Recyclable palladium-catalyzed Sonogashira-Hagihara coupling of aryl halides using 2-aminophenyl diphenylphosphinite ligand in neat water under copper-free condition

An efficient heterogeneous copper-free Sonogashira-Hagihara coupling reaction was performed in the presence of 2-aminophenyl diphenylphosphinite (L) as a ligand, Pd(OAc)(2) and a base in neat water at 25-95 degrees C. By this protocol, different aryl halides (Cl, Br, I) were reacted with phenylacetylene in good to excellent yields. The catalyst was recycled for the reaction of bromobenzene with phenylacetylene for six runs without appreciable loss of its catalytic activity. (C) 2010 Elsevier B.V. All rights reserved.