Journal of the American Chemical Society, Vol.134, No.21, 8810-8813, 2012
Oxidative gamma-Addition of Enals to Trifluoromethyl Ketones: Enantioselectivity Control via Lewis Acid/N-Heterocyclic Carbene Cooperative Catalysis
An oxidative gamma-functionalization of enals under N-heterocyclic carbene (NHC) catalysis to give unsaturated delta-lactones is disclosed. Enantioselectivity control involving the relatively remote enal gamma-carbon was achieved via Lewis acid [Sc(OTf)(3) or combined Sc(OTf)(3)/Mg(OTf)(2)] and NHC cooperative catalysis.