Al-Azemi Talal F, Vinodh Mickey
Chemistry Department, Kuwait University P.O. Box 5969, Safat 13060 Kuwait
RSC Adv. 2022 Jan 12;12(3):1797-1806. doi: 10.1039/d1ra09043g. eCollection 2022 Jan 5.
Herein, we report a methodology for constructing mechanically self-locked molecules (MSMs) through the efficient intramolecular copper(i)-catalyzed alkyne-azide cycloaddition (CuAAC) of self-threaded A1/A2-azido-propargyl-difunctionalized pillar[5]arenes. The obtained monomeric "[1]catenane" and dimeric "-catenane" were isolated and fully characterized using mass spectrometry, nuclear magnetic resonance (NMR) spectroscopy, and X-ray crystallography. Upon investigation by H NMR spectroscopy in chloroform, the observed motion for the threaded ring in the [1]catenane was reversibly controlled by the temperature, as demonstrated by variable-temperature H NMR studies. Two -catenane stereoisomers were also isolated in which the two pillar[5]arene moieties threaded by two decyl chains were aligned in different topologies. Furthermore, the conformational inversion of [1]catenane and the -catenanes triggered by solvents and guests was investigated and probed using H NMR spectroscopy, isothermal titration calorimetry, and single-crystal X-ray analysis.
在此，我们报道了一种通过自穿线的A1/A2-叠氮基-炔丙基双官能化柱[5]芳烃的高效分子内铜（I）催化炔烃-叠氮环加成反应（CuAAC）构建机械自锁分子（MSM）的方法。所得到的单体“[1]索烃”和二聚体“-索烃”通过质谱、核磁共振（NMR）光谱和X射线晶体学进行了分离和全面表征。在氯仿中通过1H NMR光谱研究发现，[1]索烃中穿线环的运动可通过温度进行可逆控制，变温1H NMR研究证明了这一点。还分离出了两种-catenane立体异构体，其中由两条癸基链穿线的两个柱[5]芳烃部分以不同的拓扑结构排列。此外，利用1H NMR光谱、等温滴定量热法和单晶X射线分析研究并探测了[1]索烃和-catenane由溶剂和客体引发的构象反转。
