gem-Dihalocyclopropane formation by iron/copper activation of tetrahalomethanes in the presence of nucleophilic olefins. Evidence for a carbene pathway

Abstract The activation of CBr 4 and CCl 4 by a bimetallic iron/copper couple in acetonitrile is a new, inexpensive, nontoxic and efficient procedure for gem -dibromo- and gem -dichloromethylenation of nucleophilic alkenes. This new route to gem -dihalocyclopropanes involves dihalocarbene species.