Construction Of Nitrogen-Containing Fused Heterocyclic Skeleton By MCRs

Multicomponent reactions(MCRs)refer to a method in which three or more components are introduced into a reaction,and a "one-pot" method is used to form a final product.MCRs can realize the diversity and complexity of product structure through the structural design of the substrate,and become an effective method for the construction of some complex heterocyclic compounds.Nitrogen-containing fused heterocyclic compounds are widely found in nature,due to their good biological and pharmacological activities,they are widely used in medicine,pesticides,dyes and the like.In this paper,we discuss the construction of nitrogen-containing fused heterocyclic skeleton by multicomponent reaction in four parts.In the first part,the research progress of multicomponent reactions to construct nitrogen-containing fused heterocyclic compounds in recent years has been introduced.In the second part,a series of 5-aminochromeno[4,3-d]pyrazolo[3,4-b]pyridine-6(3H)-one derivatives were synthesized by three-component reactions of salicylaldehydes,ethyl cyanoacetate and 5-aminopyrazoles catalyzed by TEA.The properties of the synthesized compounds were examined by fluorescence spectroscopy.In the third part,a series of pyrazolo[3,4-b]pyrrolo[3,4-d]pyridine-6(3H)-one derivatives were synthesized by three-component reactions of substituted benzoylformaldehyde,?-ketoamide and 5-aminopyrazole,under the condition of acetic acid as the reaction medium and microwave irradiation.The method has the advantages of short reaction time,high atom utilization rate and environmental friendliness.In the fourth part,a series of(1H-indol-3-yl)-N-aryl acetamide derivatives were synthesized by three-component reactions of benzoylformaldehyde,malic acid and substituted aniline as raw materials,under the conditions of acetonitrile as solvent,potassium carbonate as catalyst and microwave irradiation.The method has the advantages of simple operation,easy availability of raw materials and simple operation.