The present invention provides a method for preparing polyfunctionalized peptides and/or proteins at non-adjacent designated sites via native chemical ligation. In certain embodiments, the inventive method is a method for preparing a polyfunctionalized peptide comprising a peptidic backbone made up of four or more amino acids, wherein two or more non-adjacent amino acids are independently subsituted with a moiety having the structure: wherein A and L1 are as defined herein. In certain other embodiments, the inventive method allows the preparation of polyfunctionalized peptides having the general structure: wherein A, RP0, RP1, PX1, RX2, L1, to, s, tand q are as defined herein.