| Amide compounds(RCONR’R")play an important role in the field of natural products,agricultural chemicals,peptides,dendrimers,proteins,biologically active systems and functional materials,as well as intermediates in synthesizing other important molecules,such as complex amines and heterocycles.Therefore,the synthesis of amides is one of the most widely used reactions in organic chemistry research laboratories.In recent years,the high-yield and atom-economic synthesis of amide compounds have attracted great attention in the field of scientific research.The traditional methods of synthesizing amides involve the coupling of carboxylic acids and amines.These methods often require stoichiometric active reagents and harsh reaction conditions,and generate a lot of waste.In some cases,carboxylic acids and amines can also undergo thermal condensation,but only for simple substrates.Therefore,many transition metal-catalyzed synthesis of amides,amination of esters,oxidative amination of alcohols and aldehydes,and palladium-catalyzed carbonyl amination of aryl halides and amines and carbon monoxide have been developed in the later period.Although these methods greatly improve the reaction efficiency and atomic economy,there are still problems such as excessive raw material ratio and heavy metal pollution.From the perspective of green chemistry,the photocatalytic method has become one of the ideal methods for constructing C-N bonds due to its more environmentally friendly sustainability and mild operating conditions.However,photocatalytic methods still require photocatalysts,bases and additives.Therefore,it is still of great significance to develop a method to construct amide bonds without any photocatalyst and additives.The second chapter of this thesis developed a UV light-induced amination reaction of 1,2-diketone compounds.The system does not require any photocatalysts,oxidants,alkalis and additives,and has strong functional group tolerance,and the product generally obtains a higher separation yield,up to 97%.This method explores the reaction of various primary amines,secondary amines,amino acid derivatives and 1,2-diketone compounds.Various secondary amines including four-membered,five-membered and six-membered cyclic secondary amines and non-cyclic secondary amines can obtain excellent yields in this system.Various long-chain or heterocyclic primary amines have also achieved moderate to excellent yields.Aromatic and heterocyclic 1,2-diketone compounds are suitable for this reaction condition.When prolonging the reaction time,the template reaction can be scaled up in grams,with a yield of 76%,which further illustrates the industrial application potential of this synthetic method.Light control experiments and control experiments prove that benzoin is an intermediate product of this process.We thus propose possible reaction mechanisms.In the third chapter of this thesis,a method for the synthesis of hydrazone compounds with amide structure from o-nitrobenzaldehyde and amines promoted by ultraviolet light has been developed.That is to say,this method realizes the bifunctionalization of o-nitrobenzaldehyde.The reaction substrate is acetic acid additive,tetrahydrofuran is used as the solvent,and hydrazone compounds can be obtained under ultraviolet light irradiation.The experiment explored the reaction between o-nitrobenzaldehyde and several primary amines,and various substituted benzylamines and alkylamines are suitable for this system.Through single crystal test and literature research,the possible reaction mechanism is proposed.Although this method can only obtain hydrazone compounds with a moderate yield,it provides a new idea for the synthesis of hydrazones. |
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