Serine/threonine ligation for the chemical synthesis of proteins.

•Serine/threonine ligation has been developed for the chemical synthesis of proteins.•Ser/Thr ligation-mediated cyclization can be used for cyclic peptides synthesis.•Ser/Thr ligation is chemoselective with side chain unprotected peptides.•Ser/Thr ligation features a simple operational strategy with accessible materials.