NH₄I-promoted Cascade Synthesis Of Substituted Pyrroles And Pyridines

Nitrogen-containing heterocyclic compounds play a vital role in heterocyclic compounds.The types of nitrogen-containing heterocyclic compounds are affected by the position and number of nitrogen atoms.In addition,the size and number of rings also lead to a wide variety of such compounds.People have found that it is contained in many organisms,and it is also widely used in the synthesis of natural products,the preparation of functional materials,and bioengineering.Among them,the excellent and special photoelectric properties make some nitrogen-containing heterocyclic compounds shine in the fields of chemical sensing,dye-sensitized solar cells,and nonlinear optical materials.However,it’s still a hot research field in modern science by developing efficient and simple methods for synthesizing effective optoelectronic materials.This thesis mainly launched the research on the synthesis methods and photophysical properties of a series of optoelectronic materials developed for polyaryl substituted pyrroles,as well as the synthesis of triaryl substituted pyridines.Specific contents are as flowing:1.Under metal-free conditions,using aryl ketones,amines and nitrovinylarenes as raw materials,a three-component reaction was carried out to obtain1,2,4-triaryl-substituted pyrrole derivatives with high yield.The reaction uses ammonium iodide as a accelerant and oxygen as an oxidant.A series of polyaryl-substituted pyrrole derivatives are synthesized through continuous condensation,isomerization and cyclization reactions at high temperatures.The raw materials for this reaction are simple and do not require pre-functionalization.Under system optimized reaction conditions,this type of reaction has good functional group stability.In addition,we have studied the photophysical properties of some pyrrole products,and they show good aggregation-induced emission(AIE)activity.2.On the basis of the previous work,a two-component "one-pot" reaction was conducted to form 2,4,6-triaryl-substituted pyridine using aryl ketone and benzylamine as raw materials without nitrovinylarenes.The reaction is carried out with available raw materials under simple reaction conditions and does not need to be catalyzed by any transition metal.Furthermore,the reaction selectively forms2,3,5-triaryl-substituted pyrroles when we used 4-acetylbenzonitrile.In this method,the ammonium iodide was used as initiator and nitrogen source for a N-containing heterocycle,and oxygen as a green oxidant,which provides a new way for the synthesis of multi-substituted pyridine derivatives.