5,6-Bis(trimethylsilyl)benzo[c]furan: an isolable versatile building block for linear polycyclic aromatic compounds

Benzo[c]furans are a class of interesting and highly reactive compounds that readily undergo Diels–Alder cycloaddition with dienophiles to restore their aromaticity. Initially, the s-tetrazine approach established by Warrener was chosen for the synthesis of the title molecule. However, it was discovered that the rate of production of isobenzofuran from this approach was too slow to react with the fugitive arynes. Consequently, an alternative route was employed to realize the title molecule in a neat state. In this way, the reactions between the title molecule and arynes were successfully achieved. Herein, two synthetic approaches towards the title molecule and its further manipulation for the preparation of silylated linear polycyclic aromatic hydrocarbons (PAH) were reported.