- Photochemical desulfonylation of N-tosyl amides by 2-phenyl-N,N′- dimethylbenzimidazoline (PDMBI)
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Photoinduced electron transfer reaction between N-tosyl amides and 2-phenyl-N,N′-dimethylbenzimidazoline (PDMBI) provides an efficient approach for the desulfonylation of N-tosyl amides. Georg Thieme Verlag Stuttgart.
- Liu, Qiang,Liu, Zhengang,Zhou, Yu-Lu,Zhang, Wei,Yang, Li,Liu, Zhong-Li,Yu, Wei
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- New methodologies for the oxidation of Fischer carbene complexes: Synthesis of hydrazides
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(equation presented) We report new, high-yield methodologies for oxidizing Fischer carbenes, particularly hydrazinocarbene complexes. The reagents traditionally used to oxidize Fischer carbenes have failed because of the stability of hydrazinocarbene comp
- Perdicchia, Dario,Licandro, Emanuela,Maiorana, Stefano,Vandoni, Barbara,Baldoli, Clara
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- Uncatalyzed conversion of linear α-nitro ketones into amides by reaction with primary amines under solventless conditions
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The reaction of linear α-nitro ketones with primary amines allows the formation of amides through the cleavage of the carbon-carbon bond between the carbonyl group and the carbon-nitro group moiety, promoted by the nucleophilic effect of the amine. The re
- Ballini, Roberto,Bosica, Giovanna,Fiorini, Dennis
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- Simple RuCl3-catalyzed amide synthesis from alcohols and amines
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A catalyst for the direct synthesis of amides from amines and alcohols, generated in situ from the economically attractive and readily available RuCl3, an N-heterocyclic carbene (NHC), and pyridine, was developed. Of the screened NHC precursors, a less bulky one gave better yields for modestly sterically hindered substrates. In a search for the true catalytic intermediates, Grubbs catalysts were found to be active for the amidation of alcohols under basic conditions, suggesting that an Ru complex supported by an NHC ligand can catalyze the reaction.
- Ghosh, Subhash Chandra,Hong, Soon Hyeok
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- A polymer supported Cu(II) catalyst for oxidative amidation of benzyl alcohol and substituted amines in TBHP/H2O
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A new polymer supported copper complex of 2,6-bis(benzimidazolyl)pyridine Cu(PS-BBP)Cl2 was prepared and characterized by elemental analyses, AAS, ESR, IR and UV–Vis spectral studies, magnetic moment measurement and thermogravimetric analyses. A facile oxidative coupling of alcohols and amines to synthesize amides was developed using Cu(PS-BBP)Cl2 as a catalyst and tert-butyl hydroperoxide (TBHP) as an oxidant using water as a solvent in a one-pot process. The optimum conditions were determined for the reaction of benzyl alcohol and benzylamine by varying solvents, temperature, substrate to TBHP ratio and catalyst concentration and the yield resulted was found to be 95%. The catalyst showed excellent catalytic activity and reusability. A tentative reaction mechanism has been proposed.
- Renuka,Gayathri
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Read Online
- An azobenzene-containing metal-organic framework as an efficient heterogeneous catalyst for direct amidation of benzoic acids: Synthesis of bioactive compounds
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An azobenzene-containing zirconium metal-organic framework was demonstrated to be an effective heterogeneous catalyst for the direct amidation of benzoic acids in tetrahydrofuran at 70°C. This finding was applied to the synthesis of several important, representative bioactive compounds.
- Hoang, Linh T. M.,Ngo, Long H.,Nguyen, Ha L.,Nguyen, Hanh T. H.,Nguyen, Chung K.,Nguyen, Binh T.,Ton, Quang T.,Nguyen, Hong K. D.,Cordova, Kyle E.,Truong, Thanh
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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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- Zirconium catalyzed amide formation without water scavenging
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A scalable homogeneous metal-catalyzed protocol for direct amidation of carboxylic acids is presented. The use of 2–10?mol% of the commercially available Zr(Cp)2(OTf)2·THF results in high yields of amides at moderate temperature, using an operationally convenient reaction protocol that circumvents the use of water scavenging techniques.
- Lundberg, Helena,Tinnis, Fredrik,Adolfsson, Hans
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- Synthesis of secondary amides by direct amidation using polymer supported copper(II) complex
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A new polymer supported Cu(II) complex has been synthesized and characterized by CHN analyses, IR and UV–Vis spectral studies, ESR and thermogravimetric analyses, ICP-OES, surface area measurements. This complex was screened for their catalytic study towards the direct amidation reaction. The effects of solvents, reaction time, temperature and catalyst amount for the direct formation of amides from aldehydes and benzylamine with the aid of heterogeneous copper complex were reported. The polymer supported Cu(II) catalyst could be reused more than five times without appreciable loss of its initial activity. The plausible reaction mechanism has been proposed. The catalytic activity of the unsupported complex was also compared with the polymer supported Cu(II) complex.
- Renuka,Gayathri
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p. 195 - 202
(2018/05/04)
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- N-Acyl-N-(4-chlorophenyl)-4-nitrobenzenesulfonamides: Highly selective and efficient reagents for acylation of amines in water
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A variety of N-acyl-N-(4-chlorophenyl)-4-nitrobenzenesulfonamides (1a-e) were synthesized in one pot from 4-chloroaniline under solvent-free conditions and have been developed as chemoselective N-acylation reagents. Selective protection of primary amines in the presence of secondary amines, acylation of aliphatic amines in the presence of aryl amines, and monofunctionalization of primary-secondary diamines as well as selective N-acylation of amino alcohols using these reagents are described. All of the acylation reactions were carried out in water as a green solvent. High stability and easy preparation of these acylating reagents are other advantages of this method.
- Ebrahimi, Sara,Saiadi, Safoura,Dakhilpour, Simin,Mirsattari, Seyed Nezamoddin,Massah, Ahmad Reza
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- Synthesis of Lactones via C-H Functionalization of Nonactivated C(sp3)-H Bonds
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An electron-deficient amide is utilized as a directing group to functionalize nonactivated C(sp3)-H bonds through radical 1,5-hydrogen abstraction. The γ-bromoamides formed are subsequently converted to γ-lactones under mild conditions. The method described is not limited to tertiary and secondary positions but also allows functionalization of primary nonactivated sp3-hybridized positions in a one-pot sequence. In addition, the broad functional group tolerance renders this method suitable for the late-stage introduction of γ-lactones into complex carbon frameworks.
- Richers, Johannes,Heilmann, Michael,Drees, Markus,Tiefenbacher, Konrad
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supporting information
p. 6472 - 6475
(2016/12/23)
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- Clean synthesis of primary to tertiary carboxamides by CsOH-catalyzed aminolysis of nitriles in water
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Using CsOH as the only catalyst and utilizing its "cesium effect", a clean synthesis of a wide range of primary, secondary, and tertiary carboxamides was achieved by aminolysis reactions of nitriles with ammonia, primary, or secondary amines in water. Studies on the control reactions revealed that the reactions with ammonia most probably proceed via an aminolysis path by the initial addition of ammonia to Cs-activated nitriles to form unsubstituted amidine intermediates, while the reactions with primary or secondary amines may proceed via a hydration/transamidation path by the initial hydration of the Cs-activated nitriles to form primary carboxamide intermediates followed by their transamidation with amines through the formation of substituted amidine intermediates.
- Li, Yang,Chen, Haonan,Liu, Jianping,Wan, Xujun,Xu, Qing
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supporting information
p. 4865 - 4870
(2016/10/06)
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- Tunable dehydrogenative amidation versus amination using a single ruthenium-NHC catalyst
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Mixed N-heterocyclic carbene (NHC)/phosphine complexes of the type [RuCl(p-cymene)(bimy)(PPh3)]- PF6 (bimy = benzimidazolin-2-ylidene) have been synthesized and fully characterized. Complex 1 bearing the 1,3-dibenzylbenzimidazolin-2-ylidene ligand is able to selectively catalyze both dehydrogenative amidation, mono-, and diamination (N-alkylation) through coupling of simple alcohols with amines effectively yielding a range of amides and secondary and tertiary amines. Selectivity is achieved by controlling the fate of the common hemiaminal intermediate, which in turn can be simply influenced by the choice of base and solvent.
- Xie, Xiaoke,Huynh, Han Vinh
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p. 4143 - 4151
(2015/11/11)
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- Hafnium-catalyzed direct amide formation at room temperature
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Herein, the first example of a metal-catalyzed protocol for direct amidation of nonactivated carboxylic acids at ambient temperature (26 °C) is presented. The mild reaction conditions give rise to high yields of a range of amides in reaction times as short as 90 min, employing a commercial hafnium complex, [Hf(Cp)2Cl2], as catalyst. Amino acids are transformed into their corresponding amides without racemization, and the catalyst displays full selectivity for the amidation of carboxylic acids over esters. Electronic properties of the carboxylic acids were found to have a strong influence on the rate of the amidation reaction, and the need for a balanced amount of molecular sieves was observed to be highly important for optimal reaction outcome.
- Lundberg, Helena,Adolfsson, Hans
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p. 3271 - 3277
(2015/06/16)
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- Dynamic kinetic asymmetric ring-opening/reductive amination sequence of racemic nitroepoxides with chiral amines: Enantioselective synthesis of chiral vicinal diamines
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We report a highly diastereoselective synthesis of vicinal diamines by the treatment of nitroepoxides with primary amines and then a reducing agent. When using a chiral primary amine, racemic nitroepoxides are transformed into chiral diamines as a single enantiomers (>95:5 er) through a dynamic kinetic asymmetric transformation (DYKAT). The overall process is a one-pot procedure combining the exposure of nitroepoxides to chiral amines to afford diastereomeric mixtures of aminoimines and subsequent stereoselective imine reduction.
- Agut, Juan,Vidal, Andreu,Rodríguez, Santiago,González, Florenci V.
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p. 5717 - 5722
(2013/07/25)
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- Direct amide coupling of non-activated carboxylic acids and amines catalysed by zirconium(IV) chloride
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Amidst the green: A green, mild and effective protocol for the direct formation of secondary and tertiary amides from non-activated carboxylic acids and amines in good to excellent yields by employing ZrCl4 as the catalyst is presented (see scheme). The amide coupling protocol proved to be suitable for scaled up syntheses, and the mild reaction conditions conserve the enantiopurity of chiral starting materials. Copyright
- Lundberg, Helena,Tinnis, Fredrik,Adolfsson, Hans
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supporting information; experimental part
p. 3822 - 3826
(2012/05/20)
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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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- Catalytic amide formation with α′-hydroxyenones as acylating reagents
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α′-Hydroxyenones undergo clean, catalytic amidations with amines promoted by the combination of an N-heterocyclic carbene and 1,2,4-triazole. The Royal Society of Chemistry 2009.
- Chiang, Pei-Chen,Kim, Yoonjoo,Bode, Jeffrey W.
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supporting information; experimental part
p. 4566 - 4568
(2010/01/06)
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- PROCESS FOR PREPARING AMIDES FROM ALCOHOLS AND AMINES
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The present invention provides a process for preparing amides, by reacting a primary amine and a primary alcohol in the presence of a Ruthenium catalyst, to generate the amide and molecular hydrogen. According to the process of the invention, primary amines are directly acylated by equimolar amounts of alcohols to produce amides and molecular hydrogen (the only byproduct) in high yields and high turnover numbers. This reaction is catalyzed by a Ruthenium complex, which is preferably based on a dearomatized PNN-type ligand of formula A1 or precursors thereof of formulae A2 or A3. Use of diamines in the reaction leads to bis-amides, whereas with a mixed primary/secondary amine substrate, chemoselective acylation of the primary amine group occurs.
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Page/Page column 7; 11
(2009/05/28)
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- A convenient aminolysis of esters catalyzed by 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) under solvent-free conditions
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Aminolysis of esters by using the organocatalyst 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) is reported. Secondary and tertiary amides were synthesized from alkyl or aryl esters with a variety of primary and secondary amines in good to excellent yields (60-94%) under solvent-free conditions (SFC).
- Sabot, Cyrille,Kumar, Kanduluru Ananda,Meunier, Stéphane,Mioskowski, Charles
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p. 3863 - 3866
(2008/02/02)
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