Studies On The Reaction Of Nitrogen Containing Hetercyclic Compounds Via1,3-dipolar Cycloaddition

Heterocyclic compounds containing nitrogen atom have been widely existed innatural products and bioactive molecules, which play an important role in fields ofmedicinal chemistry, agrochemicals and so on. Skeletons of isoquinolins, pyrazolesand quinazolines are core structural units of many natural compounds which havegood biological activities and extensively application prospects. This dissertationmainly centers on1,3-dipolar cycloaddition reaction for the synthesis of isoquinolinsand pyrazolo [1,5-c] quinazoline derivatives.The paper is divided into three parts.Firstly, we introduced the development of1,3-dipolar cycloaddition reaction andits application on organic synthesis briefly.Secondly, the unexpected1-aminoisoquinoline derivatives were obtained through1,3-dipolar cycloaddition reaction. The stable nitrone1,3-dipoles were generatedwhile2-alkynylbenzaldoxime was catalyzed by lewis acid. Then nitrones reacted withisocyanides via an AuCl catalyzed giving rise to aminoisoquinoline derivatives whichmay undergo a procedure of cycloaddition, rearrangement, and elimination.Finally, an efficient route of metal-free [3+2]-dipolar cycloadditions to synthesispyrazolo [1,5-c] quinazoline derivatives was presented. So far, few methods about thesynthesis of pyrazoloquinazoline have being reported. In the dissertation weillustrated triethylamine-prompted1,3-dipolar cycloaddition reaction of N-substitutedmaleimide and quinazolines dipoles as starting materials, to construct maleimidepyrazolo[1,5-c] quinazoline in the presence of THF. The method has advantages ofavailable raw material, mild condition, excellent yield and good atomic economy.