- PtRuNi/C novel nanostructures of platinum-ruthenium island-on-Ni/Ni(OH)2 nanoparticles for the selective hydrogenation of quinoline
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Ni/C was successfully synthesized via hydrazine hydrate reduction at room temperature (RT). Pt/C, Ru/C and PtRu/C were prepared via an impregnation method. PtNi/C, RuNi/C and PtRuNi/C were synthesized via a chemical replacement method. The characterization results revealed that PtRuNi nanoparticles (NPs) were highly and uniformly dispersed on carbon black in PtRuNi/C. PtRuNi/C showed a novel nanostructure in which PtRu islands (PtRu nanoclusters or PtRu binary atoms) covered Ni/Ni(OH)2 NPs. PtRuNi/C trimetallic nanomaterial exhibited an optimum catalytic performance (turnover frequency (TOF) = 211.4 h?1 and selectivity for the production of 1,2,3,4-tetrahydroquinoline (py-THQ) > 99%) in the selective hydrogenation of quinoline at 60 °C under 5.0 MPa H2. The catalytic properties of PtRuNi/C were significantly improved as compared to bimetallic (PtNi/C, RuNi/C and PtRu/C) and monometallic (Ni/C, Pt/C and Ru/C) nanomaterials due to its unique nanostructure, with an observed nano-synergy effect among Pt-, Ru- and Ni-related species.
- Chen, Bing Hui,Liao, Jianhua,Pei, An,Ruan, Luna,Wang, Jiexiang,Yang, Kai,Zhang, Huan,Zhu, Lihua
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- Catalyst component, catalyst for olefin polymerization, and process for producing olefin polymer using catalyst
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A polymer having high catalyst activity, excellent hydrogen response, high stereoregularity and high yield can be obtained by polymerizing olefins in the presence of a catalyst for olefin polymerization comprising (A) a solid catalyst component containing magnesium, titanium, a halogen, and an electron donor compound, (B) an organoaluminum compound shown by the formula R6pAlQ3-p(R1R2N)m, and (C) an aminosilane compound shown by the formula (R3HN)nR4pSi(OR5)q.
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- PEPTIDE COMPOUNDS DERIVED FROM BORONIC ACID
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A compound of formula (I): STR1 in which: R 1 represents hydrogen or acyl, alkyl, benzyl, alkoxycarbonyl, benzyloxycarbonyl, phenoxycarbonyl, 5-[(dimethyl)amino]naphthylsulfonyl, alkoxycarbonylmethyl or carboxymethyl,R 2 represents hydrogen or phenyl, substituted or unsubstituted benzyl, 3-thienylmethyl, 2-pyridylmethyl, diphenylmethyl, fluorenyl, naphthylmethyl, benzocyclobutyl, (dicyclopropylmethyl)methyl, indanyl or (C 3-C 7 cycloalkyl)methyl,R' 2 represents hydrogen or benzylor alternativelyR 2 and R'. sub.2 together represent C 6 H 5--CH=,R. sub.3 represents substituted alkyl or guanidinophenyl, amidinophenyl, aminophenyl, guanidinobenzyl, amidinobenzyl, aminobenzyl or cycloalkyl, R 4 and R 5 each represent hydrogen or alkyl, or STR2 forms a boronic ester of pinanediol, A represents any one of the groups as defined in the description.Medicinal products.
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- Mechanism of Isomerization of 1,2,3,4-Tetrahydroisoquinoline to 5,6,7,8-Tetrahydroisoquinoline over Raney Nickel
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The isomerization of 1,2,3,4-tetrahydroisoquinoline to 5,6,7,8-tetrahydroisoquinoline proceeded over Raney nickel at ca. 200 deg C under hydrogen and nitrogen pressure in a closed reactor.Based on kinetic analyses and quantum chemical calculations we propose that the isomerization proceeds through a series of consecutive steps where dehydrogenation and hydrogenation take place in an alternate manner.The isomerization is initiated by dehydrogenation at the C-1 and N positions of 1,2,3,4-tetrahydroisoquinoline to form 3,4-dihydroisoquinoline which, in turn, is rehydrogenated into 3,4,6,7-tetrahydroisoquinoline and 3,4,5,6,7,8-hexahydroisoquinoline.The hexahydroisoquinoline is finally dehydrogenated into the isomerized product.No extra hydrogen appears to be required for the isomerization.Under a nitrogen stream in an open reactor, the selective formation of isoquinoline occurred.
- Okazaki, Hiroshi,Onishi, Kiyotaka,Ikefuji, Yoshio,Tamura, Ryuji
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p. 1321 - 1327
(2007/10/02)
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- Hydrogenation Pathway of Quinolines over Raney Nickel and Ru/C
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Quinoline, 2-methylquinoline, and 8-methylquinoline were hydrogenated over Raney Nickel (R-Ni) under 10 atm hydrogen pressure at about 200 deg C and over ruthenium on carbon (Ru/C) under 100 atm hydrogen pressure at 150 deg C.All the substrates were commonly hydrogenated into the initial products, 1,2,3,4-tetrahydroquinolines.The initial products were competitively converted over R-Ni to the final products, decahydroquinolines, directly or via 5,6,7,8-tetrahydroquinolines which were mainly formed from the initial products by isomerization.Ru/C promoted exclusively the direct hydrogenation of 1,2,3,4-tetrahydro derivatives to the final products.The hydrogenation and isomerization of 1,2,3,4-tetrahydroquinoline was completely inhibited in the competitive hydrogenation of quinoline and isoquinoline over R-Ni.Such features of these substrates are explained by the strong basicity of 1,2,3,4-tetrahydroisoquinoline.Roles of 1,2,3,4-tetrahydroisoquinoline are much moderate on Ru/C, where the ?-coordination may be important.The effects of methyl substituent and different reactivities of quinoline and isoquinoline are discussed in terms of the steric hindrance on adsorption, heats of hydrogenation, basicities, and electronic properties of the related compound, which are calculated according to the MNDO-PM3 method.
- Okazaki, Hiroshi,Onishi, Kiyotaka,Soeda, Mahito,Ikefuji, Yoshio,Tamura, Ryuji,Mochida, Isao
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p. 3167 - 3174
(2007/10/02)
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- The Intramolecular Diels-Alder Cycloaddition of N-Dienoyl Acrylimidates. An Efficient Approach for the Synthesis of Hexahydroisoquinolones and Hexahydroisoindolones
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The intramolecular Diels-Alder reaction of aza trienes featuring the N-acyl vinyl imidate moiety in the chain linking the diene and dienophile has been investigated.The acrylimidate bases 3a-d were synthesized by O-alkylation of the corresponding acrylamides 1a-d followed by deprotonation of imidate salts 2a-d.The imidates were efficiently acylated with 3,5-dienoyl chlorides 5a,e-g in yields ranging from 73 to 87percent.The trienes 6a-g underwent cycloaddition under conditions ranging from 80 to 140 deg C, affording mixtures of cis 7a-g and trans 8a-g hexahydroisoquinolones, respectively, with a preponderance of the cis cycloadduct.The stereochemistry of the major adduct was determined from proton coupling constants and conversion of 7a to the known cis-perhydroisoquinoline 18.The cis stereochemistry is understood to originate from cyloaddition in the prefered endo conformation. 2,4-Hexadienoyl imidates 20a,d also underwent cycloaddition to afford cis hexahydroisoindolones 21a,d and 22a,d.The cycloadducts 7a,e-g were reduced with NaBH4 and NaCNBH3 to the corresponding lactams 24a,e-g.
- Gutierrez, Arnold J.,Shea, Kenneth J.,Svoboda, John J.
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p. 4335 - 4344
(2007/10/02)
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- Process for production of decahydroisoquinoline
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A process for the production of decahydroisoquinoline is disclosed which comprises hydrogenating isoquinoline or partially hydrogenated isoquinoline in the presence of a ruthenium catalyst at a temperature of 110° C. to 230° C. under a hydrogen pressure of at least 10 kg/cm2 *G.
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- THE INTRAMOLECULAR DIELS-ALDER CYCLOADDITION OF N-DIENOYL ACRYLIMIDATES. NEW METHODOLOGY FOR THE CONSTRUCTION OF NITROGEN HETEROCYCLES
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N-(3,5-Hexadienoyl)-acrylimiates, which have been synthesized by acylation of 2-ethoxy-1-aza-1,3-butadienes with 3,5-hexadienoyl chloride, are found to undergo facile intramolecular Diels-Alder cycloadditions to afford predominately cis-hexahydroisoquinolines in good yields.
- Shea, K.J.,Svoboda, J.J.
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p. 4837 - 4840
(2007/10/02)
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- Conformational Equilibria due to Ring Inversion in N-Alkyl-cis-decahydroisoquinolines
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The position of conformational equilibria due to ring inversion in N-alkyl-cis-decahydroisoquinolines (alkyl = Me, Et, Pri, CH2CF3, or CH2CCl3) has been assessed directly from 13C and/or 19F n.m.r. spectra recorded at temperatures between 173 and 253 K.The measured equilibrium constants are related to the inductive effect of the N-substituent which produces an increase (Me, Et, Pri) or decrease (CH2CF3, CH2CCl3) in the magnitude of the gauche propylamine-type repulsive interaction. 13C Chemical shifts are tabulated for the carbon atoms of the two twin-chair conformations undergoing exchange.
- Bailey, Judith M.,Booth, Harold,Al-Shirayda, Hatif A. R. Y.
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p. 583 - 588
(2007/10/02)
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- N-Alkenyl decahydroisoquinolines
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1-Alkenyl-3a-substituted-phenyl decahydroisoquinolines, useful as analgetic agonists or analgetic antagonists.
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- Novel cis N-cyclopropylmethyl decahydroisoquinoline
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Cis-1-cyclopropylmethyl-3a-(substituted-phenyl) decahydroisoquinoline, useful as analgetic agonist and analgetic antagonist.
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