Iron-catalyzed cascade carbochloromethylation of activated alkenes: highly efficient access to chloro-containing oxindoles.

An iron-catalyzed carbodi- and trichloromethylation of activated alkenes with readily available dichloro- and tetrachloromethane has been developed. A diaryliodonium salt is used as an efficient oxidant in this transformation. This reaction tolerates a variety of functional groups and allows for a highly efficient synthesis of various chloro-containing oxindoles.