Traceless Staudinger acetylation of azides in aqueous buffers.

In this paper, we demonstrate the applicability of water-soluble p-dimethylaminoethyl substituted phosphinomethanethiol in acetyl transfer reactions by the traceless Staudinger ligation with unprotected ε-azido lysine containing peptides in aqueous buffer systems. Additionally, we present an improved synthesis pathway for the water-soluble phosphinothiol linkers requiring less steps in a comparable overall yield in comparison to previously published protocols.