Synthesis of α-hydroxy-ω-aminotelechelic polypeptide from α-amino acid N-carboxyanhydrides catalyzed by alkali-metal borohydrides

It is reported that alkali-metal borohydrides (MBH4, M = Li, Na and K) are efficient catalysts for ring opening polymerization (ROP) of α-amino acid N-carboxyanhydrides (NCAs). Polypeptides are prepared in quantitative yields with relatively narrow molecular weight distributions (MWDs = 1.1~1.5) which depend on the reaction temperature. End groups of the produced polypeptide are studied in detail by MALDI-ToF MS, 1H-NMR, 13C-NMR, 1H-1H COSY and 1H-13C HMQC analyses. The results indicate that α-hydroxy-ω-aminotelechelic polypeptides are formed which are suitable for postpolymerization functionalization.