We then advanced to the late-stage functionalization of more complex peptide structures 48, applying our photocatalytic conditions detailed in Scheme 3. We were able to precisely and selectively functionalize a variety of di-,tri-, penta-and hexapeptides, decorating them with a multitude of functional groups derived from the aromatic core. Notably, peptides containing residues with sensitive functionalities like thioether, phenol, and indole groups were tolerated without any interference from photocatalytic single electron transfer (SET) processes or Scheme 3. LSF of Dha-containing peptides 44 leading to conjugation and ligation. For further experimental details see the Supporting Information.