In situ synthesis of a Pd-poly (1,8-diaminonaphthalene) nanocomposite: An efficient catalyst for Heck reactions under phosphine-free conditions

Polymerization of 1,8-diaminonaphthalene was performed using palladium acetate as an oxidizing agent. During the oxidative polymerization process the electrons liberated reduced the palladium (II) ions with the formation Pd nanoparticles, these colloidal particles being stabilized within the poly (1,8-diaminonaphthalene) matrix. Electron microscope images revealed that the palladium particles were well dispersed in the polymer matrix and had an average diameter of 2.5 nm. The metal-polymer composite material was initially tested for the coupling of iodobenzene with alkene (methyl acrylate) in the presence of a base. The yield of the substituted alkene derivative was found to be excellent. A series of iodo- and bromobenzene derivatives were tested for the coupling reaction with different alkenes. A coupled product was produced with high TOF values proving the efficiency of the composite material as an efficient catalyst for the Heck reaction under phosphine-free conditions.