Fig. 2
Deracemization of rac-1Na2 upon inclusion complexation with various enantiopure guests in various solvents. a Partial 1H NMR spectra of mixtures of rac-1Na2 (0.50 mM) with (S)-G2, (S)-G3, (S)-G4, and (S)-G5 ([guest]/[1Na2] = 3) in DMSO-d6 measured at ambient temperature after heating at 80 °C for 24–48 h. [H2O]/[1Na2] = ca. 5–150. For the assignment of (P)- and (M)-helicity, see the text. b CD and absorption spectra of derac-1Na2 (0.20 mM) in the presence of 3 equivalents of achiral G1 measured in CH3CN/DMSO-d6 (ca. 29/1, v/v) or CH3CN/DIPF (ca. 29/1, v/v) at 25 °C after deracemization of rac-1Na2 upon inclusion complexation with GX ([guest]/[1Na2] = 3) in DMSO-d6 (for G2–G8) or DIPF (for (S)-G3) at 80 °C for 24–48 h. For detailed experimental procedures, see Methods (Procedure A). c Partial 1H NMR spectra of 1Na2 (0.50 mM) with (S)-G3 ([(S)-G3]/[1Na2] = 3) in CD3CN, acetone-d6, and THF-d8 measured at ambient temperature after heating at 80 °C for 26–266 h. [H2O]/[(M)-1TBA2] = ca. 5–20. Asterisk denotes the protons from unknown impurities
