Transition-Metal Catalyst Free Oxidative Radical Arylation of -Methylpyrrole.

This study represents an expansion of the application of catalysis in air through conventional coupling and free radical processes. A reactive free aryl radical intermediate was generated via the oxidation of an activated Ar-NH-NH bond by air as a simple and readily available oxidant. For this purpose, the usability of phenylhydrazine and phenylhydrazine hydrochloride salt reagents for the direct arylation of pyrrole with aryl radicals was investigated.