Using Photoresponsive End-Closing and End-Opening Reactions for the Synthesis and Disassembly of [2]Rotaxanes: Implications for Dynamic Covalent Chemistry

被引：19

作者：

Tokunaga, Yuji ^{[1
]}

Akasaka, Koichiro ^{[1
]}

Hashimoto, Nobuharu ^{[1
]}

Yamanaka, Shou. ^{[2
]}

Hisada, Kenji ^{[2
]}

Shimomura, Youji ^{[1
]}

Kakuchi, Suzuka ^{[1
]}

机构：

[1] Univ Fukui, Fac Engn, Dept Mat Sci & Engn, Fukui 9108507, Japan

[2] Univ Fukui, Fac Engn, Dept Fiber Amen Engn, Fukui 9108507, Japan

来源：

JOURNAL OF ORGANIC CHEMISTRY | 2009年 / 74卷 / 06期

关键词：

DRIVEN MOLECULAR SHUTTLE; ALPHA-CYCLODEXTRIN; ROTAXANE SYNTHESIS; DIRECTED SYNTHESIS; LIGHT; TEMPLATE; PHOTOISOMERIZATION; POLYROTAXANE; COMPLEXES; SWITCHES;

D O I：

10.1021/jo8025143

中图分类号：

O62 [有机化学];

学科分类号：

070303 ; 081704 ;

摘要：

We have synthesized two [2]rotaxanes, each possessing a (Z)-alpha-methylstilbene unit as one of its stoppers, in good yield through the photoisomerization of terminal (E)-alpha-methylstilbene units of dialkylammonium sails in the presence of the crown ether dibenzo[24]crown-8 (DB24C8). The synthesis relies on the formation of pseudorotaxane intermediates through hydrogen bond-guided self-assembly and subsequent end-closing photoisomerization. An (E)-alpha-methylstilbene unit is not sufficiently bulky to prevent dissociation of the DB24C8 unit, whereas a (Z)-alpha-methylstilbene unit acts as a true stopper. We also synthesized these [2]rotaxanes from the (Z)-alpha-methylstilbene-teriminated axle-like salts though thermodynamic covalent chemistry by taking advantage of the reversibility of the photoisomerization. To dissociate the components of the [2]rotaxanes, we performed the reverse end-opening process under UV irradiation (i.e., Z-to-E isomerization of the alpha-methylstilbene termini) in a polar solvent. These rotaxanes are stable at room temperature, but dissociate slowly to their two components at elevated temperatures.

引用

页码：2374 / 2379

页数：6