- Ammonia-borane as a Catalyst for the Direct Amidation of Carboxylic Acids
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Ammonia-borane serves as an efficient substoichiometric (10%) precatalyst for the direct amidation of both aromatic and aliphatic carboxylic acids. In situ generation of amine-boranes precedes the amidation and, unlike the amidation with stoichiometric amine-boranes, this process is facile with 1 equiv of the acid. This methodology has high functional group tolerance and chromatography-free purification but is not amenable for esterification. The latter feature has been exploited to prepare hydroxyl- and thiol-containing amides.
- Ramachandran, P. Veeraraghavan,Hamann, Henry J.
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supporting information
p. 2938 - 2942
(2021/05/04)
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- Graphene oxide: A convenient metal-free carbocatalyst for facilitating amidation of esters with amines
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Herein, we report a graphene oxide (GO) catalyzed condensation of non-activated esters and amines, that can enable diverse amides to be synthesized from abundant ethyl esters forming only volatile alcohol as a by-product. GO accelerates ester to amide conversion in the absence of any additives, unlike other catalysts. A wide range of ester and amine substrates are screened to yield the respective amides in good to excellent yields. The improved catalytic activity can be ascribed to the oxygenated functionalities present on the graphene oxide surface which forms H-bonding with the reactants accelerating the reaction. Improved yields and a wide range of functional group tolerance are some of the important features of the developed protocol.
- Patel, Khushbu P.,Gayakwad, Eknath M.,Shankarling, Ganapati S.
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p. 2661 - 2668
(2020/02/20)
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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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- Combination of Enabling Technologies to Improve and Describe the Stereoselectivity of Wolff-Staudinger Cascade Reaction
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A new, single-mode bench-top resonator was evaluated for the microwave-assisted flow generation of primary ketenes by thermal decomposition of α-diazoketones at high temperature. A number of amides and β-lactams were obtained by ketene generation in situ and reaction with amines and imines, respectively, in good to excellent yields. The preferential formation of trans-configured β-lactams was observed during the [2+2] Staudinger cycloaddition of a range of ketenes with different imines under controlled reaction conditions. Some insights into the mechanism of this reaction at high temperature are reported, and a new web-based molecular viewer, which takes advantage from Augmented Reality (AR) technology, is also described for a faster interpretation of computed data.
- Musio,Mariani,?liwiński,Kabeshov,Odajima,Ley
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supporting information
p. 3515 - 3526
(2016/10/18)
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- METHOD FOR PRODUCING CARBOXYLIC ACID AMIDE
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PROBLEM TO BE SOLVED: To use arylboronic acid with a chemical structure more simpler than that of the conventional one in a method for producing carboxylic acid amide. SOLUTION: Provided is a method for producing carboxylic acid amide capable of obtaining carboxylic acid amide by dehydration condensation reaction between carboxylic acid and amine. As the carboxylic acid, carboxylic acid having two or more hydrogen atoms at the α position, carboxylic acid having hydrogen atoms and a methyl group at the α position, α, β-unsaturated carboxylic acid or aromatic carboxylic acid is used. Further, B(OH)3, PhB(OH)2 or the like are used as a catalyst, and 4-dimethylaminopyridine, its N-oxide or the like are used as an additive. SELECTED DRAWING: None COPYRIGHT: (C)2016,JPOandINPIT
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Paragraph 0034; 0046-0047
(2017/01/31)
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- Catalytic role of PPh3 and its polymer bound analog in the amidation of carboxylic acids mediated by 2,4,6-trichloro-1,3,5-triazine
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Abstract The catalytic role of PPh3 and its polymer bound analog was investigated in the 2,4,6-trichloro-1,3,5-triazine (TCT) mediated amidation of carboxylic acids. In the presence of inorganic bases which were inert toward TCT, carboxylic acids rapidly reacted with amines to afford amides in good to excellent yields. The described method also enabled the synthesis of optically active protected dipeptides without racemization. Formation of triazinylphosphonium chloride during the PPh3 catalyzed acid activation was confirmed based on 31P NMR studies.
- Duangkamol, Chuthamat,Jaita, Subin,Wangngae, Sirilak,Phakhodee, Wong,Pattarawarapan, Mookda
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supporting information
p. 4997 - 5001
(2015/08/03)
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- Synthesis and research of benzylamides of some isocyclic and heterocyclic acids as potential anticonvulsants
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A series of benzylamides of isocyclic and heterocyclic acids was synthesized and tested in Anticonvulsant Screening Project (ASP) of Antiepileptic Drug Development Program (ADDP) of NIH. Near all synthesized derivatives of heterocyclic acids showed activity. All obtained derivatives of mono- and bicyclic isocyclic acids were inactive. The power of action of heterocyclic acids derivatives seems does not depend upon kind of heteroatom (N, O or S). One of the compounds (2-furoic acid benzylamide (4)) appeared most promising. It showed in minimal clonic seizure (6Hz) test (ASP) in rats after i. p. administration: MES ED50 = 36.5 mg/kg, TOX TD50 = 269.75 mg/kg, and PI = 7.39.
- Strupinska, Marzanna,Rostafinska-Suchar, Grazyna,Pirianowicz-Chaber, Elzbieta,Stables, James P.,Jiang, Jeff,Paruszewski, Ryszard
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p. 681 - 686
(2013/10/01)
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- Titanium(IV) isopropoxide as an efficient catalyst for direct amidation of nonactivated carboxylic acids
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Secondary and tertiary amides are formed in high yields, in an efficient and environmentally benign titanium(IV) isopropoxide catalyzed direct amidation of carboxylic acids with primary and secondary amines. Georg Thieme Verlag Stuttgart ? New York.
- Lundberg, Helena,Tinnis, Fredrik,Adolfsson, Hans
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supporting information
p. 2201 - 2204
(2012/10/30)
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