Pd(0)-Catalyzed radical aryldifluoromethylation of activated alkenes

A Pd(0)-catalyzed intramolecular aryldifluoromethylation of activated alkenes under mild reaction conditions has been developed. This reaction provides a new method for construction of a variety of difluoromethylated oxindoles. Mechanistic investigations indicate that a difluoromethyl radical, which was triggered by Pd(0), initiated the cascade sequence through an addition to the alkene.