Herein, we report an efficient enantioselective cleavage of the acyl- moiety of a set of α- phenyl ethyl esters with different chain-lengths catalyzed by lipase B from Candida antarctica (CAL-B) by comparing two reactional approaches: anhydrous media with sodium carbonates and micro-aqueous medium. The deacylation is performed in organic solvent, in the presence of Na2CO3 in the first case, and by addition of a drop of phosphate buffer solution pH 7 in the second. The results show the high efficiency of the deacylation in the presence of the sodium carbonate for the enzymatic resolution of all the esters and that in term of reactivity (31% ≤ conv ≤ 50%) and selectivity (E > 200). While, during the hydrolysis in micro-aqueous media, the conversion is strongly affected by the length of the acyl-chain side, the conversion decreases from conv = 50% with the 1-phenylethyl acetate 1a to conv = 19% with 1-phenyethyl dodecanoate 6a, and this, even if the selectivity remains high (E > 89). In both conditions, the lipase CAL-B shows a high enantioselectivities in favor of (R)-1-phenyl ethanol enantiomer (conv > 45%, E > 200) but the reactivity is modulated by the form and the size of the acyl-chain side.

中文翻译：

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CAL-B 催化对一组 α-苯基乙基酯的对映选择性脱酰基的两种方法：碳酸钠和微水介质的有机溶剂

在此，我们报告了通过比较两种反应方法：无水介质和碳酸钠，由来自南极念珠菌 (CAL-B) 的脂肪酶 B 催化的一组不同链长的 α-苯基乙酯的酰基部分的有效对映选择性裂解和微水介质。脱酰反应在有机溶剂中进行，第一种情况是在 Na2CO3 存在下，第二种情况是加入一滴 pH 为 7 的磷酸盐缓冲溶液。结果表明，在碳酸钠存在下，酶解所有酯的脱酰效率高，反应性 (31% ≤ conv ≤ 50%) 和选择性 (E > 200)。而在微水介质中水解时，转化率受酰基链侧长度的影响很大，转化率从 1-苯基乙酸乙酯 1a 的 conv = 50% 降低到 1-十二烷酸 1-苯基乙酯 6a 的 conv = 19%，即使选择性仍然很高（E > 89）。在这两种条件下，脂肪酶 CAL-B 都显示出高对映选择性，有利于 (R)-1-苯基乙醇对映异构体（转换率 > 45%，E > 200），但反应性受酰基的形式和大小调节。链侧。