title: Synthesis of enantiomerically pure P-stereogenic diphosphacrowns and their palladium complexes.
abstract: A practical synthetic route for enantiomerically pure P-stereogenic diphosphacrowns was developed by using a P-stereogenic bisphosphine as a chiral building block. Their molecular structures were confirmed by NMR spectroscopy and X-ray crystallography. Complexation of the diphosphacrowns with palladium was carried out, and the corresponding palladium complexes were obtained. The P-stereogenic diphosphacrowns were applicable to the chiral ligand for the asymmetric 1,4-addition of arylboronic acids to α,β-unsaturated ketone catalyzed by palladium. This reaction proceeded smoothly to afford the corresponding 1,4-addition products in high yield with good enantioselectivities.
authors.affiliation: Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan. ymo@chujo.synchem.kyoto-u.ac.jp
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Morisaki
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Imoto
authors.forename: Koji
authors.initials: K
authors.lastname: Hirano
authors.forename: Tamio
authors.initials: T
authors.lastname: Hayashi
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Chujo