A straightforward approach by dehydrogenative C-N coupling between aryl C-H and N-H bonds using a hypervalent iodine reagent under mild conditions offers a versatile and convenient method for synthesizing various benzimidazole-fused heterocycles.

L-shaped π-extended penta-, hexa-, and heptacycles with a pyrrolo[1,2-a][1,8]naphthyridine junction were prepared from N,N′-bis[2-(2-alkyn-1-yl)phenyl]carbodiimides or their naphthyl analogs via Rh(I)-catalyzed intramolecular [2+2+2] cycloaddition and dehydrogenative aromatization. These L-shaped compounds emit sky-blue, yellow-green, or golden-orange fluorescence, with high quantum yields.