Synthesis Of Dendritic Amphiphiles With A Hydrocarbon Or Fluorocarbon Chain And Their Applications In Catalysis

Based on the superiorities of surfactant systems and dendrimers applied in catalysis, a family of dendritic amphiphiles was synthesized from 3,3'-iminodipropionitrile, Behera's amine and alkyl or perfluoroalkyl iodide, and it's a kind of multi-functional catalytic system that is suitable for catalysis in water. Behera's amine was used as the dendron unit, and the linkage unit was prepared by hydrolysis of 3,3'-iminodipropionitrile. The dendritic structure was constructed by the link of them with amido bonds. Then, a hydrocarbon or fluorocarbon chain was attached to the molecule as the hydrophobic group, and six carboxyl groups were introduced on the surface of molecule after hydrolysis of the terminal ester groups, which acted as the hydrophilic groups as well as the quaternary ammonium center.Besides, in order to test the influence of different carbon chains on the surface activity of target molecules, the surface tension of dendritic molecules containing respectively an octyl, dodecyl, hexadecyl, perfluorobutyl,. or perfluorooctyl chain was measured, and their critical micells concentration(CMC), saturated adsorption capacity and occupation area of per molecule were determined too. The results showed that they could decreased the surface tension of water by 30-40mN/m, and the one containing a perfluorooctyl chain has the lowest CMC(1.73mmol/L) with the surface tension of water reduced to 32mN/m.The surface of these dendritic molecules displayed six carboxylic acids, and effectively catalyzed Friedlander reaction as Brφnsted acid in water, especially under solvent-free conditions. Moreover, the catalyst was separated by filtration, and could be reused several times without obvious decrease of activity. Additionally, carboxyl groups of these molecules were able to coordinate with transition metals, and formed a catalyst system that had both surface activity and Lewis acidity. Therefor the taget molecules were used as the ligand of rare earth metal salts. This kind of catalyst prepared in-situ performed well in the condensation reactions of indoles with aldehydes, and also in the preparation of functional dihydropyridines by three component sequential transformations of acetoacetic ester, benzylamine and cinnamaldehyde. Besides, on the basis of green catalysis, an effective method for Petasis reaction under solvent-free conditions was developed.