Enantioselective Molecular Recognition in a Flexible Self-Folding Cavitand.

We report a chiral deep cavitand receptor based on calix[5]arene stabilized by a cooperative network of hydrogen bonds and having a highly flexible structure. The cavitand displays enantioselective molecular recognition with a series of chiral quaternary ammonium salts, providing unprecedented stability ratios between the corresponding diastereomeric host-guest complexes. Molecular dynamics simulations corroborate the higher flexibility of the new host and the emergence of superior induced-fit behavior with regards to resorcin[4]arene derived self-folding cavitands.