Preparation of palladium nanoparticles using Euphorbia thymifolia L. leaf extract and evaluation of catalytic activity in the ligand-free Stille and Hiyama cross-coupling reactions in water

The synthesis of palladium nanoparticles (Pd NPs) using an aqueous extract of leaves of Euphorbia thymifolia L. and their application in the ligand-free Stille and Hiyama cross-coupling reactions are reported here. Pd NPs were characterized using powder XRD, TEM, FT-IR and UV-vis techniques. The synthesized Pd NPs exhibited excellent catalytic activity and the reactions generated the corresponding products in good to excellent yields. These methods have some advantages, such as efficiency, generality, high yield, elimination of ligand, organic solvent and homogeneous catalysts, cleaner reaction profiles, ease of product isolation and simplicity. The reactions were carried out in a green solvent i.e. water. The catalyst was quantitatively recovered and reused without significant loss in the catalytic activity.