Kinetic resolution of (R,S)-pyrazolides containing substituents in the leaving pyrazole for increased lipase enantioselectivity
作者:Pei-Yun Wang、Chia-Hui Wu、Jyun-Fen Ciou、An-Chi Wu、Shau-Wei Tsai
DOI:10.1016/j.molcatb.2010.04.003
日期:2010.9
With hydrolysis of (R,S)-azolides in water-saturated methyl tert-butyl ether (MTBE) via Candida antarctica lipase B (CALB) as the model system, (R,S)-pyrazolides containing a leaving 3-, 4- or 3,4-substituted-pyrazole moiety are selected as the best substrates for preparing various optically pure carboxylic acids containing an α-chiral center. Great improvements of enzyme activity for the (R)-enantiomers
以南极假丝酵母脂肪酶B(CALB)为模型体系,通过水饱和的甲基叔丁基醚(MTBE)中的(R,S)-吡咯内酯水解为模型系统,其中含有(R,S)-吡唑并含有3-,4-选择3,4-或3,4-取代的吡唑部分作为制备各种含有α-手性中心的光学纯羧酸的最佳底物。对于(酶活性的很大的改进- [R )具有优异的对映选择性-对映体(V - [R / V小号 > 100)可获得,如果([R ,小号含有留下的3-或3,4-取代的吡唑部分的R-吡唑化物用于在无水MTBE中由甲醇水解或醇解。对(R,S)-N -2-苯基丙酰基吡唑的详细动力学分析表明,在离开的吡唑部分中较大的3-取代基(例如3-(3-溴苯基)或3-(2-吡啶基))对降低无水MTBE中反应缓慢的对映异构体的催化丝氨酸的亲核攻击和质子转移,以及水饱和MTBE中两种对映异构体的亲和性和底物亲和力。该拆分平台还成功应用于通过水饱和的环己烷中的(R,S)-吡唑