Our previous results

Starting from proline-derived enamines we obtained chiral discrimination in reactions with (ethoxycarbonyl)nitrene (NCO₂Et).

The best ee (77%) for the N-substituted a-amino ketone was registered with R = CH₂OMe. The configuration of the major enantiomer was R. Using N₃CO₂Et we obtained the same substituted ketone, in better yield but with a lower ee (35%). The configuration of the major enantiomer was S ¹.