Organocatalytic Enantioselective Michael Addition of Silyl Malonate to α,β-Unsaturated Enones: One-pot Synthesis of Chiral δ-Keto Esters

We have developed organocatalytic enantioselective domino sequence of conjugate addition reaction/desilylation/decarboxylation of silyl malonate 2 to enones 1 to afford synthetically useful chiral δ-keto esters 3. The significance of the approach is highlighted by its capability to introduce δ-keto esters 3 with high enantioselectivity in one-pot. The Michael addition reaction is widely recognized as one of the most efficient carbon-carbon bond-forming reactions in organic synthesis, and the development of enantioselective catalytic Michael reaction has been the subject of intensive research. In addition to the great success catalyzed by metal complexes, the environmentally friendly organo-catalyst-mediated asymmetric Michael reaction has been explored intensively in recent years