title: Asymmetric nickel-catalyzed hydrocyanation of vinylarenes by applying homochiral xantphos ligands.
abstract: New homochiral xantphos-type diphosphonite ligands with binaphthoxy substituents have been prepared and characterized by NMR spectroscopy. These ligands have been applied in the nickel-catalyzed hydrocyanation of styrene and other vinylarenes. Enantioselectivities up to 63% ee have been obtained by using 4-isobutylstyrene as a substrate. Addition of an excess of ligand strongly inhibits the hydrocyanation reaction since the bis-chelate nickel complexes formed are highly stable and catalytically inactive.
authors.affiliation: Goldschmidt AG, Central Research, Essen, Germany.
authors.forename: W
authors.initials: W
authors.lastname: Goertz
authors.forename: P C
authors.initials: PC
authors.lastname: Kamer
authors.forename: P W
authors.initials: PW
authors.lastname: van Leeuwen
authors.forename: D
authors.initials: D
authors.lastname: Vogt