High-Yield Diastereoselective Synthesis of Planar Chiral [2]- and [3]Rotaxanes Constructed from per-Ethylated Pillar[5]arene and Pyridinium Derivatives

作者：Ogoshi Tomoki^*; Yamafuji Daiki; Aoki Takamichi; Kitajima Keisuke; Yamagishi Tada aki; Hayashi Yoshihiro; Kawauchi Susumu

来源：Chemistry - A European Journal, 2012, 18(24): 7493-7500.

DOI：10.1002/chem.201200122

• chirality
• inclusion compounds
• macrocycles
• nanostructures
• rotaxanes

Planar chiral [2]- and [3]rotaxanes constructed from pillar[5]arenes as wheels and pyridinium derivatives as axles were obtained in high yield using click reactions. The process of rotaxane formation was diastereoselective; the obtained [2]rotaxane was a racemic mixture consisting of (pS, pS, pS, pS, pS) and (pR, pR, pR, pR, pR) forms of the per-ethylated pillar[5]arene (C2) wheel, and other possible types of the [2]rotaxane did not form. Isolation of the enantiopure [2]rotaxanes with one axle through (pS, pS, pS, pS, pS)-C2 or (pR, pR, pR, pR, pR)-C2 wheels was accomplished. Furthermore, pillar[5]arene-based [3]rotaxane was successfully synthesized by attachment of two pseudo [2]rotaxanes onto a bifunctional linker. [3]Rotaxane formed in a 1:2:1 mixture with one axle threaded through two (pS, pS, pS, pS, pS)-C2, one (pS, pS, pS, pS, pS)-C2 and one (pR, pR, pR, pR, pR)-C2 (meso form), or two (pR, pR, pR, pR, pR)-C2 wheels. The [3]rotaxane enantiomers and the meso form were successfully isolated using appropriate chiral HPLC column chromatography. The procedure developed in this study is the starting point for the creation of pillar[5]arene-based interlocked molecules.

• 出版日期2012-6