Synthesis of Cyclic Peptides Containing a Thioester Handle for Native Chemical Ligation

The synthesis of cyclic peptides containing a thioester handle using a sulfo-click linker is reported. These cyclic peptides can be coupled to N-terminal cysteine-containing constructs via native chemical ligation. A successful application of a cyclic peptide bearing a thioester handle in native chemical ligation is shown by a high yielding ligation.