Online article for Non-subscribers

Pay per view

Heterocycles has a pay-per-view service for Non-subscribers.
You will be able to directly purchase the full text article through PayPal.
Your purchased Paper can be downloaded after the payment is completed.
An e-mail will be sent the URL to download the paper.
If you have any questions, please contact: purchase@heterocycles.com

Price: ¥ 4,320 (Yen only)
Period: This Article can be accessed for 7 days.

Communication | Special issue | Vol 67, No. 2, 2006, pp.567-574
Published online, 11th November, 2005
DOI: 10.3987/COM-05-S(T)74
Extending the Concept of Mixtures of Chiral Monodentate P-Ligands in Asymmetric Rh-Catalyzed Olefin-hydrogenation: Use of Oxazaphospholidines

Manfred T. Reetz* and Marek Surowiec

*Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, D-45470 Mülheim / Ruhr, Germany

Abstract

The previously described combinatorial concept of using mixtures of monodentate BINOL-derived phosphites, phosphonites or phosphoramidites as superior ligand systems in Rh-catalyzed asymmetric olefin-hydrogenation has been extended to include chiral oxazaphospholidines. Specifically, the latter were prepared from ephedrine and pseudo-ephedrine according to literature procedures. Mixtures of these P-ligands among themselves or in combination with a BINOL-derived phosphonite lead to enhanced enantioselectivity in the Rh-catalyzed hydrogenation of itaconic acid dimethyl ester (ee up to 89%).