Catalytic Enantioselective Synthesis and Switchable Chiroptical Property of Inherently Chiral Macrocycles

We report herein a strategy to construct enantiopure inherently chiral macrocycles, ABCD-type heteracalix[4]-aromatics, through a catalytic enantioselective intramolecular C−N bond forming reaction. A chiral ligand-palladium complex was found to efficiently induce the inherent chirality of molecules during the macrocyclization process with ee values up to >99%. The resulting ABCD-type heteracalix[4]aromatics displayed excellent and pH triggered switchable electronic circular dichroism and circularly polarized luminescence properties.