Application of P-Stereogenic Aminophosphine Phosphinite Ligands in Asymmetric Hydroformylation

✍ Scribed by Regine Ewalds; Eva B. Eggeling; Alison C. Hewat; Paul C. J. Kamer; Piet W. N. M. van Leeuwen; Dieter Vogt

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 191 KB
• Volume: 6
• Category: Article
• ISSN: 0947-6539
• DOI: 10.1002/(sici)1521-3765(20000417)6:8<1496::aid-chem1496>3.0.co;2-8

✦ Synopsis

New chiral aminophosphine phosphinite ligands with a stereogenic center at the aminophosphine phosphorus atom were prepared based on (R,S)-ephedrine as the chiral auxiliary and backbone. Substituents at the chiral aminophosphine as well as at the phosphinite phosphorus atom were varied. These new ligands were applied to the rhodium-catalyzed asymmetric hydroformylation of vinyl arenes. The enantiomeric excess reached up to 77 %. 1 H and 31 P NMR studies of the Rh complexes under syngas pressure reveal that [HRh(CO) 2 (P^P)] complexes with the NP* moiety in an axial position are responsible for enantioselectivity.