Synthesis, Characterization and Catalytic Activity of Ligand Stabilized Palladium Nanoparticle: A Catalyst Compliment to the Heck Coupling Reaction

The palladium metal is the most frequently used metal because of its excellent catalytic efficiency and most flexible varying oxidation state. So,  we report  that palladium nanoparticles (Pd NPs) stabilized by a ligand (o-vanilindiphenylethanedionedihydrazone, L)  using reverse micelles method have been synthesized, while all particles are in spherical shape and ranging between 10 and 15 nm. This has been characterized by 1H NMR, IR, UV, X-ray powder diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), and scanning electron microscope (SEM) analyses. These nanoparticles were used as a catalyst for coupling reaction between aryl halides with terminal alkenes, Heck reaction, in the presence of potassium carbonate (K2CO3) as a base and NMP (N-Methyl-2-pyrrolidone) as a solvent.  The present catalyst is an air and moisture stable and has significant catalytic activity in Heck cross-coupling reactions under operating conditions. Various aryl halides and terminal alkenes were coupled smoothly under air to afford the corresponding cross-coupled products in excellent yields.