基于冠醚衍生物的互穿结构(精)

基于冠醚衍生物的互穿结构

黄飞鹤*

浙江大学理学院化学系，310027，浙江杭州

Email: fhuang@zju.edu.cn

互穿结构由于它们在分子电子学和手性催化方面有着广泛的潜在应用而引起了人们的广泛关注，而一个环上至少要多少个原子才能形成互穿结构是这一领域中一个非常基本的问题，一直以来人们都认为需要至少24个原子。而通过研究，我们发现环上具有21个原子的21-冠-7也能和二级铵盐形成互穿结构，因为以苯并-21-冠-7为主体而以二级铵盐为客体，我们成功制备了三个准轮烷和一个轮烷，并且我们发现苯并-21-冠-7对二级铵盐的络合比以前常用的双苯并-24-冠-8对二级铵盐的络合还要强好几倍，这主要是21-冠-7大环相对于24-冠-8和二级铵盐有着更好的尺寸匹配。我们还发现苯并-18-冠-6和二级铵盐不能形成主客体络合物，所以苯并-18-冠-6和二级铵盐不能形成互穿结构，也就是说21-冠-7是可以和二级铵盐形成互穿结构的最小冠醚。后来为了解决苯并-21-冠-7衍生物在制备复杂互穿结构中的异构体问题，我们引入了吡啶-21-冠-7主体，我们的研究表明吡啶-21-冠-7也可以和二级铵盐形成互穿结构并且它对二级铵盐的络合比苯并-21-冠-7和双苯并-24-冠-8都要强很多。在过去两年内，我们还制备了其它一些基于冠醚衍生物的准轮烷、轮烷、索烃以及超分子聚合物等互穿结构。

OPF6HONH2OOOOPF6ONOH2OOOOOEquimolar Benzo-21-Crown-7, Me3P, CH2Cl2, rtYield: 74%A Benzo-21-Crown-7-Based [2]Rotaxane Scheme 1. Preparation of a benzo-21-crown-7 [2]rotaxane.

关键词：冠醚，互穿结构，主客体化学

参考文献：

Huang, Feihe;* et al. J. Org. Chem. 2007, 72, 6573; Tetrahedron Lett. 2007, 48, 7537; J. Org. Chem. 2007, 72, 8935; Org. Lett. 2007, 9, 5553; Org. Biomol. Chem. 2008, 6, 2103; Tetrahedron Lett. 2008, 49, 5009; J. Org. Chem. 2008, 73, 5872; J. Am. Chem. Soc. 2008, 130,

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2009, 74, In Press; Chem. Commun. 2009, In Press.

Threaded Structures Based on Crown Ether Derivatives

Feihe Huang*

Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang 310027

How big a macrocycle should be for threading to occur is a basic and important question in threaded structure chemistry. For a long time, it has been widely accepted that a macrocycle needs at least 24 atoms for the threading of an alkyl group into its cavity. Dibenzo-24-crown-8 (DB24C8) derivatives are the most widely used hosts for secondary dialkylammonium salts. However, herein, we have found that secondary dialkylammonium salts are able to thread through the cavity of benzo-21-crown-7 (B21C7) to form [2]pseudorotoaxane- and [2]rotaxane-type threaded structures. Furthermore, we also found that B21C7 can bind secondary dialkylammonium salts much stronger than DB24C8. In order to solve a symmetry-based problem in the fabrication of complicated threaded structures with B21C7 derivatives, we introduced pyrido-21-crown-7 (P21C7). We found that P21C7 can bind secondary dialkylammonium salts stronger than B21C7 and DB21C8. In last two years, we also prepared some other threaded structures including pseudorotaxanes, rotaxanes, catenanes and supramolecular polymers.