A series of donor−acceptor-type benzo[b]phosphole and naphtho[2,3-b]phosphole oxides have been synthesized through metal-catalyzed reactions as key steps, that is, (1) cobalt- and copper-catalyzed multicomponent coupling of an arylzinc reagent, an alkyne, and dichlorophenylphosphine to assemble the electron-deficient benzophosphole or naphthophosphole oxide core and (2) palladium-catalyzed cross-coupling to introduce an electron-donating substituent to the benzo or naphtho moiety. These donor−acceptor molecules are strongly fluorescent, showing weak to strong solvatochromism depending on the electron-donating substituent.