Unbiased C3‐Electrophilic Indoles: Triflic Acid Mediated C3‐Regioselective Hydroarylation of N‐H Indoles

The direct dearomative addition of arenes to the C3 position unprotected indoles is reported under operationally simple conditions, using triflic acid at room temperature. present regioselective hydroarylation a straightforward manner generate an electrophilic indole from unbiased in sharp contrast previous strategies. This atom economical method delivers biologically relevant 3-arylindolines and 3,3-spiroindolines high yields regioselectivities both intra- intermolecular processes. DFT computations suggest stabilization cationic or dicationic intermediates with H-bonded (TfOH) n clusters.