Dearomative Double Diels–Alder Reaction of C-3-Substituted Indenes and Arynes

We report the dearomative [4+2]/[4+2] (double Diels–Alder) reaction of C-3-substituted indenes and benzyne to afford a new class of bridged polycyclic hydrocarbon derivatives of the methanotetraphene family. Without C-3 substitution, the reaction proceeded via a [4+2]/[2+2] cycloaddition reaction. DFT studies compared the decisive effect of the C-3 substituent on the importance of the substitution on product selectivity. A few synthetic transformations of the product have been demonstrated.