Enantiopure P-Chiral Secondary Phosphines (P*HRR') from the Catalytic Asymmetric Hydrogenation of P═C Bonds
Ming Li1, Aaron A Mitchell1, Tian Zhang1
1Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, Canada, V6T 1Z1.
Abstract:
We report the first bottleable enantiopure P-chiral secondary phosphines from the rhodium-catalyzed asymmetric hydrogenation of phosphaalkenes. Catalytic asymmetric hydrogenation, a reaction of broad academic and industrial importance for C═C, N═C, and O═C bonds, has not previously been reported for the P═C bond. The hydrogenation of ArP═CR2 (Ar = Mes, m-Xyl and TMOP; R = Ph, 4-C6H4F) affords four unprecedented P-stereogenic secondary phosphines in 76%-90% isolated yields with 91%-97% enantiomeric excess (ee). These isolable P-chiral secondary phosphines are configurationally stable indefinitely in the solid state and show only modest loss in ee when kept in solution for over a month at room temperature.
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