Fluorescent Naphthyl‐ and Anthrylazoles from the Catalytic Coupling of Phenylazoles with Internal Alkynes through the Cleavage of Multiple CH Bonds

Bright light rings: The direct coupling of phenylazoles with an internal alkyne proceeds efficiently in the presence of a rhodium catalyst and a copper oxidant to selectively give either the 1-naphthyl- or 1-anthrylazole derivatives through the cleavage of multiple CH bonds (see scheme; 1-naphthylazole derivative not shown). Some of the products exhibit intense fluorescence in the solid state.