A novel oxidative side-chain transformation of α-amino acids and peptides by methyltrioxorhenium/H2O2 system

N-Boc derivatives of Met, Cys, and Trp, the properties of which resemble those of the respective amino acid residues present in proteins, are efficiently oxidized by methyltrioxorhenium and H2O2. A high regioselectivity for the oxidation of these residues when embedded into peptides was also found.