Efficient diastereoselective synthesis of chiral diferrocenylphosphine-diamines:: X-ray crystal structure of [(η5-C5H5)Fe{(η5-C5H3)PPh2CH(CH3) N(CH2)2(CH2)2NCH(CH3)PPh2 (η5-C5H3)}Fe(η5-C5H5)]

Three novel chiral planar diferrocenylphosphine-diamines 5(a-c) were designed and synthesized starting with(s)-( -)-N,N-dimethyl-1-ferrocenylethylamine-1 [(S)-1]. All new compounds were identified by H-1 NMR and MS. The structure of chiral diferrocenylphosphine-diamine 5c was determined by X-ray crystallography. Single crystal X-ray diffraction analysis reveals that the molecular structure of compound 5c [(eta(5)-C5H(5))Fe ((eta(5)-C5H3)PPh2CH(CH3) N(CH2)(2)(CH2)(2)NCH(CH3) PPh2-(eta(5)-C5H3))Fe(eta(5)-C5H5)] is enantiomerically pure and crystallizes in the noncentrosymmetric P2(1)2(1)2(1) space group; it maintains "Z" shape and contains a piperazine hexahydrate ring bridge. The piperazine ring adopts a favored chair conformation and the chiral center C23 and C29 substituents in S-configuration.