Reaction between terminal alkynes and phenyl iodides bearing a tethered alkyne unit can be effectively controlled by the nature of a transition metal catalyst. Whereas the use of Pd (0)/Cu (I) promotes the expected Sonogashira coupling to give phenyl alkynes, the absence of the copper co-catalyst triggers a palladium-mediated cyclisation providing 1, 2- dihydroacenaphthylene, 1H, 3H-benzo [de] isochromene,(1Z)-1-(2-propynylidene)-2, 3- ...