自负载手性孔状有机聚合物骨架的合成及不对称催化研究

In the past decade, the asymmetric catalysis has made tremendous progress. However, practical applications of homogeneous asymmetric catalysts remain limited in scope due to catalyst instability and difficulty in reuse and catalyst/product separation. Immobilization of a homogeneous catalyst can facilitate its recovery and recycle in principle, and therefore is of considerable interest to academia and industry. A large number of the research results of supported chiral catalyst system show that the choice of the supports has a decisive influence on the asymmetric catalytic performance. Utilizing the existing supports, such as organic macromolecules, inorganic porous materials, inorganic-organic hybrid materials, a lot of the excellent heterogeneous asymmetric catalytic systems have successful developed, but more reported results reflect that these supports have their limitations in heterogenerous catalysis. In this project, the applicant hope to synthesize some novel self-supported chiral porous polymer frameworks with chrial Salen complexes as building blocks, and evaluate their performance of asymmetric catalysis in chiral model reactions. We are interested in the exploration of covalently built-in chiral catalysis systems based on organic-polymer frameworks. If chiral catalytic center could be integrated into the skeleton, one would have a chance to create a novel homochiral porous polymer in which the skeleton itself serves as the chiral heterogeneous catalysts and pores provide spaces for the transformation. Novel self-supported chiral porous polymer frameworks maintain the catalytic active centers in the whole skeleton, and possess large specific surface area, pore structure, highly thermal and chemical stability, overcome some defects of previous reported supports in chiral heterogeneous catalysts. Therefore, it is important to explore the synthesis of self-supported chiral porous polymer frameworks and have important academic significance and good prospects in practical application.

不对称催化在过去几十年中取得了巨大的进展，但催化剂分离、循环及产物纯化等困难限制其在工业中的应用。手性催化剂的负载化是解决上述困难的有效方法。大量负载手性催化体系的研究结果表明载体的选择对催化性能有着决定性影响。虽然对于现有载体如有机大分子、无机多孔材料、无机-有机杂化材料等都有比较优秀的非均相不对称催化体系开发成功，但更多报道的结果却显示出这些载体都有着自身局限性。在本项目中，申请人拟利用手性金属Salen配合物作为结构基元，合成一类新型自负载手性孔状有机聚合物骨架，利用几类模型反应来评估其不对称催化性能。通过新的合成策略构筑的自负载手性骨架，保持催化活性中心均匀分布在共价连接骨架上，使整个骨架具有大比表面积、良好孔结构和高稳定性，克服了现有手性非均相催化剂的各种缺陷，有望成为一类优秀的手性多相催化剂。因此，探索自负载手性孔状有机聚合物骨架的合成具有重要的学术意义和良好的应用前景。

微孔材料由于其具有独特的物理化学性质被广泛应用在许多技术和能源相关领域，如气体吸附、气体分离、非均相催化、传感等。最近，共价联接的多孔有机聚合物表现出固有的大比表面积、高的稳定性和低骨架密度受到了研究人员的极大关注。比较经典的无机分子筛和无机有机杂化的金属有机骨架材料，多孔有机聚合物材料最大的优势就是可以通过合理的化学设计、有机结构基元和合成方法的选择实现其功能化。在本项目中，我们利用手性金属Salen配合物作为结构基元，通过Sonogashira-Hagihara偶联反应成功合成了一系列手性金属Salen基多孔有机聚合物材料。利用红外光谱、固态碳核磁谱、元素分析对聚合物骨架进行结构表征及确认；利用低温下氮气和二氧化碳的吸附表征聚合物骨架的孔结构；利用扫描电子显微镜和高分辨透射电子显微镜研究骨架的固态微结构；利用粉末χ射线衍射研究骨架的结晶性；利用热失重分析研究聚合物骨架的热稳定性；利用原子发射光谱研究骨架中金属的含量。获得了一类手性金属Salen基多孔有机聚合物材料，并利用其催化了几种不对称反应。仍然合成了一系列相关的多孔有机聚合物材料，并研究了它们在能源、环境和催化相关领域的应用。