Copper-free PdCl2/PPh3-catalyzed Sonogashira coupling reaction of aryl bromides with terminal alkynes in water

A simple, copper-free and efficient catalytic system for the Sonogashira coupling reaction of aryl bromides with terminal alkynes in pure water has been developed. The use of PdCl2/PPh3 in the presence of pyrrolidine allows the coupling reaction to proceed at 120 degrees C in moderate to excellent yields. (c) 2007 Elsevier Ltd. All rights reserved.