This study reports an intermolecular aza-[2 + 2] photocycloaddition (aza-Paternò–Büchi reaction) of indoles, which efficiently assembles planar building blocks into ladder-shape azetidine-fused indoline pentacycles with contiguous quaternary carbons. The reaction exhibits divergent head-to-head (H-H) and head-to-tail (H-T) regioselectivity and absolute exo stereoselectivity. Mechanistic studies reveal that the regio- and stereoselectivities arise from distortion-controlled C-N coupling scenarios. The method is applicable to a broad range of indoles and other aromatics, such as benzofuran, benzothiophene, and indene, demonstrating its versatility and potential for accessing structurally complex and three-dimensionally rigid molecules. The products exhibit high three-dimensionality, with many having 3D scores in the top 0.5% region compared to structures in the DrugBank database. This study expands the synthetic repertoire for energy transfer catalysis and provides a strategy to access structurally intriguing architectures with high molecular complexity and underexplored topological chemical space.This study reports an intermolecular aza-[2 + 2] photocycloaddition (aza-Paternò–Büchi reaction) of indoles, which efficiently assembles planar building blocks into ladder-shape azetidine-fused indoline pentacycles with contiguous quaternary carbons. The reaction exhibits divergent head-to-head (H-H) and head-to-tail (H-T) regioselectivity and absolute exo stereoselectivity. Mechanistic studies reveal that the regio- and stereoselectivities arise from distortion-controlled C-N coupling scenarios. The method is applicable to a broad range of indoles and other aromatics, such as benzofuran, benzothiophene, and indene, demonstrating its versatility and potential for accessing structurally complex and three-dimensionally rigid molecules. The products exhibit high three-dimensionality, with many having 3D scores in the top 0.5% region compared to structures in the DrugBank database. This study expands the synthetic repertoire for energy transfer catalysis and provides a strategy to access structurally intriguing architectures with high molecular complexity and underexplored topological chemical space.