Studies On The Synthesis Of Nitrogen-containing Heterocyclic Compounds Via Tandem Azidation/Cyclization Reactions

Organic azides are important synthetic intermediates that can be easily converted to N-containing structural motifs.This thesis deals with the studies on azide-based in C-N bond forming reactions.It includes the following three parts.In the first capter,The recent progress made on the azide-involved radical reactions for the construction of C-N bond is reviewed from the following aspects:(1)the free radical method for the preparation of organic azides;(2)the free radical reactions of organic azides.The second chapter and third chapter describe the research work during my graduate study which is summarized as follows.(1)A new method for the synthesis of quinoxalin-2(1H)-ones was developed by using N-arylenamines and TMSN3 as the starting materials and(diacetoxyiodo)benzene as oxidant.The reaction was implemented by combining two C-N bond forming processes in a tandem oxidative azidation/cyclization pattern.The present reaction conditions are mild and simple and thus are useful in practical synthesis.(2)On the basis of the above mentioned study,a new method was developed for the synthesis of imidazole derivatives.This method employs the reagent combination of(diacetoxyiodo)benzene/Cu(OAc)2/tetrbutuylammonium iodide(TABI)as oxidant,which can effect the tandem oxidative amination of C(sp2)-H and C(sp3)-H bonds.The method is simple and easy to operate,and is suitable for the preparation of trifluoromethyl-substituted imidazole compounds.