β-D-Galactose-Functionalized Pillar[5]arene With Interesting Planar-Chirality for Constructing Chiral Nanoparticles

Planar-chiral pillar[5]arenes bearing β-D-galactose substituents on both rims have been successfully synthesized and effectively separated by silica gel chromatography with a high yield. The obtained (S(p))- and (R(p))-β-D-galactose functionalized pillar[5]arenes [(S(p-D))-GP5 and (R(p-D))-GP5] exhibit the S(p) and R(p) planar chirality. Furthermore, (S(p-D))-GP5 and (R(p-D))-GP5 can not racemize according to dynamic (1)H NMR and CD spectra. Notably, GP5 is able to capture a guest molecule (DNS-CPT) to form a host-guest supramolecular amphiphile, which can further self-assemble into chiral nanoparticles with the S(p) and R(p) planar chirality of (S(p-D))-GP5 and (R(p-D))-GP5 still being retained, suggesting GP5 could be as reliable chiral sources to transfer the S(p) and R(p) planar chirality.