Abstract-Siloxy amino acid lithium salt, O-tert-butyldiphenylsilyl L-serine lithium salt, was found to be an effective catalyst for the asymmetric Michael addition reaction of malonates to enones.

Asymmetric Michael addition of carbon nucleophiles, nitroalkanes and a β-ketoester, to enones was investigated by using a primary amino acid lithium salt as a catalyst.

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Asymmetric Michael Addition of Malonates to EnonesCatalyzed by a Siloxy Amino Acid Lithium Salt. -A primary, lipophilic amino acid lithium salt effectively catalyzes the asymmetric Michael addition of malonates (II) to enones (I), (IV), and (VI) to provide the corresponding ketoesters in good yields with moderate to high enantioselectivity. However, malonate (IIe) is too bulky to react with the cyclic enone (I). The Michael addition reactions of acyclic enones (VI) with diisopropyl malonate (IId) proceed very slow to give the adducts (VII) accompanied by polar by-products. Although the reaction of cyclopentenone (IVa)