Organocatalytic enantioselective aziridination of α,β- unsaturated aldehydes

(Chemical Equation Presented) Simple chiral amines catalyze a highly chemo- and enantioselective aziridination of α,β-unsaturated aldehydes to provide 2-formylaziridines in good yields and with up to 99% ee. The synthetic utility of this organocatalytic method was exemplified in a two-step asymmetric synthesis of β-amino acid esters with readily removable protecting groups (see scheme; R¹ = tert-butoxycarbonyl, benzyloxycarbonyl).