[3 + 2] Cycloaddition promoted by zinc oxide nanoparticles anchored on reduced graphene oxide using green solvent

ABSTRACT

ZnO anchored on RGO-catalyzed [3 + 2] cycloaddition of nitriles and sodium azide in the synthesis of 5-substituted 1H-tetrazoles in water is an efficient and simple protocol with low catalyst loading under reflux condition. It is applied to a wide range of substrates with an excellent yield, simple workup procedure, recovery, and reusability of catalyst with consistent activity and high turnover number. It is proposed that the functional groups present in RGO surface are effective for preventing the aggregation of catalytically active ZnO species during the reaction. Moreover, the excellent performance of ZnO–RGO nanocomposite is ascribed to the excellent dispersity of catalyst in water, hydrophilic nature of the RGO for the accumulation of organic substrates in water, and the “Breslow effect.”

GRAPHICAL ABSTRACT

KEYWORDS:

• Cycloaddition
• nanocomposite
• nitrile
• reduced graphene oxide
• sodium azide
• zinc oxide

Additional information

Funding

The authors acknowledge UGC fund for the financial support through the Minor Project F. No: 4–4/2015–2016 (MRP/UGC-SERO).