Ruthenium-Catalyzed Hydroarylations of Methylenecyclopropanes: Mild C−H Bond Functionalizations with Conservation of Cyclopropane Rings KozhushkovSergei I. YufitDmitry S. AckermannLutz 2008 Ring conservation was observed in the first catalytic intermolecular hydroarylation of methylenecyclopropanes via C−H bond functionalization, a remarkable reactivity mode for a transformation proceeding through (cyclopropylcarbinyl)metal intermediates.