Lipase-catalyzed resolution of 4-aryl-substituted β-lactams: effect of substitution on the 4-aryl ring
作者:Jason A Carr、Talal F Al-Azemi、Timothy E Long、Jeung-Yeop Shim、Cristina M Coates、Edward Turos、Kirpal S Bisht
DOI:10.1016/j.tet.2003.09.057
日期:2003.11
reactions occurred with high enantioselectivity and substrate conversion. The effect of substitution on the C-4 aryl ring on lipase hydrolytic activity was dependent upon the steric and electronic nature of the substituent and its position on the aryl ring. The stereopreference of the lipase PS-30 for the (3S,4R) enantiomer was rationalized using a known active site model. Absolute stereochemistry of the
假单胞菌洋葱脂肪酶(PS-30)用于3-乙酰氧基-4-芳基取代的氮杂环丁烷-2-酮(> 97%ee)的水解拆分中。合成了二十三个在环的C-4中心具有不同取代基的β-内酰胺底物,并在25°C的磷酸盐缓冲液(pH 7.2,0.2 M)中进行了脂肪酶-PS催化水解。反应以高对映选择性和底物转化发生。取代对脂肪酶水解活性的C-4芳基环的影响取决于取代基的空间和电子性质及其在芳基环上的位置。脂肪酶PS-30对于(3 S,4 R使用已知的活性位点模型使对映异构体合理化。对映异构体的绝对立体化学是使用单晶X射线晶体学技术建立的。