Construction Of Nitrogen-containing Aromatic Heterocycles Through Ugi-4-CR/Copper Catalyed Tandem Reactions

Nitrogen-containing aromatic heterocycles are common in the core skeletons of many biologically active natural products and organic functional molecules.They are of great important in pesticides,medicine and industrial applications.The multi-component reaction,which could generate multiple new chemical bonds through one-step chemical reaction and easily synthesize structurally diverse compounds,had been widely used.The traditional multi-step synthesis methods of heterocyclic compounds are usually complicated and time-consuming.Copper-catalyzed [3+2] cycloaddition reaction of1,3-dipoles and unsaturated compounds overcomes these shortcomings.Various heterocyclic compounds could be synthesized by using this approach.Recently,the efficient and convenient tandem reaction which developed on the basis of copper-catalyzed coupling reaction and multi-component reaction has become a hot and important topic.In this paper,a variety of 2-substituted arylacetamide derivatives,were synthesized using Ugi four components reaction and copper-catalyzed azide-alkyne [3+2] cyclization coupling/tandem reaction.The 2-position substituents of these arylacetamide derivatives are core of [1,2,3]triazolo[1,5-a]-quinoxaline-4(5H)-one or[1,2,3]triazolo[4,5-c]quinoline-4-one.In addition,we carried out the acid-catalyzed reaction of these 2-substituted arylacetamide derivatives,resulting in two kinds of new nitrogen-containing heterocycles compounds.The reaction conditions were optimized,variety of structural skeletons were obtained by changing the starting material combinations.