Chelating phosphines are widely used as robust and reliable ligands in catalysis. We show that the anionic iron(i) complex [FeI(N(SiMe3)2)2]- is able to selectively cleave a P-aryl bond of 1,2-bis(diphenylphosphino)benzene. Furthermore, the related cis-1,2-bis(diphenylphosphino)-ethylene (dppee) binds not to the P donors but to the ethylene unit, and is (catalytically) transformed to the trans-isomer.