Palladium catalyzed synthesis of 2-trifluoromethylquinolines through a domino Sonogashira-alkyne carbocyclization process

A new, rapid and high-yielding method to prepare 3,4-disubstituted 2-trifluoromethylquinolines by a palladium catalyzed tandem Sonogashira-alkyne carbocyclization of beta-trifluoromethyl beta-enaminoketones with arynes is described. Moderate to excellent yields have been achieved under mild conditions. This reaction can also be expanded to the non-fluorine containing substrates. The reaction mechanism is also discussed.