Study On Group 9 Transition Metal-catalyzed C-H Activation Based On Oxadizole As Ditecting Group

Activation and functionalization of inactivated and ubiquitous C-H bonds have received extensive research attention,and this conversion has been efficiently achieved by group 9 transition metals with lower catalyst loading,mild reaction conditions,excellent functional group tolerance and higher selectivity.The first chapter briefly reviews the related progress in Group 9 transition metal-catalyzed directed C-H activation,mainly divides into two parts:Co(?)-catalyzed and Rh(?)-catalyzed.Including CoCp*Catalyzed Annulation reactions,Insitu Generated High-Valent Co(?)-Catalyzed Annulation Reactions and Rh(?)-Catalyzed direct C-H bond transformations to carbon-heteroatom bonds.In the second chapter,we report a study of cobalt(?)-catalyzed internal oxidative annulations with alkyne via C-H activation based on oxadizole as directing group,and prepared 1-amino isoquinolines derivatives.The catalytic reaction,which rarely uses opening/closing ring pattern,has significant advantages such as mild conditions,high efficiency,broad substrate scope and atom economy.According to the mechanism experiment including H/D exchange,KIE,substrate competition and Co-complex experiments,a probable Co(?)catalytic cycle is proposed:Co(?)as the subject in catalytic cycle zatalyzes reaction based on oxadizole as directing group,then coupling with alkynes to give the products.And the cleavage of N-O bond engenders the Co(?),re-enter the circular·system.The third chapter,we report a study of rhodium(?)-catalyzed annulations with alkyne via alkenyl C-H activation based on oxadizole as directing group,and prepared 2-acylamino and 2-amino pyridine derivatives.The catalytic reaction,which spreads to alkenyl C-H activation,has significant advantages such as high active and yield,wide substrate adaptability and good regioselectivity.According to the mechanism experiment including H/D exchange,KIE,substrate competition,a probable Rh(?)catalytic cycle is proposed:Rh(?)as the subject in catalytic cycle zatalyzes reaction based on oxadizole as directing group,then coupling with alkynes to give the 2-acylamino derivatives,also we can get the 2-amino pyridines through change the solvent.