Abstract A Brønsted acid-catalyzed cycloisomerization of functionalized alkynes is described, which is assumed to be initiated through the formation of a benzylic cation intermediate. The reaction offers a highly efficient and straightforward route to indenyl ketones with a wide range of substituents under mild conditions.
![acetic acid 1-{2-[1-acetoxy-3-(4-chloro-phenyl)-prop-2-ynyl]-phenyl}-3-(4-chloro-phenyl)-prop-2-ynyl ester Structure](https://image.chemsrc.com/caspic/453/1113009-72-5.png)
![(4-chloro-phenyl)-[3-(4-chloro-phenylethynyl)-1H-inden-2-yl]-methanone Structure](https://image.chemsrc.com/caspic/115/1113009-90-7.png)