Oxidative γ-addition of enals to trifluoromethyl ketones : enantioselectivity control via Lewis acid/N-heterocyclic carbene cooperative catalysis

An oxidative γ-functionalization of enals under N-heterocyclic carbene (NHC) catalysis to give unsaturated δ-lactones is disclosed. Enantioselectivity control involving the relatively remote enal γ-carbon was achieved via Lewis acid [Sc(OTf)3 or combined Sc(OTf)3/Mg(OTf)2] and NHC cooperative catalysis