Transition-metal-free Sonogashira-type coupling reactions in water

Microwave-assisted transition-metal-free Sonogashira-type coupling reactions are described. The reactions are run in water as the sole solvent, without the need for copper(I) or any transition-metal-phosphane complex. The scope of the methodology was tested by reaction of a wide variety of aryl halides and heteroaryl halides. The reaction was also investigated under conventional heating conditions. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)