CALB-Catalyzed Two-Step Alcoholytic Desymmetrization of 3-Methylglutaric Diazolides in MTBE
Autor: | Yuan-Rong Lai, Ting-Yi Wu, Shau-Wei Tsai |
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Rok vydání: | 2017 |
Předmět: |
Methyl Ethers
Substituent Bioengineering Glutaric acid 010402 general chemistry Glutarates 01 natural sciences Applied Microbiology and Biotechnology Biochemistry Desymmetrization Catalysis Kinetic resolution Meglutol Substrate Specificity Fungal Proteins chemistry.chemical_compound Aminolysis Organic chemistry Molecular Biology Fungal protein 010405 organic chemistry Chemistry Reaction step Temperature Stereoisomerism General Medicine Lipase Enzymes Immobilized 0104 chemical sciences Kinetics Alcohols Thermodynamics Biotechnology |
Zdroj: | Applied biochemistry and biotechnology. 185(3) |
ISSN: | 1559-0291 |
Popis: | Optically pure 3-substituted glutarates can be prepared from the alcoholic ring-opening of cyclic anhydride derivatives, esterification of 3-substituted glutaric acid, and hydrolysis, alcoholysis, aminolysis, and ammonolysis of the diester derivatives via hydrolases or organocatalysts. Unfortunately, most of them mainly focus on the first-step desymmetrization, leading to the difficulty on producing optically pure enantiomers. As a general trend in lipase-catalyzed desymmetrization of 3-methylglutarates, poorer enantiomeric excesses with lower chemical yields were found, as the methyl substituent is relatively small to induce a high enzyme stereodiscrimination. The two-step desymmetrization for CALB-catalyzed alcoholysis of 3-methylglutaric di-1,2,4-triazolide 1a in anhydrous MTBE is first developed to increase the enzyme activity in each reaction step. The enantioselectivity for the second-step kinetic resolution is furthermore improved by using 3-methylglutaric dipyrazolide 1b as the substrate. The kinetic and thermodynamic analysis is, moreover, addressed for shedding insights into the desymmetrization process. |
Databáze: | OpenAIRE |
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