关键词: 手性金属-Salen配合物, 交联聚苯乙烯, 固载, 傅克烷基化反应, 席夫碱反应

Abstract: Firstly, the Friedel-Crafts alkylation between the chloromethylated crosslinked polystyrene(CMCPS) microspheres and 2-hydroxy-4-methoxybenzaldehyde(HMBA) was carried out to afford the modified microspheres HMBA-CPS. Subsequently, the Schiff base reaction between HMBA-CPS and diaminocyclohexane was performed, leading to the microspheres Salen-CPS, on which Salen ligands were bonded. Finally, the coordination-chelating reaction of Salen-CPS with Mn salt was conducted, resulting in solid catalyst Mn(Ⅲ)Salen-CPS, on which chiral Mn(Ⅲ)-Salen complex was immobilized. The microspheres Salen-CPS and Mn(Ⅲ)Salen-CPS were fully characterized by methods such as FTIR, UV-Vis and SEM. The Friedel-Crafts alkylation between CMCPS microspheres and HMBA was mainly investigated because it was a key reaction. The results show that the Friedel-Crafts alkylation can be carried out when AlCl3 was used as Lewis catalyst and a mixture of dichloromethane and nitrobenzene was used as solvent. The new route is simple, convenient, direct and efficient. Under the suitable reaction conditions(volume ratio of dichloromethane to nitrobenzene=10∶1, temperature=40 ℃, and reaction time=10 h), modified microspheres HMBA-CPS capable of converting chloromethyl with a 51% rate can be obtained.

Key words: Chiral metal-Salen complex, Crosslinked polystyrene, Immobilization, Friedel-Crafts alkylation, Schiff base reaction