Studies On The C-H Halogenation And Aminocarbonylation On Heteroaryls

Aryl C-H bond transformations constitutes one of the most efficient methods in the generation fo C-H and C-heteroatom bonds for the synthesis of diverse aryl derivatives,it is also highly important in the synthesis of organic molecules with different functions.The focus of this thesis is the research work in the direct functionalization reactons of heteroaryl C-H functionalization,and contains four deferetion sections of research.Firstly,the metal-free C5-H halogenation reactions of 8-aminoquinolines.Without using any metal catalyst or additional oxidant,directly heating 8-aminoquinolines and N-halosuccinimides in dichloromethane provides efficiently a series of C5-halogenated 8-aminoquinolines.The work provides a new and atom economical synthetic route to functionalized 8-aminoquinolines.Secondly,Ni-catalyzed C5-and C7-H dihalogenation of 8-aminoquinolines.Using low cost,low toxicity and easily available nickel bromide as catalyst,the double C-H halogenation of 8-aminoquinolines has been realized.The reactions take place in MeCN under aerobic atmosphere,and provided C5-,C7-dihalogenated 8-aminoquinolines with good to excellent yields.Thirdly,the C2 aminocarbonylation of 8-aminoquinolines.Starting from 8-aminoquinolines and isocyanides,the selective C2 aminocarbonylation takes place and affords structurally diverse 2-aminocarbonyl-8-aminoquinolines with the co-promotion of tosyl acid and DTBP.The reactions require no catalysis or assistance of metal reagent,which is advantageous in terms of atom economy.Finally,the C2 aminocarbonylation of pyridines.On the basis of previous work,and by means of comprehensive modification and optimization,the oxalic acid/DTBP mediated C2-aminocarbonylation of pyridines and isocyanides.Also without using metal reagent,a class of 2-aminocarbonyl pyridines are synthesized in 1,2-dichloroethane under air conditions.