- Method for selective catalytic hydrogenation of aromatic heterocyclic compounds in non-hydrogen participation manner
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The invention discloses a method for selective catalytic hydrogenation of aromatic heterocyclic compounds in a non-hydrogen participation manner. The method comprises the following steps: by taking 1, 5-cyclooctadiene iridium chloride dimer as a catalyst and phenylsilane as a hydrogen source, carrying out stirring reaction under mild conditions without adding a ligand, namely catalytically hydrogenating the aromatic heterocyclic compounds to obtain hydrogenated products of the aromatic heterocyclic compounds. The method has the advantages of low cost, mild reaction conditions, high selectivity and the like, and special equipment such as a high-pressure kettle and the like and high-temperature conditions which are required when hydrogen is used are avoided.
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Paragraph 0025-0029; 0153-0157
(2021/08/19)
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- Convenient synthesis of cobalt nanoparticles for the hydrogenation of quinolines in water
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Easily accessible cobalt nanoparticles are prepared by hydrolysis of NaBH4 in the presence of inexpensive Co(ii) salts. The resulting material is an efficient catalyst for the hydrogenation of quinoline derivatives in water. The activity and chemoselectivity of this catalyst are comparable to other cobalt-based heterogeneous catalysts.
- Beller, Matthias,Dorcet, Vincent,Fischmeister, Cedric,Hervochon, Julien,Junge, Kathrin
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p. 4820 - 4826
(2020/08/14)
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- Homogeneous Hydrogenation with a Cobalt/Tetraphosphine Catalyst: A Superior Hydride Donor for Polar Double Bonds and N-Heteroarenes
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The development of catalysts based on earth abundant metals in place of noble metals is becoming a central topic of catalysis. We herein report a cobalt/tetraphosphine complex-catalyzed homogeneous hydrogenation of polar unsaturated compounds using an air- and moisture-stable and scalable precatalyst. By activation with potassium hydroxide, this cobalt system shows both high efficiency (up to 24 000 TON and 12 000 h-1 TOF) and excellent chemoselectivities with various aldehydes, ketones, imines, and even N-heteroarenes. The preference for 1,2-reduction over 1,4-reduction makes this method an efficient way to prepare allylic alcohols and amines. Meanwhile, efficient hydrogenation of the challenging N-heteroarenes is also furnished with excellent functional group tolerance. Mechanistic studies and control experiments demonstrated that a CoIH complex functions as a strong hydride donor in the catalytic cycle. Each cobalt intermediate on the catalytic cycle was characterized, and a plausible outer-sphere mechanism was proposed. Noteworthy, external inorganic base plays multiple roles in this reaction and functions in almost every step of the catalytic cycle.
- Duan, Ya-Nan,Du, Xiaoyong,Cui, Zhikai,Zeng, Yiqun,Liu, Yufeng,Yang, Tilong,Wen, Jialin,Zhang, Xumu
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supporting information
p. 20424 - 20433
(2019/12/27)
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- Method for conducting catalytic hydrogenation on nitrogen-containing unsaturated heterocyclic compound
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The invention provides a method for conducting catalytic hydrogenation on a nitrogen-containing unsaturated heterocyclic compound, and belongs to the technical field of catalytic hydrogenation. The provided method for conducting catalytic hydrogenation on the nitrogen-containing unsaturated heterocyclic compound comprises the following step: in the presence of hydrogen and a manganese catalyst, with the nitrogen-containing unsaturated heterocyclic compound as a substrate, carrying out a hydrogenation reaction. According to the method for conducting catalytic hydrogenation on the nitrogen-containing unsaturated heterocyclic compound, he adopted manganese catalyst is an NNP-type pincer manganese catalyst, has the advantages of being cheap, easy to obtain and low in toxicity compared with noble metal catalysts, has the advantages of being wide in substrate applicability and high in target product yield compared with an existing cheap metal iron catalyst or cobalt catalyst, and is higher in electron donating ability and smaller in steric hindrance compared with a PNP-type pincer manganese catalyst, and thus shows higher reaction activity in a series of hydrogenation reactions, and thetarget product yield is up to 99%.
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Paragraph 0094-0104
(2020/01/03)
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- A robust iron catalyst for the selective hydrogenation of substituted (iso)quinolones
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By applying N-doped carbon modified iron-based catalysts, the controlled hydrogenation of N-heteroarenes, especially (iso)quinolones, is achieved. Crucial for activity is the catalyst preparation by pyrolysis of a carbon-impregnated composite, obtained from iron(ii) acetate and N-aryliminopyridines. As demonstrated by TEM, XRD, XPS and Raman spectroscopy, the synthesized material is composed of Fe(0), Fe3C and FeNx in a N-doped carbon matrix. The decent catalytic activity of this robust and easily recyclable Fe-material allowed for the selective hydrogenation of various (iso)quinoline derivatives, even in the presence of reducible functional groups, such as nitriles, halogens, esters and amides. For a proof-of-concept, this nanostructured catalyst was implemented in the multistep synthesis of natural products and pharmaceutical lead compounds as well as modification of photoluminescent materials. As such this methodology constitutes the first heterogeneous iron-catalyzed hydrogenation of substituted (iso)quinolones with synthetic importance.
- Sahoo, Basudev,Kreyenschulte, Carsten,Agostini, Giovanni,Lund, Henrik,Bachmann, Stephan,Scalone, Michelangelo,Junge, Kathrin,Beller, Matthias
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p. 8134 - 8141
(2018/11/20)
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- Catalytic asymmetric hydrogenation of quinoline carbocycles: Unusual chemoselectivity in the hydrogenation of quinolines
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The reduction of quinolines selectively took place on their carbocyclic rings to give 5,6,7,8-tetrahydroquinolines, when the hydrogenation was conducted in the presence of a Ru(η3-methallyl)2(cod)-PhTRAP catalyst. The chiral ruthenium catalyst converted 8-substituted quinolines into chiral 5,6,7,8-tetrahydroquinolines with up to 91:9 er. This journal is
- Kuwano, Ryoichi,Ikeda, Ryuhei,Hirasada, Kazuki
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supporting information
p. 7558 - 7561
(2015/05/04)
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- Selectivity of Hydrogenations. Part 4. 6- and 8-Substituted Quinaldines. Yield of Tetrahydroderivatives and Basicities of Quinolines
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Hydrogenation of 6- or 8-R-substituted quinaldines over platinum in trifluoracetic acid gave higher yields (ca.90percent) of 5,6,7,8-tetrahydroderivatives than hydrogenation of the corresponding quinolines.The pKa-values of 20 quinolines and quinaldines were determined by measuring the half-neutralisation potentials in acetic anhydride.More basic quinolines gave higher yields of 5,6,7,8-tetrahydroproduct; exceptions are 6- and 8-methylquinoline and 8-tert. butylquinoline.Explanations for these observations are suggested. - Keywords:Catalytic hydrogenation; PKa-Values; Quinaldines; Quinolines; 5,6,7,8-Tetrahydroquinolines, yields of.
- Hoenel, Michael,Vierhapper, Friedrich W.
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p. 1219 - 1228
(2007/10/02)
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- COMPOSITION OF THE PRODUCTS AND KINETICS OF THE ISOPROPYLATION OF 1,2,3,4-TETRAHYDROQUINOLINE IN SULFURIC ACID
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The kinetics of the alkylation of 1,2,3,4-tetrahydroquinoline with isopropyl alcohol in 90percent sulfuric acid at 60 deg C were studied.It was established that the rate of alkylation in the 5 position is higher than for corresponding position in the acyclic analog N,2-dimethylaniline; this was ascribed to the Mills-Nixon dynamic effect.
- Okhrimenko, Z. A.,Chekhuta, V. G.,Kachurin, O. I.
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p. 409 - 412
(2007/10/02)
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