Indium-Catalyzed Cyclization Of Bimolecular Imines To Synthesize Acridine Photocatalyst

As the most important organic photocatalyst in recent years,acridine compounds have shown very strong catalytic activity in various organic transformations.Among them,the synthesis of 9-aryl acridine photocatalysts has attracted the attention of many organic synthesis workers.Currently,organic chemists have developed a large number of methods for the synthesis of 9-aryl acridine photocatalysts,but the introduction of harsh reaction conditions,complex substrates,and highly active and sensitive reagents has always brought great difficulties to the efficient construction of such molecules.Therefore,exploring simpler and more efficient methods for the synthesis of 9-aryl acridine photocatalysts has become one of the research focuses of current scholars.On the other hand,the method of constructing cyclic molecules through diene synthesis reactions has been widely used in the fields of medicine and chemical industry,and its advantages of high conversion efficiency have been recognized by people.However,this mode is often used for cyclization reactions between olefins C=C,but there are few precedents for cyclization of C=N to construct heterocyclic molecules.Therefore,the development of chemical conversion using C=N imines as substrates is of great significance.Based on this,this paper proposes a simpler and more efficient method for the synthesis of 9-aryl acridine photocatalysts.Firstly,this article analyzes and summarizes the advantages and disadvantages of current synthesis methods for 9-aryl acridine compounds,and develops a method for synthesizing 9-aryl dihydroacridine compounds through indium catalyzed bimolecular N-arylamine substrate cyclization reaction.This article screened the catalysts,solvents,and temperatures for the reaction through single factor control experiments,and determined the optimal reaction conditions based on this.At the same time,we investigated the substrate suitability of 9-aryldihydroacridine products through substrates with different Electronic effect and spatial effects.In addition,a reliable mechanism for this reaction was proposed through intermediate capture,control,and competitive experiments,and the product was dehydrogenated to obtain 9-aryl acridine compounds.This experiment greatly enriches the molecular library of 9-aryl acridine compounds and proposes a novel method for constructing heterocyclic molecules based on the Povarov reaction.Subsequently,this paper continued to analyze and compare the molecular structure differences between 9-aryldihydroacridine compounds and acridine photocatalysts,and designed a route for the synthesis of acridine photocatalysts from 9-aryldihydroacridine compounds through tandem Buchwald coupling,oxidative dehydrogenation and ion exchange reactions.This paper shows the process of condition optimization of this route,and examines the influence of substrates with different Electronic effect and spatial effects on the reaction.At the same time,this article attempted to scale up the reaction and verified its amplification ability.In addition,this article characterized the photophysical properties of all 9-aryl acridine photocatalysts and investigated their catalytic performance through dehydrogenation cyclization reactions and SnAr reactions.The results indicate that this type of 9-aryl acridine photocatalyst has extremely active optical properties and strong catalytic activity.Finally,this article provides a summary and outlook for the experimental part.The method used in this article to synthesize 9-aryl acridine photocatalysts has the advantages of simple operation,environmental friendliness,and high yield and efficiency.However,it is expected that in the future,further regulation of the reaction system will continue to expand the substrate range of this reaction,increase substrate compatibility and product diversity.