New studies on the reactivity of allyl difluorophosphate palladium complexes: synthesis of the first difluorophosphate metallocene derivatives

The reaction of [Pd(eta(3)-2Me-C3H4)(mu-PO2F2}](3) 1, previously synthesize d by us, with P- or S-donor ligands leads to the new derivatives [Pd(eta(3) -2Me-C3H4)(PO2F2)L] (L = PMePh2; P(OR)(3), R = Me, Et, Ph; SPPh3) and [Pd(e ta(3)-2Me-C3H4)L-2]PO2F2 (L = SPPh3). The neutral and ionic derivatives wit h L = tetrahydrothiophene, were detected by H-1-NMR. The fluxional behavior of SPPh3 complexes has been analyzed and a dissociation of SPPh3 ligand ev idenced. When 1 is made to react with M(eta(5)-C5R5)(2)Cl-2 (M = Ti, R = H, Me; M = Mo, R = H) the new metallocene derivatives M(eta(5)-C5R5)(2)(PO2F2 )(2) are obtained. Using M(PPh3)PF6 (M = Ag, Cu) the complex [Pd(eta(3)-2Me -C3H4)(PPh3)(2)]PF6 and M(PO2F2)(x) (M = Ag, x = 1; M = Cu; x = 2) are form ed. A similar reaction takes place between [Pd(eta(3)-2Me-C3H4)(PO2F2)(PPh3 )] and Ag(ClO4)PPh3. With AuPPh3PF6 and 1 no reaction is observed. The deri vatives trans-[PdCl(mu-Cl)(PR3)](2) (R = Ph, Cy) and [Pd(eta(3)-2Me-C3H4)(P hCN)(2)]PO2F2 are formed after the reaction of [Pd(eta(3)-2Me-C3H4)(PO2F2) (PR3)] and PdCl2(PhCN)(2). 1 or [Pd(eta(3)-2Me-C3H4)(PO2F2)(PPh3)], 2, does not react with weak acids However, HCl gives rise to [Pd(eta(3)-2Me-C3H4)C l(PPh3)] after the reaction with 2. HBF4 also reacts with 1 or 2 and by mea ns of F-19-NMR studies at low temperatures BF4- coordination has been obser ved when a non-coordinating solvent is used. (C) 1999 Elsevier Science S.A. All rights reserved.