Directing-Group-Assisted Ir/Co-Catalyzed Inert C-H Bond Activation And Functionalization

Directing-groups-assisted transition metal-catalyzed inert C–H bond activation has been frequently used in organic synthesis for the chemical bond formation.The coordination of heteroatom within directing group to the metal cation center obviously enhanced its reactivity and enabled the ortho-C–H activation and functionalization in high regioselectivity.This catalysis strategy shows mild condition,easy handling and simplicity thus being used to construct C–C bonds and C–X bonds.This thesis intiates the studies with respect to the inert C–H bond actiovation by employing iridium and cobalt catalysis in the presence of the N-containing directing group,which are listed as following:?1?The direct ortho-amidation of azoxybenzenes with 1,4,2-dioxazol-5-ones was successfully realized in the presence of bis[?pentamethylcyclopentadienyl?dichloro-iridium]?[Cp*IrCl₂]₂?,silver hexafluoroantimonate?AgSbF₆?,1,2-dichloroethane?DCE?,which proceded at 100 ^oC for 20 h under nitrogen condition to generate the amidation products.In this reaction system,1,4,2-dioxazol-5-ones as an amidating reagent can be selectively amidated in the ortho position of azoxybenzenes to obtain a series of products in good yields.Moreover,we also succeeded in the synthetically useful transformation of the aminatedazoxybenzenes.?2?The first Co-catalyzed cyclization of 3-aryl-1,2,4-oxadiazolone with 1,3-diyne has been developed in the condition of PivOH as an additive,manganese acetate dihydrate?Mn?OAc?₃·2H₂O?as an oxidant,and 2,2,2-trifluoroethanol?TFE?as reaction medium.The bis-cyclization and mono-cyclization processes can be well controlled by tuning reaction temeperature,providing a new method for the synthesis of?-conjugated molecules.