Asymmetric Synthesis of α‐Amino Acids Bearing a 3‐Alkyloxindole Structural Motif.

We report a diastereoselective Mannich‐type reaction of 3‐alkyloxindole with N‐tert‐butanesulfinyl imino ester. This method provides a concise route to α‐amino acid derivatives bearing a 3‐alkyloxindole structural motif. This protocol has the advantage of using readily accessible starting materials and is operationally simple. A plausible transition‐state mode for the observed stereoselectivity is presented. [ABSTRACT FROM AUTHOR]