A new template synthesis of triphosphorus macrocycles has been developed based upon the intramolecular hydrophosphination of allylphosphine coordinated to the (η5- cyclopentadienyl) iron (II) cation; the resulting tri-secondary macrocycle 1, 5, 9- triphosphacyclododecane is readily alkylated with ethene to give (η3-1, 5, 9-[12] aneP3Et3) Fe (η5-Cp)+ which is in turn liberated as the free ligand stereospecifically as the syn–syn ...
