PdCl 2 (Ph 3 P) 2 /Salicylaldimine Catalyzed Diarylation of Anilines with Unactivated Aryl Chlorides

Triphenylphosphine and salicylaldimine could be used as a mixed ligand system to obtain a high catalytic activity for palladium catalyzed diarylation of primary anilines with unactivated aryl chlorides by the synergistic effect of ligands. The activity and selectivity of the catalytic system could be improved by modifying the structure of salicylaldimine. In refluxing o ‐xylene, PdCl 2 (Ph 3 P) 2 with 2,5‐ditrifluoromethyl N ‐phenylsalicylaldimine as a coligand shows high efficiency for the diarylation of various anilines. The catalytic system shows good toleration for the steric hindrance of the substrates. The facile catalytic system works as well on the multiple arylation of 1,1′‐biphenyl‐ 4,4′‐diamine with aryl chlorides to afford N , N , N′ , N′ ‐tetraaryl‐1,1′‐biphenyl‐4,4′‐diamines which are important intermediates of organic light emitting diode (OLED) hole transport materials.