Study On The Construction Of Benzothiphene Polycyclic Fused Ring Derivatives From Azadiene

Benzothiophene and its derivatives are widely present in natural products,and its unique properties make it useful for the treatment of some diseases and the synthesis of semiconductor materials.Exploiting a simple and efficient synthesis strategies for benzothiophene derivatives has been the focus of scientists.In this thesis,benzothiophene-derived azadiene is used as the reaction substrate,Under the two conditions of catalyst and no catalyst,We synthesized benzothiophene condensed pyrrole,benzothiophene condensed seven-membered,eight-membered aza derivatives and benzothiophene spiro derivatives,these provided new methods for the synthesis of various benzothiophene derivatives.1)First,we used o-nitroacetophenone to synthesize various substituted benzothiophene-derived azadienes,which reacted with isatin-derived MBH carbonate.By using different catalysts to alter the reaction sites of reactants,different substituents of benzothiophene derivatives can be synthesized.The reaction conditions are mild,the raw materials are easily available,the substrate scopes are wide range,and the controllability of the catalyst selection makes the obtained products have diversity.2)Without catalyst,the cyclization of azadiene and azomethimine ylide was studied,and a series of five-membered azospiro ring and seven-membered triaza fused ring were obtained with good yield.Among them,the seven-membered nitrogen heterocycles can be inserted through the use of trimethylsulfoxide iodide to obtain the relatively rare eight-membered three-nitrogen fused ring.The reaction yield is high and the raw materials are easily available.The development of this strategy is the eightmembered three-nitrogen fused ring.The synthesis of nitrogen fused rings provides an easier way.3)Compare the azadiene derived from benzothiophene with the azadiene derived from benzofuran or indene,Explored the difference in reactivity between them.4)All the above reaction mechanisms were predicted,some novel mechanisms were verified by DFT theoretical calculation.A total of 120 new compounds were synthesized in the full text.All the compounds were characterized by MP,IR,NMR and HRMS,the representative compounds were verified by single crystal diffraction.