Metal-free carbon as a catalyst for oxidative coupling: solvent-enhanced poly-coupling with regioselectivity

Abstract

Herein, heterogeneous, inexpensive, metal-free, and environmentally friendly graphene oxide (GO) was developed for the oxidative polycoupling of 2-naphthols in aqueous sodium hydroxide in the presence of air. This study demonstrates that GO can function as a heterogeneous catalyst, and solvent plays a vital role in the coupling. Upon changing the solvent from toluene to water, transformation of products from homocoupling to polycoupling materials occurs.