Aminoclay decorated with nano-Pd(0) picolinic acid complex as a novel efficient, heterogeneous, and phosphine ligand-free catalyst in Heck reaction under solvent-free conditions

Abstract

A new heterogeneous phosphine ligand-free nano-Pd(0) picolinic acid complex was synthesized under mild and ecofriendly conditions with a short and simple process in green solvent. In this work, as a novel functionalization method, the surface of aminoclay was decorated via ionic bond formation between the picolinic acid complex of nano-Pd(0) and the amino group on its surface. Then, the prepared heterogeneous catalyst was characterized by TEM, FE-SEM, ICP, IR, XRD, TGA, EDX, XPS and UV–visible techniques and was subsequently employed as an efficient and reusable heterogeneous catalyst for selective Heck coupling of aryl halide and n-butyl acrylate under solvent-free conditions. The catalyst was recoverable simply by centrifuging and was reusable for at least seven runs with a minimum amount of palladium leaching. Also, the mercury poisoning test confirmed the heterogenous nature of the catalyst.