Iron-Catalyzed Hydrogenation of Amides to Alcohols and Amines

This article describes the iron-catalyzed hydrogenation of unactivated amides. Under the optimal conditions, a PNP-ligated Fe catalyst affords 25–300 turnovers of products derived from C–N bond cleavage. This reaction displays a broad substrate scope, including a variety of 2° and 3° amide substrates. The reaction progress of N,N-dimethylformamide hydrogenation has been monitored in situ using Raman spectroscopy. This technique enables direct comparison of the relative activity of the Fe-PNP catalyst to that of its Ru analogue. Under otherwise identical conditions, the Fe and Ru catalysts exhibit rates within a factor of 2.