Development of Unique Quinoline-Based Macrocyclic Systems and Strategic Applications in Versatile Chemistry

Macrocyclic compounds exhibit unique properties due to their large ring-shaped structures, which have captivated chemists in recent decades. These molecules exert specific functions in a multidisciplinary basis, e.g. chemistry, materials science, and biology. Crown ethers, calix [n] arenes, and porphyrinoids, which contain several ether/phenol/pyrrole subunits, represent milestones in these molecular categories with unparalleled functional diversity. In contrast, macrocycles exploiting quinoline as a key unitary element to construct specific macrocyclic architecture have received limited attention and been barely explored. In this report, we summarize the recent advances in oligo-quinoline macrocycles TriQuinoline (TQ), oxa-TriQuinoline (o-TQ), TEtraQuinoline (TEQ), and indole/quinoline hybrid macrocycle In2Q2. Particular emphasis is placed on the synthesis, structure, and application of these molecules in organometallic and supramolecular chemistry, which may guide new molecular designs in the heterocycle-based macrocycle family.