Magnesium Catalysts Design In Asymmetric Ring-Forming,Ring-Opening And Dearomatic-Ring's Reactions

Ring-forming and ring-opening reactions play important roles in building of complex structures and highly fuctional compounds.So it is important to introduce stereocontrol process into these reactions.In this dissertation,some representative ring-forming,ring-opening and dearomatic-ring's reactions have been realized by our designing of serials of magnesium catalysts.This dissertation includes eight chapters.The first three chapters introduced our initial trial of designing and developing of chiral magnesium catalysts and employing them in direct functionalized the ? site of carbonyl compounds.In this part,the first chapter included the introduction of some representative direct ?-functionalized reactions and related catalytic systems.In the second chapter,we achieved the site-specific funtionalization of linear ketones by employing a Salen-Mg catalyst,and applied it into[4+2]cyclization with nitroalkenes.In the third chapter,we designed a novel combinational magnesium catalyst and applied it into highly enantioselective cross reactions of enones.Based on the former section,in the forth chapter,we studied the activation mode of the magnesium catalyst,on considering of the charactors of the bifunctional catalytic abilities of magnesium,we achieved the asymmetric ring-opening reactions between indole and aziridines.Then we tried to apply the ring-opening reaction into dearomatization of naphthols.By designing of a new type of oxazoline-OH chiral ligand,the highly enantioselective dearomatization reaction of ?-naphthols could be realized.In the following part,the successful application of C-C bond formative conjugate reaction in the enantioselective dearomatization of ?-naphthols has been achieved.In the seventh chapter,some other ketone' s nucleophilic reactions were tried under different catalytic conditions.The formal ?-site selection problem has been solved.The last section is the summary of the magnesium mediated ring-forming and ring-opening reactions.