Mild palladium-catalysed highly efficient hydrogenation of CN, C–NO₂, and CO bonds using H₂ of 1 atm in H₂O

Here we present the first example of a mild and high-efficiency protocol enabling a process in water using 1 atm of H₂ for the efficient and selective hydrogenation of nitriles, nitro compounds, ketones, and aldehydes to yield primary amines and alcohols with satisfactory yields of up to >99%. Several palladium-based nanoparticle catalysts were prepared from K₂PdCl₄ and ligands, and one of them was found to be the best and most suitable for the hydrogenation of CN, C–NO₂, and CO bonds. In addition, the catalyst Pd-NPs can be easily recycled and reused without losing their activity and selectivity. A plausible mechanism for the hydrogenation of a CN bond was also proposed, representing the first example that possesses great potential for sustainable industrial purposes.