Highly enantioselective copper-catalyzed conjugate addition of diethylzinc to enones using chiral spiro phosphoramidites as ligands

J Org Chem. 2003 Feb 21;68(4):1582-4. doi: 10.1021/jo026611m.

Abstract

Novel monodentate chiral spiro phosphoramidite ligands have been readily synthesized in good yields from enantiomerically pure 1,1'-spirobiindane-7,7'-diol. The new ligands were highly efficient in the copper-catalyzed conjugate addition of Et(2)Zn to enones with up to 98% enantiomeric excess.