Highly Efficient Catalyst Systems Using Iron Complexes with a Tetradentate PNNP Ligand for the Asymmetric Hydrogenation of Polar Bonds

Abstract

Iron competes with pricey ruthenium: The first catalyst systems using iron complexes for asymmetric H2 hydrogenation at 50 °C and asymmetric transfer hydrogenation at room temperature has been discovered. The transfer hydrogenation activity is similar to that of the best ruthenium catalyst. Surprisingly, the precatalysts have a tetradentate diiminodiphosphine ligand which has no NH functionality.