New Applications of Bis(oxazoline) Ligands in Catalysis:  Asymmetric 1,2- and 1,4-Addition of ZnR₂ to Carbonyl Compounds

Abstract

The enantioselective addition of ZnR(2) to aldehydes (1,2) and cyclic enones (1,4) was accomplished using bis(oxazolines) as chiral ligands. The requirement for hydroxymethylene side chains in the ligands strongly suggests that bimetallic catalysts are decisive for high enantiocontrol in these additions. [structure: see text]