Lemke M.-K, Schwab P, Fischer P, Tischer S, Witt M, Noehringer L, Rogachev V, Jäger A, Kataeva O, Fröhlich R, Metz P * Technische Universität Dresden und Westfälische Wilhelms-Universität Münster, Germany; Tomsk Polytechnic University, Russia
A Practical Access to Highly Enantiomerically Pure Flavanones by Catalytic Asymmetric Transfer Hydrogenation.
Angew. Chem. Int. Ed. 2013;
52: 11651-11655
Key words
rhodium - kinetic resolution - diamine ligands
Significance
Chiral flavanone moieties are among the largest secondary metabolites in plants. As such, they have been known for their antifungal, antibacterial, and antiviral effects. The authors present a practical and convenient method for the synthesis of both enantiomers of this class of molecules.
Comment
The catalytically active rhodium hydride species was generated in situ prior to the addition of the substrate. This method allowed the authors to reduce catalyst loading to 0.5 mol% while retaining high enantioselectivities. They were able to synthesize both enantiomers of the natural product glabrol.
