CN-Doped Cobalt Oxide Composite: An Economic and Reusable Catalyst with Multitasking Catalytic Capability for Alkyne and Nitrile Hydrations and Nitro Reductions

Abstract

A heterogeneous CoOCN composite was synthesized via a one-pot reaction of [Co(NO3)2] and urea at 500 °C in a muffle furnace. The composite was fully characterized by FTIR, Raman, powder XRD, and XPS techniques. The catalyst was found to be efficient for the hydrations of aryl alkynes and nitriles under aerobic conditions. In addition, the catalyst exhibits high catalytic performance for the reduction of nitroarenes under inert gas-free conditions. This multitasking CoOCN composite was found to be highly suitable for all derivatives of nitrobenzene, alkynes, and nitriles because good to excellent yields were obtained. The catalyst was recovered quantitatively from the reaction mixture by simple filtration and consequently reused for seven consecutive cycles in all reactions without significant loss of catalytic activity. Hence, the synthesized CN-doped CoOCN composite worked as a multitasking catalyst for various value-added organic transformations, and it is highly economical and reusable for up to seven catalytic cycles without any activation, with even the last cycle producing reasonable yields of up to 48–50%.

Keywords

• heterogeneous catalysts
• cobalt oxide
• alkyne hydration
• nitrile hydration
• nitro reduction
• catalysis