Iron-Catalyzed Cross Dehydrogenative Coupling (CDC) of Indoles and Benzylic C-H Bonds

An efficient method for the synthesis of 3-alkylated indoles is described. The oxidative cross-coupling reaction of diphenylmethane derivatives with indoles at the C-3 position was achieved employing the N,N-dimethylcarbamoyl moiety as an auxiliary group in the presence of iron(II) chloride (FeCl2) and 2,3-dichloro-5,6-dicyanoquinone (DDQ).