78031-66-0Relevant academic research and scientific papers
ASYMMETRIC SYNTHESIS OF AMINO ACIDS VIA THE CATALYTIC REDUCTION OF SUBSTITUTED ACYLAMINOACRYLIC ACID AZLACTONES. 26. AMINOLYSIS OF 2-METHYL-4-BENZYLOXAZOLIN-5-ONE UPON REACTION WITH S-PHENYLALANINE DERIVATIVES
Lyubeznova, M. R.,Karpeiskaya, E. I.,Klabunovskii, E. I.,Koreshkov, Yu. D.,Lutsenko, A. I.,Lubuzh, E. D.
, p. 731 - 737 (2007/10/02)
The kinetics of aminolysis and racemization of 2-methyl-4-benzyloxazolin-5-one upon reaction with S-phenylalanine methyl ester have been studied in dimethoxyethane solvent.The rates of aminolysis and racemization are comparable.Addition of an achiral component, namely Et3N, to the reaction mixture, however, dramatically increases the rate of racemization.The presence of Et3N also increases the ratio of rate constants for the formation of RS- and SS-diastereomers, which determines the reaction stereoselectivity.
Efficient 1,4-Asymetric Induction Utilizing Electrostatic Interaction between Ligand and Substrate in the Asymmetric Hydrogenation of Didehydrodipeptides
Yamagishi, Takamichi,Ikeda, Satoru,Yatagai, Masanobu,Yamaguchi, Motowo,Hida, Mitsuhiko
, p. 1787 - 1790 (2007/10/02)
Electrostatic interaction between the amino group of the achiral 3-dimethylaminopropylidenebismethylenebis(diphenylphosphine) (1) and the carboxy group of the substrate enable an effective 1,4-asymmetric induction in the RhI-catalysed hydrogenation of didehydrodipeptides, to give (S,S)-or (R,R)-products selectively.The selectivity reached up to 94percent diastereoisomeric excess with acetyl didehydrodipeptides and 92percent with benzyloxycarbonyl substrates.
ASYMMETRIC HOMOGENOUS REDUCTION OF DEHYDROPEPTIDES
El-Baba, S.,Nuzillard, J. M.,Poulin, J. C.,Kagan, H. B.
, p. 3851 - 3862 (2007/10/02)
Monodehydropeptides with the dehydroaminoacid fragment in C-terminal or N-terminal position were synthetized as well as a family with the general formula Ac-ΔPhe-(Gly)n-Leu-OR (n = 0-2, R = H or Me).Asymmetric reduction of these compounds catalyzed by chiral rhodium complexes was investigated.The results were discussed in terms of double asymmetric induction.A method was developped to avoid the use of both enantiomers of the substrate or of the catalyst, it consists in the total reduction of a racemic dehydropeptide.The products distribution gives access to the two desired facial selectivities.
A NOVEL ROUTE TO DIPEPTIDE AND ITS DERIVATIVE BY MEANS OF THE PALLADIUM CATALYZED FACILE CLEAVAGE OF 1-(1-METHOXYCARBONYL)ALKYL-3-SUBSTITUTED-4-ARYLAZETIDIN-2-ONES
Ojima, Iwao,Suga, Shigemi,Abe, Rumiko
, p. 3907 - 3910 (2007/10/02)
1-(1-Methoxycarbonyl)alkyl-3-substituted-4-arylazetidin-2-ones were found to be cleaved exclusively at the N-C4 bond by the hydrogenolysis on palladium catalyst to give the corresponding dipeptide and its derivative in excellent yields.
