不均一系触媒による酸素を用いた芳香環 C-H 結合の酸化的分子変換法の開発

Oxidation of aryl amines has been extensively utilized for the synthesis of nitrogen-containing functional materials. Among them, a number of methods for C-C bond forming reaction of aryl amines have been developed. Although oxidative biaryl coupling of aryl amines using stoichiometric metal or organic oxidants has been reported, the catalytic oxidation methods have been rarely studied to date. The aerobic oxidation is an attractive approach toward environmentally friendly synthesis of nitrogen-containing biaryl compounds. Recently, we developed a heterogeneous rhodium-catalyzed aerobic oxidative biaryl coupling reaction of aryl amines to provide various aminobiaryls such as BINAM derivatives, naphthidines, benzidines, and bicarbazoles. This heterogeneously catalyzed method can be adapted to highly selective cross-coupling reaction and the intramolecular biaryl coupling reaction of aryl amines. Additionally, we developed an aerobic direct C-H oxidation of polycyclic aromatics using a recyclable heterogeneous catalyst. In this account, our recent research activities regarding the heterogeneously catalyzed aerobic oxidative transformations of aromatic C-H bonds are described.