Continuous catalytic transfer hydrogenation of methanol as hydrogen source to synthesize aromatic amines

A mild and efficient method for continuous transfer hydrogenation of nitroaromatics catalyzed by Ru-Fe bimetallic catalyst with methanol as hydrogen source was developed. Ru-Fe bimetallic catalysts were prepared by impregnation method and characterized by inductively coupled plasma-mass spectrometry (ICP-MS), transmission electron microscopy (TEM), X-ray diffraction (XRD), and hydrogen temperature-programmed reduction (H-2-TPR). The results showed that the catalyst had smaller particle size and better dispersion. On the Ru-Fe bimetallic catalyst, the continuous transfer hydrogenation of nitroaromatics and methanol to aromatic amines without external hydrogenation source was successfully realized. A series of amines with high yields were successfully obtained by adjusting the reaction conditions. In particular, the method exhibited excellent selectivity and conversion for the hydrogenation of unsaturated group (aldehyde, carbonyl or alkynyl) substituted nitroaromatics.