Catalytic oxidations of acetyl-protected peptide amide substrates, which resemble alpha-amino acid residues of proteins, using the iron-based catalyst [Fe^II(N4Py)(MeCN)](ClO4)₂ (1) and oxone (KHSO₅) have been investigated. Reaction of Ac-Gly-NHtBu with 1 mol % of the catalyst (1) and excess oxone in aqueous solution results in fragmentation of the peptide backbone to generate N-tert-butylglyoxylamide and acetamide. The alpha-hydroxy derivative of Ac-Gly-NHtBu was determined to be a component of the reaction mixture, consistent with cleavage occurring via alpha-hydroxylation and breakdown of the resultant hemiaminal.  Oxidations of side-chains were observed with substrates derived from Phe, Tyr, Trp, and Met. Kinetic data for reactions of the iron-oxo species [Fe^IV(O)(N4Py)]²⁺ derived from 1 with the peptide substrates were obtained by monitoring reactions with UV-vis spectroscopy.