One-pot palladium-catalyzed C-I and C-H bond activation and subsequent Suzuki-Miyaura cross-coupling of 2-aryl-3-iodo-4-(phenylamino)quinolines with arylboronic acids

The 2-aryl-3-iodo-4-(phenylamino)quinolines undergo one-pot palladium-mediated C-I and C-H bond activation and subsequent Suzuki-Miyaura cross-coupling with arylboronic acids under anhydrous conditions to afford mixture of 2,3-diaryl-4-(phenylamino)quinolines (minor) and 2-aryl-4-([(1,1′-biaryl)-2-yl]amino)quinoline derivatives (major). The 2,3-diaryl-4-(phenylamino)quinolines were isolated as major products when 2 M K₂CO₃ was used as a base. A plausible mechanism, which implicates a six-membered palladacycle intermediate is proposed for the formation of the observed mixture of products. The prepared compounds were characterized using a combination of spectroscopic and X-ray crystallographic techniques.