Synthesis of <i>N</i>-Alkoxycarbonyl Ketimines Derived from Isatins and Their Application in Enantioselective Synthesis of 3-Aminooxindoles

A simple and general method in the synthesis of <i>N</i>-alkoxycarbonyl ketimines derived from isatins has been described first. Generally, the enantioselective addition of 1,3-dicarbonyl compounds to this kind of ketimine affords chiral 3-amino oxindoles in high yield and excellent ee