Template synthesis of 9-membered triphospha-macrocycles with rigid o-phenylene backbone functions

eta(5)-Cp(R)Fe(CH3CN)(1,2-diphosphinobenzene)]+ complexes are readily formed from eta(5)-Cp(R)FeL3]+ salts and act as template precursors for the intramolecular hydrophosphination of co-ordinated trivinylphosphine with 1,2-diphosphinobenzenes. This sequence constitutes a versatile synthetic route to a new class of co-ordinated triphosphacyclononanes bearing a rigid o-phenylene backbone link. The efficiency of the synthesis depends markedly upon the nature of the Cp(R) ligand. The new secondary phosphine macrocycles prepared by this route are readily alkylated to tritertiary triphosphine macrocycles bearing alkyl and pendant functions.