- Hybrid catalysts based on platinum and palladium nanoparticles for the hydrogenation of terpenes under slurry conditions
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Catalysts based on platinum and palladium nanoparticles immobilized in mesoporous phenolformaldehyde polymers modified with sulfo groups have been used for the hydrogenation of a number of terpenes, such as (S)-(–)-limonene, α-terpinene, γ-terpinene, and terpinolene. It has been found that Pd-containing catalysts exhibit higher activity in the exhaustive hydrogenation of terpenes, whereas Pt-containing catalysts have high selectivity for p-menthene.
- Karakhanov,Boronoev,Subbotina,Zolotukhina,Maximov,Filippova, T. Yu.
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Read Online
- Continuous synthesis of menthol from citronellal and citral over Ni-beta-zeolite-sepiolite composite catalyst
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One-pot continuous synthesis of menthols both from citronellal and citral was investigated over 5 wt% Ni supported on H-Beta-38-sepiolite composite catalyst at 60–70 °C under 10–29 bar hydrogen pressure. A relatively high menthols yield of 53% and 49% and stereoselectivity to menthol of 71–76% and 72–74% were obtained from citronellal and citral respectively at the contact time 4.2 min, 70 °C and 20 bar. Citral conversion noticeably decreased with time-on-stream under 10 and 15 bar of hydrogen pressure accompanied by accumulation of citronellal, the primary hydrogenation product of citral, practically not affecting selectivity to menthol. A substantial amount of defuctionalization products observed during citral conversion, especially at the beginning of the reaction (ca. 1 h), indicated that all intermediates could contribute to formation of menthanes. Ni/H-Beta-38-sepiolite composite material prepared by extrusion was characterized by TEM, SEM, XPS, XRD, ICP-OES, N2 physisorption and FTIR techniques to perceive the interrelation between the physico-chemical and catalytic properties.
- Er?nen, Kari,M?ki-Arvela, P?ivi,Martinez-Klimov, Mark,Muller, Joseph,Murzin, Dmitry Yu.,Peurla, Markus,Simakova, Irina,Vajglova, Zuzana
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- Method of producing hydrogen of the reaction product and substrate
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PROBLEM TO BE SOLVED: To provide a new production method requiring no reactor having high stirring power for high-temperature and high-pressure conditions in a gas-liquid catalytic reaction of a liquid phase of a substrate with hydrogen in the presence of a solid catalyst. SOLUTION: Micro or nano bubbles are introduced into a liquid phase consisting of a solvent and a substrate so that a reaction product is produced by gas-liquid contact of the substrate with hydrogen in the presence of the solid catalyst. The substrate is one of organic compounds having an unsaturated carbon bond and secondary and tertiary alcohols. COPYRIGHT: (C)2013,JPOandINPIT
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Paragraph 0047; 0048
(2017/03/24)
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- A simple and straightforward approach toward selective C=C bond reduction by hydrazine
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A simple and straightforward method for reducing the C=C double bond with hydrazine is described. A number of representative C=C bonds in various steric and electronic environments were examined. Substituted alkenes can be selectively reduced in EtOH in the presence of hydrazine to give the corresponding products in up to 100% yields.
- Chen, Hao,Wang, Jianmin,Hong, Xuechuan,Zhou, Hai-Bing,Dong, Chune
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supporting information
p. 758 - 761
(2012/11/07)
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- Stereoretentive halogenations and azidations with titanium(IV) enabled by chelating leaving groups
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Titaniumdoes it again! With the help of nucleophile-assisting leaving groups (NALGs), alkyl bromides, iodides, and, for the first time, azides are obtained from sulfonates withcomplete retention of configuration. Critical to the design of these new titanium(IV) reactions has been the use of NALGs which are thought to chelate the Lewis acid reagent in the transition state promoting an SNi-type mechanism. (Chemical Equation Presented)
- Lepore, Salvatore D.,Mondal, Deboprosad,Song, Ye Li,Bhunia, Anjan K.
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supporting information; body text
p. 7511 - 7514
(2009/03/12)
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- Regioselective radical cyclization initiated by the reaction of allylic hydroperoxides with iron(II) sulfate
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Treatment of 1-methyl-2-methylene-1-cyclohexyl hydroperoxide with a mixture of FeSO4/CuCl2 yielded 1-(1-chlorocyclohexyl)ethanone as the major product consistent with 6-endo-trig cyclization of the intermediate 5-acetylhex-5-enyl rad
- Masuyama, Araki,Sugawara, Tomohiro,Nojima, Masatomo,McCullough, Kevin J.
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p. 353 - 366
(2007/10/03)
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- Chemoselective reductive deoxygenation of α,β-unsaturated ketones and allyl alcohols
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A simple and convenient procedure for a highly chemoselective reductive deoxygenation of α,β-unsaturated ketones and allyl alcohols to olefins by sodium cyanoborohydride and boron trifluoride etherate in dry THF is described.
- Srikrishna, Adusumilli,Viswajanani, Ranganathan,Sattigeri, Jitendra A.,Yelamaggad, Channabasaveshwar V.
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p. 2347 - 2350
(2007/10/02)
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- Photochemical Transformations VI: Organic Iodides (Part 5) - Templet Effect of Transition Metal Ions on Photocyclization of Some Olefinic Acyclic Terpene Iodides
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Photocyclization of citronellyl iodide in the presence of certain transition metal salts especially CuCl, results in a significant increase (from 16percent to 35percent) in the yield of the cyclization products.Similar results have been obtained with geranyl and neryl iodides (11, 17).This enhancement of cyclization/elimination ratio is sought to be explained in terms of a templet effect of the transition metal ion.
- Subbarao, Kanury V.,Damodaran, N. P.,Dev, Sukh
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p. 1008 - 1011
(2007/10/02)
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- INVESTIGATION OF COMPOUNDS OF THE MENTHANE SERIES. XVI. REDUCTION OF o- AND p-ISOPROPENYLTOLUENES WITH CALCIUM HEXAAMMONIATE
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In the reduction of o- and p-isopropenyltoluenes with calcium hexaammoniate in the presence of protic and aprotic solvents 1,2-addition of hydrogen mostly occurs with the formation of o- and p-cymenes and o- and p-menthatrienes, which under the reaction conditions give the products from 1,2- and 1,4-addition of hydrogen.
- Bazyl'chik, V. V.
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p. 1847 - 1851
(2007/10/02)
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- Hydrogen Participation vs. Elimination. The Role and Fate of Neighboring Hydrogen in Solvolysis of Neomenthyl Tosylate
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Product composition and α-d1 and β-d3 isotope effects in the solvolysis of neomenthyl tosylate (8-OTs) were determined in 70 percent aqueous trifluoroethanol and 70 percent aqueous ethanol.Both trifluoroethanolysis and ethanolysis gave 1-2 percent neomenthol (97percent d3), 12-13percent cis-4-menthanol (100percent d3), 2-3percent trans-4-menthanol (100percent d3), 66-70percent 3-p-menthene (83percent d3 and 17percent d2), and 5-9percent 4,8-p-menthene (97percent d3), respectively.These results and the high value of the β-d3 isotope effect (kH/kD=2.45) were interpreted in terms of rate-determining hydride shift followed by elimination which accounts for 75percent of all products.In 85percent of the elimination productsthe migrating hydrogen (deuterium) is not the one being eliminated.
- Hirsl-Starcevic, Sanja,Majerski, Zdenko,Sunko, Dionis E.
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p. 3388 - 3393
(2007/10/02)
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- PHOTOCHEMICAL TRANSFORMATIONS-II ORGANIC IODIDES-II: CITRONELLYL IODIDE, 2,3-DIHYDRO-6(Z)-FARNESYL AND 2,3-DIHYDRO-6(E)-FARNESYL IODIDES
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Experimental parameters governing ?-electrons participation during photolysis of citronellyl iodide have been investigated.Photoproducts resulting from irradiation of 2,3-dihydro-6(Z)- and 2,3-dihydo-6(E)-farnesyl iodides have been characterised.
- Saplay, K. M.,Sahni, Ranjana,Damodaran, N. P.,Dev, Sukh
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p. 1455 - 1461
(2007/10/02)
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