- A convenient route to prepare isodicyclopentadiene-precursor of 1,5-dihydro-pentalene
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A new route to prepare tricyclo[5.2.1.02,6]deca-2,4-diene (isodicyclopentadiene) was developed. This new route passes through a brominated (5-bromotricyclo[5.2.1.02,6]dec-3-ene) derivative obtained from tricycle[5.2.1.02,6]dec-3-ene (8,9-dihydrodicyclopentadiene) and NBS with a good yield. The complete assignment of protons and carbons on nuclear magnetic resonance spectra was done for dicyclopentadiene and the chemically transformed compounds by 2D NMR techniques.
- Burgos O,Chávez,Manríquez,Alegría
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- Colloid and Nanosized Catalysts in Organic Synthesis: XXII. Hydrogenation of Cycloolefins Catalyzed by Immobilized Transition Metals Nanoparticles in a Three-Phase System
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The processes of unsaturated cyclic hydrocarbons hydrogenation in a three-phase gas-liquid-solid catalyst system in the presence of nanostructured nickel, cobalt, or iron catalysts in a flow reactor at 130°C and atmospheric pressure have studied. RX3Extra activated carbon, γ-Al2O3, NaX zeolite, and Purolite CT-175 cation-exchange resin have been used as supports; NaBH4 and NH2NH2·H2O were used as reducing agents. The catalytic activity of supported nanoparticles and their selectivity with respect to the product of exhaustive hydrogenation have been investigated.
- Nebykov,Popov, Yu. V.,Mokhov,Latyshova,Shcherbakova,Nemtseva,Shishkin
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p. 1985 - 1989
(2019/11/29)
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- Dendrimer-Encapsulated Pd Nanoparticles, Immobilized in Silica Pores, as Catalysts for Selective Hydrogenation of Unsaturated Compounds
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Heterogeneous Pd-containing nanocatalysts, based on poly (propylene imine) dendrimers immobilized in silica pores and networks, obtained by co-hydrolysis in situ, have been synthesized and examined in the hydrogenation of various unsaturated compounds. The catalyst activity and selectivity were found to strongly depend on the carrier structure as well as on the substrate electron and geometric features. Thus, mesoporous catalyst, synthesized in presence of both polymeric template and tetraethoxysilane, revealed the maximum activity in the hydrogenation of various styrenes, including bulky and rigid stilbene and its isomers, reaching TOF values of about 230000 h?1. Other mesoporous catalyst, synthesized in the presence of polymeric template, but without addition of Si(OEt)4, provided the trans-cyclooctene formation with the selectivity of 90–95 %, appearing as similar to homogeneous dendrimer-based catalysts. Microporous catalyst, obtained only on the presence of Si(OEt)4, while dendrimer molecules acting as both anchored ligands and template, demonstrated the maximum activity in the hydrogenation of terminal linear alkynes and conjugated dienes, reaching TOF values up to 400000 h?1. Herein the total selectivity on alkene in the case of terminal alkynes and conjugated dienes reached 95–99 % even at hydrogen pressure of 30 atm. The catalysts synthesized can be easily isolated from reaction products and recycled without significant loss of activity.
- Karakanov, Edward A.,Zolotukhina, Anna V.,Ivanov, Andrey O.,Maximov, Anton L.
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p. 358 - 381
(2019/04/04)
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- Colloid and Nanosized Catalysts in Organic Synthesis: XIX.1 Influence of the Support Nature on Hydrogenation Catalysis of Cyclic Olefins by Nickel Nanoparticles
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Gas-phase hydrogenation of cycloalkenes in the presence of nickel nanoparticles supported on Ceokar-2, BAU-A activated carbon, alumina, and NaX zeolite proceeds at 140–240°C and atmospheric pressure of hydrogen. The conversion and selectivity depend on the type of support and on the hydrogen excess.
- Popov, Yu. V.,Mokhov,Nebykov,Shcherbakova,Dontsova
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- Hydrogenation of Dicyclopentadiene in the Presence of a Nickel Catalyst Supported onto a Cation Exchanger in a Flow-Type Reactor
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The process of dicyclopentadiene hydrogenation in the gas–liquid–solid catalyst system with a catalyst of nickel nanoparticles supported onto a Purolite CT-175 cation exchange resin was studied. The surface structure of the catalyst and the kinetics of the dicyclopentadiene hydrogenation process were examined. Optimum conditions were found for the production of endo-tetrahydrodicyclopentadiene and the simultaneous production of endo-tetrahydrodicyclopentadiene and 5,6-dihydrodicyclopentadiene at atmospheric pressure.
- Popov, Yu. V.,Mokhov,Nebykov,Latyshova,Shcherbakova,Panov
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p. 444 - 449
(2018/08/17)
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- Catalyst-free hydrogenation of alkenes and alkynes with hydrazine in the presence of oxygen
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A series of alkenes and alkynes was subjected to reduction with hydrazine hydrate in ethanol in the presence of oxygen. An efficient method was developed for the reduction of C-C double bonds and C-C triple bonds with diimide, generated in situ from hydrazine hydrate by oxidation with oxygen. The reduction process proceeded for 24-48? hours with high chemoselectivity and excellent yields. This reduction procedure offers synthetic advantages over metal-catalyzed hydrogenation as well as other systems. Georg Thieme Verlag Stuttgart New York.
- Menges, Nurettin,Balci, Metin
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p. 671 - 676
(2014/04/03)
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- Colloid and nanodimensional catalysts in organic synthesis: I. Investigation of hydrogenation selectivity of unsaturated compounds with hydrazine hydrate and aluminum hydride
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Results of investigation of selective hydrogenation of unsaturated carbon-carbon bonds with hydrazine hydrate or complex metal hydrides in the presence of metal nanoparticles are reported. Conditions of exhaustive and partial hydrogenation of some derivatives of norbornene, styrene, and unsaturated carboxylic acids are developed.
- Popov,Mokhov,Nebykov
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p. 444 - 448
(2014/05/20)
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- Highly selective mono-hydrogenation of dicyclopentadiene with Pd-nanoparticles
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In this paper, we present a new protocol to synthesize dihydrodicyclopentadienes (DHDCP), via mono hydrogenation of dicyclopentadiene. With the use of Pd-nanoparticles as catalysts the products are formed highly selective under mild conditions. The ratio between the DHDCP and the tetrahydrodicyclopentadiene (THDCP) can be shifted by variation of the hydrogen pressure from 7:1 to 1:8, with high conversions of over 85 %. The product DHDCP is an essential building block in co-polymerizations. Also we show an easy recycling concept for the nanocatalyst by phase separation. With simple filtration the solid products DHDCP and THDCP can be isolated and the liquid catalyst phase can directly be reused. Over all recycling runs a steady high conversion of about 75 % was observed.
- Behr, Arno,Manz, Vanessa,Lux, Adrian,Ernst, Andrea
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p. 241 - 245
(2013/07/27)
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- MODIFIED NAPHTHALENE FORMALDEHYDE RESIN, TRICYCLODECANE SKELETON-CONTAINING NAPHTHOL COMPOUND AND ESTER COMPOUND
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A modified dimethylnaphthalene formaldehyde resin obtained by modifying a polyfunctional dimethylnaphthalene formaldehyde resin having a constituent unit represented by the following general formula [1] in a molecule thereof with at least one member selected from the group consisting of a phenol represented by the following general formula [2], a naphthol represented by the following general formula [3] and a naphthol represented by the following general formula [4] provided that at least any of the naphthol represented by the general formula [3] or the naphthol represented by the general formula [4] must be included.
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Page/Page column 8
(2012/09/25)
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- Scope, limitations and mechanistic aspects in the selective homogeneous palladium-catalyzed reduction of alkenes under transfer hydrogen conditions
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A new and efficient mild Pd/P(t-Bu)3 catalyst for selective reduction of various alkenes under transfer hydrogen conditions has been developed leading to the corresponding saturated derivatives in chemical yields varying from 65 to 98%. Mechanistic rationale of this reaction has been also demonstrated.
- Brunel, Jean Michel
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p. 3899 - 3906
(2008/02/03)
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- Pd/P(t-Bu)3: A mild catalyst for selective reduction of alkenes under transfer-hydrogenation conditions
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A new and efficient mild Pd/P(t-Bu)3 catalyst for selective reduction of various alkenes under transfer-hydrogenation conditions has been developed leading to the corresponding saturated derivatives in chemical yields varying from 65% to 98%. Georg Thieme Verlag Stuttgart.
- Brunel, Jean Michel
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p. 330 - 332
(2007/10/03)
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- Production process for high purity tricyclo-[5. 2.1.0 2,6]decane-2-carboxylic acid ester
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An object of the present invention is to provide a process for producing high purity tricyclo[5. 2. 1. 02,6]decane-2-carboxylic acid ester which has a small content of an unsaturated compound and which has an excellent fragrance and is useful as a perfume or a perfume component. In a process for producing tricycle[5. 2. 1. 02,6]decane-2-carboxylic acid ester by reacting tricycle[5. 2. 1. 02,6]deca-3-ene with carbon monoxide and alcohol in the presence of HF, carried out separately are (a) a step in which tricycle[5. 2. 1. 02,6]deca-3-ene is reacted with carbon monoxide to produce acyl fluoride and (b) a step in which acyl fluoride obtained in the step described above is reacted with alcohol to produce an ester, whereby tricyclo[5. 2. 1. 02,6]decane-2-carboxylic acid ester having a small content of an unsaturated compound can be obtained at a high yield. Also, the reaction conditions at the step (a) described above are selected or a step for carrying out isomerization reaction of tricyclo[5. 2. 1. 02,6]decane-2-carboxylic fluoride obtained at the step (a) is interposed between the step (a) and the step (b), whereby capable of being efficiently produced is tricycle[5. 2. 1. 02,6]decane-2-carboxylic acid ester having a structural ratio of 1.0 or more in exo-tricyclo[5. 2. 1. 02,6]decane-endo-2-carboxylic acid ester/endo-tricyclo[5. 2. 1. 02,6]decane-exo-2-carboxylic acid ester Further, the crude product of tricyclo[5. 2. 1. 02,6]decane-2-carboxylic acid ester thus obtained is subjected to contact treatment with specific glycol in the presence of an acid catalyst and then distilled, whereby high purity tricyclo[5. 2. 1. 02,6]decane-2-carboxylic acid ester which is reduced in impurity aldehyde and which is excellent in a fragrance can industrially advantageously be produced.
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Page/Page column 8
(2010/02/11)
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- Determination of dicyclopentadiene and its derivatives as compounds causing odors in groundwater supplies
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A study of organic pollutants causing odor events in the groundwater from the Lower Llobregat aquifer system has been conducted. This aquifer acts as water reserve of Barcelona (northeast Spain) when the quality of the raw water from the Llobregat River is low. Closed-loop stripping analysis (CLSA), purge-and-trap (P and T), sensory GC, and flavor profile analysis (FPA) have been used as analytical methodologies to identify the compounds responsible for the odor events. Industrial organochlorinated solvents-di-to hexachlorinated saturated and unsaturated hydrocarbons-dioyclopentadiene (DCPD) and its derivatives 8-dihydroD-CPD, tetrahydroDCPD, and adamantane (the trimer of DCPD) are among the most significant compounds identified in the groundwater. DCPD with a mean concentration of 1 μg/L in almost all analyzed wells is the compound causing the odor incidents, regardless that some organochlorinated solvents such as 1,1,2-trichloroethane, trichloroethylene, and perchloroethylene might be even 2 or 3 orders of magnitude more concentrated than DCPD. The synthesis of dihydroDCPD was performed for confirmatory purposes. Trained and untrained panelists have established the threshold odor for this compound in the range of 1025 ng/L. Although further research is needed, it is possible that an illegal landfill closed in the 1970s could be the origin of the different pollutants found. A study of organic pollutants causing odor events in the groundwater from the Lower Llobregat aquifer system has been conducted. This aquifer acts as water reserve of Barcelona (northeast Spain) when the quality of the raw water from the Llobregat River is low. Closed-loop stripping analysis (CLSA), purge-and-trap (P&T), sensory GC, and flavor profile analysis (FPA) have been used as analytical methodologies to identify the compounds responsible for the odor events. Industrial organochlorinated solvents - di- to hexachlorinated saturated and unsaturated hydrocarbons - dicyclopentadiene (DCPD) and its derivatives 8-dihydroD-CPD, tetrahydroDCPD, and adamantane (the trimer of DCPD) are among the most significant compounds identified in the groundwater. DCPD with a mean concentration of 1 μg/L in almost all analyzed wells is the compound causing the odor incidents, regardless that some organochlorinated solvents such as 1,1,2-trichloroethane, trichloroethylene, and perchloroethylene might be even 2 or 3 orders of magnitude more concentrated than DCPD. The synthesis of dihydroDCPD was performed for confirmatory purposes. Trained and untrained panelists have established the threshold odor for this compound in the range of 10-25 ng/L. Although further research is needed, it is possible that an illegal landfill closed in the 1970s could be the origin of the different pollutants found.
- Ventura, Francesc,Romero, Jordi,Pares, Joan
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p. 2368 - 2374
(2007/10/03)
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- Hydrogenation of olefins with hydrated nickel chloride, lithium and a catalytic amount of naphthalene
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The reaction of different olefins or dienes with a mixture of nickel (II) chloride dihydrate, an excess of lithium powder and a catalytic amount of naphthalane (17 mol%) in THF at room temperature, leads to the formation of the corresponding alkanes. The incorporation of deuterium oxide to the nickel salt complex yields deuterated hydrocarbons. Finally, in the case of dienes as starting materials the method can serve for mono or dihydrogenation depending on the amount of nickel salt used.
- Alonso, Francisco,Yus, Miguel
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p. 6925 - 6928
(2007/10/03)
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- Kinetic isotope effect in the hydrogenation of tricyclo-(5,2,1,02.6)-deca-3,8-diene on platinum metals
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The hydrogenation of dicyclopentadiene 21.6)-deca-3,8-diene> by protium and deuterium on Pt, Pd, Ir, Rh, and Ru blacks in hexane at atmospheric or higher hydrogen pressures has been studied at 298-423 K.The kinetic isotope effect has been shown to vary from 1.33 to 2.50 according to the nature of the metal.The main product of complete hydrogenation is endo-tetrahydrodicyclopentadiene 2.6)-decane>: its yield under comparable conditions is higher in a deuterium atomosphere than in the presence of protium.
- Ualikhanova, A.,Temirbulatova, A. E.,Dembitskii, A. A.,Mailyubaev, B. T.,Korolev, A. V.
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p. 240 - 242
(2007/10/02)
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- Dicyclopentadiene Oxidation. IV. Oxidation of 4,5- and 8,9-Dihydro-dicyclopentadiene
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A mixture of exo- and endo-4,5-dihydro-dicyclopentadiene 5 and also pure endo-8,9-dihydro-dicyclopentadiene 7 and pure exo-dicyclopentadiene 10 was oxidized in the absence and in the presence of catalysts.The compounds containing the norbornene structure mainly gave the corresponding exo-epoxides.No catalytic effects were observed in the formation of these norbornene epoxides.Compound 7 containing only the cyclopentene structure mainly yielded the corresponding hydroperoxide 9.In this case a catalytic effect of epoxidation catalysts was observed : in the presence of such catalysts the epoxide was increased. The results obtained prove the mechanism of dicyclopentadiene oxidation proposed by us.
- Schnurpfeil, D.,Lauterbach, G.
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p. 121 - 128
(2007/10/02)
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