Oxa-TriQuinoline: A New Entry to Aza-Oxa-Crown Architectures

A new 15-membered-macrocyclic molecular entity, oxa-TriQuinoline (o-TQ), was designed and synthesized. In o-TQ, three oxygen atoms were joined onto three quinoline units at the 2- and 8-positions in a head-to-tail fashion via three-fold SNAr reactions, giving rise to the characteristic N3O3 aza-oxa-crown architecture. o-TQ can serve as a new tridentate nitrogen ligand to capture a Cu(I) cation and adopt a bowl shape, before supramolecular complexation with corannulene and [12]CPP occurs via π–π and CH–π interactions. In the presence of the Cu(I) cation, the non-emissive o-TQ becomes a highly emissive material in the solid state, whereby the emission wave-lengths depend on the ancillary ligand on the Cu(I) cation. The o-TQ/Cu(I) complex is able to promote carbene catalysis to provide a range of enamines with a gem-difluorinated terminus.