Highly Chemoselective Reduction of Amides to Amines over a Ruthenium‐Molybdenum Bimetallic Catalyst

Abstract

AbstractThe chemoselective reduction of amides is important in the synthesis of fine chemicals and inter‐mediates. However, the highly stable amide bond due to the orbital overlap between the nitrogen lone pair and the antibonding orbital of the carbonyl group poses a significant limitation in developing suitable heterogeneous catalysts. In this work, we have developed a highly efficient and robust Ru‐(0.2)Mo/TiO2 catalyst for the chemoselective reduction of primary amides. As a consequence, the catalyst afforded 83.1 % conversion with 80 % selectivity of the primary amine after reaction for 12 h for the HDO of cyclohexanecarboxamide at 160 °C. Moreover, the catalyst also presented excellent reusability and substrate diversity. The characterizations of the catalyst revealed that Ru promoted the reduction of Mo6+ to Mo5+ and Mo0, and the resultant low‐coordinated Mo5+ is responsible for the selective activation of the C=O bond of the amide, while RuMo alloy promoted the activation of hydrogen.