Study On C-h Functionalized Coupling Reaction Of Aromatic Ring In Sm-cu I System

C-H functionalization is one of the current research hotspots in organic synthetic chemistry.It is of great significance to realize the C-H functionalization of aromatic rings through multi-component reactions to construct new C-C bonds.And with the help of multi-component reaction,it provides a novel synthetic method for constructing diaryl skeleton derivatives.The one-pot anhydrous and oxygen-free catalytic method in Sm-Cu I system is a new breakthrough in the methodology and catalysis field.The combined use of the two metals also enriches the application range of Sm reagent.The first is the study of the multi-component C-H functional coupling reaction of halobenzene,DMF and ester in the Sm-Cu I system.And the conditions were optimized and the ranges of substrates were investigated in detail,the best conditions and the applicability ranges of esters and halobenzenes were obtained.Through the analysis of the results,we get the influences of various esters and various substituted halobenzenes on the reaction,and the regularity of the reaction is summarized:The shorter the ester chain,the better the reaction.The ortho-substituted bromobenzenes are better than the meta-substituted bromobenzenes,for ortho-substituted bromobenzenes,electron donating substituents are better than electron withdrawing substituents.And we infer the causing factors from the electronic effects and steric hindrance.In the process of studying the mechanism,a four-component cross-reaction is used to obtain a competitive relationship:the self-coupling tendency is greater than the cross-coupling,and the ratio is about 2.6:1.The second is the study of the C-H functionalized coupling condensation reaction of benzaldehyde and ester in the Sm-Cu I system.Based on the study of the three-component reaction,the possibility of condensation of substituted benzaldehyde with ester after self-coupling was explored.Experiments show that benzaldehyde can replace halobenzene and DMF to react with esters and the products are all diaryl skeleton derivatives.In the summarized rules,the electronic effect has little influence on the reaction.And benzaldehyde cross-coupling experiments can also be carried out,self-coupling tendency is greater than cross-coupling,the ratio is about 2:1.In the thesis,¹H NMR,¹³C NMR,HRMS,and X-ray single crystal diffraction were performed on the compounds obtained in the experiment.See the appendix for the characterization data and spectra.