圆柱型超分子反应器的构建及其在环化反应的应用研究

Supramolecular capsules, which posses isolated cavites analogous to enzymic binding pockets, can alter guest conformations or stabilize reactive intermediates. They are widely used in cycloaddition reactions. Although cyclizations assisted by supramolecular reactors have made some progress, there are still some scientific problems such as few modes of reactions and limitation of macrocyclic synthesis. The main reason is the lack of new and efficient supramolecular reactors and the construction of such compounds with higher activation energy. This project intends to synthesize a series of new cylindrical capsules by modifying the side walls and cavities of urea cavitands. On the basis of this, the functionalized capsules will be applied to the study of the cyclization of medium and large rings, such as carbene insertion reaction of alkane and remote C-H bond activation. At the same time, NMR analysis is used to monitor some of the cyclization intermediates, which will reveal related reaction mechanism. This research will enrich the chemical space of the middle or macrocyclic compounds.

超分子胶囊具有类似于酶的空腔结构，能够改变客体分子的构象或稳定反应中间体，被广泛应用于环加成反应。尽管超分子反应器辅助环化反应取得了一定进展，但是存在反应类型稀少与大环受限的科学问题。其主要原因是缺乏新型、高效的超分子反应器以及构建大环化合物所需的反应活化能较大。本项目拟使用脲基碗型超分子作为原型，对其侧壁和空腔进行修饰获得一系列新圆柱型超分子胶囊。在此基础上，并将功能化的胶囊应用于中、大环环化反应的研究，如烷烃卡宾插入反应、远程C-H键活化反应，同时，采用NMR分析手段监测部分环化反应中间体，揭示相关的反应机理，从而丰富中环或大环化合物的化学空间。

本项目基于雷琐酚杯[4]芳烃独特的半球形骨架，发展了自下而上及融合并入高效构筑水溶性功能化超分子杯的新策略，实现对天然酶微环境的仿生模拟，并提出受限空间影响小分子行为的概念。基于发展的合成新策略，建立了功能化分子杯主体库。进一步通过多重非共价键协同作用，实现分子选择性识别，例如水中极性小分子的选择性识别、异构体间的选择识别和偶极分子中的阳离子识别。利用分子杯的深穴疏水空腔模拟酶的口袋和定向识别，将分子实现去对称化。