|
Microbial arene oxidation (MAO) refers to the process by which microbial enzymes convert aromatic compounds into more highly oxidized products. Although a number of oxidized products are possible, the most commonly employed for organic synthesis are ''cis''-1,2-dihydroxy-cyclohexa-3,5-dienes ("dihydrodiols").〔Johnson, R. A. ''Org. React.'' 2004, ''63'', 117. 〕 ==Introduction== Microbial enzymes are able to catalyze chemical transformations that would otherwise be prohibitively slow or require harsh conditions. The oxidation of aromatic compounds to dearomatized products is an example of one such transformation, and the dihydrodiol products that result are useful synthetic intermediates. Since a seminal study by Gibson of ''Pseudomonas putida'' in 1968,〔Gibson, D. T.; Koch, J. R.; Kallio, R. E. ''Biochemistry'' 1968, ''7'', 2653〕 four classes of enzymes have been identified that accomplish arene oxidation to dihydrodiols: * Toluene dioxygenases (TDs) * Naphthalene dioxygenases (NDs) * Biphenyl dioxygenases (BPDs) * Benzoic acid dioxygenases (BZDs) The substrate specificity of these enzymes is lower than their names suggest. Enantiomeric purities in excess of 90% are regularly obtained for reactions of prochiral substrates. Enantiomeric purity is also dependent on the substrate. For instance, 1,4-substituted benzenes often render diols of lower enatiomeric purity. However, accessing the "unnatural" enantiomer of product is often difficult without tailored enzymes. ''(1)'' 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Microbial arene oxidation」の詳細全文を読む スポンサード リンク
|
