Besides serving as therapeutic agents and building blocks for glycoprotein synthesis, homogeneous synthetic glycopeptides also benefit understanding function of specific glycoform. However, the selectivity coupling of oligosaccharides to a given peptide remains challenging despite the fact that the synthesis of structure-defined complex oligosaccharides has been greatly facilitated by chemoenzymatic based approaches. Herein, a Ca²⁺-promoted glycosylation approach was developed to exclusively modify phenolic peptide using a panel of biologically important glycans.