Copper-catalyzed modular synthesis of aromatic-interrupted Aza[6]helicenes with chiroptical properties

Azahelicenes have garnered significant attention due to their fascinating chiral helical structures and diverse chemical, chiroptical, and optoelectronic properties, which establish them as highly sought-after organic functional materials. These compounds hold great promise for applications in supramolecular chemistry, molecular recognition, chemosensing, biological chemistry, and optoelectronic materials. Here, we present a modular [2+2+2] synthesis method for the preparation of aromatic-interrupted aza[6]helicenes using polycyclic alkenes and diaryliodonium salt as substrates. This approach is designed to precisely control the regioselectivity of the bifunctional cyclization reaction process. Through post-modification and chiral resolution, a range of chiral aromatic-interrupted aza[6]helicene compounds exhibiting circularly polarized luminescence and large asymmetric factors are obtained.