[n]carbohelicenes (C) with three different lengths (n = 5, 7, 9), and compared their chiroptical properties, aromaticity, and ultrafast dynamics in the excited state. 9) As another type of helicene analog, heterohelicenes, in which heteroatoms are embedded into the helicene backbones, have also attracted attention because of their excellent luminescence and redox properties. Generally, heterohelicenes are more electron-rich compared with carbohelicenes, thus their HOMO energy levels are continuously destabilized with the π-extension. Therefore, it is more difficult to synthesize longer heterohelicenes with full conjugation, whereas several heterohelicenes with a double-layered structure have been synthesized; one example is diazatrioxa- [13]helicene D. 12) Furthermore, a triple-layered structure was accomplished with oxa[n]helicene E (n = 17, 19) albeit with disrupted π-conjugation. To qualitatively evaluate the electronic properties of helicenes, however, it is necessary to systematically synthesize fully conjugated heterohelicenes of different lengths, therefore, a synthetic strategy toward longer heterohelicene would be indispensable. Currently, few systematic synthetic methods are available for the synthesis of heterohelicenes. We recently reported one-shot oxidative fusion reactions of ortho-phenylene-bridged oligopyrroles to afford various heterocirculenes and heterohelicenes. Notably, tetraaza [8]circulenes, with planar structures excluding any sterically encumbering substituents, are fairly soluble in THF and DMSO. 16) This property arises from effective hydrogenbonding interactions between the pyrrolic NH site and the H-bond accepting solvent molecule. Inspired by this molecular design principle, we report a synthetic challenge for longer azahelicenes with outer-pointing pyrrolic NH sites. By exploiting the one-shot oxidative fusion reactions of suitably designed indole-terminated acyclic oligopyrroles (vide infra), a series of benzannulated aza[n]helicenes were obtained. This structure is suitable for suppressing the elevation of the HOMO energy levels by virtue of Clar's sextet rule. In other words, the designed benzannulated aza-[n]helicenes are an ideal platform to accomplish longer fully conjugated hetero [n]helicenes with respect to solubility and stability issues. Comprehensive characterizations by NMR, UV/Vis and fluorescence spectroscopy, electrochemistry, as well as CD and CPL spectra of the enantiomers revealed the π-conjugation along the helix and between the layers.