A Chiral Ag-Based Catalyst for Practical, Efficient, and Highly Enantioselective Additions of Enolsilanes to α-Ketoesters

A Ag-based chiral catalyst promotes efficient and highly enantioselective aldol additions of ketone-derived enolsilanes to α-ketoesters in the presence of a readily available amino acid-based ligand and commercially available AgF2. α-Ketoester substrates may bear alkyl, alkenyl, and aryl substituents; reactions proceed to >98% conversion to afford the desired tertiary alcohols in 61−>98% isolated yield and 60−96% ee. In contrast to previously reported approaches, highest enantioselectivities are observed with sterically demanding substrates, and reactions can be carried out in undistilled solvent, in air with as little as 1 mol % catalyst.