Expedient synthesis of gem-dialkylbenzyl heterocycles through olefinic hydroarylation

Friedel-Crafts Reactions with N-Heterocyclic Alcohols

N-Heterocyclic alcohols are shown to be excellent substrates for superacid-promoted Friedel-Crafts reactions. The N-heterocyclic alcohols ionize to produce reactive, dicationic intermediates which provide good to excellent yields of arylation products.

Dispersion-Controlled Regioselective Acid-Catalyzed Intramolecular Hydroindolation of cis-Methindolylstyrenes To Access Tetrahydrobenzo[ cd]indoles

Readily prepared cis-β-(α',α'-dimethyl)-4'-methindolylstyrenes undergo acid-catalyzed intramolecular hydroindolation to afford tetrahydrobenzo[ cd]indoles. Our experimental and computational investigations suggest that dispersive interactions between the indole and styrene preorganize substrates such that 6-membered ring formation is preferred, apparently via concerted protonation and C-C bond formation. When dispersion is attenuated (by a substituent or heteroatom), regioselectivity erodes and competing oligomerization predominates for cis substrates. Similarly, all trans-configured substrates that we evaluated failed to cyclize efficiently.