To conclude, we have described the first efficient synthesis of peptide-EBX reagents both in solution and on solid phase. The unique reactivity of EBXs allowed efficient cross-coupling with Cys or C-terminal radical generated under mild photoredox conditions, without the need for any metal catalyst or strong activating reagents, in contrast to previously existing peptidebased hypervalent iodine reagents. The decarboxylative alkynylation method could then be applied intramolecularly to the synthesis of macrocycles incorporating a rigid and linear phenylalkyne unit. This methodology allowed to access rapidly cyclic peptides acting as potential inhibitors for Keap1-Nrf2 protein-protein interactions. The importance of the alkyne moiety is further supported by the lower binding affinity observed after reduction to the alkane.