An intramolecular approach towards the regioselective construction of 2,3-diarylated indoles is reported. The reaction follows an intramolecular electrophilic N−H and C−H bond functionalization between the aniline and acetylene. This methodology employs the concept of a traceless tether to provide access to the free 2,3-diarylated indole products comprising a total of 18 examples. Hypervalent iodine reagents were identified as suitable promoters and four different protocols are provided, including stoichiometric and catalytic transformations.
Indole Synthesis through Sequential Electrophilic N-H and C-H Bond Activation Using Iodine(III) Reactivity
Chem. Eur. J. 2016, 22, 4351-4354.