Studies On Synthesis Of The Quinoline Derivatives From 2-Aminobenzaldehyde Or Benzo[c]isoxazole

Quinoline compounds are nitrogen-containing heterocyclic compounds that can be found in abundance in nature.Most of the early drug discovery in human society contains quinoline structures.Scientists have created a range of quinoline derivatives thanks to the advancement of organic synthetic chemistry,which are widely employed in the domains of medicines,dyes,functional materials,and daily chemical.As a result,the discovery and development of more efficient,simple,green,and environmentally friendly synthetic methods for quinoline derivatives has become a research hotspot in organic synthetic chemistry.In this paper,the cyclization reaction was used as the synthetic strategy,and 2-aminobenzaldehyde derivatives or benzo[c]isoxazoles were used as starting materials for the synthesis of quinoline derivatives through Lewis acid promotion or catalysis.A green reaction capable of forming both C-C and C-N bonds in one step.The main research contents are as follows:1.Under metal-free,1,2,3,4-tetrahydroacridine derivatives and 2-substituted quinoline derivatives were efficiently and easily synthesized by intermolecular condensation from 2-aminobenzaldehyde derivatives and ketones(cyclic ketones and methyl ketones).The reaction was promoted by trifluoroacetic acid,and a series of1,2,3,4-tetrahydroacridine derivatives and 2-substituted quinoline derivatives were synthesized after isomerization,condensation and cyclization.It has the advantages of cheap and readily available raw materials,good functional group tolerance and a wide range of substrates.2.Under metal-free,11H-indeno[1,2-b]quinolin-11-one derivatives were synthesized by [4+2] cycloaddition using 2-aminobenzaldehyde derivatives and 1-indanone as starting materials.The reaction was promoted by trifluoroacetic acid,oxygen and dimethyl sulfoxide were used as oxidants,and a series of 11H-indeno[1,2-b]quinolin-11-one derivatives were obtained after isomerization,condensation,cyclization and dehydrogenation.The reaction conditions are simple,no metal catalysts are required,and no prefunctionalization is required.3.Under iron catalysis,using 2-methylquinoline derivatives and benzo[c]isoxazole as starting materials,and N,N-dimethylacetamide as C1 source,the2,3’-biquinoline derivatives.Under the catalysis of ferric chloride,2-methylquinoline can generate 2-vinylquinoline in situ,and then undergo ring expansion reaction with benzo[c]isoxazole to obtain a series of 2,3’-biquinoline derivatives.In one step,this process creates two C-C bonds and one C-N bond.