Details

Autor(en) / Beteiligte

• Tao, Xinfeng
• Zheng, Botuo
• Bai, Tianwen
• Li, Min-Hui
• Ling, Jun

Titel

Polymerization of N‑Substituted Glycine N‑Thiocarboxyanhydride through Regioselective Initiation of Cysteamine: A Direct Way toward Thiol-Capped Polypeptoids

Ist Teil von

• Macromolecules, 2018-06, Vol.51 (12), p.4494-4501

Ort / Verlag

American Chemical Society

Erscheinungsjahr

2018

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Because of the high reactivity, N-carboxyanhydride (NCA) can be initiated by the thiol group. On the contrary, N-thiocarboxy­anhydride (NTA) is more stable and is able to tolerate it. Herein, we apply cysteamine as a regioselective initiator for ring-opening polymerization (ROP) of N-substituted glycine N-thiocarboxy­anhydride (NNTA) to synthesize well-defined thiol-capped polypeptoids. ROPs of sarcosine NTA (Sar-NTA) and N-ethylglycine NTA (NEG-NTA) are well controlled when [M]/[I] ≤ 100 with high yields (>87.5%) producing polypeptoids with designable molecular weights and low polydispersity indices (<1.2). All the polypeptoid chains contain a thiol end group, which is confirmed by NMR analyses, MALDI-ToF MS spectra, and Ellman’s assay. Through radical-mediated thiol–ene reaction with styrene, all the thiol chain ends are transferred to oligostyrene, revealing the convenience of further modification. Benefiting from the thiol–ene click chemistry, thiol-capped polysarcosine (PSar) and poly­(N-ethylglycine) (PNEG) are promising candidates to replace PEG for their nontoxicity and biocompatibility.