- The synthesis of amines by the homogeneous hydrogenation of secondary and primary amides
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Amides can be hydrogenated to amines using a catalyst prepared in situ from [Ru(acac)3] and 1,1,1-tris(diphenylphosphinomethyl)ethane; water is required to stabilize the catalyst and primary amines can only be formed (selectivity up to 85%) if ammonia is also present. The Royal Society of Chemistry.
- Nú?ez Magro, Angel A.,Eastham, Graham R.,Cole-Hamilton, David J.
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Read Online
- One-pot reductive amination of carboxylic acids: a sustainable method for primary amine synthesis
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The reductive amination of carboxylic acids is a very green, efficient and sustainable method for the production of (bio-based) amines. However, with current technology, this reaction requires two to three reaction steps. Here, we report the first (heterogeneous) catalytic system for the one-pot reductive amination of carboxylic acids to amines, with solely H2 and NH3 as the reactants. This reaction can be performed with relatively cheap ruthenium-tungsten bimetallic catalysts in the green and benign solvent cyclopentyl methyl ether (CPME). Selectivities of up to 99% for the primary amine could be achieved at high conversions. Additionally, the catalyst is recyclable and tolerant for common impurities such as water and cations (e.g. sodium carboxylate).
- Coeck, Robin,De Vos, Dirk E.
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supporting information
p. 5105 - 5114
(2020/08/25)
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- PRODUCTION METHOD OF AMIDE COMPOUND
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PROBLEM TO BE SOLVED: To provide a production method of an amide compound, which can use a variety of carboxylic acid halides and can produce a desired amide compound at a yield higher than a batch process by suppressing a side reaction. SOLUTION: Provided is a production method of an amide compound using a flow type reactor, in which the flow type reactor includes: a first flow path; a second flow path; a first mixing means provided at a confluent part of the first flow path and the second flow path; and a third flow path that is connected to the first mixing means and arranged on a down stream side of the first mixing means, the production method comprising: a mixing step of obtaining a mixed liquid by circulating a first liquid containing the carboxylic acid halide in the first flow path, circulating a second liquid containing an amine compound having a molecular weight of 1,000 or less, an inorganic alkali and water in the second flow path, and mixing the first liquid and the second liquid by the first mixing means to obtain a mixture; and a reaction step of obtaining an amide compound by circulating the mixed liquid in the third flow path and reacting the carboxylic acid halide and the amine compound in the third flow path. SELECTED DRAWING: Figure 1 COPYRIGHT: (C)2020,JPO&INPIT
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Paragraph 0134-0137
(2020/10/08)
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- Substrate-selective dehydrocondensation at the interface of micelles and emulsions of common surfactants
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Scratch the surface: Dehydrocondensations between carboxylates and amines by using an amphiphilic 1,3,5-triazinylammonium-based coupling agent were accelerated by the interfacial effect of micelles and emulsions of common surfactants (see figure). The reaction of carboxylates was promoted by both anionic and nonionic surfactants, and that of amines was promoted by only a nonionic surfactant. High selectivities for more lipophilic substrates were observed in micelles or emulsions. Copyright
- Kunishima, Munetaka,Kikuchi, Kanako,Kawai, Yukio,Hioki, Kazuhito
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supporting information; experimental part
p. 2080 - 2083
(2012/05/20)
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- PRODUCTION OF AMINES
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A process for the hydrogenation of carboxylic acids and/or derivatives, particularly amides, is described. The process includes reacting an acid or derivative such as an amide with a source of hydrogen in the presence of a catalyst system. The catalyst system obtainable by combining: (a) a source of ruthenium, and (b) a phosphine compound of general Formula I: (Formula I). The hydrogenation reaction is carried out in the presence of a low concentration of water or at low pressure or in the presence of a source of ammonia or the hydrogenation reaction is carried out in the absence of water or a combination of these factors is utilised. The invention also relates to the use of ammonia in the production of primary amines by hydrogenation of carboxylic acids and/or derivatives thereof or a process for the production of primary amines generally.
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Page/Page column 24
(2008/06/13)
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- DEHYDRATING CONDENSATION AGENT HAVING PROPERTY OF ACCUMULATING AT INTERFACE WITH WATER
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The present invention provides a 1,3,5-triazine compound represented by the following formula I: This compound can be synthesized easily and more economically and can be used as a dehydrating condensing agent having the property of accumulating at a water interface. In the case where carboxylic acid, amine, alcohol or other reaction substrate is amphiphilic, when mixing the dehydrating condensing agent of the present invention, which is amphiphilic, and the substrate to form various molecular aggregate phase including micelles in an aqueous solution, the substrate and the dehydrating condensing agent can be accumulated at the water interface. As a result, the concentration of the substrate increases locally at the water interface, and condensation reaction can be performed extremely efficiently.
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Page/Page column 17-18
(2008/06/13)
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- Ester Aminolysis: New Reaction Series for the Quantitative Measurement of Steric Effects
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Further development of theoretical methods for computing steric effects on chemical reactivity requires a large body of new reliable quantitative data for calibration and for testing.We report here on design criteria for reaction series suitable for obtaining these data and on a successful implementation that shows promise of providing access to a particularly broad range of steric hindrance and which additionally has shown a new form of steric hindrance.The series examined in the present study is ester aminolysis in the form RCOOC6H4NO2-p + R'NH2 in acetonitrile solution.A primary purpose of the examination has been to ascertain whether aminolysis may be a useful general series or whether known or unexpected complications might render it unsuitable.We have measured rate constants for a matrix of reactions using five different R groups and four different R' groups, each reaction at a series of concentrations of amine.This is the first systematic study of the sumultaneous action of steric hindrance effects in both the acylating agent and the entering nucleophile.The reactions showed both a second-order term k2 and a relatively less important third-order term k32.The Taft equation was applied to subsets of the rate constants.For each amine there were data for a set of esters for which the R group was the variable.The slopes ρs for these sets were nearly unity.For each ester there were corresponding data for a series of amine reactions in which R' was the variable.These sets also gave good correlations, but the slopes ρs' were considerably larger, about 2.3.This unusually large difference in response to structural effects in the acylating agent and in the nucleophile is unexpected and appears to arise from a new type of steric hindrance.An obvious explanation based on bond lengths proves to be quantitatively insufficient; that explanation postulates that there is greater hindrance for the amine because the C-N bond is short in comparison with the C-C bond.The difference may be due instead to a requirement for special orientation within the transition state, a matter currently under theoretical investigation.The k2 and the k3 sets gave similar correlations, an important finding in at least two respects.It means that steric effects are well-defined in this example of ester aminolysis, and it means also that the extra molecule of amine is far enough from the reaction center so that no additional steric hindrance results.The reactions observed in the present study cover a range of 5 powers of 10 in relative rate constants.Preliminary studies with other examples of aminolysis suggest that a range of relative rate constants covering well in excess of 12 powers of 10 should be observable.
- DeTar, DeLos F.,Delahunty, Claire
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p. 2734 - 2739
(2007/10/02)
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