Non-metal with metal behavior: metal-free coordination-insertion ring-opening polymerization

被引：6

作者：

Wang, Xin ^{[1
,3
]}

Xu, Jiaxi ^{[1
,3
]}

Li, Zhenjiang ^{[1
]}

Liu, Jingjing ^{[1
,3
]}

Sun, Jie ^{[2
]}

Hadjichristidis, Nikos ^{[3
]}

Guo, Kai ^{[1
]}

机构：

[1] Nanjing Tech Univ, Coll Biotechnol & Pharmaceut Engn, State Key Lab Mat Oriented Chem Engn, 30 Puzhu Rd South, Nanjing 211816, Peoples R China

[2] Nanjing Tech Univ, Coll Food Sci & Light Ind, 30 Puzhu Rd South, Nanjing 211816, Peoples R China

[3] King Abdullah Univ Sci & Technol KAUST, KAUST Catalysis Ctr, Phys Sci & Engn Div, Polymer Synth Lab, Thuwal 23955, Saudi Arabia

来源：

CHEMICAL SCIENCE | 2021年 / 12卷 / 32期

基金：

中国国家自然科学基金;

关键词：

DIIMINATE ZINC CATALYSTS; ESTER-EXCHANGE-REACTIONS; EPSILON-CAPROLACTONE; CYCLIC ESTERS; L-LACTIDE; POLYLACTONES; COMPLEXES; MECHANISM; ALUMINUM; KINETICS;

D O I：

10.1039/d1sc02551a

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

The "coordination-insertion" ring-opening polymerization (ROP) mechanism has so far been the monopoly of metal catalysts. In this work, we present a metal-free "coordination-insertion" ROP of trimethylene carbonate (TMC) and epsilon-caprolactone (epsilon-CL), as well as their sequential block copolymerization, with N-trimethylsilyl-bis (trifluoromethanesulfonyl)imide (TMSNTf2) as the non-metallic initiator/catalyst. TMSNTf2 was proposed to work through an unprecedented metal-free "coordination-insertion" mechanism, which involves the coordination of monomer to the Si atom of TMSNTf2, the nucleophilic attack of the -NTf2 group on the coordinated monomer, and the cleavage of the acyl-oxygen bond of the monomer. The proposed metal-free "coordination-insertion" ROP was studied by NMR, SEC, and MALDI-TOF analyses. In addition, the TMSNTf2-mediated ROP of TMC and epsilon-CL led to linear and cyclic polymers following two-stage first-order polymerization processes, as evidenced by structural analyses and kinetics study, which further demonstrated the metal-free "coordination-insertion" mechanism.

引用

页码：10732 / 10741

页数：10

共 45 条

[1] Metal Triflimidates: Better than Metal Triflates as Catalysts in Organic Synthesis - The Effect of a Highly Delocalized Counteranion [J].