Preparation Of Three Covalent Organic Framework Materials And Their Applications In Catalytic Coupling Reactions

The preparation and application of heterogeneous catalysts that can be recycled and reused have always been one of the hot spots in chemical research.The covalent organic framework material is an organic porous material which is formed by reversible covalent bonds of various building units.Due to its uniform pores,diverse building blocks and excellent chemical stability,it has a wide range of applications in gas adsorption,photovoltaic materials and drug carriers.In recent years,covalent organic framework materials with various metals or functional groups have been widely used in the field of catalysis.Their excellent chemical stability and high reactivity are of great significance for the study of various organic synthesis reactions.Based on the excellent properties of covalent organic framework materials,three covalent organic framework materials were prepared by different preparation methods.After the modification,different metal supported covalent organic framework materials were prepared,respectively is Pd@TMC-Bpy COF,Cu@PI-COF,Pd@N₃-COF,the catalysts were characterized by FT-IR,XRD,SEM,TEM,XPS,TGA,elemental analysis and the catalytic activity of catalysts was investigated by catalyzing different coupling reactions.The details are as follows:The covalent organic framework material was prepared by grinding method,and the metal palladium was coordinated by solvent reflux to obtain the covalent organic framework material Pd@TMC-Bpy COF.As a catalyst,a variety of Suzuki-Miyaura coupling reaction products were prepared by substituted phenylboronic acid and substituted bromobenzene.The preparation method is simple and efficient,the reaction time is short,the catalyst is easy to recycle and the catalytic efficiency is high.The covalent organic framework material was prepared by calcination method,and the metal copper was coordinated by solvent reflux to obtain the covalent organic framework material Cu@PI-COF.A plurality of N-aryl compounds were prepared by substituted boric acid and an amine at room temperature without the aid of any base or additive.The reaction conditions are mild,the catalyst has a wide application range and the target yield is high.The covalent organic framework material N₃-COF was prepared by the method of standing at room temperature.The metal palladium was coordinated by solvent reflux to obtain the covalent organic framework material Pd@N₃-COF.Using this as a catalyst,a variety of arylboronate esters were prepared by substituted bromobenzene and pinacol borate.The method is simple and environmentally friendly.