Expanding the Diversity of Unnatural Cell‐Surface Sialic Acids

Introduction of sialic acid analogues to cells, rather than their upstream N-acetylmannosamine (ManNAc) precursors, improves the delivery of bioorthogonal functional groups to the cell surface and enables the incorporation of photoactivatable azides into glycoconjugates (see scheme). Supporting information for this article is available on the WWW under http: //www. wiley-vch. de/contents/jc₂268/2004/z789ₛ. pdf or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.