Fig. 9. (a) Beer's chiral rotaxane (S)-22 for selective chiral anion binding.31 (b) Representative anionic guests (used as TBA salts) and the selectivity observed for the preferred enantiomer in each case. (c) Modelled structure of (S)-22 with N-Boc-(S)-proline. R = 4-(C6H4)-C(4-(C6H4)-tBu)3 Reprinted with permission from ref. 31. Copyright 2017 American Chemical Society. Counter ions omitted for clarity.
