Furthermore, in addition to the use of non-proteinogenic amino acids carrying alkenes, we also explored the on-resin installation of similar radical traps. The N-terminus of H-AFAC-NH2 was functionalised on-resin using a solution of pentafluorophenyl acrylate (12) to afford the linear acrylamide peptide, 13. When subjected to the optimised cyclisation conditions the starting peptide was fully consumed within 60 min; LC-MS analysis of the crude reaction material suggested the formation of an interesting phosphonium salt byproduct (Figure ) but no cyclised material was observed.