Synthesis and characterization of recyclable and recoverable MMT-clay exchanged ammonium tagged carbapalladacycle catalyst for Mizoroki-Heck and Sonogashira reactions in ionic liquid media

An efficient synthesis of an ammonium tagged carbapalladacycle 5, in modest yield, has been achieved. Further, the clay-nanocomposite 6 was prepared by ion exchange of 5 into clay interlayers as a new organic-inorganic hybrid catalytic system. The ionic tag of the ammonium supported carbapalladacycle 5 assists in the pillaring process and enhances the organophilicity of catalyst 6 in the interlayers of clay. The catalytic activity in ammonium based ionic liquid (TMBA] NTf2 of both the homogeneous and heterogeneous recyclable catalysts 5 and 6 respectively in micromolar concentration of palladium has been tested for Mizoroki-Heck and Sonogashira reactions in good yields with high TON/TOF and negligible metal leaching. Effect of solvent and temperature on the catalytic activity has also been examined. (C) 2010 Elsevier B.V. All rights reserved.