One-pot three-component synthesis of 2-Amino-4H-Chromene derivatives by using monodisperse Pd nanomaterials anchored graphene oxide as highly efficient and recyclable catalyst

Abstract

An efficient and environmentally benign method has been developed for the synthesis of 2-amino-4H-chromene derivatives via one-pot multi component condensation of resorcinol (1), malononitrile (2), and various aromatic aldehydes (3a–j), using highly monodisperse palladium nanoparticles supported with graphene oxide (Pd@GO) as a heterogeneous catalyst. An advantageous of this method is that monodisperse Pd@GO nanoparticles can be easily separated and reused several times for further runs. This highly stable and monodisperse catalyst has been used for the first time as highly efficient, long lived and isolable catalyst for the synthesis of 2-amino-4H-chromene derivatives from resorcinol, aromatic aldehydes and malononitrile with great catalytic performance and easy work-up procedure. The structure and morphology of synthesized catalyst were characterized by using different techniques such as, transmission electron microscopy (TEM), the high resolution electron micrograph (HRTEM), X-ray diffraction (XRD), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). The highly crystalline, colloidally stable and highly monodisperse Pd@GO formation were shown by using these techniques. Besides, the Pd@GO has been found to be highly efficient and recyclable heterogeneous catalyst for the synthesis of 2-amino-4H-chromene derivatives.