- Highly efficient and enantioselective enzymatic acylation of amines in aqueous medium
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A new strategy based on the unique catalytic properties, stability and enantioselectivity of the relatively unknown penicillin acylase from Alcaligenes faecalis has been developed for the effective and enantioselective acylation of amines in aqueous medium. In contrast to lipase-catalyzed acylations in organic solvents, the penicillin acylase-catalyzed acylation of amines in aqueous solution is a rapid and chemoselective process leading to a product which can subsequently be deacylated by the same enzyme, imposing secondary enantiocontrol and leading to effective resolution.
- Guranda, Dorel T.,Van Langen, Luuk M.,Van Rantwijk, Fred,Sheldon, Roger A.,Svedas, Vytas K.
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- Method for preparing amide compounds through ionic liquid catalysis in high-pressure environment
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The invention relates to a method for preparing amide compounds through ionic liquid catalysis in a high-pressure environment. According to the method, ionic liquid 1-ethyl-3-methylimidazolium acetateis used as a catalyst and a solvent, oxygen is used as an oxidizing agent, and aromatic methanol or alkyl alcohol is converted into an amide compound under the conditions of high pressure and heating. The synthesis method provided by the invention has the advantages that the raw material and technical cost is low; compared with other traditional methods, the method is safe, low in toxicity, economical and environmentally friendly; and the method has few steps, is simple and convenient to operate, is beneficial to large-scale synthesis, and has important significance for synthesis of amide compounds and large-scale industrialization of preparation.
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Paragraph 0038-0041
(2021/01/24)
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- Direct amidation of non-activated carboxylic acid and amine derivatives catalyzed by TiCp2Cl2
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This paper described a mild and efficient direct amidation of non-activated carboxylic acid and amine derivatives catalyzed by TiCp2Cl2. Arylacetic acid derivatives reacted with different amines to afford the corresponding amides in good to excellent yield except of aniline. Aryl formic acids failed to react with aniline but smoothly reacted with aliphatic amines and benzylamine in moderate to good yield, fatty acids reacting with benzyl and aliphatic amines give amides in good to excellent yield. Chiral amino acids derivatives were transformed into amides without racemization in moderate yield. The possible mechanism of direct amidation catalyzed by TiCp2Cl2 was discussed. This catalytic method is very suitable for the amidation of low sterically hindered arylacetic acid, fatty acids with different low sterically hindered amines except aniline, as well as the amidation of aryl formic acid with benzyl and aliphatic amines.
- Wang, Hui,Dong, Wei,Hou, Zhipeng,Cheng, Lidan,Li, Xiufen,Huang, Longjiang
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- Solvent-Free N-Alkylation of Amides with Alcohols Catalyzed by Nickel on Silica–Alumina
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The N-alkylation of phenylacetamide with benzyl alcohol has been studied using Ni/SiO2–Al2O3. In the optimized conditions, the desired product was isolated in an excellent 98 % yield. The reaction could advantageously be performed in neat conditions, with a slight excess of amide and a catalytic amount of base. These conditions were tested on a large range of amides and alcohols, affording 24 compounds in 13 to 99 % isolated yields.
- Charvieux, Aubin,Le Moigne, Louis,Borrego, Lorenzo G.,Duguet, Nicolas,Métay, Estelle
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supporting information
p. 6842 - 6846
(2019/11/11)
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- Catalytic amidation of unactivated ester derivatives mediated by trifluoroethanol
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A catalytic amidation method has been developed, employing 2,2,2-trifluoroethanol to facilitate condensation of unactivated esters and amines, enabling the synthesis of a range of amide products in good to excellent yields. Mechanistic studies indicate the reaction proceeds through a trifluoroethanol-derived active ester intermediate.
- Caldwell, Nicola,Jamieson, Craig,Simpson, Iain,Watson, Allan J. B.
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supporting information
p. 9495 - 9498
(2015/06/08)
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- N-Heterocyclic carbene-based well-defined ruthenium hydride complexes for direct amide synthesis from alcohols and amines under base-free conditions
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Readily synthesized, well-defined N-heterocyclic carbene-based ruthenium(II) hydride complexes were developed for amide synthesis from alcohols and amines under base-free conditions. Diverse amides were synthesized in fair-to-excellent yields. In the case of secondary amines, where direct dehydrogenative amidation is not feasible, a catalytic amount of a base was required to promote the transamidation of esters, which are byproducts of alcohol dimerization.
- Kim, Kunsoon,Kang, Byungjoon,Hong, Soon Hyeok
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p. 4565 - 4569
(2015/06/08)
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- Method for preparation of amide and imide from alcohol and nitrogen Containing Compound
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The present invention relates to a method for preparing amide and imide from alcohol and a nitrogen containing compound and, more specifically, to a method for preparing amide and imide by using: a catalytic composition obtained by reacting a mixture of a transition metal complex and an N-heterocyclic carbene precursor with base or by reacting an N-heterocyclic carbene precursor with a mixture of a transition metal complex and base; or a transition metal complex catalyst including an N-heterocyclic carbene.
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Paragraph 0231-0234
(2016/12/07)
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- Ruthenium-catalyzed redox-neutral and single-step amide synthesis from alcohol and nitrile with complete atom economy
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A completely atom-economical and redox-neutral catalytic amide synthesis from an alcohol and a nitrile is realized. The amide C-N bond is efficiently formed between the nitrogen atom of nitrile and the α-carbon of alcohol, with the help of an N-heterocyclic carbene-based ruthenium catalyst, without a single byproduct. A utility of the reaction was demonstrated by synthesizing 13C or 15N isotope-labeled amides without involvement of any separate reduction and oxidation step.
- Kang, Byungjoon,Fu, Zhenqian,Hong, Soon Hyeok
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supporting information
p. 11704 - 11707
(2013/09/02)
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- Dehydrogenative amide synthesis: Azide as a nitrogen source
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A new atom-economical strategy to amide linkage from an azide and alcohol liberating hydrogen and nitrogen was developed with an in situ generated ruthenium catalytic system. The reaction has broad substrate generality including diols for the synthesis of cyclic imides.
- Fu, Zhenqian,Lee, Jeongbin,Kang, Byungjoon,Hong, Soon Hyeok
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supporting information
p. 6028 - 6031
(2013/02/22)
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- Thermodynamics of phenylacetamides synthesis: Linear free energy relationship with the pK of amine
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The effective equilibrium constants K′C expressed through the total concentrations of the reagents for the synthesis of N-phenylacetyl-derivatives in aqueous medium from phenylacetic acid and various primary amino compounds have been determined with penicillin acylase as a catalyst. Broad specificity of penicillin acylase (EC 3.5.1.11) to amino components made possible to investigate the acylation of primary amines with different structures and physicochemical properties. Analysis of different components of the effective standard Gibbs energy change ΔGC o′ has revealed favorable thermodynamics for the synthesis of phenylacetamides from unionized substrates forms, however the ionization of reactants carboxy and amino groups in aqueous solutions pushes the equilibrium position to the hydrolysis especially in case of highly basic amines. A linear correlation between the standard Gibbs energy change for amide bond formation from the unionized reagents species and the basicity of amino group was observed: ΔGTo=-3.56pKamine+7.71(kJ/mol). The established linear free energy relationship (LFER) allows to predict the thermodynamic parameters for direct condensation of phenylacetic acid with any amine of known pK. Condensation of phenylacetic acid and amines with pK value within 1.5-8.5 was shown to be thermodynamically favorable in homogeneous aqueous solution. .
- Guranda, Dorel T.,Ushakov, Gennadij A.,Yolkin, Petr G.,Svedas, Vytas K.
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- Synthesis of an acyltrifluoroborate and its fusion with azides to form amides
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A uniquely stable acyl potassium trifluoroborate, potassium (2-phenylacetyl)trifluoroborate, has been synthesized and isolated. In the presence of an activating Lewis acid, this reagent reacts with azides to form amides in good yields.
- Molander, Gary A.,Raushel, Jessica,Ellis, Noel M.
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supporting information; experimental part
p. 4304 - 4306
(2010/09/04)
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