A Highly Selective Palladium-Catalyzed Aerobic Oxidative Aniline-Aniline Cross-Coupling Reaction.

The first catalytic oxidative aniline-aniline cross-coupling reaction using oxygen as the terminal oxidant is reported. Anilines possessing a pyrrolidino group can be preferentially oxidized under mild aerobic conditions and reacted with other anilines to afford a variety of nonsymmetrical 2-aminobiphenyls with high selectivities. A heterogeneous palladium catalyst is used for the dehydrogenative cross-coupling of anilines with structurally diverse arenes. This reaction does not require stoichiometric oxidants and is an economical and environmentally friendly method.