Highly efficient catalyst systems using iron complexes with a tetradentate PNNP ligand for the asymmetric hydrogenation of polar bonds

Abstract

(Chemical Equation Presented) 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. © 2008 Wiley-VCH Verlag GmbH & Co. KGaA.