Transition Metal Catalyzed Functionalizative Cyclization Reaction Of Dienes

Transition metal catalyzed functionalizative cyclization reaction of dienes is a versatile tool for the construction of carbocyclic and heterocyclic rings,which are widely present as motif in pharmaceuticals and natural products.The topic of this dissertation is centered around developing the methods of synthesizing cyclic molecules from diene substrates.The detailed content contains the following two parts:1)nickel-catalyzed regio-and diastereoselective hydroarylative and hydroalkenylative cyclization of 1,6-dienes.An unprecedented nickel-catalyzed hydroarylative and hydroalkenylative cyclization of unsymmetrically substituted 1,6-dienes with organoboronic acid was developed by using Me OH as the hydrogen source and employing commerically available Ni(COD)₂as the catalyst precursor.A series of biologically interesting cyclic products were affored in moderate to good yields with high regio-and diastereoselectivities.2)palladium-catalyzed enantioselective carbonylative Heck cyclization of o-iodoanilines with allenes.The construction of chiral aza-quaternary carbon centres via C-N bond formation has been achieved by palladium-catalyzed asymmetric carbonylative cyclization of o-iodoanilines with allenes,providing chiral dihydroquinolinone derivatives with moderate to high yield and enantiomeric ratio(e.r.).The e.r.could be elevated to 99:1through the recrystallization of the isolated products.Subjecting o-iodoaniline into the reaction system by syringe pump facilitated diminishing the side reactions of reactive o-iodoanilines and improving the chemoselectivity.Utilizing the chirality induction of assembled aza-quaternary stereogenic center,molecules bearing vicinal chiral quaternary carbon centers or multiple chiral centers can be rapidly prepared.