Cross-Aldol Reaction of Activated Carbonyls with Nitrosocarbonyl Intermediates: Stereoselective Synthesis toward α‑Hydroxy-β-amino Esters and Amides

A practical
and flexible strategy toward α-hydroxy-β-amino
esters and amides, which are important biological motifs, based on
an organocatalytic cross-aldol reaction of in situ-generated nitrosocarbonyl
intermediates followed by hydrogenation is presented. The protocol
features operational simplicity, high yields, a wide substrate scope,
and high regio- and diastereoselectivity profiles. The utility of
this method was showcased through the synthesis of bestatin analogues
and indole formation.