37784-25-1Relevant academic research and scientific papers
Application of aminoacylase I to the enantioselective resolution of α-amino acid esters and amides
Youshko, Maxim I.,Van Langen, Luuk M.,Sheldon, Roger A.,Svedas, Vytas K.
, p. 1933 - 1936 (2007/10/03)
Aminoacylase I from Aspergillus melleus, a readily available and inexpensive enzyme mainly used in the industrial production of enantiopure L-amino acids from their N-acetyl derivatives, is shown to hydrolyze the esters and amides of natural and non-natural amino acids with high enantioselectivity (for the ester hydrolysis, E is up to 76, in case of amides E >300). The reaction rates of amide and ester hydrolysis are comparable, and in some cases these conversions proceeded even faster than 'traditional' aminoacylase- catalyzed hydrolysis of N-acetyl derivatives thus providing new possibilities for the resolution of the corresponding racemates. This novel approach provides an alternative route for the biocatalytic production of optically active amino acids and their derivatives.
O-Benzyl derivatives of (S)-(+) and (R)-(-)-2-aminobutan-1-ol as new resolving agents for racemic acids. Practical resolutions of N-acyl derivatives of phenylglycine and 4-hydroxyphenylglycine
Touet, Joel,Faveriel, Laurent,Brown, Eric
, p. 2957 - 2960 (2007/10/02)
Treatment of the readily available (S)-(+) and (R)-(-)-2-aminobutan-1-ol 1 with sodium hydride followed by benzyl chloride, or a substituted benzyl halide, afforded the corresponding O-benzyl bases 2-5 in high yields. These new bases are recommended for the large scale resolution of racemic acids. For instance, they proved efficient for the practical resolution of N-acetylphenylglycine (±)-7, N-acetyl-(4-hyroxylphenyl)glycine (±)-9 and N-chloroacetyl-(4-hydroxyphenyl) glycine (±)-10.
Racemization of Optically Active Aromatic N-Acetylamino Acids and Asymmetric Transformation of N-Acetyl-2-(4-hydroxyphenyl)glycine via Salt Formation with Optically Active α-Methylbenzylamine
Shiraiwa, Tadashi,Sakata, Shinji,Natsuyama, Hisashi,Fujishima, Keiko,Miyazaki, Hideya,et al.
, p. 965 - 970 (2007/10/02)
The racemization rates of N-acetyl-(S)-tyrosine, N-acetyl-(S)-phenylalanine, N-acetyl-(R)-2-(4-hydroxyphenyl)glycine , N-acetyl-(R)-2-phenylglycine, and N-acetyl-(S)-alanine were measured by use of (RS)-α-methylbenzylamine as base-catalyst.The first-order rate constant for racemization tended to increase with an increase in the polar substituent constant of the N-acetylamino acid side chain.The racemization appeared to be subject to the inductive effect by the side chain.An asymmetric transformation of (RS)-AcHpg by using (R)-MBA, based on the result of racemization, gave an optically pure salt of (R)-AcHpg with (R)-MBA by successive use of the filtrate as the solvent.Optically pure (R)-2-(4-hydroxyphenyl)glycine was separated from the salt in 87-90percent yield based on the starting (RS)-AcHpg.In addition, the asymmetric transformation of (R)-AcHpg was achieved by using (S)-MBA to give optically pure (S)-Hpg in 80percent yield after purification of the salt of (S)-AcHpg with (S)-MBA followed by hydrolysis.
