Difluoromethylcarbene for iron-catalyzed cyclopropanation

Abstract

Difluoroethylsulfonium salt, Ph₂S⁺CH₂CF₂H OTf⁻, was developed into a convenient difluoromethylcarbene reagent for the iron-catalyzed cyclopropanation of terminal olefins, giving various difluoromethyl–cyclopropanes with excellent diastereoselectivities and in high yields.