Halofluorination of N-protected α,β-dehydro-α-amino acid esters—A convenient synthesis of α-fluoro-α-amino acid derivatives

Abstract

N-protected dehydroamino acid methyl esters have been converted to α-fluoro-β-halo amino acid derivatives under halofluorination reaction conditions. The influences of the nitrogen protecting group of the substrates and of the halonium electrophile on the reaction outcome and the stability of the obtained products have been studied. Furthermore, reduction of the halogen substituent (Cl or Br) under radical conditions provided a possibility for follow-up reactions. Nucleophilic substitution reactions, however, failed.