β2, 2‐Amino Acid N‐Carboxyanhydrides Relying on Sequential Enantioselective C(4)‐Functionalization of Pyrrolidin‐2,3‐diones and Regioselective Baeyer–Villiger Oxidation

A catalytic enantioselective entry to beta-2,2-amino acids enabling their direct coupling with nucleophiles is described. The approach is based upon an effective bifunctional Bronsted base catalyzed construction of a quaternary carbon stereocenter at C4 position of pyrrolidin-2,3-diones. Subsequent regioselective Baeyer-Villiger oxidation of the resultant adducts gives beta-2,2-amino acid N-carboxy anhydrides as the reactive species, which can further react with nucleophiles. Following this strategy both, 2,2-amino acid derivatives with different functionalities at the newly created stereocenter, and spirocyclic structures can be efficiently prepared.