Annulation Cascade of Aryl Alkynes Induced by Alumina‐Mediated CF Bond Activation.

Alumina‐mediated CF activation (AmCFA) is an established method to generate incipient phenyl cation (IPC) through polarization of C(aryl)F bonds. Herein, it is reported that AmCFA can be used to induce intramolecular arylation of aryl alkynes containing one, two, and three triple bonds. During the reaction, a single formally eliminated hydrogen fluoride (HF) leads to the formation of two, three, and four CC bonds, respectively. Thus, the transformation gives rapid access to π‐extension and serves as an interesting example of solid‐state rational domino annulation enabling the bottom‐up construction of nanographenes. [ABSTRACT FROM AUTHOR]