Reaction of vinyl triflates of α-keto esters with primary amines: efficient synthesis of aziridine carboxylates

Vinyl triflates of α-keto esters react smoothly with primary amines to provide aziridine carboxylates in good yields. In all cases, little or no stereoselectivity was observed. A mechanistic study has shown that aziridine carboxylates are strictly formed under kinetic control. The origin of this lack of stereoselectivity is explained by a non- or poorly stereoselective proton transfer.