Synthesis of Axially Chiral Amino Acid Derivatives via the Selective Monoesterification of 1,1′-Biaryl-2,2′-dicarboxylic Acids

Axially chiral amino acid derivatives were synthesized via a selective single-step monoesterification of 1,1'-binaphthyl-2,2'-dicarboxylic acids. In the presence of Ag2CO3, the alkylative monoesterification of a 1,1'-binaphthyl-2,2'-dicarboxylic acid with an alkyl halide proceeded selectively in a single operation. Curtius rearrangement of the monomethyl ester and successive alcoholysis of the corresponding isocyanate afforded the N-protected binaphthyl amino acids.