- Selective Synthesis of Primary Amines from Nitriles under Hydrogenation Conditions
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The hydrogenation of aliphatic nitriles over Pd/C, Pd/Al2O3, and Pd?Au/Al2O3 catalysts were evaluated for the selective hydrogenation of aliphatic nitriles to the corresponding primary amines. The highest selectivity (>99%) toward primary amines was achieved when the reaction was carried out in acetic acid using 10 mol% of 25% Pd-5% Au/Al2O3 under relatively low hydrogen pressure (0.8 MPa). Characterization of the catalysts by XRD, CO adsorption experiments, and EXAFS revealed that the excellent selectivity of 25% Pd-5% Au/Al2O3 toward the synthesis of primary amines is determined by the electronic properties and/or the surface structure resulting from alloying Pd with Au. (Figure presented.).
- Yoshimura, Masatoshi,Komatsu, Akira,Niimura, Masaru,Takagi, Yukio,Takahashi, Tohru,Ueda, Shun,Ichikawa, Tomohiro,Kobayashi, Yutaka,Okami, Hiroki,Hattori, Tomohiro,Sawama, Yoshinari,Monguchi, Yasunari,Sajiki, Hironao
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- Highly Selective Hydrogenative Conversion of Nitriles into Tertiary, Secondary, and Primary Amines under Flow Reaction Conditions
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Flow reaction methods have been developed to selectively synthesize tertiary, secondary, and primary amines depending on heterogeneous platinum-group metal species under catalytic hydrogenation conditions using nitriles as starting materials. A 10 % Pd/C-packed catalyst cartridge affords symmetrically substituted tertiary amines in good to excellent yields. A 10 % Rh/C-packed catalyst cartridge enables the divergent synthesis of secondary and primary amines, with either cyclohexane or acetic acid as a solvent, respectively. Reaction parameters, such as the metal catalyst, solvent, and reaction temperature, and continuous-flow conditions, such as flow direction and second support of the catalyst in a catalyst cartridge, are quite important for controlling the reaction between the hydrogenation of nitriles and nucleophilic attack of in situ-generated amines to imine intermediates. A wide variety of aliphatic and aromatic nitriles could be highly selectively transformed into the corresponding tertiary, secondary, and primary amines by simply changing the metal species of the catalyst or flow parameters. Furthermore, the selective continuous-flow methodologies are applied over at least 72 h to afford three different types of amines in 80–99 % yield without decrease in catalytic activities.
- Furugen, Chikara,Ito, Naoya,Jiang, Jing,Park, Kwihwan,Sajiki, Hironao,Shimizu, Eisho,Yamada, Tsuyoshi
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- Conversion of Primary Amines to Symmetrical Secondary and Tertiary Amines using a Co-Rh Heterobimetallic Nanocatalyst
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Symmetrical tertiary amines have been efficiently realized from amine and secondary amines via deaminated homocoupling with heterogeneous bimetallic Co2Rh2/C as catalyst (molar ratio Co:Rh=2:2). Unsymmetric secondary anilines were produced from the reaction of anilines with symmetric tertiary amines. The Co2Rh2/C catalyst exhibited very high catalytic activity towards a wide range of amines and could be conveniently recycled ten times without considerable leaching. (Figure presented.).
- Chung, Hyunho,Han, Seulgi,Chung, Young Keun,Park, Ji Hoon
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supporting information
p. 1267 - 1272
(2018/02/12)
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- Catalyst-Dependent Selective Hydrogenation of Nitriles: Selective Synthesis of Tertiary and Secondary Amines
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In the presence of palladium on carbon (Pd/C) as a catalyst, hydrogenation of aliphatic nitriles in cyclohexane efficiently proceeded at 25-60 °C under ordinary hydrogen gas pressure to afford the corresponding tertiary amines. However, the use of rhodium on carbon (Rh/C) led to the highly selective generation of secondary amines. Hydrogenation of aromatic nitriles and cyclohexanecarbonitrile selectively produced secondary amines in the presence of either Pd/C or Rh/C.
- Monguchi, Yasunari,Mizuno, Masahiro,Ichikawa, Tomohiro,Fujita, Yuki,Murakami, Eri,Hattori, Tomohiro,Maegawa, Tomohiro,Sawama, Yoshinari,Sajiki, Hironao
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p. 10939 - 10944
(2017/10/27)
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- Making Copper(0) Nanoparticles in Glycerol: A Straightforward Synthesis for a Multipurpose Catalyst
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Small zero-valent copper nanoparticles (CuNPs) have been straightforwardly prepared from Cu(I) and Cu(II) precursors in glycerol and in the presence of polyvinylpyrrolidone as stabilizer. Thanks to the negligible vapor pressure of the solvent, these original nano-systems could be directly characterized in glycerol as well as in the solid state, exhibiting relevantly homogeneous colloidal dispersions, also even after catalysis. CuNPs coming from the well-defined coordination complex di-μ-hydroxobis[(N,N,N′,N′-tetramethylethylenediamine)copper(II)] chloride {[Cu(κ2-N,N-TMEDA)(μ-OH)]2Cl2} have been highly efficient in C–C and C–heteroatom bond formation processes. This new catalytic system has proved its performance in C–N couplings and in the synthesis of differently substituted propargylic amines through cross-dehydrogenative couplings, multi-component reactions such as A3 (aldehyde-alkyne-amine) and KA2 (ketone-alkyne-amine) couplings, as well as in the formation of heterocycles such as benzofurans, indolizines, and quinolines under smooth conditions. No significant copper amount was detected in the extracted organic compounds from the catalytic phase by inductively coupled plasma-atomic emission spectroscopic (ICP-AES) analyses, proving a highly efficient immobilization of copper nanoparticles in glycerol. From a mechanistic point of view, spectroscopic data (infrared and ultraviolet-visible spectra) agree with a surface-like catalytic reactivity. (Figure presented.).
- Dang-Bao, Trung,Pradel, Christian,Favier, Isabelle,Gómez, Montserrat
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p. 2832 - 2846
(2017/08/23)
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- PROCESS FOR PRODUCTION OF TERTIARY AMINES
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A process for producing a tertiary amine from an alcohol and a primary or secondary amine by use of a film type catalyst, which comprises circulating the reaction fluid through a reaction tank equipped with an external circulation line packed with the film type catalyst at a rate of at least three times/h to conduct the reaction.
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Page/Page column 16-18
(2008/06/13)
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