胺基功能化ZPS-PVPA固载手性MnⅢ(salen)的合成及不对称催化烯烃环氧化

以聚(苯乙烯-苯乙烯基膦酸)-磷酸氢锆(ZPS-PVPA)为催化剂载体, 通过3-氨丙基三甲氧基硅烷对其中无机磷酸氢锆的羟基进行修饰, 再与均相手性Mn^Ⅲ(salen)催化剂进行轴向配位固载, 实现了手性均相催化剂的非均相化. 催化剂的表征结果证实制得了非均相催化剂. 随后, 考察了该非均相催化剂对α-甲基苯乙烯、 苯乙烯以及茚不对称环氧化反应的催化性能. 结果表明, 以间氯过氧苯甲酸(m-CPBA)为氧化剂, 在 0 ℃反应 3 h, 催化剂用量为 0.03 mmol, 在轴向配体 N-甲基吗啉氮氧化物(NMO)的参与下, 催化剂能高效催化α-甲基苯乙烯的不对称环氧化, 反应的对映选择性(e. e.值)可达 91.5%, 转化率为 99%. 此外, 以茚为底物考察了催化剂的循环使用性能, 结果表明, 催化剂重复使用10次后, 反应的e. e.值(>90%)远高于在相同条件下均相Mn^Ⅲ(salen)催化剂催化茚反应的e. e.值(65%).

Synthesis of Amine Functionalized ZPS-PVPA Supported Chiral MnⅢ(salen) and Asymmetric Catalytic Olefin Epoxidation†

Using zirconium poly(styrene-phenylvinyl-phosphonate)-phosphate(ZPS-PVPA) as a catalyst carrier, the hydroxyl group in the inorganic zirconium hydrogen phosphate was modified by 3-aminopropyltrimethoxysilane. Then, the chiral Mn^Ⅲ(salen) was axially immobilized onto amine functionalized ZPS-PVPA. The immobilized catalyst were characterized by FTIR, DR UV-Vis, AAS, SEM, TEM, XPS, X-ray and EDS. The successful preparation of heterogeneous catalysts was confirmed. Subsequently, the catalytic performance of the supported catalyst for α-methylstyrene, styrene and indene was examined in detail. The results showed that the reaction was carried out at 0 ℃ for 3 h, the amount of catalyst was 0.03 mmol, the e. e. value was 91.5% with a 99% conversion when α-methylstyrene was investigated using m-chloroperoxybenzoic acid as oxidant and in the present of the axial ligand N-methylmorpholine nitrogen oxide(NMO). In addition, the recycling performance of the catalyst was examined using indene as a substrate. After 10 times of repeated use of the catalyst, the e. e. values(>90%)are significantly better than those achieved under a homogeneous counterparts(e. e. 65%).