Chemoselective hydrogenation of functionalized nitroarenes using MOF-derived co-based catalysts

•Co/C–N was prepared by simple pyrolysis of MOFs.•Nitroarenes are converted to anilines with other reducing groups remaining intact.•Co-N centers present in the catalyst lead to the unique chemoselectivity.•The reaction showed a first-order dependence on H2 pressure.

The synthesis, characterization, and application of nitrogen-doped carbon supported Co catalysts in selective hydrogenation of nitroarenes are described. The cobalt-based catalysts are prepared by simple pyrolysis of ZIF-67, a typical MOF material, under inert atmosphere. Physicochemical properties of the Co/C–N catalysts have been investigated by X-ray diffraction, elemental analysis, atomic absorption spectroscopy, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The Co-based materials were found to be highly efficient in the chemoselective hydrogenation of nitroarenes. A broad range of substituted nitroarenes are converted to the corresponding anilines in excellent yields under industrially viable conditions with other reducing groups remaining intact. In situ ATR-IR and XPS characterizations reveal that the Co-N centers present in the catalyst favor the preferential adsorption of nitro groups, leading to this unique chemoselectivity. The kinetic parameters of 4-nitrostyrene hydrogenation over the Co/C–N catalyst were investigated.

Graphical abstractA novel MOF-derived metallic cobalt-based catalyst is developed for chemoselective hydrogenation of substituted nitroarenes. A broad range of substituted nitroarenes are converted to the corresponding anilines in 93–99% yields under industrially viable conditions with other reducible groups remaining intact.Figure optionsDownload full-size imageDownload high-quality image (116 K)Download as PowerPoint slide