Synthesis of Chiral syn-α-Substituted β-Amino Ketones

Significance

The strategy reported is especially useful for the preparation of chiral β-amino ketones 5. Obtaining the same product from the addition of ketone enolates (A) to sulfinimines 1 is complicated by regioselective deprotonation issues if the ketone is not symmetrical. Thus, the use of a Weinreb amide enolate circumvents this limitation by allowing modular assembly of R²/R³ substituents of 5. The aminoamides 3 were shown to be easily derivatized into useful building blocks.