【摘要】 采用量子力学与分子力学组合的ONIOM方法,研究了布洛芬在MOR分子筛12元环孔道限域环境的手性转变.反应通道研究发现:标题反应有7条路径,质子从手性碳的一侧向另一侧迁移可分别以羰基、甲基和羰基联合、羧基以及羧基和苯环联合作桥实现.反应势能面计算发现:在羧基内实现质子迁移后,手性C上的质子以新羰基O为桥迁移到苯环,接着苯环上的质子又以羰基为桥在纸面里迁移到手性碳的手性转变过程是主反应路径.决速步骤是质子从手性碳向新羰基氧的迁移过程,决速步骤吉布斯自由能垒是263.4kJ·mol^-1,相对于裸反应决速步骤的能垒287.1kJ·mol^-1有明显降低.结果表明:MOR分子筛12元环孔道对布洛芬的手性转变反应具有限域催化作用.更多还原

【Abstract】 The chiral transition of ibuprofen molecules confined in the MOR zeolite 12-ring channels was studied by introducing the ONIOM methods using combination of quantum mechanics and molecular mechanics.The study of reaction channel shows that there are seven paths in the title reaction where proton respectively using carbonyl andMethyl/carbonyl groups or carbonyl and carbonyl/benzene ring groups as the transfer bridge from one side to the other of chiral C.Calculations of potential energy surface show that after the implementation of a proton transfer in the carboxyl,the chiral transition,that protons in the chiral C transfer to the benzene ring using the new carbonyl O as the migration bridge,then protons in the benzene ring transfer to chiral C in paper-based using the carbonyl O as the migration bridge,is the main reaction paths.the chiral transition process of chiral carbon is the main reaction path.The protons transfer process from chiral C to the new carbonyl O is the determining step,the gibbs free energy barrier of the step-determining the gibbs free energy barrier of the step-determining step,where protons transfer from chiral C to the new carbonyl O,is 263.4kJ·mol-1,which is significantly lower than the gibbs free energy-1 barrier 287.1kJ·mol of the step-determining step of bare reaction.The results show that the MOR zeolite 12-ring channels has a confined catalysis on the chiral transition of ibuprofen molecules.更多还原