Synthesis And Application Of Diurea-based Organic Catalyst

In This thesis,we designed and synthesized urea-based multi-carboxylic acid and perfluoroalkyl quaternary ammonium catalysts involving urea using 4,4'-diphenylmethane diisocyanate (MDI) as the linking group. For the symmetry of diphenylmethane diisocyanate (MDI) and the formation of urea which had the performance of multiple catalytic sites, we prepared two kinds of catalytic activity catalysts using Bahera's amine and primary amine having tertiary carbon center. The former catalyst has more Br(?)nsted acid catalytic sites, could catalyze some organic synthesis reaction better; the other catalyst with the quaternary ammonium cation center could be applied to phase transfer catalysis, and introduction of long fluorinated chains made the catalyst have better surface activity, so as to achieve the purpose of emulsion catalysis in water-phase.Reacted with Behera's amine using MDI as a linking group and then urea-based multi-carboxylic catalyst was obtained through hydrolysis of tert-butylester in formic acid. The catalyst contains multi-catalytic acids and urea-based multi-catalytic sites, urea-based group may form hydrogen bonds with reactants in organic reaction, and the role of multi-carboxylic acid (Br(?)nsted acid) may also catalyze some organic synthesis reactions. Selected thre e-component synthesis of 2-amino-benzop yran reaction to examine the catalytic properties of different solvents and catalyst amounts, it was found that the catalyst reached moderate yield in ethanol with the amount of 5mol% catalyst. The catalyst solubility in organic solvents is poor, so it could be easily separated after reaction and it could be reused for 3 times, the yields did not reduce significantly.Reacted with N, N'-2-butyl-ethylenediamine using MDI as a linking group and then urea-based perfluoroalkyl quaternary ammonium catalyst was obtained through the reaction with long chain perfluoroalkyl iodide. The catalyst also contains urea and quaternary ammonium groups, and long-fluorine hydrophobic group which can reduce the surface tension of water. The CMC value of this catalyst were determined by testing the surface tension of their water solution in different concentration, the results showed that the catalyst had a certain surfactivity and could lower the surface tension of water at lower concentration to 41dyn·cm-1. We chose Morita-Baylis-Hillman(MBH) reaction in water phase to examine the catalytic performance. The results showed that the catalyst have a certain catalytic activity. When the electron deficient olefins was acrylonitrile, the yields are slightly higher then it was methyl acrylate. And the different substituent groups in aromatic aldehydes also had a certain influence, the results were better when the substituent groups were electron-withdrawing groups. However, organic synthesis reactions catalyzed in water is consistent with the requirements of green chemistry.