Simple and Efficient Preparation of O- and S-GIcNAcylated Amino Acids through InBr3-Catalyzed Synthesis of β-N-Acetylglycosides from Commercially Available Reagents

The facile synthesis of serine, threonine, and cysteine beta-glycosides using commercially available peracetylated beta-N-acetylglucosamine (beta-Ac(4)GlcNAc) and catalytic amounts of indium bromide (InBr3) is described. This method involves only inexpensive reagents that require no further modification or special handling. The reagents are simply mixed, dissolved, and refluxed to afford the GlcNAcylated amino acids in great yields (70-80%). This operationally simple procedure should facilitate the study of O-GlcNAcylation without necessitating expertise in synthetic carbohydrate chemistry.