materials in the method can be obtained from biomass such as cellulose, starch, agricultural and forestry residues or the like. The method is a new route for preparing succinic acid diester that does not rely on fossil resourse. As the reaction condition in the process is moderate and has a high succinic acid diester selectivity, it has important application prospect.
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Paragraph 0073-0078
(2017/01/09)
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- Interfacing Microbial Styrene Production with a Biocompatible Cyclopropanation Reaction
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Abstract The introduction of new reactivity into living organisms is a major challenge in synthetic biology. Despite an increasing interest in both the development of small-molecule catalysts that are compatible with aqueous media and the engineering of enzymes to perform new chemistry in vitro, the integration of non-native reactivity into metabolic pathways for small-molecule production has been underexplored. Herein we report a biocompatible iron(III) phthalocyanine catalyst capable of efficient olefin cyclopropanation in the presence of a living microorganism. By interfacing this catalyst with E.coli engineered to produce styrene, we synthesized non-natural phenyl cyclopropanes directly from D-glucose in single-vessel fermentations. This process is the first example of the combination of nonbiological carbene-transfer reactivity with cellular metabolism for small-molecule production.
- Wallace, Stephen,Balskus, Emily P.
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supporting information
p. 7106 - 7109
(2015/06/08)
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- Efficient microwave-assisted esterification reaction employing methanesulfonic acid supported on alumina as catalyst
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A rapid and efficient protocol assisted by microwave irradiation for the synthesis of esters using methanesulfonic acid (CH3SO3H) supported on Al2O3 (AMA) as catalyst and free of solvent is described. The products were obtained in good yields and purity, with reduced reaction time, and the process is simple and environmentally benign. Copyright
- Fabian, Lucas,Gomez, Matias,Kuran, Juan A. Caturelli,Moltrasio, Graciela,Moglioni, Albertina
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p. 2386 - 2392
(2014/07/22)
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- An efficient renewable-derived surfactant for aqueous esterification reactions
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An efficient and simple approach for the aqueous esterification of a range of carboxylic acids with alcohols has been developed using catalytic amounts of a glucose-derived N-alkanoyl-N-methyl-1-glycamine non-ionic biosurfactant (C12MG). Excellent yields to final products were obtained under mild conditions and the protocol was amenable to both aromatic and long alkyl chain acids (e.g. fatty acids).
- Rajabi, Fatemeh,Luque, Rafael
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p. 5152 - 5155
(2014/01/23)
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- HYDROGENATION PRODUCTS FROM BIOLOGICALLY-DERIVED CARBOXYLIC-ACID ESTERS
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The production of organic acids in low-cost, high-efficiency fermentation system makes available a new route to chemical production from biomass. A process for producing a hydrogenation product involving carboxylic acid esters recovered directly from a fermentation process is described.
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Page/Page column 19
(2014/07/08)
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- ALCOHOL-MEDIATED ESTERIFICATION OF CARBOXYLIC ACIDS WITH CARBONATES
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A process for making esters from organic acids by means of reacting a carboxylic acid with dialkylcarbonate in an alcohol-containing solvent without any extrinsic acid or base catalyst is described. A benefit of the preparation process is that it can make the separation and extraction of ester products simpler and more facile vis-a-vis conventional isolation techniques.
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Page/Page column 11
(2014/05/24)
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- Transformation of amides into esters by the use of chlorotrimethylsilane
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A mild transformation of various amides and imides into the corresponding esters and diesters in good yields by using chlorotrimethylsilane and alcohols at rt are described. Either primary, secondary, or tertiary amide or imide can be used in this transformation. Primary and secondary alcohols gave better yields than tertiary alcohols.
- Xue, Cuihua,Luo, Fen-Tair
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p. 359 - 362
(2015/02/02)
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- Visible light photoredox-catalyzed deoxygenation of alcohols
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Carbon-oxygen single bonds are ubiquitous in natural products whereas efficient methods for their reductive defunctionalization are rare. In this work an environmentally benign protocol for the activation of carbon-oxygen single bonds of alcohols towards a reductive bond cleavage under visible light photocatalysis was developed. Alcohols were activated as 3,5-bis(trifluoromethyl)-substituted benzoates and irradiation with blue light in the presence of [Ir(ppy)2( dtb-bpy)](PF6 ) as visible light photocatalyst and Hünig's base as sacrificial electron donor in an acetonitrile/water mixture generally gave good to excellent yields of the desired defunctionalized compounds. Functional group tolerance is high but the protocol developed is limited to benzylic, α-carbonyl, and α-cyanoalcohols; with other alcohols a slow partial C-F bond reduction in the 3,5-bis(trifluoromethyl)benzoate moiety occurs.
- Rackl, Daniel,Kais, Viktor,Kreitmeier, Peter,Reiser, Oliver
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p. 2157 - 2165
(2015/01/09)
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- Palladium complexes with N-heterocyclic carbene ligands as catalysts for the alkoxycarbonylation of olefins
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Palladium catalysts, generated from Pd(OAc)2 and 2 equiv of N,N-dialkylbenzimidazolium iodide, are effective for the alkoxycarbonylation of olefins in high yields (>90%). Alkoxycarbonylation of 1-hexene in dimethylacetamide is achieved within 24 h at 110 C using 1 mol % catalyst, 1000 psi CO, and ethanol. Reactions can be prepared in air, without the need of an acid additive to produce ethyl 2-methylhexanoate and ethyl heptanoate in approximately a 2:1 ratio.
- Roberts, Gina M.,Pierce, Philip J.,Woo, L. Keith
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p. 2033 - 2036
(2013/05/21)
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- METHOD FOR CONTINUOUSLY PREPARING CARBOXYLIC ACID ESTER
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A method for continuously preparing a carboxylic acid ester is disclosed. In the method of the present invention, a vertical reactor is filled with a solid catalyst, a carboxylic acid and an alcohol are introduced into a lower part of the vertical reactor, esterification is performed to form an esterized mixture, the esterized mixture is output from an upper part of the vertical reactor, and distillation is performed to isolate the carboxylic acid ester. The method of the present invention is simple, easily controlled and environmental friendly, and has significantly high conversion rate and selectivity.
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Paragraph 0027; 0029; 0034
(2013/11/19)
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- Synthesis of monoesters and diesters using eco-friendly solid acid catalysts - Cerium(IV) and thorium(IV) phosphates
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In the present endeavour, amorphous cerium phosphate (CP) and thorium phosphate (TP) have been synthesized by sol-gel method and also under microwave irradiation to yield CPM and TPM. CP, TP, CPM and TPM have been characterized for elemental analysis (ICP-AES), spectral analysis (FTIR), thermal analysis (TGA), X-ray diffraction studies, SEM, EDX, surface area (BET) and surface acidity (NH3-TPD). The potential use of these materials as solid acid catalysts has been explored by studying esterification as a model reaction. Monoesters such as ethyl acetate (EA), propyl acetate (PA), butyl acetate (BA), benzyl acetate (BzAc) and diesters such as diethyl malonate (DEM), diethyl succinate (DES), dibutyl phthalate (DBP), dioctyl phthalate (DOP) have been synthesized. Esterification conditions have been optimized by varying several parameters such as reaction time, catalyst amount and mole ratio of reagents. The catalytic activity has been compared and correlated with reference to surface acidity of the catalysts. It is found that catalytic activity of CPM > CP > TP M > TP. The regenerated catalysts could be reused upto two catalytic runs without significant loss in % yields of esters formed. The highlighting feature of the present work is the catalysts CPM and TPM that are synthesized in a much shorter reaction time with higher surface acidity giving good % yield of esters.
- Parangi, Tarun,Wani, Bina,Chudasama, Uma
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p. 430 - 438
(2013/09/23)
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- Continuous flow hydrogenation using an on-demand gas delivery reactor
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A continuous-flow approach to the hydrogenation of alkenes utilizing Wilkinson's catalyst is reported. The approach relies on a newly developed coil design in which it is possible to load gas and heat the reaction mixture simultaneously. The hydrogenation of various substrates has been performed successfully on small scale and can be scaled up substantially.
- Mercadante, Michael A.,Kelly, Christopher B.,Lee, Christopher,Leadbeater, Nicholas E.
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supporting information; experimental part
p. 1064 - 1068
(2012/08/27)
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- Catalytic activity of a supported palladium-benzimidazole complex toward alkene hydrogenation
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A polymer anchored palladium complex was synthesized by sequential attachment of benzimidazole and palladium chloride to chloromethylated polystyrene divinyl benzene co-polymer with 6.5 % cross-linking. The product was characterized by XPS, UV-vis. spectrophotometry, FTIR and TGA. Various physico-chemical properties such as bulk density, surface area and swelling behavior in different solvents were also measured. The polymer anchored complex was tested as a catalyst for reduction of olefins. The kinetics of hydrogenation of 1-hexene was studied by varying the temperature, catalyst concentration and substrate concentration. The energy and entropy of activation were evaluated from the kinetic data. The catalyst could be recycled a number of times and no leaching of metal from the catalyst surface was observed.
- Alexander,Udayakumar,Gayathri
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scheme or table
p. 367 - 372
(2012/08/07)
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- Reduction of benzylic alcohols and α-hydroxycarbonyl compounds by hydriodic acid in a biphasic reaction medium
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The synthetic protocol for the reduction of alcohols to hydrocarbons by using hydriodic acid, first described by Kiliani more than 140 years ago, was improved to be more applicable to organic synthesis. Instead of a strongly acidic, aqueous solution, a biphasic toluene-water reaction medium was used, which allowed the conversion of primary, secondary and tertiary benzylic alcohols, in good yields and short reaction times, into the corresponding hydrocarbons. Red phosphorous was used as the stoichiometric reducing agent. Keto, ester, amide or ether groups are tolerated, and catalytic amounts of hydriodic acid (0.2 equiv) in the presence of 0.6 equiv phosphorous are sufficient to achieve conversion.
- Dobmeier, Michael,Herrmann, Josef M.,Lenoir, Dieter,Koenig, Burkhard
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supporting information; experimental part
p. 330 - 336
(2012/05/20)
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- Synthesis of functionalized dialkyl ketones from carboxylic acid derivatives and alkyl halides
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Unsymmetrical dialkyl ketones can be directly prepared by the nickel-catalyzed reductive coupling of carboxylic acid chlorides or (2-pyridyl)thioesters with alkyl iodides or benzylic chlorides. A wide variety of functional groups are tolerated by this process, including common nitrogen protecting groups and C-B bonds. Even hindered ketones flanked by tertiary and secondary centers can be formed. The mechanism is proposed to involve the reaction of a (L)Ni(alkyl)2 intermediate with the carboxylic acid derivative.
- Wotal, Alexander C.,Weix, Daniel J.
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supporting information; experimental part
p. 1476 - 1479
(2012/05/21)
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- Hydrogenation of olefins catalyzed by polymer-supported palladium-imidazole
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A polymer-supported palladium-imidazole catalyst was used to catalyze the hydrogenation of various olefins under mild conditions. The rate of hydrogenation was studied. The effects of factors such as substrate concentration, catalyst concentration, partial pressure of hydrogen and temperature on initial rate of reaction of selected olefins were investigated. A mechanism for the reaction was proposed from the rate equation. The effects of the solvent and structure of the olefin on the rate of hydrogenation were investigated. The catalyst showed good reusability without any leaching of metal from the support. The homologous analog of the polymer-supported catalyst could not be used as catalyst for the hydrogenation of olefins in methanol because there was precipitation of the metal during reaction.
- Velu, Udayakumar,Stanislaus, Alexander,Virupaiah, Gayathri,Shivakumaraiah,Balasubramanian, Viswanathan
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experimental part
p. 280 - 285
(2011/10/05)
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- CARBOXYLIC ACID RECOVERY AND METHODS RELATED THERETO
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A method of producing an alkyl ester of a carboxylic acid is provided, the method comprising: adding an alkanol and a mineral acid to a carboxylic acid salt to provide a carboxylic acid/alkanol solution and a precipitated mineral acid salt; separating the mineral acid salt from the carboxylic acid/alkanol solution; esterifying the carboxylic acid; and isolating an alkyl ester of the carboxylic acid.
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Page/Page column 23-26
(2011/06/25)
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- Vapor pressures and enthalpies of vaporization of a series of the symmetric linear n -alkyl esters of dicarboxylic acids
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Vapor pressures and the molar enthalpies of vaporization of the linear aliphatic alkyl esters of dicarboxylic acids R-CO2-(CH 2)n-CO2-R with n = (0 to 4) with R = C 2H5, n-C3H7, and n-C 4H9 have been determined using the transpiration method. A linear correlation of enthalpies of vaporization (at T = 298.15 K) of the esters with the number n and with Kovat's indices has been found, proving the internal consistency of measured data.
- Lipp, Svetlana V.,Krasnykh, Eugenii L.,Verevkin, Sergey P.
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body text
p. 800 - 810
(2011/11/05)
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- Preparation of silica-supported sulfate and its application as a stable and highly active solid acid catalyst
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Silica sulfate was prepared by a simple procedure, and proved to be an efficient and recyclable solid acid catalyst. SO3H groups were successfully introduced to silica surface while keeping its structure intact, as proved by XRD patterns and SEM images of the catalyst. With the catalysis of the supported sulfate materials, many of the ketones are efficiently transformed into the corresponding lactones with 30% hydrogen peroxide. In addition, the high performance of silica sulfate as a heterogeneous catalyst was further demonstrated for the esterification of varieties of carboxylic acid with ethanol.
- Yang, Zhi-Wang,Niu, Leng-Yuan,Jia, Xiao-Jie,Kang, Qiao-Xiang,Ma, Zhen-Hong,Lei, Zi-Qiang
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experimental part
p. 798 - 802
(2011/12/21)
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- Anchored montmorillonite diphenyl phosphino palladium(II) chloride mediated hydrogenation of maleic anhydride and its related geometric isomers: A kinetic study
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A kinetic study of hydrogenation of maleic anhydride and few related geometrical isomers has been carried out with anchored montmorillonite diphenyl phosphino palladium(II) chloride as the catalyst in the temperature range of 288-306 K. Reaction kinetics indicated first order dependence on [H2]. A mechanism consistent with the experimental data has been proposed. The activation and thermodynamic parameters have been evaluated.
- Hemasri,Rao, Y. Jaya Prakash,Rajanna,Saiprakash
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experimental part
p. 2565 - 2574
(2010/11/05)
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- A convenient methodology for the chemoselective reduction of a wide variety of functionalized alkenes
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An efficient method to effect chemoselective reduction of alkenes (including trisubstituted olefins) possessing various sensitive and/or reducible groups such as acetals, allylic alcohols, benzyl ethers, epoxides, esters, halides, nitriles, and sulfones is reported. The reduction is facile at 0 °C in aqueous N,N-dimethylacetamide containing sodium borohydride in the presence of 15 mol % ruthenium(III) chloride. Regioselective reduction of dienes is also feasible if the double bonds are sufficiently different in their structural environment.
- Babler, James H.,White, Nicholas A.
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experimental part
p. 439 - 441
(2010/03/04)
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