Studies On The Synthesis And Applications Of Pyrroloquinoline And Isoxazoline Derivatives

Heterocyclic compounds are an extremely important branch of organic chemistry and widely exist in nature,accounting for almost one half of the entire discovered organic compounds.Among the numerous heterocyclic compounds,nitrogen-heterocyclic compounds such as pyrrole,quinolone,pyrroloquinoline and isoxazoline are particularly prominent.They are the key skeleton of a large amount of pharmacologically active molecules and natural products,as well as the synthetic intermediates of abundant bioactive molecules such as amino acids and alkaloids.Furthermore,these compounds are widely used in the fields of organic synthetic chemistry,medicinal chemistry and functional materials.As a consequence,the study on synthetic methods for nitrogen-containing heterocyclic compounds is still one of the research focuses in the field of organic synthesis.Notwithstanding there have been a large number of methods reported by extensive literatures,it is still of great significance to synthesize more diverse nitrogen-containing heterocyclic compounds by exploiting the environmentally friendly,highly-efficient and atom-economic research strategies.On this basis,the present dissertation is principally concentrated upon the preparation of pyrroloquinoline and isoxazoline derivatives.(1)The cyclopropylimine rearrangement/Povarov reaction cascade for the assembly of pyrrolo[3,2-c]quinoline derivatives.This paper developed a cascade reaction for the synthesis of a series of pharmacologically significant hexahydropyrroloquinolines from anilines and cyclopropyl aldehydes.This method has the advantages of simple raw materials,atomic economy and high yield,which is more advantageous than the existing methods for synthesizing pyrrolo[3,2-c]quinolines.(2)Synthesis of polysubstituted isoxazolines.This dissertation allowed the assembly of a vast array of 3,5-disubstituted and 3,4,5-trisubstituted isoxazoline derivatives under simple base conditions via[3+2]-dipolar cycloaddition of ketoxime esters and aldehydes.This protocol provides an easy-to-handle and rapid access to multi-substituted isoxazolines without assistance of any transition metal catalyst.In addition,there is no regional selectivity in this reaction.