Selective Construction Of Indoloquinoline/Pyridine Derivatives

Quinoline and indole molecular skeleton exist in many natural products with biological activity,and these compounds are also very important in pharmaceutical chemistry.The synthesis of these derivatives has attracted extensive attention of synthetic workers.In particular,indole-quinolines and carbolines are important alkaloids with unique biological and pharmacological activities.Generally,the synthesis methods of these compounds need to start from functionalized indole,which require the use of transition metal catalyst and equivalent oxidation reagent,which not only cost a lot,but also bring some environmental problems.Therefore,it is necessary to develop a convenient,low-cost and convenient method to synthesize indole-quinolines and carbolines.This dissertation focuses on the construction of important biological activity of indole and quinoline and indoloquinolines,and using simple and easy indole and other simple organic small molecules as starting materials.It mainly includes the following two parts:In the first part of the study,iron-catalyzed indolo[2,3-c]quinolines synthesis from nitroarenes and benzylic alcohols/aldehydes promoted by elemental sulfur has been reported.By screening the reaction conditions such as temperature,the optimized conditions are that Fe Br₃ was used as catalysts,N-methylpyrrolidone was used as solvent,160 ^oC,under argon atmosphere,through nitro reduction,benzyl alcohol oxidation,condensation,cyclization oxidation to obtain indolo[2,3-c]quinolines with 32 substrates and providing a new method for the synthesis of such compounds.In the second part of the study,3-indole carboxaldehyde and3-aminocyclohexenone were used as starting materials.By the screening of conditions,the optimized conditions are that NIS was used as catalyst,benzoic acid was used as additive,dichlorotoluene were solvent,130 ^oC,under air atmosphere,γ-carbolines containing indole skeletons were synthesized through condensation and oxidation.The method doesn’t require the use of metal catalysts,and has good functional group tolerance,providing a green and simple synthesis method for the synthesis of polysubstitutedγ-carbolines.