Direct N-Glycofunctionalization of Amides with Glycosyl Trichloroacetimidate by Thiourea/Halogen Bond Donor Co-Catalysis.

Using a halogen bond (XB) donor and Schreiner's thiourea as cooperative catalysts, various amides, including the asparagine residues of several peptides, were directly coupled with glycosyl trichloroacetimidates to give unique N-acylorthoamides in good yields. Synthetic applications of N-acylorthoamides, including rearrangement to the corresponding β-N-glycoside, were also demonstrated.