Download PDF
Synfacts 2008(2): 0160-0160  
DOI: 10.1055/s-2007-992483
Metal-Catalyzed Asymmetric Synthesis and Stereoselective Reactions
© Georg Thieme Verlag Stuttgart · New York

Lanthanum-Catalyzed Asymmetric Cyclopropanation

Contributor(s): Mark Lautens, Praew Thansandote
H. Kakei, T. Sone, Y. Sohtome, S. Matsunaga*, M. Shibasaki*
The University of Tokyo, Japan
Further Information

Publication History

Publication Date:
23 January 2008 (online)

    Permissions and Reprints

Significance

The authors describe a catalytic asymmetric Corey-Chaykovsky cyclopropanation of enones with dimethyloxosulfonium methylide. The catalytic system is a lanthanum complex with lithium atoms and chiral BINOL-type ligands. The scope is broad and trans adducts are the sole isomers obtained in all cases. In a competition between double bonds of varying electronic properties, the reaction is highly chemoselective for the more electron-deficient olefin.