Amide Group Assisted Site-selective C-H Functionalizations Of Aromatic Amine Derivatives

The introduction of directing groups were one of the most hotspots of modern synthetic chemistry due to their unique characteristics like easily removable,high reactivity and localization.The strategy of directing group assisted C-H bond activation were also identified as one of the most efficiency approach to construct the molecular scaffold of drugs and natural products.In recent years,many great advances had been achieved in transition mental catalyzed C-C and C-X coupling reactions.However,with the increasing demanding of atomic economy and green chemistry,suitable methodologies of C-H bond transformation with sustainable metal catalyst or metal-free catalyst become more and more important during chemstry researchs.This dissertation mainly focused on the amide group assisted inexpensive Ni?II?and metal-free catalyzed C?sp²?-H bond functionalization of aromatic amine derivatives.The contents were listed as follows:1.A nickel?II?-catalyzed site-selective o-C-H bond trifluoromethylation of anilines were developed by using picolinamide as the directing group,Langlois'reagent CF₃SO₂Na as the trifluoromethyl resources.A coordinating activation strategy were performed in this catalyst-in-water system which were found could be reutilized eight times at least and were successfully applied in synthesis of the dye acid red 266.In addition,a series of control experiments indicated that a single electron transfer?SET?mechanism was involved in this process.2.We carried out a amide group assisted remount C-H bond halogenation of 8-aminoquinolines based on simple and highly halide-atom economy HX reagents?X=Cl,Br and I?.The reaction featured high atom-economic“X”resources,broad substrate scope and well function group tolerance.At the same time,the structure of the product was confirmed by X-ray crystallography and a plausible oxidative mechanism was provided.3.A facile trifluoroacetyl iodobenzene?PIFA?mediated site-selective C-H bond hydroxylation of 8-aminoquinoline amids at C-5 position is established.The reaction proceeded smoothly under metal-free conditions and affording desired products with broad scopes in moderate to good yields.This new strategy has been successfully applied in the synthesis of new ratiometric fluorescence sensor for Zn²⁺ions with good water-solubility.