The Study On Copper-catalyzed Imine-involved Creation/functionalization Of Six-membered N-heterocycles

Six-membered N-heterocycles,the core structures of numerous bioactive and functional products,extensively exist in numerous products related to human life such as medicines,pesticides and functional materials.From the viewpoint of green and sustainable chemistry concerns,the synthetic strategies enabling atom-economic,green and practical construction and structural modification of six-membered N-heterocycles has long been a hot topic in synthetic organic chemistry.In addition,as a cost-effective and earth-abundant metal,copper has been widely investigated and applied in the field of catalysis,including the manufacture of pharmaceuticals,materials and fine chemicals.On the basis of our related research work,this thesis mainly describes the copper-catalyzed imine-involved creation/functionalization of six-membered N-heterocycles.The content of the thesis is composed of the following two sections:In the first section,we present a direct dehydrogenative?-C–H amination of tetrahydroquinolines?THQs?using various amino agents by selective Cu/O₂/TEMPO catalyst system,which enables divergent access to 2-aminoquinolines.During the reaction,the catalyst system preferentially oxidizes the tetrahydroquinolines between two amino reactants.The developed chemistry features broad substrates,excellent functional tolerance,high chemo-selectivity,and no need for preparation of specific aminating agents,which offers a practical way for diverse and atom-economic synthesis of 2-aminoquinolines that are difficult to prepare or inaccessible with the existing C–H amination approaches.In the secod section,by employing in situ generated imine as a substrate protection&activation strategy,we demonstrate an aerobic copper-catalyzed synthesis of quinazolinones by a multicomponent cascade reaction of aniline,formaldehyde and primary amines in one single operation.The developed chemistry proceeds with the merits of broad substrate scope,excellent functional group tolerance and chemo-selectivity,release of H₂O as a single by-product,and use of the naturally abundant Cu/O₂ system.Also,the unique selectivity in conjunction with the multiple C-H functionalization and C-N bond formation of the simple substrates constitute the striking features of this work.