Halogenolysis of a Nickelalactone Complex Produces β‐Halo‐Anhydrides

Nickelalactone complex [(dppe)Ni{κ2-C,O-CH2CH2C(=O)O}] {dppe = 1,2-bis(diphenylphosphino)ethane} reacts with halogens to form 3-halo-propionic anhydrides, [(dppe)NiX2], and [(dppeO2)3Ni][NiX4] (X = Cl, Br, I). Studies of model complexes [(dppe)Ni(O2CtBu)2] and [(dppe)NiBr(O2CtBu)] suggest that oxidation to NiIII and P–O reductive elimination are key steps in this reaction.