| 초록 |
The reactivity ratio is one of the important factors in synthesizing the copolymer of the desired composition. The reactivity ratios of four different type of α-amino acid N-carboxy anhydrides (NCAs) have been studied. Copolymerizations of L-alanine with NCAs chosen from four distinct categories, i.e. γ-benzyl-L-glutamate, S-benzyl-L-cysteine, or O-benzyl-L-serine are performed by using N-heterocyclic carbenes organocatalyst at mild conditions. The reactivity ratios estimated in the study show big differences from those of reported systems that obtained in the absence of any catalyst. Most of the previous reports showed blocky copolypeptides were synthesized regardless of the type of NCAs, while variety of copolypeptide structures are accessible based on the type of NCAs in the study. Specifically copolypeptides of alternating and statistical repeating units are generally obtained rather than blocky unit. It was evidenced by matrix-assisted laser desorption/ionization-time of flight. |
