A New Reagent for Polypeptide Synthesis: μ‐Oxo‐bis‐[tris‐(dimethylamino)‐phosphonium]‐bis‐tetrafluoroborate

Abstract

The products 1 and 2 (X = OTs) have been isolated from the reaction between hexamethylphosphortriamide and p‐toluene sulfonic anhydride and the latter converted into μ‐oxo‐bis‐[tris‐(dimethylamino)‐phosphonium]‐bis‐tetrafluoroborate 2 (X = BF₄). This is a practical reagent for the formation of the peptide link. Where racemisation is possible via oxazolone formation this can be decreased by the addition of 1‐hydroxybenzotriazole or N‐hydroxysuccinimide. These additives may also increase the efficiency of condensation at glycine and proline residues.