- Reactivity of α-Amino Acids in the Reaction with Esters in Aqueous–1,4-Dioxane Media
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The kinetics of the reaction of a series of α-amino acids with 4-nitrophenyl acetate, 4-nitrophenyl benzoate, and 2,4,6-trinitrophenyl benzoate in aqueous 1,4-dioxane medium has been studied. Kinetics of the reactions involving 4-nitrophenyl acetate and 2,4,6-trinitrophenyl benzoate has complied with the Br?nsted dependence and revealed linear correlation between rate constant logarithm and the energy difference of the frontier orbitals of α-amino acids anions.
- Kochetova,Kustova,Kuritsyn
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- Microwave-assisted synthesis of amide under solvent-free conditions
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An efficient and environmentally friendly synthetic method for the synthesis of primary amides under microwave irradiation was described, in which the primary amine was directly reacted with acid without any catalytic agents. The reaction took place in 8-12-min, which was much shorter than the traditional synthetic methods, with almost quantitative yields. The influential factor of the reaction was discussed. The tautomerization between the carboxylic acid group and the H atom in α-carbon of L-amino acid was observed, presumably a dehydrated intermediate forming from this tautomerized isomer. Copyright Taylor & Francis Group, LLC.
- Wang, Xiao-Jian,Yang, Qian,Liu, Fei,You, Qi-Dong
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p. 1028 - 1035
(2008/09/18)
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- Amidoearbonylation of aldehydes utilizing cobalt oxide-supported gold nanoparticles as a heterogeneous catalyst
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Cobalt oxide-supported gold-nanoparticles-catalyzed transformation of aldehydes and their equivalents to N-acyl-α-arnino acids was achieved. The desired products were obtained in moderate to excellent yields under milder reaction conditions than previous reports employing octacarbonyldicobalt as a catalyst. Copyright
- Hamasaki, Akiyuki,Liu, Xiaohao,Tokunaga, Makoto
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supporting information; experimental part
p. 1292 - 1293
(2009/12/03)
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- Palladium-catalyzed amidocarbonylation improved by recyclable ionic liquids
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Two types of ionic liquids (halide anion ionic liquids and Brensted acidic ionic liquids) were first applied to improve the palladium-catalyzed amidocarbonylation. Both the palladium catalyst and the ionic liquids could be recycled at least five times without significant loss in catalytic activity. Georg Thieme Verlag Stuttgart.
- Zhu, Bingchun,Jiang, Xuanzhen
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p. 2795 - 2798
(2008/02/11)
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- A study of amidocarbonylation reactions catalyzed by Pd/HZSM-5
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A HZSM-5-supported palladium catalyst, which was prepared by the conventional impregnation method, was utilized in amidocarbonylation reactions. Several important parameters were optimized to give moderate to excellent yields. The catalyst recycling of Pd/HZSM-5, for the first time, was achieved for at least four run times without depreciation of catalytic activity. The studies of TEM images revealed that agglomeration of the palladium species of Pd/ HZSM-5 catalyst was avoided after reaction, which was quite different from the case of Pd/C catalyst.
- Ke, Wu Yang,Xuan, Zhen Jiang
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p. 806 - 809
(2007/10/03)
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- METHOD OF AMIDOCARBONYLATION REACTION
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A novel method of an amidocarbonylation reaction among an aldehyde compound, an amide compound, and carbon monoxide, which comprises using a palladium-supporting crosslinked-polymer composition containing palladium clusters having a major-axis length of 20 nm or shorter to conduct the amidocarbonylation reaction. Thus, an N-acyl-±-amino acid can be more efficiently and selectively synthesized in a clean reaction system. Also provided is a catalyst for use in the method.
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Page/Page column 11
(2008/06/13)
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- Efficient synthesis of N-acyl-α-amino acids via polymer incarcerated palladium-catalyzed amidocarbonylation
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A novel polymer incarcerated Pd catalyst (PI Pd 7c) was synthesized from amide-containing polymer 6b, and this catalyst was shown to be effective in amidocarbonylation, which is a versatile one-pot method for the preparation of N-acyl-α-amino acids. The reactions proceeded smoothly with a wide variety of substrates, and no leaching of the Pd metal to the reaction mixture was detected.
- Akiyama, Ryo,Sagae, Takahiro,Sugiura, Masaharu,Kobayashi, Shu
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p. 3806 - 3809
(2007/10/03)
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- Platinum-catalyzed amidocarbonylation
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The first example of platinum-catalyzed amidocarbonylation of aldehydes with amides and carbon monoxide is described. In contrast to precedent palladium catalysis, a remarkable ligand acceleration by phosphines was observed. Furthermore, an optically active N-acetyl amino acid was partially epimerized under the platinum-catalyzed conditions, while faster racemization was observed under the palladium catalysis.
- Sagae, Takahiro,Sugiura, Masaharu,Hagio, Hiroyuki,Kobayashi, Shu
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p. 160 - 161
(2007/10/03)
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- Efficient Asymmetric Hydrogenations of (Z)-2-Acetamidoacrylic Acid Derivatives with the Cationic Rhodium Complex of (2S,4S)-MOD-BPPM
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The preparation of (2S,4S)-MOD-BPPM ((2S,4S)-N-(t-butoxycarbonyl)-4-phosphino>-2-phosphino>methyl>pyrrolidine) and its application to highly effective asymmetric hydrogenations of (Z)-2-acetamidoacrylic acid derivatives are described.
- Takahashi, Hisashi,Achiwa, Kazuo
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p. 305 - 308
(2007/10/02)
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- A general and accurate nmr determination of the enantiomeric purity of α-aminoacids and α-aminoacid derivatives
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Derivatization of α-aminoacids, α-aminoesters and α-aminolactones as N-acetyl derivatives allow the accurate NMR determination of the enantiomeric purity. In these conditions the major coordination site with a chiral shift reagent will correspond to the NMR observation site. Experimental factors leading to the highest ΔΔδ values are ascertained. No straightforward correlation with absolute configurations can be established.
- Calmes, Monique,Daunis, Jacques,Jacquier, Robert,Verducci, Jean
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p. 2285 - 2292
(2007/10/02)
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- NEW SYNTHETIC ROUTE TO N-ACYL-α-AMINO ACIDS VIA AMIDOCARBONYLATION BY MEANS OF HOMOGENEOUS BINARY CATALYST SYSTEMS
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New catalytic processes which lead to the formation of N-acyl-α-amino acids promoted by homogeneous binary systems are described: (a) the isomerization-amidocarbonylation of allylic alcohols catalyzed by transition metal binary systems, e.g., Co-Rh, Co-Pd, Co-Fe, giving various aliphatic N-acyl-α-amino acids; (b) the isomerization-amidocarbonylation of oxiranes catalyzed by cobalt-Lewis acid systems giving N-acyl-α-amino acids; The process is extremely effective for the synthesis of N-acetylphenylalanine from styrene oxide and (c) the hydroformylation-amidocarbonylation of trifluoropropene catalyzed by cobalt-rhodium binary system giving N-acetyltrifluorovaline in excellent regioselectivity and yield.Possible mechanisms for these new processes are discussed.
- Hirai, Kenji,Fujita, Makoto,Fuchikami, Takamasa
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p. 203 - 214
(2007/10/02)
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- DIRECT CONVERSION OF ALLYLIC ALCOHOLS INTO N-ACYL-α-AMINO ACIDS BY CATALYTIC AMIDOCARBONYLATION BY MEANS OF HOMOGENEOUS BINARY SYSTEMS
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N-Acyl-α-amino acids are synthesized by the amidocarbonylation of allylic alcohols catalyzed by homogeneous binary systems which consist of cobalt carbonyl and rhodium (or iron or palladium) complexes.
- Hirai, Kenji,Takahashi, Yoshitaka,Ojima, Iwao
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p. 2491 - 2494
(2007/10/02)
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