Encouraging Progress in the ω-Aspartylation of Complex Oligosaccharides as a General Route to β-N-Linked Glycopolypeptides

Described herein is a method for the joining of complex peptides to complex oligosaccharides via an N-linkage. The omega-aspartylation is conducted by coupling fully deprotected glycosylamine with a peptide containing a unique thioacid at the omega-aspartate carboxyl. In the presence of HOBT, under conditions that, in principle, allow for oxidation, complex components are combined in encouraging yields to produce structurally and stereochemically defined N-linked glycopolypeptides wherein the carbohydrate domain can be quite complex. Various mechanisms for oxidative coupling are proposed.