Diels-Alder cycloadditions of N-arylpyrroles via aryne intermediates using diaryliodonium salts.

With a strategy of the formation of benzynes by using diaryliodonium salts, a cycloaddition reaction of N-arylpyrroles with benzynes was reported. A wide range of bridge-ring amines with various substituents have been synthesized in moderate to excellent yields (35-96%). Furthermore, with a catalytic amount of TsOH·H2O, these amines can be converted into the corresponding N-phenylamine derivatives easily, which are potentially useful in photosensitive dyes.