An iminium salt was easily prepared using the oxidation of amino ketene silyl acetal with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone, and the subsequent nucleophilic addition to this iminium species proceeded efficiently to afford alpha-amino esters in good yields.

Aminocarboxylic acids (hydrazinocarboxylic acids) and esters P 0270 A New Synthetic Method for α-Alkoxycarbonyl Iminium Salt and Its Reaction with Nucleophiles. -(SHIMIZU*, M.; ITOU, H.; MIURA, M.; J. Am. Chem. Soc. 127 (2005) 10, 3296-3297; Dep. Chem. Mater., Fac. Eng., Mie Univ., Tsu, Mie 514, Japan; Eng.) -Nuesgen 31-072