The MCM-41 -supported thioether palladium(0) complex is a highly active catalyst for the copper-free Sonogashira coupling of aryl iodides with terminal alkynes in water at room temperature under aerobic conditions. This phosphine-free heterogeneous palladium catalyst can be easily recovered from the products and reused many times without loss of activity. (C) 2007 Elsevier B.V. All rights reserved.