Pollok Corina H, Zhang Qi, Tiefenbacher Konrad, Merten Christian
Ruhr-Universität Bochum, Fakultät für Chemie und Biochemie, Organische Chemie 2, Universitätsstraße 150, 44801, Bochum, Germany.
Department of Chemistry, University of Basel, St. Johanns-Ring 19, CH-4056, Basel, Switzerland.
Chemphyschem. 2017 Aug 5;18(15):1987-1991. doi: 10.1002/cphc.201700610. Epub 2017 Jun 23.
The hexameric capsule of resorcin[4]arene 1 is capable of encapsulating tertiary amines, which has recently been used in the application of [(1) (H O) ] as (co-)catalyst in various asymmetric reactions. However, not much is known about the highly asymmetric but conformationally very dynamic structure of the capsule after uptake of chiral molecules. Therefore, in this contribution, we utilize electronic circular dichroism and vibrational circular dichroism spectroscopy to investigate how several chiral guest molecules affect the structural preferences of the capsule [(1) (H O) ]. In particular, we show that one small chiral amine encapsulated in [(1) (H O) ] is sufficient to control and dictate the stereochemical preferences of the entire capsule. Furthermore, neither strong π-π interactions nor a significant steric bulk are required for this induction. The observation of such a chiral imprint of the guest's stereochemistry onto its host molecule is expected to have implications also for other supramolecular capsules.
间苯二酚[4]芳烃1的六聚体胶囊能够包封叔胺，其最近已被用作[(1)(H₂O)]在各种不对称反应中的（共）催化剂。然而，关于摄取手性分子后胶囊高度不对称但构象非常动态的结构，人们了解得并不多。因此，在本论文中，我们利用电子圆二色光谱和振动圆二色光谱来研究几种手性客体分子如何影响胶囊[(1)(H₂O)]的结构偏好。特别地，我们表明包封在[(1)(H₂O)]中的一个小手性胺足以控制和决定整个胶囊的立体化学偏好。此外，这种诱导既不需要强π-π相互作用，也不需要显著的空间体积。预计客体立体化学对手性主体分子的这种手性印记观察结果对其他超分子胶囊也有影响。
