摘要
利用1,2:5,6-二氧-异丙叉基-3-氧-亚甲基-[5-(3-叔丁基-2-羟基苯甲醛)]-α-D-呋喃葡萄糖与(1S,2S)-(-)-1,2-二苯基乙二胺缩合生成新型手性Salen配体,再与Mn3+配位制得糖衍生的手性Salen-Mn(Ⅲ)配合物.利用核磁共振波谱、傅里叶变换红外光谱、紫外-可见光谱和元素分析方法对配体和配合物进行了表征.分别以NaClO和间氯过氧苯甲酸(m-CPBA)为氧化剂,考察了该配合物催化烯烃不对称环氧化反应的性能.结果表明,在配体羟基的对位引入手性糖基对催化效果有一定的影响.并且以m-CPBA为氧化剂考察了催化剂在离子液体[bmim]PF6中苯乙烯环氧化反应的循环使用性能.催化剂在使用四次后,对映体过量值仍能达到51%.
A novel chiral salen ligand was synthesized through the reaction of 1,2 ： 5,6-di- O-isopropylidene-3- O- methylene-[ 5-（ 3-tert-butyl-2-hydroxybenzaldehyde ）]-α-D-glucofuranose with （ 1S, 2S ）-（ - ）-1, 2- diphenylethylenediamine. The sugar-based chiral salen-Mn（ Ⅲ ） complex was prepared from this ligand. The ligand and complex were characterized by nuclear magnetic resonance, Fourier transform infrared spectroscopy, ultraviolet-visible spectroscopy, and elemental analysis. The complex was then used as a catalyst for the asymmetric epoxidation of alkenes using NaClO and m-chloroperoxybenzoic acid as the oxidants. The results showed that the chiral sugar moiety that was incorporated into C5（5＇） of the ligand had certain effect on enantioselectivity. Furthermore, the recycle ability of the catalyst was studied in the epoxidation of styrene with m-chloroperoxybenzoic acid as terminal oxidant in the presence of the ionic liquid [bmim]PF6. The enantiomeric excess of the epoxides was still 51% even after the catalyst was used three times.
出处
《催化学报》
SCIE
CAS
CSCD
北大核心
2007年第7期601-606,共6页
基金
国家自然科学基金(20376017)
