A series of diverse and complex hybrid structures of indole bearing fluorene were obtained in the presence of DDQ with high regioselectivity under mild conditions from biaryl tethered 3-(methylene)indoline in good to excellent yields. The strategy involves tandem allylic Csp3–H oxidation and subsequent intramolecular carbon–carbon bond formation. The yield of the product was dramatically improved in the presence of additives such as FeCl3 and molecular sieves (4 Å). A possible mechanism is proposed for this tandem process.
