Pd-Catalyzed\nDual C–H Activation/Cyclization:\nConvergent and Divergent Synthesis of 1‑Azahelicenes

Herein, we report a convergent synthesis of 1-azahelicenes\n using\neasily available quinoline derivatives and cyclic diaryliodonium salts\nas starting materials. This reaction undergoes a palladium-catalyzed\ndual C–H activation/cyclization process to give facile access\nto a wide range of 1-aza[5]helicenes and 1-aza[6]helicenes with abundant\nfunctional groups (including F, Cl, Br, I, CF<sub>3</sub>, SeR, SR,\nand heteroaryl) in moderate to excellent yields, thereby providing\nnew opportunities to fine-tune the properties of the helicene backbone.\nIn addition, the obtained products could be further transformed into\nhelicene-based Lewis base catalysts and redox switch materials easily.\nNotably, one selected 1-azahelicene shined bright yellow light by\naggregation. These features enlarge the chemical space of 1-azahelicenes\nand inspire further utilization in other areas of research.