Xu Jiaxi, Hadjichristidis Nikos
King Abdullah University of Science and Technology (KAUST), Physical Sciences and Engineering Division, KAUST Catalysis Center, Polymer Synthesis Laboratory, Thuwal, 23955, Saudi Arabia.
Angew Chem Int Ed Engl. 2021 Mar 22;60(13):6949-6954. doi: 10.1002/anie.202015339. Epub 2021 Feb 24.
We report a new synthetic methodology for poly(ester amide)s by anionic ring-opening copolymerization of N-sulfonyl aziridines and cyclic anhydrides. Phosphazenes organocatalysts have been found to promote a highly-active, controlled, and selective alternating copolymerization in the absence of any competitive side reaction (zwitterionic mechanism and exchange transacylations). Mechanistic studies have shown first-order dependence of the copolymerization rate in N-sulfonyl aziridines and phosphazenes, and zero-order in cyclic anhydrides. This one-pot methodology leads not only to homopolymers but also to poly(ester amide)-based block copolymers. Two catalytic cycles involving ring-opening alternating copolymerization of N-sulfonyl aziridines with cyclic anhydrides and ring-opening polymerization of N-sulfonyl aziridines have been proposed to explain the one pot synthesis of poly(ester amide)-based homo- and block copolymers.
我们报道了一种通过N-磺酰基氮丙啶与环状酸酐的阴离子开环共聚反应合成聚（酯酰胺）的新方法。已发现磷腈有机催化剂能在没有任何竞争性副反应（两性离子机理和交换转酰基反应）的情况下促进高活性、可控且选择性的交替共聚反应。机理研究表明，共聚反应速率对N-磺酰基氮丙啶和磷腈呈一级依赖性，对环状酸酐呈零级依赖性。这种一锅法不仅能得到均聚物，还能得到基于聚（酯酰胺）的嵌段共聚物。已提出两个催化循环，包括N-磺酰基氮丙啶与环状酸酐的开环交替共聚反应以及N-磺酰基氮丙啶的开环聚合反应，以解释基于聚（酯酰胺）的均聚物和嵌段共聚物的一锅合成。
