A Novel Highly Selective Chiral Auxiliary for the Asymmetric Synthesis of<scp>l</scp>- and<scp>d</scp>-α-Amino Acid Derivatives via a Multicomponent Ugi Reaction

Abstract

This paper describes the synthesis of a bicyclic beta-amino acid scaffold in both pure enantiomeric forms and its application as chiral auxiliary in an intramolecular version of the Ugi multicomponent reaction (U-5C-4CR) to prepare alpha-amino acid derivatives of both D- and L-series in a straightforward and very stereoselective manner. The mild conditions required for the Ugi condensation and for the removal of the chiral auxiliary make this method very attractive to prepare a wide range of differently structured N-alkylated and unalkylated amino acid derivatives.