A new template for the synthesis of triphosphorus macrocycles
Abstract
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 isomer; related reactions with phenyl(allyl)phosphine lead directly to the triphenyl macrocycle (1,5,9-[12]aneP3Ph3) which is also liberated stereospecifically.