Chiral ligand-controlled asymmetric conjugate addition of α-trimethylsilanylacetate to acyclic and cyclic enones

Article abstract of DOI:10.1248/cpb.52.125

The reaction of lithium ester enolate with enones provides a challenge for chemoselectivity, that is, discrimination between a conjugate addition and a 1,2-addition. Asymmetric conjugate addition of a lithium enolate of α-trimethylsilanylacetate to acyclic and cyclic α,β-unsaturated ketones was mediated by an external chiral ligand to give the corresponding 1,4-adducts in good enantioselectivity of 74% and good chemoselectivity.