Chiral Supramolecular Self-Assembly Catalysts with Enhanced Metal Ion Interaction for Higher Enantioselectivity

Understanding the interaction between metal ions as catalytic centers and supramolecular scaffolds as chiral substrates plays an important role in developing chiral supramolecular catalysts with high enantioselectivity. Herein, we found that compared with l-norleucine chiral amphiphile (l-NorC₁₆), l-methionine chiral amphiphile (l-MetC₁₆) with the only heteroatom of S site difference in the hydrophilic group can form a similar supramolecular chiral nanoribbon (NR) with the bilayer structure through the self-assembly approach; yet, the interaction between the Cu(II) ion catalytic centers and supramolecular scaffolds is reinforced, favoring the chirality transfer and therefore enhancing their catalytic enantioselectivity of Diels–Alder reaction from 23% [l-NorC₁₆-NR-Cu(II)] to 78% [l-MetC₁₆-NR-Cu(II)]. Our work demonstrates a new strategy from the perspective of strengthening the metal ion–supramolecular scaffold interaction for the preparation of chiral supramolecular catalysts with good catalytic enantioselectivity.