Kinetic Resolution of β-Amino Esters by Acylation Using Immobilized Penicillin Amidohydrolase
| Autor: | Ping Tu Wang, Patrick B. Mullins, Bryan Hayden Landis, Karen E. Mullins |
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| Rok vydání: | 2002 |
| Předmět: | |
| Zdroj: | Organic Process Research & Development. 6:539-546 |
| ISSN: | 1520-586X 1083-6160 |
| Popis: | Penicillin amidohydrolase [EC 3.5.1.11] was used to resolve stereoisomers of a β-amino acid ester (ethyl 3-amino-5-(tri-methylsilyl)-4-pentynoate) by phenylacetylation. After screening commercially available sources of the immobilized enzyme, one was found to be significantly more efficient, and this was developed at 1-L scale reaction. The effects of phenylacetic acid concentration, β-amino acid ester concentration, and pH on bioconversion rates and side reactions were examined. The enzymatic reaction was monitored off-line by naphthoylation of samples and chiral analytical chromatography. The best conditions for the bioconversion were pH 5.7, 28 °C, and 14 000 units of enzyme activity per liter. The phenylacetic acid concentration was set at 50 g/L (0.37 M), and the amine at 100 g/L (0.47 M). Under these conditions, yields of the desired (S)-amino acid ester were on the order of 90% with ee's of 95% or greater in less than 12 h. This process, along with a slight modification, was tested through 15 cycle... |
| Databáze: | OpenAIRE |
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