Peptide Functionalisation Through Isoimide Intermediates

Abstract

Abstract We have developed new synthetic methods for the modification of peptides, exploiting acyl transfer reactions of isoimides. We have developed a new approach for the chemoselective synthesis of N-glycopeptides, using a Ag(I)-promoted coupling. We have successfully applied the Ag(I)-promoted coupling of aspartic acid containing peptide thioamides and glycosyl amines to the chemoselective synthesis of N glycosylated asparaginyl motifs. The methodology employs peptides possessing a thioamide group adjacent to the aspartic acid residue. Intramolecular Ag(I)-promoted coupling of the aspartic acid side-chain carboxylate with the thioamide generates an isoimide intermediate that is trapped ..