Simple and Efficient Preparation of O- and S-GlcNAcylated Amino Acids through InBr 3 -Catalyzed Synthesis of β- N-Acetylglycosides from Commercially Available Reagents.

The facile synthesis of serine, threonine, and cysteine β-glycosides using commercially available peracetylated β- N-acetylglucosamine (β-Ac4 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.