Studies On The ?-position Oxidation Reaction Of N-benzyl Arylamine Promoted By DDQ

Amine compounds are a common and important organic substance in nature,and are widely used in all aspects of production and life.Among the many amine compounds,allylamines and benzimidazoles have attracted everyone's attention because of their important biological activities.The unique structural characteristics enable it to combine with many biological targets to produce important activities.At present,they have found their practical applications in many fields.For example,in medicine,allylamine has important medical value and can be used as natural drug intermediates,etc.At the same time,benzimidazoles with different substituents have shown the potential for antipsychotic,antiulcer,antiviral,antibacterial,antitumor,antihypertensive,antidiabetic,anti-HIV clinical and other biological activities.In agriculture,compounds with a benzimidazole structure also have fungicidal properties and regulate plant growth,and are often used in the production of pesticides.In addition,benzimidazole is also popular in the field of materials science,and can be used as a raw material for preparing photochemical sensor polymers,electrolyte membranes,and catalysts.Combined with the research work of this research group,this thesis mainly introduces the method and strategy of allylation reaction without metal catalysis and oxidative coupling reaction to synthesize allylamine and benzimidazole.The main contents are as follows:The first part of work: synthesis of allyl amine compoundsIn this part of the work,2,3-dichloro-5,6-dicyanobenzoquinone(DDQ)was used as the oxidant to realize the allylation reaction of N-benzylarylamine ?-position without metal catalysis,and to prepare a Series of allyl amine compounds.During the experiment,N-benzylaniline was first used as the reaction material,and the target product was obtained by intramolecular dehydrogenation coupling under mild conditions under the oxidation of DDQ.And under the optimal reaction conditions,the universality of the substrate was investigated,and target compounds with diverse structures were obtained.Then,related nuclear magnetic detection and analysis were done on the reaction process,and the mechanism of the reaction process was explored.Finally,a reasonable mechanism is proposed to explain the response.The second part of work: the synthesis of benzimidazole compoundsIn this part of the work,the method and strategy of preparing 1,2-disubstituted benzimidazole compounds by intramolecular dehydrogenation coupling of DDQ oxidation was studied.In the experiment process,N,N'-dibenzyl o-phenylenediamine was first used as the raw material for the reaction.Under the oxidation of DDQ,the target product was obtained through intramolecular dehydrogenation coupling,and then a series of conditions were screened.,Established the optimal reaction conditions,and carried out the general applicability of the substrate under the optimal reaction conditions,and obtained a series of benzimidazole target compounds with diverse structures.Finally,a reasonable mechanism is proposed to explain the observed reactivity and selectivity.In the course of the experiment,it was also found that under certain circumstances,N-benzyl o-phenylenediamine can form the corresponding benzimidazole product through air oxidation and p-cyanobenzaldehyde cyclization,which is a general 1,2-disubstituted product.The synthesis of benzimidazole provides an alternative.The synthetic strategy of benzimidazole compounds developed in this subject has mild reaction conditions,high yield,low cost,simple operation,good substrate universality,and can be used for the extensive synthesis of benzimidazole and its derivatives.