- Structure of catalytically active Rh-In bimetallic phase for amination of alcohols
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The structure of Rh-In bimetallic catalysts supported on carbon for amination of alcohols was determined by XRD, TEM-EDX, XPS, CO adsorption and EXAFS. At low In/Rh ratio (In/Rh ≤ 0.2), Rh metal particles with sizes of a tetragonal RhIn alloy with a particle size of ～20 nm was formed. This tetragonal alloy has a structure with a = 0.315 nm and c = 0.328 nm where metal atoms are located at (0, 0, 0) and (0.5, 0.5, 0.5). The catalytic activity of the tetragonal RhIn alloy is much higher than that of Rh metal particles with or without indium oxide species. With an excess amount of In (In/Rh > 1) on the high Rh loading (20 wt%) catalyst, the cubic RhIn phase with a CsCl structure was observed instead of the tetragonal RhIn phase, and the catalytic activity was much decreased.
- Takanashi, Tsukasa,Tamura, Masazumi,Nakagawa, Yoshinao,Tomishige, Keiichi
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- Reversible Interconversion between 2,5-Dimethylpyrazine and 2,5-Dimethylpiperazine by Iridium-Catalyzed Hydrogenation/Dehydrogenation for Efficient Hydrogen Storage
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A new hydrogen storage system based on the hydrogenation and dehydrogenation of nitrogen heterocyclic compounds, employing a single iridium catalyst, has been developed. Efficient hydrogen storage using relatively small amounts of solvent compared with previous systems was achieved by this new system. Reversible transformations between 2,5-dimethylpyrazine and 2,5-dimethylpiperazine, accompanied by the uptake and release of three equivalents of hydrogen, could be repeated almost quantitatively at least four times without any loss of efficiency. Furthermore, hydrogen storage under solvent-free conditions was also accomplished.
- Fujita, Ken-Ichi,Wada, Tomokatsu,Shiraishi, Takumi
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- Regioselectivity and selective enhancement of carbon dioxide fixation of 2-substituted aziridines to 2-oxazolidinones under supercritical conditions
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Under supercritical CO2 conditions, regioselectivity in the carbon dioxide fixation of 2-substituted aziridines to 2-oxazolidinones was observed with good yields around 75%. Furthermore, when propylene imine was used in the place of aziridine,
- Kawanami, Hajime,Ikushima, Yutaka
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- Synthesis of 1,2-propanediamine via reductive amination of isopropanolamine over Raney Ni under the promotion of K2CO3
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Catalytic amination of isopropanolamine and ammonia to 1,2-propanediamine over Raney Ni with potassium carbonate as the additive was reported. Characterization of N2 adsorption–desorption and XRD were performed to reveal the textural and structural properties of the catalysts. With the additive of potassium carbonate, the selectivity of 1,2-propanediamine was improved, while the side generation of 2,5-dimethylpiperazine was suppressed. The catalytic reaction parameters were optimized and the yield of 1,2-propanediamine reached 80% under the optimized reaction condition.
- Yu, Qin-Wei,Li, Ya-Ni,Zhang, Qian,Wang, Wei-Qiang,Mei, Su-Ning,Hui, Feng,Shi, Jian,Zhao, Feng-Wei,Yang, Jian-Ming,Lu, Jian
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p. 2019 - 2026
(2019/09/09)
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- METHOD FOR PRODUCING AMINES FROM GLYCERIN
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The present invention relates to a process for preparing amines by reacting glycerol with hydrogen and an aminating agent from the group of ammonia and primary and secondary amines in the presence of a catalyst at a temperature of from 100° C. to 400° C. and a pressure of from 0.01 to 40 MPa (from 0.1 to 400 bar). Preference is given to using glycerol based on renewable raw materials. The catalyst preferably comprises one metal or a plurality of metals or one or more oxygen compounds of the metals of groups 8 and/or 9 and/or 10 and/or 11 of the Periodic Table of the Elements. The invention further relates to the use of the reaction products as an additive in cement or concrete production and in other fields of use. This invention further provides the compounds 1,2,3-triaminopropane, 2-aminomethyl-6-methylpiperazine, 2,5-bis(aminomethyl)piperazine and 2,6-bis(aminomethyl)piperazine.
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Page/Page column 12-13; 14
(2010/10/03)
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- METHOD FOR PRODUCING AMINES FROM SUGAR ALCOHOLS
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The present invention relates to a process for preparing amines by reacting sugar alcohols with hydrogen and an aminating agent selected from the group of ammonia and primary and secondary amines in the presence of a catalyst at a temperature of from 100° C. to 400° C. and a pressure of from 1 to 40 MPa (from 10 to 400 bar). The catalyst preferably comprises one metal or a plurality of metals or one or more oxygen compounds of the metals of groups 8 and/or 9 and/or 10 and/or 11 of the Periodic Table of the Elements. The sugar alcohol is preferably obtained by hydrogenating the corresponding sugars. The invention further relates to the use of the reaction products as an additive in cement or concrete production and in other fields of use.
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Page/Page column 10
(2010/12/29)
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- Reductive amine deallyl- and debenzylation with alkali metal in Silica Gel (M-SG)
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Alkali metals in silica gel (the M-SG materials) are effective reagents for reductive deallylation, debenzylation, debenzhydrylation, and detritylation of amines. As such, these reagents provide a convenient alternative to traditional metal ammonia solutions for this class of deprotections.
- Nandi, Partha,Dye, James L.,Jackson, James E.
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supporting information; experimental part
p. 3864 - 3866
(2009/09/28)
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- Azo dyes
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Compound of the formula (I) whereinR is hydrogen or optionally substituted C1-C6-alkyl,R1 is hydrogen or C1-C6-alkyl,R2 is hydrogen, optionally substituted C1-C6-alkyl or optionally substituted phenyl,the ring D is optionally substituted by one or more identical or different substituents selected from the group consisting of C1-C6-alkyl, C1-C6-alkoxy, halogen, especially F, Cl and Br, and SO3H,m is 0 or 1,n is 1, 2 or 3 and as a function of nX is a mono-, di- or trivalent acyl radical, pyrimidine or 1,3,5-triazine radical which is not fiber-reactive.
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- Process for preparing pyrazines from hydroxyamines
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This invention relates to the reaction of hydroxyamines to form pyrazines by a process comprising reacting said hydroxyamine in the presence of a catalyst which may be a transition metal catalyst optionally containing an alkaline earth metal oxide, or alternatively the catalyst may be a rhodium, ruthenium or palladium-containing compound and a phosphine-containing compound.
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- Process for preparing pyrazines from hydroxyamines
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This invention relates to the cyclocondensation of hydroxyamines to form pyrazines by a process comprising reacting said hydroxyamine in the presence of a catalyst comprising a rhodium, ruthenium or palladium-containing compound and a phosphine-containing compound under mild conditions.
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- A New Method for Obtaining Isotopic Fractionation Data at Multiple Sites in Rapidly Exchanging Systems
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A new method for rapidly and conveniently obtaining isotopic fractionation factors in dilute aqueous solutions of compounds containing rapidly exchanging OH, NH, and SH groups is described.Shifts in the positions of NMR peaks for spectroscopically observable nuclei induced by isotopic substitution are the basis of this procedure which has the unique capability of separately measuring the isotopic exchange constants simultaneously for several different groups in the same molecule.The results for a series of alcohols, amines, thiols, phenols, acids, and amides with use of 13C NMR spectroscopy are reported.Atypically low values of Kfrac are observed in several cases, indicating that there are strong internal hydrogen bonds in competition with those to water, yielding conformational information.
- Jarret, Ronald M.,Saunders, Martin
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p. 2648 - 2654
(2007/10/02)
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- Novel polytriazine compounds
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Novel tetraalkyl piperidine radical containing polytriazine compounds are produced by reacting a dihalogen-triazine with a bifunctional compound containing amine, alcohol, mercaptan or phenol groups at least one of the bifunctional compounds containing a tetraalkyl piperidine radical. The compounds are valuable light stabilizers for synthetic polymers, particularly polyolefin in the form of fibers or films.
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