Pergamon Tetrahedron: Asymmetry, Vol. 7, No. 12, pp. 3339-3342, 1996 Copyright © 1996 Elsevier Science Ltd Printed in Great Britain. All rights reserved PII: S0957-4166(96)00437-5 0957-4166/96 $15.00 + 0.00 A Novel Chiral Phosphinediamine Ligand and Asymmetric Hydrogenation of Acrylic Acid Derivatives Issaku Yamada, Motowo Yamaguchi, and Takamichi Yamagishi* Departmentof Industrial Chemistry,Facultyof Engineering, Tokyo Metropolitan University, 1-1 Minami-ohsawa, Hachioji, Tokyo 192-03,Japan Abstract: A novel chiral phosphinediamine ligand (PN 2) was prepared from (S)-I- phenylethylamine and dichloroisopropylphosphine. The rhodium-PN 2 catalyst utilizing selective ligation of the amino unit and electrostatic interaction between the ligand and a substrate gave high enantioselectivities up to 92% ee in asymmetric hydrogenations of acrylic acid derivatives..Copyright © 1996 ElsevierScience Ltd A variety of chiral phosphorus ligands were reported and applied to the asymmetric catalytic reactions. 1 Many of them have chiral carbon(s) in their molecular structures in order to provide a chiral field. Chiral phosphine ligands having chiral phosphorus atom(s)2 are effective for induction of asymmetry in the metal- catalyzed asymmetric reactions because the stereogenic center exists near the reaction site. These ligands, however, have a drawback in the difficulties of their synthesis. Monophosphine ligands having two such substituents which have a site, such as N, O or S, capable of coordinating to metal can be prepared easily. If one of two coordination sites of these ligands ligates to the metal selectively in addition to the ligation of phosphorus atom, the phosphorus atom will become stereogenic to afford an effective chiral field (Scheme 1). The monophosphine ligands designed with such a concept has not been reported to our knowledge. 3 We have designed a novel chiral monophosphine ligand having two 2-(1-N,N-dimethylaminoethyl)phenyl units: (S,S)-alkylbis[2-(1-N,N-dimethylaminoethyl)phenyl]phosphine, PN 2 ligand. Upon selective ligation of the amino unit, free amino moiety would serve to have a secondary interaction with the substrate, for example an electrostatic interaction with the carboxyl unit of substrate. Y P Y I R Y=N, O, orS Scheme I [ ] ""M'" \R R/P"M "'X Selective ligation 3339