PlanarChiral Macrocyclic Host Pillar5arene No Rotation of Units

Planar-Chiral Macrocyclic Host Pillar[5]arene: No Rotation of Units and Isolation of Enantiomers by Introducing Bulky Substituents Tomoki Ogoshi, * Kae Masaki, Ryohei Shiga, Keisuke Kitajima, and Tada-aki Yamagishi Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa 920 -1192, Japan 2/25/2011 1 Received January 10, 2011

Pillar[5]arene cyclodextrin 2/25/2011 The composition of pillar[5]arene is almost the same as that of typical calixarenes. 2

Background of present work……. First reported in 2008, JACS Side view 2/25/2011 upper view 3

In the present work……. 2/25/2011 4

They synthesized (c) and (d) Studied Host-guest properties by adding OTMA 2/25/2011 5

Variable-temperature partial 1 H NMR spectra of (a) Cy-C 2 -Pillar and (b) Cy-C 1 -Pillar in toluene-d 8. Planar chirality and restricted rotation Of pillar arene were confirmed by VT-NMR and Chiral HPLC studies 2/25/2011 6

2/25/2011 (a) Chiral HPLC traces of Cy-C 1 -Pillar and (b) the first fraction of Cy-C 1 -Pillar byholding at 40 Cfor 18 h. Hexane/Et. OH= 97/3 (vol%) was used as eluent. (c) UV-vis and (d) CD spectra of the first and second fractions (14 μLmol-1 cm-1) inhexaneat 25 C. 7

Host-guest properties……. Peaks of Cy-C 1 -Pillar become broadening New peaks from complexes and free OTMA 1 H NMR spectra of (a) Cy-C 1 -Pillar, (b) OTMA, and (c) the 1: 1 mixture of Cy-C 1 -Pillar and OTMA in 10 m. M in CDCl 3 at 25 C. 2/25/2011 8

Job plots of the complex between Cy-C 1 -Pillar and OTMA (1: 1 stoichiometry). The Job plots were conducted by varying the mole fractions of guest OTMA and host Cy-C 1 -Pillar. Integration ratios between complexed and uncomplexed peaks of phenyl proton peak of Cy-C 1 -Pillar were utilized. Concentration: [OTMA]+[Cy-C 1 -Pillar] = 10 m. M. Association constant was 830 M-1 2/25/2011 9

In conclusion…. . • Developed a planar chiral host molecule • Enantiomers were separated and characterized • Host-guest properties Schematic representation of the rotation movements of bulky percyclohexyl-substituted pillar[5]arenes. 2/25/2011 Thanking you 10