(R,S)-2-chlorophenoxyl pyrazolides as novel substrates for improving lipase-catalyzed hydrolytic resolution
作者:Min-fang Kao、Pei-yu Lu、Jou-yan Kao、Pei-yun Wang、An-chi Wu、Shau-Wei Tsai
DOI:10.1002/chir.21024
日期:2012.1
condition of Candida antartica lipase B as biocatalyst, 3‐(2‐pyridyl)pyrazole as leaving azole, and water‐saturated methyl t‐butyl ether as reaction medium at 45°C were first selected for performing the hydrolytic resolution of (R,S)‐2‐(4‐chlorophenoxyl) azolides (1, 2, 3, 4). In comparison with the kinetic resolution of (R,S)‐2‐phenylpropionyl 3‐(2‐pyridyl)pyrazolide or (R,S)‐α‐methoxyphenylacetyl 3‐(
首先选择在温度为45°C的条件下以南极假丝酵母脂肪酶B作为生物催化剂,以3-(2-吡啶基)吡唑为吡咯和水饱和的甲基叔丁基醚作为反应介质的最佳反应条件进行([R ,小号)-2-(4- chlorophenoxyl)azolides(1,2,3,4)。与(R,S)-2-苯基丙酰基3-(2-吡啶基)吡唑内酯或(R,S)-α-甲氧基苯基乙酰基3-(2-吡啶基)吡唑内酯,在相同的反应条件下,具有优异的对映选择性,每种对映体的活性均高出两个数量级以上。然后分辨率扩展到其他([R ,小号)-3-(2-吡啶基)吡唑酰胺(5,6,7含有2-氯,3-氯或2,4-二氯取代基,提供良好的)(É > 48)达到出色的(E > 100)对映选择性。热力学分析1,2,和4,5,6,7证明了酰基或离去基团对不同的焓和熵对吉布斯自由能差异的深远影响。彻底的动力学分析进一步表明,在6的基础上,4和7的出色对映体比率分别是由于