Rao Si-Jia, Zhang Qi, Ye Xu-Hao, Gao Chuan, Qu Da-Hui
Key Laboratory for Advanced Materials and Institute of Fine Chemicals, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Meilong Road No. 130, Shanghai, 200237, China.
Chem Asian J. 2018 Apr 4;13(7):815-821. doi: 10.1002/asia.201800011. Epub 2018 Mar 2.
The structural complexity of mechanically interlocked molecules are very attractive to chemists owing to the challenges they present. In this article, novel mechanically interlocked molecules with a daisy-chain-containing hetero[4]rotaxane motif were efficiently synthesized. In addition, a novel integrative self-sorting strategy is demonstrated, involving an ABB-type (A for host, dibenzo-24-crown-8 (DB24C8), and B for guest, ammonium salt sites) monomer and a macrocycle host, benzo-21-crown-7 (B21C7), in which the assembled species in hydrogen-bonding-supported solvent only includes a novel daisy-chain-containing hetero[4]pseudorotaxane. The found self-sorting process involves the integrative recognition between B21C7 macrocycles and carefully designed components simultaneously containing two types of secondary ammonium ions and a host molecule, DB24C8 crown ether. The self-sorting strategy is integrative to undertake self-recognition behavior to form one single species of pseudorotaxane compared with the previous report. This self-sorting system can be used for the efficient one-pot synthesis of a daisy-chain-containing hetero[4]rotaxane in a good yield. The structure of hetero[4]rotaxane was confirmed by H NMR spectroscopy and high-resolution electrospray ionization (HR-ESI) mass spectrometry.
由于机械互锁分子所带来的挑战，其结构复杂性对化学家极具吸引力。在本文中，高效合成了具有含雏菊链杂[4]轮烷基序的新型机械互锁分子。此外，还展示了一种新型的整合自分类策略，该策略涉及一种ABB型单体（主体A为二苯并-24-冠-8（DB24C8），客体B为铵盐位点）和大环主体苯并-21-冠-7（B21C7），其中在氢键支持的溶剂中组装的物种仅包括一种新型的含雏菊链杂[4]准轮烷。所发现的自分类过程涉及B21C7大环与精心设计的同时包含两种仲铵离子和主体分子DB24C8冠醚的组分之间的整合识别。与先前的报道相比，该自分类策略是一种能够进行自识别行为以形成单一物种准轮烷的整合策略。这种自分类系统可用于高效一锅法合成含雏菊链的杂[4]轮烷，产率良好。通过1H NMR光谱和高分辨率电喷雾电离（HR-ESI）质谱对杂[4]轮烷的结构进行了确认。
