One‐Pot Gold/Acid‐Catalyzed Synthesis of Indolo[1,2‐a ]quinolin‐5(6H )‐ones from 1‐(2‐Ethynylphenyl)‐1H ‐indoles

We present a method for the synthesis of substituted indolo[1,2-a]quinoline-5(6H)-ones starting from 1-(2-ethynylphenyl)-1H-indoles. The transformation involves gold-catalyzed oxidation of the triple bond followed by acid-promoted intramolecular cyclization at the indole C2 position. Demonstrating noteworthy versatility, the reaction tolerates a wide array of substituents on the indole core and proceeds in good to excellent yields (up to 93%).