Study On The Cyclization Reaction Of Aromatic Compounds With Ortho Bifunctional Groups

Ortho bifunctional compounds are commonly used as starting substrates to produce cyclization compounds in organic synthesis.These compounds may react with itself or another molecule to form cyclic or polycyclic products due to the adjacent two functional groups.In this thesis,we have developed new methods for the synthesis of different cyclic compounds with different ortho bifunctional substrates.It mainly includes the following four parts.The first part:ynones were attacked by ethanones in the presence of cesium carbonate to give allene intermediate,which presumably underwent an intramolecular nucleophilic addition/fragmentation cascade resulting in alkynes insertion into the carbon-carbon 6-bonds of the ethanones to give hydroxydienones.When the temperature increased,the reaction of ynones bearing an ortho-halide substituted with ethanones underwent further nucleophilic atomatic substitution to afford the desired chromones.In this part,a total of 23 compounds were synthesized with 55%-95%yields.In the second part,in the presence of cesium carbonate,ynones bearing an ortho-amino group reacted with ethanones through conjugated addition/carbon carbon bond cleavage/nucleophilic aromatic substitution tandem reaction to obtain 4-quinolnoes in good yields.A total of 14 quinoline compounds were synthesized by this method.Single Z type target products were obtained in 2-4 hours.The third part:an amido copper(?)intermediate was obtained under the condition of ortho alkynyl enaminone as a start substrates in the presence of the metal copper and benzoyl peroxide.The intermediate underwent isomerization and further reacted with orth alkynyl to form an indenone intermediate,which exchanged ligand with ortho nitrogen atom followed by reductive dlimination to prepare the target indeno[1,2-c]pyrrolones.15 indeno[1,2-c]pyrrolones were obtained with 45%-90%yield by this method.In the fourth part,ortho-alkenyl benzaldehydes were attacked by the nucleophile of 1,3,5-trimethoxybenzene to form carbocation under the catalysis of the metal iron,subsequently the carbocation reacted with ortho alkenyl followed by isomerization to give indenes.The reaction took place under 60? with aqueousferricperchlorate as the catalyst.13 indenes were obtained under the condition.All new compounds in this paper were characterized by 1H NMR?13C NMR and HRMS.