Highly active, thermo‐responsive polymeric catalytic system for reuse in aqueous and organic CuAAC reactions
Highly active, thermo‐responsive polymeric catalytic system for reuse in aqueous and organic CuAAC reactions
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DOI：
10.1002/pola.24723
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发表时间：
2011-07
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通讯作者：
Sofie Wallyn;M. Lammens;R. O’Reilly;F. D. Prez
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文献类型：
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作者：
Sofie Wallyn;M. Lammens;R. O’Reilly;F. D. Prez
三-(苄基三唑基甲基)胺 (TBTA) 被固定在苯乙烯单体上，随后与 N-异丙基丙烯酰胺 (NIPAM) 共聚，为铜辅助点击化学提供催化活性热响应共聚物。 P(TBTA-co-NIPAM) 共聚物的合成方法是每条链加入 2 至 10 个配体单元，分子量可调 (28-148 kDa)。 1H NMR 光谱、尺寸排阻色谱 (SEC) 和元素分析 (EA) 的结合证实了这些聚合物的受控合成，并允许量化 TBTA 官能化单体的掺入程度。负载溴化铜(I)后，将该均相催化剂体系添加至水/乙酸乙酯两相体系中。使用这种双相系统，水性点击反应可以在室温下进行，而有机点击化学可以在催化剂体系的浊点温度以上进行。聚合物催化剂体系可以利用其较低临界溶解温度（LCST）行为通过萃取进行再生，然后重新用于进一步的铜（I）催化叠氮化物-炔环加成（CuAAC）反应。虽然在水性点击反应中铜浸出导致催化活性降低，但有机相中的回收实验表明，这种共聚物支撑的系统可以实现有效的回收和再利用。 © 2011 Wiley periodicals, Inc. J Polym Sci 第 A 部分：Polym Chem，2011
Tris-(benzyltriazolylmethyl)amine (TBTA) has been immobilized onto a styrenic monomer and subsequently copolymerized with N-isopropyl acrylamide (NIPAM) to afford catalytically active thermo-responsive copolymers for copper assisted click chemistry. P(TBTA-co-NIPAM) copolymers were synthesized with incorporation of between 2 and 10 ligand units per chain and tuneable molecular weight (28–148 kDa). A combination of 1H NMR spectroscopy, size exclusion chromatography (SEC) and elemental analysis (EA) confirmed the controlled synthesis of these polymers and allowed for quantification of the degree of TBTA-functionalized monomer incorporation. After loading with copper(I) bromide, this homogeneous catalyst system was added to a water/ethyl acetate two-phase system. Using this biphasic system aqueous click reactions could be performed at room temperature, while organic click chemistry could be performed above the cloud point temperature of the catalyst system. The polymer catalyst system could be regenerated via extraction by making use of its lower critical solution temperature (LCST)-behavior, and then reused for further copper(I) catalyzed azide-alkyne cycloaddition (CuAAC) reactions. While a reduced catalytic activity is observed as a result of copper leaching in aqueous click reactions, the recycling experiments in the organic phase demonstrated that this copolymer supported system allows for efficient recycling and reuse. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011