Oligo(metallocene)s Containing Keto-Bridged Phospholyl Rings



A chiral racemic tris(phosphaferrocene) complex showing two bridging keto functionalities has been prepared diastereoselectively through the elaboration of a single 2,5-diester-substituted phosphaferrocene. The reaction profile involves the intervention of a single trinuclear complex, which contains two phosphametallocene units and an η1-coordinated phospholyl ligand 9, whose organisation determines the stereochemistry of the final product. This complex evolves smoothly to give a chiral triphosphametallocene (±)-(R*,R*)-[2,5-(2′-CO2Me-3′,4′-Me2PC4-FeCp*)-(η5-Me2PC4)FeCp*] 10.