Synthesis of 2-hydroxy-1,4-naphthoquinone derivatives using Cu (II) immobilized on hyperbranched polyglycerol functionalized graphene oxide catalyst

Molecules with the napthoquinone structure are of interest because of their occurrence in nature and their widespread biological properties. Also, quinone derivatives have been introduced as fluorescence materials [1]. Recently, two dimensional carbon based nanostructures such as graphene and graphene oxide have used as substrate for polymer matrices. Because of large surface area and presence of oxygen containing groups on basal surfaces and sheet edges of the GO materials, polymers can be adsorbed onto the graphene surface [2]. Hyperbranched polymers grafted covalently or non-covalently to a substrate which have been used for the generation of hybrid structures be it in the field for surface and particle functionalization. A class of hyperbranched polymers is polyglycerol with tree-like structure and a large number of hydroxyl functional groups in its backbone and environs [3]. The chemical grafting of HPG onto the surface of graphene oxide also supply a suitable surface for their functionalized with organic compound to obtain novel nanostructures. Herein, we would like to report the synthesis and application of Cu (II) immobilized on hyperbranched polyglycerol functionalized graphene oxide as an environmentally-benign, highly efficient and reusable catalyst for the preparation of aminonaphthoquinone derivatives via one-pot three-component condensation reaction under solvent-free conditions.