- Novel bridged tetradentate fourth subgroup metal complex as well as preparation method and application thereof (by machine translation)
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The invention provides a novel bridged tetradentate fourth subgroup metal complex and a preparation method and application thereof, wherein the complex has a formula a structure, the temperature tolerance is good, and the complex can maintain very high catalytic activity under 120 °C, can obtain ultrahigh molecular weight polyethylene, and can catalyze ethylene and norbornene, 1 - hexene and 1 - octene copolymerization reaction to obtain a polymer product with high comonomer insertion rate. (by machine translation)
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Paragraph 0223-0227
(2020/10/14)
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- Catalytic hydrogenation products of aromatic and aliphatic dicarboxylic acids
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Hydrogenation of aromatic dicarboxylic acids gave 100 % selectivity to respective cyclohexane dicarboxylic acid with 5 % Pd/C catalyst. 5 % Ru/C catalyst was observed to give over hydrogenation products at 493 K and at lower temperature (453 K) the selectivity for cyclohexane dicarboxylic acids was increased. Hydrogenation of phthalic acid with Ru-Sn/Al2O3 catalyst was observed to give phthalide instead of 1,2-benzene dimethanol or 2-hydroxy methyl benzoic acid. Ru-Sn/Al2O3 catalyst selectively hydrogenated the carboxylic group of cyclohexane dicarboxylic acids to give cyclohexane dimethanol. Use of proper catalysts and reaction conditions resulted in desired products.
- Shinde, Sunil B.,Deshpande, Raj M.
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p. 1137 - 1142
(2019/04/05)
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- ZINC COMPLEX
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A zinc complex characterized in exhibiting an octahedral structure and being configured from repeating units represented by general formula (I): wherein L represents a linker region, and R1 represents a C1-4 alkyl group, which can have a halogen atom.
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Paragraph 0160-0161
(2016/05/19)
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- Iron(II) pincer-catalyzed synthesis of lactones and lactams through a versatile dehydrogenative domino sequence
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The synthesis of lactones and lactams by using iron(II) pincer-catalyzed dehydrogenative methodology was developed. Starting from 1,n-diols or 1,n-amino alcohols, this domino transformation takes place through initial dehydrogenation of the substrates, subsequent intramolecular cyclization, and final oxidation to afford the desired products in good yields. The ability to access heterocycles of different sizes makes this protocol especially versatile, in which two consecutive oxidation reactions are performed without requiring an external oxidant. In this paper, we report the application of the Fe-MACHO-BH complex [carbonylhydrido(tetrahydroborato)[bis(2-diisopropylphosphinoethyl)amino]iron(II)] in this atom-efficient and environmentally benign process, for which molecular hydrogen is formed as the only stoichiometric side product. Just a little pinch: The iron(II) pincer-catalyzed synthesis of lactones and lactams from easily available 1,n-diols and 1,n-amino alcohols is explored. The use of a nontoxic metal as well as the generation of molecular hydrogen as the only stoichiometric byproduct makes this method a highly atom-efficient and environmentally benign process.
- Pea-Lpez, Miguel,Neumann, Helfried,Beller, Matthias
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p. 865 - 871
(2015/03/14)
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- 1-Aryl-5-(1H-pyrrol-1-yl)-1H-pyrazole-3-carboxamide: An effective scaffold for the design of either CB1 or CB2 receptor ligands
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New 1-aryl-5-(1H-pyrrol-1-yl)-1H-pyrazole-3-carboxamides were synthesized as cannabinoid (CB) receptor ligands. Compound 11 (CB1 Ki = 2.3 nM, CB1 SI = 163.6) showed CB1 receptor affinity and selectivity superior to Rimonabant and AM251. Acute administration of 2 mg/kg 11 reduced sucrose, but not regular food, intake in rats. On the other hand, compound 23 (CB2 Ki = 0.51 nM, CB2 SI = 30.0) showed significant affinity and selectivity for the CB2 receptor. The results presented here show that the 1-aryl-5-(1H-pyrrol-1-yl)-1H-pyrazole-3- carboxamide may serve as an effective scaffold for the design of either CB 1 or CB2 receptor ligands.
- Piscitelli, Francesco,Ligresti, Alessia,La Regina, Giuseppe,Gatti, Valerio,Brizzi, Antonella,Pasquini, Serena,Allar, Marco,Carai, Mauro Antonio Maria,Novellino, Ettore,Colombo, Giancarlo,Di Marzo, Vincenzo,Corelli, Federico,Silvestri, Romano
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experimental part
p. 5641 - 5653
(2012/01/02)
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- Dihalocarbene insertion reactions into C-H bonds of compounds containing small rings: Mechanisms and regio- and stereoselectivities
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(Chemical Equation Presented) Novel insertion reactions of dichloro- and dibromocarbene into carbon-hydrogen bonds adjacent to cyclopropane rings are reported. It is found that the predominant isomers formed in the reactions with bicyclo[4.1.0]heptane result from insertion into the endo carbon-hydrogen bonds alpha to the three-membered ring. In the reactions of bicyclo[3.1.0]hexane, however, the exo dihalocarbene insertion products are formed as the major isomers. In some compounds cyclopropane rings "activate" adjacent carbon-hydrogen bonds, whereas other systems containing three-membered rings do not. Moreover, the influence of various substituents (methyl, geminal dimethyl, phenyl, methoxy, and ethoxy) attached to bicyclo-[3.1.0]hexane and bicyclo[4.1.0]heptane in dihalocarbene reactions has been studied. The findings can be explained by the concept of maximum orbital overlaps of Walsh orbitals of the cyclopropane rings and the α carbon-hydrogen bonds. In stark contrast, selective insertion into the tertiary carbon-hydrogen bonds of the cyclobutane ring in bicyclo[4.2.0]octane is observed.
- Brinker, Udo H.,Lin, Guoying,Xu, Linxiao,Smith, William B.,Mieusset, Jean-Luc
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p. 8434 - 8451
(2008/02/13)
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- A practical and efficient procedure for reduction of carboxylic acids and their derivatives: use of KBH4-MgCl2
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The use of KBH4-MgCl2 to reduce carboxylic acids and their derivatives to the corresponding alcohols or the respective reduced products is described. Methyl (S)-3,4-O-isopropylidene-3,4-dihydroxy butanoate 2 used as a reference substrate was reduced with KBH4 and MgCl2 in 1:1 mol ratio to (S)-1,2-O-isopropylidene-1,2,4-butanetriol 1.
- Qiu, You-Chun,Zhang, Fu-Li,Zhang, Chun-Nian
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p. 7595 - 7598
(2008/03/14)
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- Mild and convenient method for reduction of aliphatic and aromatic carboxylic acids and anhydrides with (pyridine)(tetrahydroborato)zinc complex as a new stable ligand-metal tetrahydroborate agent
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Structurally different aliphatic and aromatic carboxylic acids and anhydrides are efficiently reduced to their corresponding alcohols with a new modified zinc tetrahydroborate agent, (pyridine)(tetrahydroborato)zinc complex, [(Py)Zn(BH4)2], in refluxing THF.
- Zeynizadeh, Behzad,Zahmatkesh, Karam
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p. 522 - 525
(2007/10/03)
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- Three bacteriorhodopsins with ring-didemethylated 6-s-locked chromophores and their properties
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Three novel, 6-s-locked rigidified retinals, racemic all-E 1,5-didemethyl-8,16-methanoretinal, all-E, 1,1-didemethyl-8,18-methanoretinal and all-E 8a,18-didehydro-1,1-didemethyl-8,18-methanoretinal were prepared in good yield in high purity on a 100-mg scale.For the preparation of the key intermediate in the synthesis of 1,5-didemethyl-8,16-methanoretinal, reductive cyanation of an unsaturated cyanohydrin to the corresponding conjugated nitrile was accomplished using triethylsilane and trifluoroacetic acid.The three locked retinals interact with bacterioopsin to form bacteriorhodopsin with about the same rate as the native chromophore.This work proves that steric interaction of the 1,1-dimethyl group in the chromophore is an important factor in binding to bacterioopsin.
- Groesbeek, M.,Galen, A. J. J. van,Ippel, J. H.,Berden, J. A.,Lugtenburg, J.
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p. 237 - 246
(2007/10/02)
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- Lanthanoids in Organic Synthesis. I. The Novel Reduction of Carboxylic Acids with Samarium Diiodide-Base System
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Aromatic and aliphatic carboxylic acids were rapidly reduced with samarium diiodide by the addition of base in the presence of protic solvent at room temperature to the corresponding alcohols.Sodium benzoate was similarly reduced with samarium diiodide in the presence of H2O in a good yield.In the similar reactions of benzoic acid derivatives bearing carboxyl, formyl, carbamoyl, methoxyl, and chloro groups, these functional groups were also reduced to the corresponding alcohol or amine derivatives.Interestingly, the carboxyl and formyl groups of benzoic acids were partly reduced into the methyl group.
- Kamochi, Yasuko,Kudo, Tadahiro
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p. 3049 - 3054
(2007/10/02)
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- CATALYTIC SYNTHESIS OF N-ALKYLOCTAHYDROISOINDOLES
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Catalytic hydroamination of 1,2-bis(hydroxymethyl)cyclohexane by aliphatic nitriles over a nickel catalyst yielded a series of N-alkyl-substituted octahydroisoindoles.Conditions for their synthesis were selected.The IR, PMR, and mass spectra and the proba
- Kozintsev, S. I.,Zhavrid, A. S.,Serzhanin, A. I.,Kozlov, N. S.
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p. 1346 - 1348
(2007/10/02)
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