Hydrogen-bonding induced construction of a multiple double-helical system via a macrocycle-containing propargylamine backbone

<div><p>Two macrocyclic compounds containing propargylamine backbone have been synthesised via Mannich three-component reaction. The macrocycle <b>3a</b> shows the intramolecular self-folding conformation. The macrocycle <b>3b</b> self-assembles via multiple weak interactions to form a multiple double-helical system, which shows the alternate helical handedness.</p>