Synthesis of heterocyclic allenes via palladium-catalyzed hydride-transfer reaction of propargylic amines

reaction: see text] Propargylic diisopropylamines containing heterocycles, which were prepared readily from heterocyclic bromides and propargyldiisopropylamine by the Sonogashira coupling reaction, underwent the allene transformation reaction in the presence of Pd(2)(dba)(3).CHCl(3) catalyst (2.5 mol %) and 1,2-bisbis(pentafluorophenyl)phosphino]ethane (10 mol %) at 100 degrees C in CHCl(3), giving the corresponding heterocyclic allenes in good to high yields via the palladium-catalyzed hydride-transfer reaction.