Transition Metal Catalyzed Functionalization Of Sp~2 Carbon-hydrogen Bonds Coordinated By Nitrogen-containing Functional Groups

Recent years,transition metal catalyzed C-H bond activation functionalization reaction continued to be highly concerned by organic chemists.Development in this field has provided new strategies to construct carbon-carbon bond and carbon-hetero bond.Direct founctionalization of C-H bond could be achieved via transition-metal-catalyzed chelation assisted C-H activation.Such as olefination,nitration,cyanation,hydroxylation,alkylation and arylation.We conducted research on the basis of previous works and had achieved three new methods of C-H activation and functionalization reaction.1.Palladium-catalyzed direct ortho-nitration of azoarenes using NO2 as nitro source.A palladium-catalyzed direct ortho-nitration reaction of azoarenes was developed in which NO2 was used as both nitro source and oxidant for the first time.The nitration products were converted into o-aminoazoarenes or benzotriazole derivatives by a simple reduction.2.Palladium-catalyzed ary1 C(sp2)-H bond hydroxylation of 2-ary1pyridine using TBHP as oxidant.An efficient synthesis of phenols via Pd-catalyzed,pyridyl-directed homogeneous hydroxylation of the aryl C-H bond was developed,in which tertbutyl hydroperoxide was used as the sole oxidant.The method had a broad group tolerance and was available for both electron-rich and electron-deficient substrates.3.Rhodium(?)-catalyzed direct cyanation of aromatic C-H bond to form 2-(alkylamino)benzonitriles using N-nitroso as directing group.2-(Alkylamino)benzonitriles were synthesized via a rhodium-catalyzed cyanation on the aryl C-H bond and subsequent denitrosation of N-nitrosoarylamines using a removable nitroso as the directing group,in which N-cyanoN-pheny 1-p-methylbenzenesulfonamide(NCTS)was used as the "CN" source.Then,we did a lot of work and made discussions in the mechanism research...