To enhance the practicability of the functionalization reactions, we then performed them directly on solid phase (Fig ). To our delight, the resin-bound peptide-EBXs reacted efficiently with protected cysteine to give S-alkynylation products 5h and 5i in excellent overall yields. Interestingly, for peptide sequences FLEEV and FLAFF, switching the resin cleavage condition from HFIP/DCM to more acidic TFA/TIPS/H2O, we could at the same time remove the protecting groups on the side-chains and hydrate the triple bond of the thioalkyne to generate the corresponding thioester product 9a/9b in 22%/19% over 13 steps. Furthermore, we can extend our previous method for Cys-Lys stapling on solid phase by introducing an orthogonal protecting group on Cys. The stapling reaction, followed by acidic hydration of the thioalkyne, afforded the N-terminus-Cys cyclization product 10. Unfortunately, the photomediated decarboxylative alkynylation was not successful on solid phase so far. Thiol and carboxylic acid alkynylation can be performed in tandem to access more functionalized products (Fig 4c ). For example, addition of protected cysteine on peptide-EBX 3g, followed in one-pot by C-terminal decarboxylative alkynylation with PhEBX under photoredox conditions gave dual functionalized product 11 in 42% isolated yield. In addition, the S-alkynylation product can undergo Ru II -catalyzed azide-thioalkyne cycloaddition (RuAtAC)