Preparation and facile addition reactions of iminium salts derived from amino ketene silyl acetal and amino silyl enol ether

While iminium salts generated by the oxidation of amino ketene silyl acetals show intriguing reactivities to give useful γ-oxo-α-amino esters via reactions with silyl enol ethers in good yields, new iminium salts are also prepared by the oxidation of amino silyl enol ethers. They undergo facile addition reaction with various nucleophiles to give α-amino ketone derivatives in good yields.