Fig. 2. Synthesis and characterisation of the CDIs investigated in this study. (a) Synthetic procedures of the l- (a-series) and d-valinol (b-series)-derived CDIs 4ab. (i) K2CO3, MeOH, CH2Cl2. (ii) biphenyl azide, Cu(MeCN)4PF6, TBTA, CH2Cl2. (iii) 525 nm LED, CHCl3. (iv) HCl, Et2O, CH2Cl2. (v) Octanoyl chloride, DMAP, pyridine, CH2Cl2. (b) Single crystal X-ray diffraction structure of 2b. Solvent molecules were omitted for clarity. (c) Single crystal X-ray diffraction structure of 3b. Solvent molecules were omitted for clarity. (d) Partial 1H NMR spectra of CDI 4a in 1,1,2,2-tetrachloroethane-d2 at 25 °C and 100 °C.
