苯并噁嗪-异腈新型点击反应聚合活性评价及其在荧光/吸附性功能聚合物构筑中的拓展研究

Benzoxazines are a class of six-membered heterocyclic compounds, which can be synthesized from phenolic derivatives, formaldehyde, and primary amines via catalyst-free Mannich reaction, and with strong structure-designing flexibility. There are only few reports regarding the building of functional polymers by utilizing the chemical reactivity of benzoxazines so far. On the other hand, as the isomer of cyanide, isocyanide compounds possess strong nucleophilicity and reactivity. In the preliminary investigation of this project, we found the occurrence of catalyst-free reaction between benzoxazines and isocyanides solutions under room temperature. Inspired by this, this proposal focuses on the specific reaction between benzoxazine and isocyanide to investigate the corresponding reaction and controlling mechanism. Based on this, the polymerization activity of this reaction will be systematically characterized here to explore the controlling mechanism about the molecular weight, molecular weight distribution and polymerization rate of resultant polymers. Such benzoxazine-isocyanide reaction will be utilized further to realize the construction of multi-configurational, fluorescent/absorptive functional polymers by using multifunctional benzoxazine and isocyanides as starting substrates. Fluorescence probing and absorption performance of obtained polymers will be systematically studied further. This investigation is aim to expand the utilization scope of abundant benzoxazine derivatives and provide some experience for the synthesis of novel functional polymers via mild and efficient route.

苯并噁嗪类分子是由酚类、甲醛及伯胺通过无催化的Mannich反应得到的六元杂环化合物，其分子设计具有高度的灵活性。目前与利用苯并噁嗪环的化学反应活性来构筑功能聚合物的相关报道还较少。作为腈类化合物的同分异构体，异腈类化合物具有较强的亲核性和反应活性。申请人发现苯并噁嗪和异腈类化合物在室温下无催化溶液混合即发生了化学反应。基于该发现，本项目拟以目前尚未报道的苯并噁嗪-异腈基团之间的特异反应为研究对象，通过小分子模型反应对相关的反应机理及调控机制进行探讨。在此基础上，综合评价该反应的聚合活性，探明对所得聚合物的分子量及分布、聚合速率等的调控机制。进而以多官能、功能性苯并噁嗪/异腈为反应底物，对该反应体系在具有不同分子构造的荧光/吸附性功能聚合物构筑中的拓展进行尝试，系统分析所得聚合物的荧光传感及吸附性能。从而为结构丰富的苯并噁嗪类物质的拓展利用及通过温和、高效的途径合成功能聚合物提供经验储备。

以温和高效的官能团反应构筑结构多样、形态可控及目标功能集成的聚合物材料是相关领域的基础问题之一。同时满足无需贵金属催化、条件温和、反应位点明确及反应底物易得等要求的新型聚合反应模块的开发对功能聚合物的可控制备具有重要的推动作用。本项目以苯并噁嗪-异腈之间的特异性反应（Benzoxazine-isocyanide chemistry, BIC）为研究对象，开展了如下的研究：1）通过单官能苯并噁嗪及异腈化合物之间的小分子模型反应对相关的反应机理及反应底物的普适性进行了探究，筛选出辛基膦酸作为有效催化剂并优化了反应条件；2）成功构建了基于BIC的溶液法、固相法及BIC/Sol-gel共反应聚合体系，探讨了相关的聚合动力学及调控机制；3）以BIC为核心手段成功制备出一系列线型、枝化、交联及复合型聚酰胺类化合物，通过反应底物设计赋予所制备材料目标功能特性，探讨了所制备聚合物材料在光学探针、电化学探针、电致变色、染料吸附、非均相催化及钙钛矿太阳能电池缺陷钝化等方面的应用；4）成功制备出一系列基于小分子及聚合物的功能性异腈类化合物，并对其在光学探针及电化学探针方面的应用进行了探究。本项目的研究可为结构丰富的苯并噁嗪类物质化学活性的拓展利用及通过温和、高效的途径合成新型功能聚合物提供一定理论及实践方面的支撑。