Gallium(III) chloride-catalyzed three-component coupling of naphthol, alkyne and aldehyde: a novel synthesis of 1,3-disubstituted-3H-benzo[f] chromenes

Three-component coupling of naphthol, alkyne and aldehyde has been achieved in the presence of 10 mol % gallium(III) chloride in toluene under reflux conditions to afford the corresponding 1,3-disubstituted-3H-benzo[f]chromenes in good yields. This is the first example on the preparation of chromenes from naphthol, alkyne and aldehyde.