Facile three-component domino reactions for the synthesis of 2-arylimidazo[1,2-a]pyridines and 2-arylimidazo[2,1-a]isoquinolines

The three-component domino reactions of pyridine/isoquinoline, phenacyl bromide, and substituted (E)-N-hydroxyarylimidoyl chloride in the presence of triethylamine afforded a series of 2-arylimidazo[1,2-a]pyridines and 2-arylimidazo[2,1-a]isoquinolines. This one pot three-component transformation presumably proceeds via ylide generation/annulation/fragmentation/dehydration domino sequence of reactions.