Formation of nickeladihydropyran by oxidative addition of cyclopropyl ketone. Key intermediate in nickel-catalyzed cycloaddition.

Cyclopropyl phenyl ketone underwent oxidative addition to Ni(PCy3) generated from Ni(cod)2 and PCy3 to give a nickeladihydropyran, which is a key intermediate for the Ni(0)-catalyzed homo- or heterocycloaddition to give cyclopentane compounds having two carbonyl substituents at the 1,3-position.