Palladium-catalyzed direct synthesis of carbazoles via one-pot N-arylation and oxidative biaryl coupling: synthesis and mechanistic study.

An efficient catalytic system has been developed for the synthesis of carbazoles by one-pot N-arylation and oxidative biaryl coupling. A significant substituent effect of the diarylamine intermediate on oxidative coupling was observed. Mechanistic studies of oxidative coupling, including trapping of reaction intermediates and kinetic isotope effect experiments, are also presented.