Chemodivergent reactions are more advantageous in organic
synthesis
that yield diversely functionalized scaffolds from common starting
materials. Herein, we report an efficient metal-free chemodivergent
protocol for the synthesis of 1-substituted 9H-pyrrolo[1,2-a]indole derivatives in the presence of catalytic amounts
of Lewis acid/Brønsted acid conditions using 3-substituted indoles
and β-trifluoromethyl-α,β-unsaturated ketones. Fine-tuning
of the catalyst and solvent system in the reaction conditions deliver
the trifluoromethyl, trifluoroethylcarboxylate, or carboxylic acid
substituents on the C1-position of 9H-pyrrolo[1,2-a]indole derivatives in situ. It is postulated that the
solvent and LA/BA catalyst interaction was found to be crucial for
the catalytic C–F activation in these transformations.