An air-stable P-chiral phosphine ligand for highly enantioselective transition-metal-catalyzed reactions.
A new P-chiral phosphine ligand, (R,R)-2,3-bis(tert-butylmethylphosphino)quinoxaline, has been prepared by the reaction of enantiomerically pure tert-butylmethylphosphine-borane with 2,3-dichloroquinoxaline. This ligand, in contrast to most of the previously reported P-chiral ligands, is an air-stable solid and exhibits excellent enantioselectivities in both Rh-catalyzed asymmetric hydrogenations and Rh- or Pd-catalyzed carbon-carbon bond-forming reactions.
Imamoto
Tsuneo
T
Department of Chemistry, Faculty of Science, Chiba University, Chiba 263-8522, Japan. imamoto@faculty.chiba-u.jp
Sugita
Keitaro
K
Yoshida
Kazuhiro
K