离子液体功能化手性salen Mn(Ⅲ)配合物不对称催化仲醇氧化动力学拆分反应  

Ionic Liquid-functionalized Chiral salen Mn(Ⅲ) Complex for Asymmetric Oxidative Kinetic Resolution of Racemic Secondary Alcohols

作　　者：黎成勇[1] 谭蓉[1] 赵江峰[1] 银董红[1,2] 

机构地区：[1]湖南师范大学精细催化合成研究所,长沙410081 [2]湖南中烟工业有限责任公司技术研发中心,长沙410014

出　　处：《高等学校化学学报》2014年第2期297-302,共6页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金(批准号:21003044;20973057);湖南省自然科学基金(批准号:10JJ6028)资助~~

摘　　要：采用共价键联法,将亲水性咪唑类离子液体结构引入手性salen Mn(Ⅲ)配合物的C5位,制备了离子液体功能化手性salen Mn(Ⅲ)配合物.傅里叶变换红外光谱、紫外光谱和旋光分析等结果表明,咪唑类离子液体结构已嫁接到手性salen Mn(Ⅲ)配合物结构中,且嫁接过程未破坏催化活性中心.在以PhI(OAc)2为氧化剂,H2O/CH2Cl2为溶剂的(+/-)-α-甲基苯甲醇不对称氧化动力学拆分反应中,该催化剂表现出比传统手性salen Mn(Ⅲ)催化剂更高的催化活性,仲醇的转化率达到63%以上,对映选择性为99%,拆分效率为18.3%.可通过调变溶剂实现催化剂的分离并重复使用3次以上.实验结果表明,亲水性咪唑离子液体可改善水相反应传质问题且有利于稳定催化活性中间体,从而提高催化活性及稳定性.Hydrophilic imidazolium-based ionic liquid （ IL ） was introduced into the framework of the chiral salen Mn（Ⅲ） complex by covalent linkage, which provided a ionic liquid-functionalized chiral salen Mn（Ⅲ） complex. Fourier transform infrared spectrometry, UV-Vis and thermal analysis results showed that the chiral salen Mn（Ⅲ） complex was modified with the IL moiety with the intact active site. The catalytic performance of IL-functionalized chiral salen Mn （Ⅲ） complex in the asymmetric oxidation kinetic resolution （ OKR ） of secondary alcohols was investigated. It was found that the surfactant-type complex showed higher catalytic activity than neat chiral salen Mn（Ⅲ） complex. Secondary alcohol conversion was more than 63%, enantios-elective could reach 99% and separation efficiency was 18 . 3%. Catalyst could be facilely recovered from the reaction system for reuse 3 times by controlling solvent. The hydrophilic imidazolium-based IL was thought to improve the mass transfer associated with the aqueous reaction and stabilize the transition state, which in turns enhanced the activity and stability of the catalysts.

关 键 词：对映选择性 离子液体 手性salenMn(Ⅲ)配合物 不对称氧化动力学拆分 仲醇 

分 类 号：O621[理学—有机化学] O643[理学—化学]