The Investigation of a Switchable Iridium Catalyst for the Hydrogenation of Amides: A Case Study of C–O Versus C–N Bond Scission

This Letter studies a switchable Cp*-iridium catalyst supported by a 1,10-phenanthroline-2,9-diol (Cp* = pentamethylcyclopentadienyl) for the hydrogenation of amides. Depending on the reaction conditions, a single catalyst provides access to two distinct products arising from either C–O or C–N bond scission of the amide. Under typical hydrogenation conditions (40 bar H2, 110 °C), selective deoxygenation of the amide is observed without acidic additives. Investigations were performed to determine the origin of the C–O bond-scission products. Upon the addition of base, however, a switch in the selectivity was observed providing C–N bond-cleaved products. These studies present fundamental insights for the rational design of hydrogenation catalysts.