Borobox Ligands for Asymmetric Henry Reactions

Significance

The Pfaltz group has extended the scope and applications of its borabox ligand which was first introduced in 2005 for asymmetric cyclopropanation and desymmetrization of meso diols (Angew. Chem. Int. Ed. 2005, 44, 4888). Asymmetric Henry reaction of several nitro­methane derivatives with a wide range of aromatic and aliphatic aldehydes catalyzed by a copper-borabox complex gave addition products in good yields with modest to excellent dr and ee values.