An effective medium of H2O and low-pressure CO2 for the selective hydrogenation of aromatic nitro compounds to anilines

Chemoselective hydrogenation of water-insoluble aromatic nitro compounds can be achieved over Ni catalysts in a H2O–compressed CO2 system at 35–50 °C without using any environmentally harmful solvent. The effective CO2 pressure is much lower than the critical pressure of CO2. The hydrogenation of nitro group should be the rate-determining step.