Ultrafine hybrid Cu2O–Fe2O3 nanoparticles stabilized by hexaphenylbenzene-based supramolecular assemblies: a photocatalytic system for the Ullmann–Goldberg coupling reaction

Abstract

Ultrafine hybrid Cu2O–Fe2O3 NPs have been prepared using the supramolecular assemblies of hexaphenylbenzene (HPB) derivative 3 as nanoreactors and stabilizers. The as-prepared hybrid Cu2O–Fe2O3 NPs serve as an efficient and recyclable photocatalytic system for carrying out C–N coupling between aryl halides and various amines (aliphatic, aromatic and N-heterocyclic) at room temperature in mixed aqueous media under visible light irradiation. Amazingly, Cu2O–Fe2O3 NPs also exhibited high efficiency in the reactions involving the synthesis of biologically important N-substituted carbazole derivatives. The work being presented in this article demonstrates the preparation of a ‘dip strip’ coated with the as-prepared catalytic system and utilization of this paper strip as a recyclable and portable heterocatalytic system for carrying out the Ullmann–Goldberg coupling.