摘要
合成并表征了新型单面桥连手性卟啉（1a）及其铁配合物（1b），利用分子力学方法和^1 HNMR对手性卟啉的空间构象及手性空腔特征进行了分析．将化合物1b用于苯乙烯衍生物的催化环氧化反应，结果表明，轴向配体的存在使化合物1b获得了较高的对映选择性（e．e．为73％～80％），反应产率及速率也有大幅度提高，4-叔丁基吡啶的效果最好．催化体系中轴向配体控制了反应底物向化合物1b手性空腔的定向趋近，从而有效地提高了手性催化性能．
Novel mono-faced bridged chiral porphyrins la and iron complex lb were synthesized and characterized. Conformation analysis was performed by using molecular mechanics conformation search method. The theoretic viable lowest energy conformation of compound la greatly coincided with ^1H NMR data. Compound lb was used as the catalyst in asymmetric styrene devivatives epoxidation. In the absence of nitrogen base lig- and, the epoxides were formed on a lower e. e. （25%--28%）, when axial ligand was present, compound lb exhibited an increased epoxidation rate, yield and much higher e. e. （73%--80%）. The added nitrogen base can efficiently block the oxidation reaction at the unhinded side of the porphyrin ring and directionally control the oxygen transfer and substrate approach to the chiral cavity.
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
2007年第11期2128-2132,共5页
Chemical Journal of Chinese Universities
基金
国家自然科学基金(批准号:20471037和20776085)
上海市自然科学基金(批准号:03ZR14061)资助
关键词
手性卟啉
不对称催化
e.e.值
构象分析
Chiral porphyrin
Asymmetric catalysis
e.e. value
Conformation analysis
