Au-Catalyzed Aerobic Dehydrogenative Aromatization to <i>m</i>-Phenylenediamine Derivatives via Product Selectivity Control

<i>m</i>-Disubstituted arenes are important in various fields but difficult to be directly synthesized by classical methods in the case of two electron-donating substituents due to the <i>o</i>,<i>p</i>-orientation. Dehydrogenative aromatization from nonaromatic cyclohexenone motifs and nucleophiles via 1,2- and 1,4-addition to produce <i>m</i>-disubstituted arenes is promising as the novel process overcoming the intrinsic problems derived from using aromatic compounds as the substrates; however, there are no reports on tandem oxidation involving dehydrogenative aromatization for one-step synthesis via simultaneous 1,2- and 1,4-addition or <i>m</i>-phenylenediamine derivative synthesis because of the quite difficult product selectivity control. Here, by utilizing the unique dehydrogenation catalysis of CeO₂-supported Au nanoparticles, we have developed one-step synthesis of various <i>m</i>-phenylenediamine derivatives via selective aerobic dehydrogenative aromatization from cyclohexenone motifs and secondary amines. In addition, the product selectivity switch to enaminones or <i>N</i>,<i>N</i>-disubstituted anilines was also achieved by tuning the reaction conditions.