Synthesis Of Azaspirocycles And Perfluorinated Phenols/Anilines By Photoredox Catalysis

Azaspirocycles compounds as well as phenol and aromatic amines proved to be the indispensable building skeleton synthetic intermediates in natural products and pharmaceutical active molecules.It is a task that organic chemists have been trying endlessly in recent years,which introducing several functiaonal groups into the azaspirocycles skeletons to synthesize more potentially valuable azaspirocycles compounds.It will offer opportunity for synthetic practioners to get some molecules with physiological activity.Based on previous research,it focused on the research of introducing perfluoromethyl groups and functional aromatic groups into azaspirocycles skeletons via effective,mild and green visible light induce.Furthermore,introducing more perfluorinated moieties into phenols/anilines was also studied.The main contents are as follows:Firstly,a visible-light-induced dearomation cyclilation of N-alkyl-N-benzy lacrylamides for synthesizing di-cyclic azaspirocyclic cyclohexadienones was studied.Under the irradiation of LED,using Ru?bpy?₃Cl₂ as catalyst,as well as H₂O as an external oxygen source,the initial substrate N-alkyl-N-benzylacrylamides and aryl radical produced from diazonium salt underwent cascade Meerwein addition/cyclilation,effectively constucting a series of di-cyclic azaspirocyclic cyclohexadienonesSecondly,a visible-light-induced dearomatizing spirocyclization of N-alkyl-N-benzylacrylamides toward perfluorinated azaspirocyclic cyclohexadienones was proposed.Using R_f-X?X=I or Br?as the R_f radical source,the reaction underwent cascade radical addition/dearomative cyclization process by Ir photocatalyst under the irradiation of blue LEDs,leading to various 2-azaspiro[4.5]deca-6,9-diene-3,8-diones.In addition,a route of visible-light-induced ortho-selective perfluoroalkylation of various free phenols/anilines was designed.Using economic bromides/iodides as the radical source and Ru?bpy?₃Cl₂ as catalyst,various para-substituted phenols/anilines underwent perfluoroalkylation efficiently,leading to a series of perfluoroalkylated phenols/anilines in moderated to good yields.