Chiral N-Heterocyclic Carbene/Pyridine Ligands for the Iridium-Catalyzed Asymmetric Hydrogenation of Olefins

摘要

The development of chiral iridium catalysts, which were inspired by the Crabtree catalyst, has considerably enhanced the application range of the asymmetric hydrogenation of olefins. In contrast to rhodium and ruthenium diphosphine complexes, the iridium-based catalysts do not require a coordinating group near the C=C bond and, therefore, enable the hydrogenation of a much wider range of alkenes.