Preparation And Catalytic Properties Of Polymer-based Silsesquioxane Supported Chiral Catalysts

Recently, the interest in developing asymmetric catalytic reaction in aqueousmedium has been significantly surged. As an important chiral synthesis method, theasymmetric transformation has been wildely used in the manufacture of chiralsecondary alchol and1,2,3,4-Tetrahydroquinolies. However, the ketone and thequinolines can not be dissolved well in the water phase. It is not good for thereaction. Therefore, in this paper, we made immobilized and amphiphilic catalysts.Then,we used them in the the asymmetric transformation of chiral ketone andquinolines in the water phase to explore their effects.1) We used the (S,S)-DPEN to made the Polyhedral Oligomeric Silsesquioxane(POSS) bilfunctional catalyst modified with monosulfonamide Rh. After that, we did aserious characterization, such as HNMR, XPS, ICP, and so on. Through immobilizingthe quaternary ammonium salt on the POSS, we got the phase-transfer function inthe catalyst. In the asymmetric transformation reaction, the catalyst showed the highcatalytic activity and enantioselectivity. The reaction can get99%convertion and96%ee within one hour. Its catalytic activity is higher than its homogeneous counterpartin asymmetric transformation. Moreover, it can be conveniently recovered andreused at least12times without loss of its catalytic efficiency.2) We still used the (S,S)-DPEN to made Amphiphile-POSS-TsDPEN which aremodified with the PEG. It holds many hydrophobic alkyl chain. After that, we did aserious characterization, such as HNMR, GPC. We let the [RuCl2(η6-C6Me6)]2anchored in the Amphiphile-POSS-TsDPEN to give the catalystAmphiphile-POSS-TsDPEN-Ru. The well catalytic activity and enantioselectivity inasymmetric asymmetric transformation quinolines reaction was obtained in this case.The catalyst can achieve99%conversion and92%ee.