Majchrzak Mariusz, Kacprzak Karol, Piętka Marta, Garbarek Jerzy, Taras-Goślińska Katarzyna
Faculty of Chemistry, Adam Mickiewicz University in Poznań, 8 Uniwersytetu Poznańskiego Str., 61-614 Poznań, Poland.
Polymers (Basel). 2025 Jun 15;17(12):1661. doi: 10.3390/polym17121661.
A novel and general approach to the practical ROMP polymerization of cinchona alkaloid derivatives providing novel hybrid materials having quinine attached on a poly(norbornene-5,6-dicarboxyimide) matrix is presented. The concept involves an easy modification of quinine (in general, any cinchona alkaloid) toward clickable 9-azide that reacts with -propargyl--5-norbornene--2,3-dicarboxylic imide in Cu(I)-catalyzed Huisgen cycloaddition (click chemistry). The resulting monomers undergo a controllable ROMP reaction that leads to novel polymers of a desired length and solubility. This sequence allows for the facile preparation of a regularly decorated polymeric material having one quinine moiety per single mer of the polymer chain inaccessible using typical immobilization methods. A poly(norbornene-5,6-dicarboxyimide) type of polymeric matrix was selected due to the high reactivity of the -norbornene motif in Ru(II)-catalyzed ROMP and its chemical and thermal stability as well as convenient, scalable access from inexpensive -5-norbornene--2,3-dicarboxylic anhydride ('one-pot' Diels-Alder reaction of dicyclopentadiene and maleic anhydride). An appropriate combination of a Grubbs catalyst, Ru(II) (G1, G2), and ROMP conditions allowed for the efficient synthesis of well-defined soluble polymers with mass parameters in the range = 2.24 × 10 - 2.26 × 10 g/mol and = 2.90 × 10-3.05 × 10 g/mol with good polydispersity, = 1.32-1.35, and excellent thermal stability (up to 309°C T). Spectroscopic studies (NMR and electronic circular dichroism (ECD)) of these products revealed a linear structure with the slight advantage of a -configuration of an olefinic double bond. The resulting short-chain polymer discriminates mandelic acid enantiomers with a preference for the ()-stereoisomer in spectrofluorimetric assays. This concept seems to be rather general with respect to other molecules dedicated to incorporation into the poly(norbornene-5,6-dicarboxyimide) chain.
本文提出了一种新颖且通用的方法，用于金鸡纳生物碱衍生物的实用开环易位聚合反应，该反应可提供新型杂化材料，其中奎宁连接在聚（降冰片烯-5,6-二羧酸酰亚胺）基质上。该概念涉及将奎宁（一般而言，任何金鸡纳生物碱）轻松修饰为可点击的9-叠氮化物，其在铜（I）催化的惠斯根环加成反应（点击化学）中与炔丙基-5-降冰片烯-2,3-二羧酸酰亚胺反应。所得单体进行可控的开环易位聚合反应，生成具有所需长度和溶解性的新型聚合物。该序列允许轻松制备规则修饰的聚合物材料，聚合物链的每一个单体单元都有一个奎宁部分，这是使用典型固定方法无法实现的。选择聚（降冰片烯-5,6-二羧酸酰亚胺）类型的聚合物基质是因为降冰片烯基序在钌（II）催化的开环易位聚合反应中具有高反应性，以及其化学和热稳定性，并且可以通过廉价的5-降冰片烯-2,3-二羧酸酐（二环戊二烯与马来酸酐的“一锅法”狄尔斯-阿尔德反应）方便地大规模获得。Grubbs催化剂Ru（II）（G1、G2）与开环易位聚合条件的适当组合，能够高效合成定义明确的可溶性聚合物，其质量参数范围为 = 2.24×10 - 2.26×10 g/mol和 = 2.90×10 - 3.05×10 g/mol，具有良好的多分散性， = 1.32 - 1.35，以及出色的热稳定性（高达309°C T）。对这些产物的光谱研究（核磁共振和电子圆二色性（ECD））揭示了一种线性结构，其中烯烃双键的 -构型略有优势。所得的短链聚合物在荧光光谱分析中能够区分扁桃酸对映体，对（）-立体异构体具有偏好。就其他致力于掺入聚（降冰片烯-5,6-二羧酸酰亚胺）链中的分子而言，该概念似乎相当通用。
