Reactivities in olefin‐difluorocarbene reactions

The relative rates of addition of difluorocarbene to a series of methyl‐substituted olefins have been determined and correlated with similar data for dichlorocarbene, chlorofluorocarbene and ground‐state oxygen atoms. The electrophilic nature and stabilization of difluorocarbene by the fluorine substituents is discussed. Relative activation energies for the difluorocyclopropane‐forming reaction have been estimated and correlated with properties of the olefins as derived from molecular orbital theory.