Selectivity enhancement of epoxide hydrolase catalyzed resolution of 2,2-disubstituted oxiranes by substrate modification
作者:Ingrid Osprian、Wolfgang Stampfer、Kurt Faber
DOI:10.1039/b005203p
日期:——
A series of (±)-2,2-disubstituted oxiranes bearing an alkene or alkyne functional group were resolved by bacterial epoxide hydrolases with excellent selectivities. The presence of a carbon–carbon double or triple bond furnished a highly flexible system for substrate modification, which allowed the enantioselectivity to be tuned by rational substrate modification. Thus, a significant selectivity enhancement of more than a ten-fold increase of E-values was achieved by appropriate choice of the C–C multiple bond, i.e. by (i) choosing an alkene or alkyne moiety or by (ii) variation of the E/Z-configuration of olefinic substrates. The enantioenriched epoxides and vicinal diols thus obtained may be easily transformed into ω-functionalized building blocks containing a chiral fully substituted carbon atom by oxidative cleavage of the carbon–carbon multiple bond.
一系列带有烯烃或炔烃官能团的(±)-2,2-二取代环氧化物通过细菌环氧化物水解酶得到了极佳的选择性拆分。碳-碳双键或三键的存在为底物修饰提供了一个高度灵活的系统,使得通过合理的底物修饰可以调节对映选择性。因此,通过适当选择C-C多重键,即通过(i)选择烯烃或炔烃部分或(ii)改变烯烃底物的E/Z构型,实现了E值超过十倍的显著选择性增强。由此获得的具有对映体富集的环氧化物和邻二醇可以通过碳-碳多重键的氧化断裂,容易地转化为含有手性完全取代碳原子的ω-官能化构建单元。