Palladium-catalyzed Sonogashira coupling reaction followed by isomerization and cyclization

2-Iodoaniline reacts with terminal acetylenic carbinols in THF at 80 °C in the presence of a catalytic amount of PdCl₂(PPh₃) ₂ and CuI along with aqueous tetrabutylammonium hydroxide to afford the corresponding 2-arylquinolines in good yields. The catalytic pathway seems to be proceeded via a sequence involving initial Sonogashira coupling between 2-iodoaniline and terminal acetylenic carbinols to form coupled acetylenic carbinols, isomerization of coupled acetylenic carbinols to α,β- unsaturated ketones, and cyclodehydration.