- Stereoselectivity in Reactions of Metal Complexes. Part X. Kinetics and Stereoselectivity of the Inner-sphere Electron-Transfer Reaction between+ (bamap=2,6-Bis(3-carboxy-1,2-dimethyl-2-azapropyl)pyridine) and Optically Active Iron(II) Complexes
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The kinetics of the electron-transfer reaction between racemic or optically active + and optically active Fe2+ complexes of the three new pentadentate ligands bamap, alamp, and valmp has been investigated.All the reacting species show C2 symmetry.With respect to aquo-Fe2+, the reaction rate for the Fe2+ complexes is enhanced by a facter of 1E4 to 1E5, and the observed kΔΛ/kΛΛ ratio is 1.0, 1.9, and 1.2, respectively.In all cases where stereoselectivity is observed, the reaction is faster between the complexes of opposite absolute configurations (ΔΛ or ΛΔ) than between species with the same configuration (ΛΛ or ΔΔ).The stereoselectivity effects are discussed on the basis of the structure of the transition state and the interatomic distances between the two metal centers at the moment of electron transfer.
- Bernauer, Klaus,Pousaz, Phillippe,Porret, Joelle,Jeanguenat, Andre
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- Preparation method and application of N-lauroyl-L-alanine
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The invention discloses a preparation method of N-lauroyl-L-alanine. The preparation method comprises the following steps: preparing L-alanine salt, preparing pasty N-lauroyl-L-alanine salt, and preparing an N-lauroyl-L-alanine crude product and the like. The invention further provides application of amino acid in the daily chemical field and industries such as agriculture and medicines. The aminoacid provided by the invention has high performance, and has an obvious effect in the aspects of bacterium inhibition, pesticide removal, peculiar smell elimination and the like.
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Paragraph 0116; 0118; 0124; 0130; 0136; 0142; 0147; 0148
(2018/11/22)
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- Natural amino acid salt catalyzed aldol reactions of isatins with ketones: highly enantioselective construction of 3-alkyl-3-hydroxyindolin-2-ones
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Abstract The asymmetric synthesis of 3-alkyl-3-hydroxyindolin-2-ones via direct aldol reaction of isatin with ketones catalyzed by natural amino acid salts is described, in which the phenylalanine lithium salt was found to be the best catalyst. This strategy was then applied to a variety of isatin and ketone substrates and the corresponding aldol products were obtained in excellent yields (up to 97%) with good to excellent enantioselectivities (up to 90%).
- Chen, Gong,Ju, Yuan,Yang, Tao,Li, Zicheng,Ang, Wei,Sang, Zitai,Liu, Jie,Luo, Youfu
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p. 943 - 947
(2015/09/01)
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- Synthesis of enantiomerically enriched (R)-13C-labelled 2-aminoisobutyric acid (Aib) by conformational memory in the alkylation of a derivative of L-alanine
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The method of Kouklovsky and coworkers for the enantioselective alkylation of cyclic N-naphthoyl derivatives of amino acids was used to introduce a 13C label into one of the two enantiotopic methyl groups of 2-aminoisobutyric acid (Aib) by retentive alkylation of L-alanine with 13CH3I. Conditions were identified for optimization of yield and enantiomeric purity, and the absolute configuration of the labelled product was established.
- Fletcher, Stephen P.,Sola, Jordi,Holt, Dean,Brown, Robert A.,Clayden, Jonathan
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experimental part
p. 1304 - 1309
(2011/10/18)
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- Hydration of amino acids from ultrasonic measurements
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In this paper the results of compressibility of aqueous solutions of amino acids in water and in aqueous HCl and NaOH solutions at 25 °C are presented. The effect of the charged protonated amino groups and deprotonated carboxylic groups on the hydration number was tested. The idea of additivity of the hydration number with the constituents of the solute molecule was successfully applied and discussed.
- Burakowski, Andrzej,Gliński, Jacek
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experimental part
p. 12157 - 12161
(2011/01/11)
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