Study On The Synthesis Of Xanthenes,α-Ami-nophosphonates And2,3-Dihydroquinazolin-4-ones Catalyzed By PS-PEGOSO₃H

In recent years, with the concept of " green chemistry" have been proposed, Polymer-supported catalysts have attracted much attentions due to their inherent advantages in synthetic chemistry, such as simplification of reaction procedures including easy separation of products, easy work-up, and recyclability. Polymer-supported acid catalysts also have attracted much attentions. At present, Polymer-supported acid catalysts mainly include silica gel supported, activated carbon supported, the carbonization of biomass supported, polyethylene glycol (PEG) supported, resin supported, etc.In the thesis, first of all, the research progress of Polymer-supported acid catalysts in the systhesis is reviewed, then we are going to study the scope of Polymer-supported acid catalysts (PS-PEGOSO3H) which was previously reported in our laboratory. Three chapter parts are included in this thesis.1. PS-PEGOSO3H is used as an excellent catalyst for the three-component reaction of an aldehyde and two5,5-dimethyl-1,3-cyclohexanediones to give either bis(3-hydroxy-5,5-dimethyl-2-cyclohexene-l-one) derivatives at room temperature or1,8-dioxo-octahydroxanthenes at100℃. The advantages of this method include high selectivity in different conditions, good yields, and short reaction time. The catalyst was recycled for five cycles with almost unaltered catalytic activity. In addition, water was chosen as a green environment friendliness solvent.2. α-Aminophosphonates are synthesized by the three-component reaction between aryl aldehydes, aromatic amines and diethyl phosphite (triethyl phosphite) catalyzed by polystyrene-poly(ethylene glycol) sulfonic acid (PS-PEGOSO3H) at room temperature. The results have shown that polystyrene-poly(ethylene glycol) sulfonic acid catalyst have advantages of high activity, be easily recovered and reused.3. One-pot synthesis of2,3-dihydroquinazolin-4-ones and quinoline respectively catalyzed by polystyrene-poly(ethylene glycol) sulfonic acid (PS-PEGOSO3H). The ratio of materials, the time of reaction and reaction temperature were investigated for the optimized reaction conditions.