8. Chiral Boron-Bridged Bisoxazolines: Readily Available Anionic Ligands for Asymmetric Catalysis
   Clément Mazet, Valentin Köhler, Andreas Pfaltz*
   Angew. Chem. Int. Ed. 2005, 44, 4888-4891
   [ Highlighted in: Chem. Eng. News 2005, 83(36), 40-48 ]

Asymmetric cyclopropanation and monobenzoylation reactions of meso diols employing borabox catalysts 1 (M=Cu) result in high enantioselectivities. The borabox ligands are anionic analogues of the bisoxazolines 2 and are readily prepared by lithiation of oxazolines and subsequent trapping with boron halides. The considerable potential of borabox ligands in asymmetric catalysis is shown.

open archive unige:6980

Editor’s version DOI: 10.1002/anie.200501111