Carbazole Annulation via Cascade Nucleophilic Addition-Cyclization Involving 2-(Silyloxy)pentadienyl Cation
Jacob R Stepherson1, Caitlan E Ayala1, Thomas H Tugwell1
1Department of Chemistry, 232 Choppin Hall, Louisiana State University , Baton Rouge, Louisiana 70803, United States.
Abstract:
We report a new strategy toward the synthesis of highly functionalized carbazoles via 2-(silyloxy)pentadienyl cation intermediates, which were generated upon ionization of vinyl-substituted α-hydroxy silyl enol ethers under Brønsted acid catalysis. These electrophilic species were found to readily undergo cascade reactions with substituted indoles to generate carbazole molecular scaffolds in good yields via a sequence of regioselective nucleophilic addition, followed by intramolecular dehydrative cyclization.
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