76715-96-3

Upstream product

• 109927-10-8 racemic Ac-Phe-ΔPhe-OMe 
• 57986-20-6 N-acetyl dehydrophenylalanyl-(S)-phenylalanine methyl ester 
• 13649-97-3 (S)-4-benzyl-2-methyl-4H-oxazol-5-one 
• 15028-44-1 DL-phenylalanine methyl ester 
• 82690-96-8 N-Acetyldehydrophenylalanylphenylalanine methyl ester 

Relevant 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

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

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

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.

EFFECTIVE ASYMMETRIC HYDROGENATION OF DEHYDRODIPEPTIDES WITH RHODIUM(I)-NEW CHIRAL DIPHOSPHINITE SYSTEMS

Rh(I)-new chiral diphosphinite systems with terminal amino groups were very effective for asymmetric hydrogenation of dehydrodipeptides with free carboxyl group and a chiral carbon.The effectiveness of the diphosphinite catalysts strongly suggests the contribution of electrostatic effect to asymmetric induction.

SYNTHESIS OF OPTICALLY ACTIVE N--β-AMINO ALCOHOLS BY HOMOGENEOUS AND HETEROGENEOUS ASYMMETRIC HYDROGENATIONS

Asymmetric hydrogenations of N-(N-acetyldehydrophenylalanyl)-β-amino alcohol benzyl ethers were carried out by using either rhodium complexes with chiral and achiral phosphines or 10percent palladium on carbon.The effects of the chiral center in the β-ami