A synthetic route to a new surface-active phosphine ligand: 12-DPDP (12-diphenylphosphinododecylphosphonate)

Article abstract of DOI:10.1016/S0040-4020(00)00546-9

A water-soluble phosphonate-functionalized phosphine ligand Na₂[Ph₂P(CH₂)₁₂PO₃] (8), was prepared in eight steps from cyclododecanone. Phosphine 8 reacts with [Rh(COD)Cl]₂ in methanol to give the new complex Na₂[Rh(COD)(Ph₂P(CH₂)₁₂PO₃)Cl] (9). Complex 9 is inactive in the catalytic hydrogenation of 1-hexene and cyclohexene due to the decomposition of 9 to rhodium metal in the presence of hydrogen gas. Hydrogenation of decene using [Rh(COD)₂]BF₄ and 3 equiv. of 8 in an aqueous emulsion was achieved using 1 atm H₂. ³¹P NMR studies on 8 suggest a lack of well-defined aggregation in water, which has been ascribed to the steric bulk of the diphenylphosphino group. (C) 2000 Elsevier Science Ltd.