Journal of the American Chemical Society, Vol.122, No.38, 9134-9142, 2000
Enantioselective Lewis acid catalyzed Michael reactions of alkylidene malonates. Catalysis by C-2-symmetric bis(oxazoline) copper(II) complexes in the synthesis of chiral, differentiated glutarate esters
Ct-symmetric bis(oxazorine)-Cu(TT) 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 beta-substituents using catalyst la. The glutarate eater 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.