Carboxylic Acid Initiated Organocatalytic Ring-Opening Polymerization of N‑Sulfonyl Aziridines: An Easy Access to Well-Controlled Polyaziridine-Based Architectural and Functionalized Polymers

• Published in: Macromolecules Vol. 52; no. 22; pp. 8793 - 8802
• Main Authors: Yang, Ruhan, Wang, Ying, Luo, Wenyi, Jin, Yaocheng, Zhang, Zhen, Wu, Chuande, Hadjichristidis, Nikos
• Format: Journal Article
• Language: English
• Published: American Chemical Society 26.11.2019
• Subjects: acetic acid; aziridines; benzoic acid; catalytic activity; moieties; organocatalysts; palmitic acid; polymerization; polymers; syringic acid; vanillic acid
• DOI: 10.1021/acs.macromol.9b01716
• ISSN: 0024-9297; 1520-5835

A highly easy and efficient metal-free methodology for the synthesis of polyaziridine-based polymers with controlled architectures and desired functionalities was developed by organocatalytic ring-opening polymerization (ROP) of N-sulfonyl aziridines with a carboxylic acid as initiator. 1,5,7-Triaza­bicyclo[4.4.0]­dec-5-ene (MTBD) and phosphazene t-Bu-P4 organocatalysts have demonstrated high catalytic efficiency in connection with the controlled/living character of the ROP of 2-methyl-N-tosylaziridines (TsMAz) initiated by benzoic acid. Aryl carboxylic acids bearing an azido or a hydroxyl group as well as bio-derived vanillic acid and syringic acid and alkyl- and alkenyl-substituted carboxylic acids, such as acetic acid, palmitic acid, and methacrylic acid, can all initiate the ROP of TsMAz toward well-defined P­(TsMAz)­s. α,ω-Diamino telechelic, star-shaped P­(TsMAz)­s, and poly­(styrene-co-methacrylic acid)-graft-poly­(2-methyl-N-tosylaziridine) [P­(St-co-MAA)-g-P­(TsMAz)] have been conveniently synthesized from the corresponding multicarboxyl (macro)­initiators. Finally, this protocol has been applied for the synthesis of a linear photoresponsive P­(TsMAz) and an aggregation-induced emission (AIE)-active 4-arm P­(TsMAz) star from the corresponding functionalized carboxylic acids.