N‐Formylation of Amino Acid Esters and Peptides via Peroxide–Mediated Decarboxylative Coupling with α‐Keto Acids

N‐formyl amino acids and peptides play a crucial role in protein biosynthesis and in the design and development of antimicrobial peptides. In this study, we report an efficient N‐formylation of amino acid esters and peptides with α‐keto acids via peroxide‐mediated decarboxylative coupling, where only water/tertiary butanol and carbon dioxide were formed as by‐products. H₂O₂ was found to be ideal for the N‐formylation of substituted amino acids, while TBHP was successful for unprotected amino acid esters and oligopeptides. The methodology was extended for the synthesis of bioactive N‐formyl methionine and f‐MLP. The synthesized library includes N‐ferrocenyl‐N‐formyl amino acid and peptide derivatives, which might serve as a hybrid material for medicinal and electrochemical applications.