Study On The Cobalt-catalyzed Amide-directed Ferrocene C(sp~2)-H Anination Reaction

More and more reports have indicated that ferrocene and its derivatives have important applications in the field of chemical synthesis,materials and pharmaceuticals.Traditionally,ferrocene derivatives are synthesized by using Friedel acylation reaction,excess alkyl lithium or alkylmercury reagents,or prefunctionalization of the Cp ring prior to the transmetallation step.Although these conventional methods have played an important role in the development of ferrocene derivatives,harsh conditions and poor functional group tolerance limited their further application.Therefore,it is particularly important to develop a more simple and efficient method for synthesizing ferrocene derivatives.The first chapter introduces the recent development and synthesis of ferrocene derivatives.In recent years,transition metal catalyzed carbon-hydrogen bond functionalization has developed rapidly and acted as the direct and effective tools in organic synthesis.According to the bonding type of ferrocene derivatives,the methods of transition metal-catalyzed ferrocene functionalization based on the chelating agent are divided into two categories:C-C bond and C-X bond.The C-C bond type method could be classified into arylation,alkylation,alkenylation and alkynylation,acylation and imidization cyclization.And the C-X bond type could be introduced into chalcogenization,ammoniation and boronization.In the second chapter,the cobalt-catalyzed amide-directed ferrocene C(sp~2)-H amination reaction was studied.Carbon-hydrogen bond activation strategy was employed to realize the amination reaction of ferrocene C(sp~2)-H with cobalt as a catalyst and amide as the directing group,and 1-pyrrolidine-1-carbonylferrocene(1a)and 3-phenyl-1,4,2-dioxazol-5-one(2a)is a reaction model for the ferrocene.Subsequently,the effect of reaction solvents,additives,temperatures,catalyst equivalents and additive equivalents on the reaction were investigated.The optimal conditions are mild and with a wide range of substrates.Multiple types of3-substituted-1,4,2-dioxazol-5-ones,bearing heterocyclic aromatic hydrocarbon,alkyl group,ferrocene,or[2.2]paracyclophane can be prepared.Various ferrocene derivatives are also well compatible.In addition,the reaction has good practicability and the reaction with 5 mmol scale can be realized with reduced catalyst loading and prolong reaction time.