Synthesis of Polycyclic Aromatic Hydrocarbons (PAHs) via a Transient Directing Group.

In this work, an efficient synthetic route was developed to construct PAHs with diverse shape, width, and edge topology. The precursors of PAHs were obtained by using a direct arylation of arenes via a transient ligand-directed C-H functionalization strategy and the cycloaromatization was readily achieved by using a Brønsted acid catalyst. This novel route provides an opportunity to build up PAHs in a highly efficient manner.