Synthesis and Chiroptical Properties of Planar Chiral Azahelicenes Based on [2.2]Paracyclophane

Three pairs of planar chiral heteroarenes were synthesized using palladium-catalyzed Buchwald–Hartwig coupling and hypervalent iodine-mediated oxidative cyclization from optically pure 4-amino[2.2]­paracyclophane. Among them, an enantiomer of planar chiral azahelicene was found to have circularly polarized luminescence activity that was remarkably stronger than that of planar chiral heteroarenes.