C-H Functionalization Of N-hetero Compounds

The direct construction of the C-X (X: C, O, N, et al) bonds throughC-H functionalization reaction has been one of the most important fieldin organic synthesis. Owing to the unique physiological and biologicalactivities of N-hetero compounds, these compounds have been widelyused in biomedicine science. Therefore, exploring the C-H bondfunctionalization reaction of N-containing heterocycles has significantacademic value and potential application value.This paper consists of three parts:(1) The methods for the formation of both carbon-carbon andcarbon-heteroatom bonds by the C-H bond functionalization of C2position of indole and azole substrates were reviewed, respectively. Inaddition, the C-H functionalization reactions of α-carbon atoms ofα-aminoacetophenone were also discussed.(2) The dehydrogenation cross-coupling reaction between the sp~2C2-H bond of benzothiazole and the sp~3C-H bond adjacent to a nitrogenor an oxygen atom has been studied. In the presence of the TBHP andzinc salt system, the C-H bond could be activated to construct C-C bondleading to various benzothiazole derivatives in moderate to good yields.This method has some advantages such as mild conditions, inexpensiveand easily available starting materials, and good atom-economyefficiency.(3) The novel method for the synthesis of benzamidine derivatives bythe oxidation reaction of the α-carbon of α-amino acetophenone witharomatic amines has been explored. In the presence of Ag2CO3andCu(OAc)2and inorganic base, the α-C-H bond of α-amino acetophenonecan be oxidated and react with aromatic amines to afford a variety ofbenzamidine derivatives in moderate yields.