【作者】 胡小艳；

【导师】 傅相锴；

【作者基本信息】 西南大学 ， 有机化学， 2011， 硕士

【摘要】 环氧化合物,尤其是手性环氧化合物的合成在有机合成上具有重要意义,Jacobsen小组设计出的Salen Mn(Ⅲ)催化剂常用于催化烯烃的不对称环氧化。而由于均相手性Salen Mn(Ⅲ)催化剂与产物难以分离,不利于回收和循环使用,人们将目光更多的关注在手性Salen Mn(Ⅲ)催化剂的多相化研究。本文采用直接沉淀合成法,在无模板剂存在的条件下,用自制的聚(苯乙烯-苯乙烯基膦酸)与磷酸二氢钠做磷源合成出不同比例的有机聚合物—无机杂化载体材料聚(苯乙烯-苯乙烯基膦酸)—膦酸锌Zn(NaPO4)l-x(O3PG)x·mH2O (x=0.35-1.0, G为聚(苯乙烯-苯乙烯基))。用FT-IR、DR UV-Vis、N2吸附、TG、XRD、SEM、TEM等手段对其进行了表征。结果表明,这类新型杂化材料是晶态的,具有规整的层状结构,并结合实验数据提出了其可能的理想结构模型。另外,与本课题组合成的聚(苯乙烯-苯乙烯基膦酸)—磷酸锆(ZPS-PVPA)载体材料进行了对比。对这二类载体进行氯甲基化、酚羟基化或氨基吡啶修饰后轴向配位固载手性SalenMn(Ⅲ),合成了新型的手性Salen Mn(Ⅲ)多相催化剂。同时考察了三种氧化体系下,反应的温度、溶剂、催化剂用量、助催化等因素对非功能化烯烃的不对称环氧化反应的催化性能的影响。结果表明,这些固载催化剂具有与均相Jacobsen催化剂相当或更高的催化活性、对映选择性,并具有优良的重复使用性。令人感兴趣的是在这三种氧化体系中,都存在着没有助催化剂的参与时,固载催化剂取得更优的转化率及ee值。另外,用酚羟基化修饰的固载催化剂考察了非官能化烯烃的扩大化反应,所获得的ee值没有明显降低,为工业化的扩大应用增大了可能性。更多还原

【Abstract】 The importance of chiral building blocks, such as optically active epoxides, for drugs and vitamins synthesis has been published largely on homogeneous Jacobsen-type complexes in recent years. However, such catalysts are not easily recovered for reuse or recycle. The last decades have witnessed an intense research effort to heterogenize chiral Jacobsen-type salen Mn(Ⅲ) complexes on supports in an attempt to make them recyclable.A series of novel layered of zinc poly(styrene-phenylvinylphosphonate)-phosphate Zn(NaPO4)l-x(O3PG)x·mH2O (x=0.35-1.0, G is poly(styrene-phenylvinyl)) have been synthesized under mild conditions in the absence of template agent in this paper. The phenylvinylphosphonate and sodium dihydrogen phosphate have been used as phosphorus resource. These compounds were well characterized by FT-IR、DR UV-Vis、N2 volumetric adsorption、TG、XRD、SEM、TEM. The results showed that the new hybrid materials are crystalline with regular layered structure, and the ideal structure model is proposed. In addition, which was used to compare with the support ZPS-PVPA synthesized by our group.Based on our previous work, the chiral salen Mn(III) complex axially immobilized onto diphenol modified ZnPS-PVPA or aminopyridine modified ZnPS-PVPA and ZPS-PVPA. The supported catalysts were used to catalyze the asymmetric epoxidation of styrene,α-methylstyrene and indene. To gain a better catalytic effect, we investigate the effects of various reaction parameters such as catalyst amount, solvent, oxidant and axial additive on the asymmetric epoxidation of olefins. The catalytic results show that the heterogeneous catalysts effectively catalyze the epoxidation of the various olefins in comparable or even higher conversion and enantioselectivity than those of homogeneous catalyst. It is interesting to find out that remarkably increases of conversions and ee values were obtained in the absence of axial additives for the asymmetric epoxidation with the heterogeneous catalyst. Moreover, these diphenol modified catalysts could be efficiently used in large-scale reactions with the enantioselectivity being maintained at the same level, which offer a great possibility for application in industry.更多还原