Synergy of axial and point chirality to construct helical N-Heterotriangulene-Based supramolecular polymers

Abstract

We report on the cooperative supramolecular polymerization of a series of N-heterotriangulenes that aggregate into helical columnar stacks by the operation of H-bonding interactions between the peripheral amide groups and π-stacking of the central aromatic moieties. The helical outcome of the highly stable supramolecular polymers stems from the joint effect of the point chirality dictated by the stereogenic centers at the side chains that, in turn, conditions the molecular atropisomerism generated by the restricted rotation of the peripheral benzamide moieties affording a propeller-like geometry. To the best of our knowledge, this is the first example in which two different elements of asymmetry act together to bias the helicity of chiral supramolecular polymers.