Preparation of a titania-supported highly dispersed palladium nano-catalyst and its application in Suzuki and Heck coupling reactions

In this work, palladium complexes nanoparticles in titania are prepared by a pH‐controlled adsorption and without pH‐controlled adsorption method. This method results in high‐dispersion palladium on the titania surface. We demonstrate the use of the titania‐supported palladium as an efficient catalyst for Suzuki and Heck reactions of a representative range of aryl bromides and chlorides. The reusability of catalyst was tested, and deactivation process of the catalyst was not observed after four recycles. The catalysts were characterized by FT‐IR, NMR, elemental analysis, field emission scanning electron microscopy, transmission electron microscopy and X‐ray diffraction. Copyright © 2013 John Wiley & Sons, Ltd. A representative range of substrates such as various aryl chlorides and bromides was applied. Catalyst 2/TiO2 demonstrated high activity in Suzuki and Heck reactions of inactive aryl chlorides having electron‐donating substituents. To generalize, phenylbronic acid derivatives and different alkenes were used in the C‐C coupling reactions in the presence of 2/TiO2 which resulted in high yields.