Copper complex with N-,O- architecture grafted graphene oxide nanosheet as a heterogeneous catalyst for Suzuki cross coupling reaction

Abstract

We report a straight forward synthesis of a heterogeneous catalyst by covalently immobilizing copper Schiff base complex on the surface of amino functionalized graphene oxide (AGO) for the Suzuki coupling of substituted aryl halides with arylboronic acids. The as-synthesized complex and subsequent catalyst were characterized for their structural features using suitable techniques. The analysis confirmed that the Cu bound to Schiff base (L) ligand via bi(N-,O-) linkage and Cu-L immobilization on AGO was due to its amino functionality. The catalyst exhibited excellent yield of 94% for Suzuki coupling reactions as analyzed by gas chromatography. The catalyst was recycled for 5 successive reactions with insignificant loss in efficiency. ICP-AES analysis showed the catalyst retained 87.5% of its active metal center after 5th iteration. High yield, environmentally benign, easy work-up procedure, easy separation of catalyst and mild reaction conditions are some of the important facets this catalyst offer.