Diastereoselective alkylation of acetoacetates of chiral inductors. Synthetic applications

Oxidative asymmetric umpolung alkylation of Evans’ β-ketoimides using dialkylzinc nucleophiles

Umpolung alkylation of Evans’ auxiliary substituted β-ketoimides affords the diastereomerically pure products in yields ranging from 40 to 80%.

Easy approach to chiral Michael adducts by Eu+3-catalyzed conjugate addition

Michael addition of enantiopure N-acetoacetyl-oxazolidin-2-ones is shown to take place in the presence of catalytic amounts of Eu(+3) salts and complexes in high yields, very reduced reaction times, and moderate diastereoselectivity. The level of diastereoselectivity can be significantly enhanced by the suitable exploitation of the easy epimerization of the adducts in the presence of silica gel.