Study On Cu-MOF-catalyzed C-N And C-CN Bonds Formation Reaction

N-aryl compounds and nitriles are widely used in medicine,pesticides,natural products,and are also an important part of many chemical materials.Therefore,the synthesis of these compounds has been one of the hot topics in the field of organic synthesis.Among them,transition metal(mainly palladium and copper)/ ligand is commonly used for the efficient construction of C-N and C-CN bonds catalytic system.But there are two drawbacks in this system: one is catalyst or ligand is difficult to separate from the reaction mixture for homogeneous catalytic system.It is unable to realize the catalytic system used in circulation;another one is that is difficult to remove metal during separating the products,Causing metal residue pollution.Metal organic framework material(MOFs)is a major breakthrough in the field of inorganic chemistry in the past twenty years.It is using oxygen,nitrogen and other multidentate organic ligands and metal ions through self-assembly with periodic network structure of a zeolite material,which have high specific surface area,high porosity and due to the strong coordination bond was enhanced by the presence of the chemical and thermal stability etc.At present,MOFs has been applied to many fields such as gas storage,adsorption and separation,application of optical,electric and magnetic fields,the application of drug storage and delivery,and it also has wide application in heterogeneous catalysis.However,the use of Cu-MOFs to catalyze the construction of C-N and C-CN bonds is still very limited,the structural diversity is poor,the breadth and depth of research is not enough.Based on the above,this paper is committed to the development of a new and efficient "Cu-MOF" catalyst,further developping and improving the copper catalyzed C-N and C-CN bonds reactions,the specific work includes the following parts:In the first part,we studied the cross coupling reaction of MOF-199 catalyzed nitrogen containing heterocycles with aryl halides.The coupling reaction of toluene and pyrrole was used as model reaction.Under the optimum reaction conditions [MOF-199(10 mmol%),NaOH(1 mmol),DMSO(1 mL),120 oC,12 h],the yield of the model reaction was up to 98%.Applicability results of the substrate in this catalytic system showed that various substituted aryl iodides with four nitrogen-containing heterocyclic(pyrrole,indole,three triazole and imidazole)coupling reactions can be carried out smoothly,synthesized 26 kinds of target products which yields between 50-98%,the single reaction agent in copper rush spillage less than 0.18%,and the catalyst circulation five times can still maintain good catalytic effect.The second part explores the coupling of C-N or C-O Cu-MOF selective catalytic reaction of halogenated aromatic hydrocarbons and alcohol amines,through selective coupling,changing the reaction conditions to achieve the same substrate of C-N or C-O on the basis of this,we selected the iodine toluene and ethanol amine as a model reaction.First of all,the conditions of C-N coupling reaction were optimized.The optimum reaction conditions were [MOF-253.0.5CuI(10 mol%),Cs2CO3(1 mmol),DMF(1 mL),120 oC,24 h],and the reaction yield was up to 92%.The catalytic system can be extended to a wide range of different aromatic amines and aromatic amines coupling reaction,synthesized 16 kinds of target products,and the yields of 55-93%.It is a pity that the C-O coupling products have not been obtained when the different catalysts and reaction conditions are changed.The third part,we synthesized four kinds of Cu-MOF materials(organic ligands were imidazole,2-hydroxy pyrimidine hydrochloride,1,3,5-benzenetricarboxylate and terephthalic acid)as heterogeneous copper catalyst,MOF-199 catalyst system was established,in order to realize the three hydrated potassium ferrocyanide as cyanation of cyanide source aromatic iodides.Under the optimum reaction conditions of[MOF-199(10 mmol%),Na2CO3(2 equiv.),DMSO(1 mL),140 oC,24 h],the yield of cyanation reaction to model methoxy iodobenzene and three hydrated potassium ferrocyanide reached 98%.In the optimal reaction conditions,10 kinds of aromatic nitrile compounds with different substituents were synthesized.Their yields were between 72-98%,the recycle of catalyst showed that recycled 5 times,can still maintain good catalytic activity,the yield reached above 90%.In summary,three kinds of Cu-MOFs catalytic systems were established in this paper,which can realize the N-aromatization reaction of nitrogen containing heterocycles,the selective N-radical reaction of alcohols,and the cyanation reaction of aryl iodides with potassium ferrocyanide.The three catalytic systems have high catalytic efficiency,wide adaptability to substrates and the catalyst can be recycled,and the heterogeneous catalytic construction methods of C-N and C-CN bonds have been developed and perfected.