Asymmetric formation of C - N bonds in chiral enol ethers

Article abstract of DOI:10.1016/S0040-4020(01)86538-8

Attack of EtO₂CN on an enol ether carrying (S,S)-hydrobenzoin as chiral auxiliary gives diastereoselective aziridination with diastereomeric excess> 95%. Easy subsequent hydrolysis gives partially racemised α-amino ketone 4. Other chiral auxiliaries does not allow isolation of intermediate aziridines and the α-amino ketone is isolated with a 75:25 enantiomeric ratio. The thermolysis of EtO₂CN₃ in most of the same enol ethers gives the acetals of the α-amino ketone with prevailing opposite configuration at the new formed chiral centre.