Application Of C-H Activation/Cyclization Strategy In The Efficient Construction Of Fused Aza-Heterocyclic Compounds

Nitrogen-containing heterocycles are ubiquitous in medicine,pesticides and functional materials.The synthesis of indole aza-heterocycles and sulfoximine skeletons,which are significant components of aza-heterocyclic compounds,has been the focus of synthetic chemists due to their unique biological or pharmaceutical properties and ease of post-modification characteristics.In another aspect,the1,2-dicarbonyl compounds are highly enriched in reactivity due to the presence of their adjacent electron-deficient bicarbonyl groups,and are often utilized as worthy synthons or precursors in organic synthesis and materials science.This thesis focuses on the innovative synthesis of various aromatic nitrogen-containing heterocyclic compounds based on the strategy of C-H bond activation/cyclization reactions.Part I:the research achievements for the synthesis of benzosulfonimide skeletons,dicarbonyl skeletons and indoloheterocyclic skeletons among the recent years are summarized.Part II:we developed a one-pot multicomponent reaction for the synthesis of iminosulfoximine-containing 10-membered ring structure motifs.The first step of this reaction was putatively proposed to be the transition metal-catalyzed highly selective C-H/N-H bifunctionalization to obtain a tricyclic heterocycle,which could be oxidized through ring-opening protocol by m-CPBA to chemo-and regioselectively deliver the macrocyclic（10-membered ring）iminosulfonium heterocycle.Part III:a series of iminosulfone-concentrated heterocyclic compounds with stereoselectivity were developed using asymmetric functionalization of C-H bonds promoted by chiral Cp*Rh^III catalysts.It was found that oxidative ring opening of this product was able to give decameric cyclic azacyclic compounds with better chiral retention.Part IV:we report I₂/Ph I（OAc）₂ catalyzed system to promote the intramolecular oxidation of C-H/N-H amination of（E/Z）-2-indolylenimines.The reaction proceeded smoothly under environmentally benign conditions,and the pyrrolo[2,3-b]indole compounds could be produced in excellent yields using metal-free conditions.The I⁺-mediated catalytic cycle was mechanistically proposed based on a series of experimental studies.