ORGN 530 |
| Selective modification of amino groups is of great importance in bioconjugation. Successful development of efficient methods for N-terminal alpha-amino group ligation of peptides would facilitate bioconjugate synthesis, positional proteomics studies and peptide microarray fabrication. However, it remains a significant challenge to selectively modify the N-terminal alpha-amino group of unprotected peptides with other nucleophilic side chain residues, such as the lysine amino group remaining intact. Here we report an efficient method for selective N-terminal alpha-amino group ligation of unprotected peptides in aqueous medium via oxidative coupling of alkynes with amines using manganese porphyrins as catalysts and hydrogen peroxide as the terminal oxidant. Mechanistic studies suggested that ketene generated from alkyne oxidation is a key intermediate for the coupling reaction. Currently, we are expanding the scope of this bioconjugation reaction. |
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Physical Organic Chemistry, Metal-Mediated Reactions, Asymmetric Reactions and Syntheses
8:00 PM-10:00 PM, Tuesday, August 21, 2007 BCEC -- Exhibit Hall - B2, Poster
Division of Organic Chemistry |