Asymmetric Synthesis Of 1,2-dihydroquinoline Compounds Catalyzed By Nitrogen Heterocyclic Carbene

As an important synthetic unit in the field of organic synthesis,because of its unique biological activity,it has attracted great attention in the field of organic synthesis,and how to construct nitrogen-containing hexacyclic compounds with efficient and concise synthesis strategy has been a hot while challenging topic research in this field.As an organic small molecule catalyst,N-Heterocyclic Carbenes(NHC)has a unique activation pattern that not only enables high yield and high stereo-selective control of existing reactions,but also synthesizes skeleton compounds that cannot be synthesized by conventional methods.This paper uses bromocinnamic aldehyde to undergo self-oxidation under NHC catalysis to give ?,?-unsaturated acylazolidine ion intermediate and react with N-Ms o-amino aromatic aldehydes to form dihydroquinoline compounds with chiral centers.In this article,we reveal that through proper substrate design,two aldehydes can be chemoselectively,transformed to dihydroquine compounds with excellent optical purity.This thesis is devided to three main parts:In the first part,the research and development of NHC catalysis were introduced,and the reaction of active ?,?-unsaturated acylazolium intermediates was discussed.The reaction of NHC catalyzed carbonyl compounds aldehyde,ester,acyl chloride and carboxylic acid derivatives to react with a series of electrophilic or nucleophilic substrates,and construct C-C bond,C-N bond,C-O bond efficiently,and to control many reactions with high stereoselectives.The second part mainly tells the research purpose and significance of this topic.The functional molecules containing quinoline skeleton have been reported to be widely used in natural products,pesticides and medicine through literature research.These functional molecules have biological activities of antifungal,antibacterial,antiviral and anticancer,and are valuable in the field of organic synthesis.The synthetic methods of chiral quinoline molecules,such as asymmetric hydrogenation,intramolecular reaction and dearylation,are also reviewed.In the third part,the target molecule was designed and the model reaction was determined by catalyzing the reaction of bromocinnamic aldehyde and o-aminobenzaldehyde by azacyclocarbin.Then,the catalyst,base,solvent,temperature,concentration and other elements were evaluated to figure out the optimal reaction conditions of the model reaction,The optimal conditions were used in the examination of the substrate scopes of the two aldehydes.Finally,the target molecules are transformed to valuable functional molecules.