Practical and Efficient Organocatalytic Enantioselective α-Hydroxyamination Reactions of β-Ketoamides

The first organocatalytic general, efficient and highly enantioselective -hydroxyamination reactions of -ketoamides with nitrosobenzene are described using a thiourea/tertiary amine bifunctional catalyst. Significantly, the products were obtained in high enantiomeric purity using a low catalyst loading, and in the context of sustainable development, the full reaction mixture, including solvent, catalyst and excess substrate, can be recycled without significant erosion in the efficiency and enantioselectivity of the reaction. The described catalytic transformations secure a practical synthetic access to stereodefined and conformationally constrained -amino acid derivatives exhibiting a quaternary chiral center at the position.