Authors: Sherine N. Khattab, Ramon Subirós-Funosas, Ayman El-Faham, Fernando Albericio
Herein, the use of the BOP (bis(2-oxo-3-oxazolidinyl)phosphorodiamidic) moiety in peptide synthesis in both solution and solid-phase is expanded through the introduction of the most common additives to carbodiimides: HOBt, HOAt and OxymaPure. In addition, the derivative of the amide counterpart, N-Oxyma, was also prepared. Stand-alone coupling reagents derived from bis(2-oxo-3-oxazolidinyl)phosphorodiamidic chloride (BOP-Cl) show efficient performance in solution and solid-phase peptide synthesis. In particular, the OxymaPure derivative shows the additional advantage of being highly soluble in DMF and even fairly soluble in CH3CN, which can extend its use for the synthesis of complex peptides. These new stand-alone coupling reagents have the advantage of not bearing any counteranion such as PF6 or BH4, whose presence can jeopardize the purification of final peptides prepared in solution.
Keywords: phosphinic coupling reagent; peptide; Oxyma; solution phase;solid phase