- Direct amide synthesis from alcohols and amines by phosphine-free ruthenium catalyst systems
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Amides are synthesized directly from alcohols and amines in high yields using an in situ generated catalyst from easily available ruthenium complexes such as the (p-cymene)ruthenium dichloride dimer, [Ru(p-cymeme)Cl 2]2, or the (benz
- Ghosh, Subhash Chandra,Muthaiah, Senthilkumar,Zhang, Yao,Xu, Xiangya,Hong, Soon Hyeok
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- The selective reaction of primary amines with carbonyl imidazole containing compounds: Selective amide and carbamate synthesis
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matrix presented A new highly selective synthesis of amides and carbamates is described. In both cases the syntheses involve the formation of carbonyl imidazole intermediates which subsequently undergo previously unreported selective reactions with primary amines. Acid imidazolides with sufficient chain length will exclusively react with primary amines even in the presence of secondary and tertiary functionality. The imidazole carboxylic esters of secondary or tertiary alcohols also react selectively with primary amines, forming controlled carbamate structures.
- Rannard, Steve P.,Davis, Nicola J.
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- Direct amide synthesis from either alcohols or aldehydes with amines: Activity of Ru(II) hydride and Ru(0) complexes
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An in situ generated catalyst from readily available RuH 2(PPh3)4, an N-heterocyclic carbene (NHC) precursor, NaH, and acetonitrile was developed. The catalyst showed high activity for the amide synthesis directly from either alcohols or aldehydes with amines. When a mixture of an alcohol and an aldehyde was reacted with an amine, both of the corresponding amides were obtained with good yields. Homogeneous Ru(0) complexes such as (4-1,5-cyclooctadiene)(6-1,3,5- cyclooctatriene)ruthenium [Ru(cod)(cot)] and Ru3(CO)12 were also active in the amidation of an alcohol or an aldehyde with the help of an in situ generated NHC ligand.
- Muthaiah, Senthilkumar,Ghosh, Subhash Chandra,Jee, Joo-Eun,Chen, Cheng,Zhang, Jian,Hong, Soon Hyeok
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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 0047-0050
(2021/01/24)
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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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- 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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- PROCESS OF FORMING AN AMIDE
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A process is provided for the synthesis of an amide. A primary or secondary amine and a primary alcohol, with the amine and the alcohol being either moieties of different reactants or moieties of the same molecule, are contacted in the presence of a Ruthenium (II) catalyst. The Ruthenium (II) catalyst is free of a phosphine ligand. The process is also carried out in the absence of a phosphine. Providing the Ruthenium (II) catalyst includes providing an N-heterocyclic carbene.
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Page/Page column 20-24
(2011/04/19)
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- METHOD FOR PREPARATION OF AMIDES FROM ALCOHOLS AND AMINES BY EXTRUSION OF HYDROGEN
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The present invention relates to a method for preparation of carboxamides using alcohols and amines as starting materials in a dehydrogenative coupling reaction catalyzed by a ruthenium N-heterocyciic carbene (NHC) complex, which may be prepared in situ.
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Page/Page column 9
(2012/01/13)
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- N-heterocyclic carbene based ruthenium-catalyzed direct amide synthesis from alcohols and secondary amines: Involvement of esters
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A well-defined N-heterocyclic carbene based ruthenium complex was developed as a highly active precatalyst for the direct amide synthesis from alcohols and secondary amines. Notably, reaction of 1-hexanol and dibenzylamine afforded 60% of the corresponding amide using our catalytic system, while no amide formation was observed for this reaction with the previously reported catalytic systems. Unlike the previously reported amidation with less sterically hindered alcohols and amines, involvement of ester intermediates was observed (Figure presented).
- Chen, Cheng,Zhang, Yao,Hong, Soon Hyeok
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experimental part
p. 10005 - 10010
(2012/02/05)
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- Amide synthesis from alcohols and amines catalyzed by ruthenium N-Heterocyclic carbene complexes
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The direct synthesis of amides from alcohols and amines is described with the simultaneous liberation of dihydrogen. The reaction does not require any stoichiometric additives or hydrogen acceptors and is catalyzed by ruthenium N-heterocyclic carbene complexes. Three different catalyst systems are presented that all employ 1,3-diisopropylimidazol-2-ylidene (IiPr) as the carbene ligand. In addition, potassium iert-butoxide and a tricycloalkylphosphine are required for the amidation to proceed. In the first system, the active catalyst is generated in situ from [RuCl2(cod)] (cod = 1,5-cyclooctadiene), 1,3-diisopropylimidazolium chloride, tricyclopentylphosphonium tetrafluoroborate, and base. The second system uses the complex [RuCl 2(IiPr)(p-cymene)] together with tricyclohexylphosphine and base, whereas the third system employs the Hoveyda-Grubbs lst-generation metathesis catalyst together with 1,3-diisopropylimidazolium chloride and base. A range of different primary alcohols and amines have been coupled in the presence of the three catalyst systems to afford the corresponding amides in moderate to excellent yields. The best results are obtained with sterically unhindered alcohols and amines. The three catalyst systems do not show any significant differences in reactivity, which indicates that the same catalytically active species is operating. The reaction is believed to proceed by initial dehydrogenation of the primary alcohol to the aldehyde that stays coordinated to ruthenium and is not released into the reaction mixture. Addition of the amine forms the hemiaminal that undergoes dehydrogenation to the amide. A catalytic cycle is proposed with the {(I(Pr)RuII} species as the catalytically active components.
- Dam, Johan Hygum,Osztrovszky, Gyorgyi,Nordstrom, Lars Ulrik,Madsen, Robert
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supporting information; experimental part
p. 6820 - 6827
(2010/08/07)
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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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experimental part
p. 4266 - 4270
(2010/09/20)
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- Intramolecular and intermolecular Schmidt reactions of alkyl azides with aldehydes
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Despite recent advances in the use of alkyl azides in ring expansion reactions of ketones, there has been little work done on the corresponding chemistry of aldehydes. In the present study, the Lewis acid-promoted reactions of alkyl azides with aldehydes
- Lee, Huey-Lih,Aubé, Jeffrey
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p. 9007 - 9015
(2008/02/10)
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- Oxidative amide synthesis and N-terminal α-amino group ligation of peptides in aqueous medium
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A new method for oxidative synthesis of amides from alkynes and amines in high yields (up to 96%) using [Mn(2,6-Cl2TPP)Cl] 1 as a catalyst and Oxone/H2O2 as an oxidant in aqueous medium has been developed. This method could be used for N-terminal α-amino group ligation of unprotected peptides with aryl, aliphatic, and internal alkynes under mild conditions. Copyright
- Chan, Wing-Kei,Ho, Chi-Ming,Wong, Man-Kin,Che, Chi-Ming
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p. 14796 - 14797
(2008/02/05)
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- Synthesis of carboxamides by LDA-catalyzed Haller-Bauer and Cannizzaro reactions
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Equation presented. The first direct synthesis of N-alkylcarboxamides and N,N-dialkylcarboxamides by Haller-Bauer (HB) and Cannizzaro-type reactions has been realized. Lithium N,N-diisopropylamide (LDA) catalyst was successfully used in not only the HB reaction of benzylic ketones with lithium N-alkylamides to give the corresponding carboxamides and hydrocarbons but also in the Cannizzaro-type reaction of aldehydes with lithium N-alkylamides or lithium N,N-dialkylamides to give the corresponding carboxamides and alcohols.
- Ishihara, Kazuaki,Yano, Takayuki
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p. 1983 - 1986
(2007/10/03)
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