Enantioselective Lewis Acid Catalyzed Michael Reactions of Alkylidene Malonates. Catalysis byC₂-Symmetric Bis(oxazoline) Copper(II) Complexes in the Synthesis of Chiral, Differentiated Glutarate Esters

C 2 -symmetric bis(oxazoline)−Cu(II) complexes 1 catalyze the Mukaiyama Michael reaction of alkylidene malonates and enolsilanes. The use of hexafluoro-2-propanol is essential to induce catalyst turnover. High enantioselectivities are exhibited by bulky alkylidene malonate β-substituents using catalyst 1a . The glutarate ester products are readily decarboxylated to provide chiral 1,5-dicarbonyl synthons. Crystallographic characterization of substrate−catalyst complexes provides insight into the binding event with these catalysts and affords a rationale for the observed facial selectivities.