Toward Synthesis of α-Alkyl Amino Glycines (A3G), New Amino Acid Surrogates

Abstract
A general method giving access to protected α-alkyl amino glycines (A3G) 4 from the previously described precursor α-isopropylthioglycine 1 is described. In the presence of N-bromosuccinimide, displacement of the thiol by a large variety of amines afforded the corresponding racemic amino acid mimics. The efficiency of the reaction was strongly dependent on the protective groups of the nucleophile used in the condensation.