Organometallic chemistry of diphosphazanes - 13.1 palladium complexes of unsymmetrical diphosphazanes Ph2PN(Pri)PYY′

Article abstract of DOI:10.1016/0277-5387(95)00561-7

Unsymmetrical diphosphazanes Ph₂PN(Prⁱ)PYY′ [YY′ = O₂C₁₂H₈ (L¹), O₂C₂₀H₁₂ (L²); Y = Ph and Y′ = OC₆H₄Br-4 (L³), OC₆H₄Me-4 (L⁴), OC₆H₃Me₂-3,5 (L⁵), N₂C₃HMe₂-3,5 (L⁶)] react with cis-[PdCl₂(COD)] (COD = cycloocta-1,5-diene) giving the chelate complexes of the type cis-[PdCl₂{η²-Ph₂PN(Pr ⁱ)PYY′}] [YY′ = O₂C₁₂H₈ (1), O₂C₂₀H₁₂ (2); Y = Ph and Y′ = OC₆H₄Br-4 (3), OC₆H₄Me-4 (4), OC₆H₃Me₂-3,5 (5), N₂C₃HMe₂-3,5 (6)]. The P-N bond in 3 and 5 undergoes a facile cleavage in methanol solution to give cis-[PdCl₂{η¹-Ph₂P(OMe)}{η ¹-PhP(NHPrⁱ)(Y′)}] [Y′ = OC₆H₄Br-4 (7), OC₆H₃Me₂-3,5 (8)]. Reactions of Pd₂(dba)₃·CHCl₃ (dba = dibenzylideneacetone) with the diphosphazanes Ph₂PN(Prⁱ)PPhY′ [Y′ = OC₆H₄Me-4 (L⁴), N₂C₃HMe₂-3,5 (L⁶), N₂C₃H₃ (L⁷)] in the presence of MeI yields cis-[PdI₂{η²-Ph₂PN(Prⁱ)PPhMe}] (9); the P-O or P-N(pyrazolyl) bond of the starting ligands is cleaved and a P-C(Me) bond is formed. An analogous oxidative addition reaction in the presence of Ph₂PN(Prⁱ)PPh₂ (L⁸) yields cis-[PdI(Me)(η²-L⁸)] (10) and cis-[PdI₂(η²-L⁸)] (11). The structures of 8 and 9 have been determined by X-ray diffraction. Copyright