Synthesis, reactivity and catalytic activity in transfer hydrogenation of ketones of ruthenium(II) and ruthenium(IV) complexes containing the novel N-thiophosphorylated iminophosphorane-phosphine ligands Ph2PCH2P{=NP(=S)(OR)2}Ph2 (R = Et, Ph)

Iminophosphorane-phosphines Ph2PCH2P{=NP(=S)(OR)(2)}Ph-2 (R=Et 1a, Ph 1 b) have been prepared by treatment of bis(diphenylphosphino)methane with an equimolar amount of thiophosphorylated azides (RO)(2)P(=S)N-3. Dimers [{Ru(eta(6)-p-cymene)(mu-Cl)Cl}(2)] and [{Ru(eta(3):eta(3)-C10H16)(mu-Cl)Cl}(2)] react with a two-fold excess of 1a,b yielding the neutral complexes [Ru(eta(6)-p-cymene)Cl-2,(kappa(1)-P-Ph2PCH2P {=NP(=S)(OR)(2)}Ph-2)] (R=Et 2a, Ph 2b) and [Ru(eta(3):eta(3)-C10H16)Cl-2(kappa(1)-P-Ph2PCH2P{=NP(=S)(OR)(2)}Ph-2)] (R=Et 5a, Ph 5b), respectively. Treatment of 2a,b and 5a,b with one equivalent of AgSbF6 affords the cationic species [Ru(eta(6)-p-cymene)Cl(kappa(2)-P,S-Ph2PCH2P{=NP(=S)(OR)(2)}Ph-2)][SbF6], (R=Et 3a, Ph 3b) and [Ru(eta(3):eta(3)-C10H16)Cl(kappa(2)-P,S-Ph2PCH2P{=NP(=S)(OR)(2)}Ph-2)][SbF6] (R=Et 6a, Ph 6). respectively. The structure of the cation of complex 6a has been confirmed by X-ray crystallography. The preference observed for the kappa(2)-P,S- vs. kappa(2)-P,N-coordination of 1a,b seems to be sterically controlled since theoretical calculations on the models [Ru(eta(6)-C6H6)Cl(kappa(2)-P,N-H2PCH2P{=NP(=S)(OH)(2)}H-2)](+) A and [Ru(eta(6)-C6H6)Cl(kappa(2)-P,S- H2PCH2P{=NP(=S)(OH)(2)} H-2)](+) B show that isomer A is ca. 5.0 kcal mol(-1) more stable than B. Dicationic complexes [Ru(eta(6)-p-cymene)(kappa(3)-P,N,S-Ph2PCH2P{=NP(=S)(OR)(2)}Ph-2)][SbF6](2) (R=Et 4a, Ph 4b) and [Ru(eta(3):eta(3)-C10H16)-(kappa(3)-P,N,S-Ph2PCH2P{=NP(=S)(OR)(2)}Ph-2)][SbF6](2) (R=Et 7a, Ph 7b) have been obtained by treating 2a,b and 5a,b, respectively, with two equivalents of AgSbF6. The reactivity of [Ru(eta(6)-p-cymene)(kappa(3)-P,N,S-Ph2PCH2P{=NP(=S)- (OEt)(2)}Ph-2)][SbF6], 4a towards neutral and anionic ligands has been explored allowing the synthesis of complexes [Ru(eta(6)-p-cymene)(L)(kappa(2)-P,S-Ph2PCH2P{=NP(=S)(OEt)(2)}Ph-2)][SbF6](2) (L=Nequivalent toCMe 8, PMe3 9, PMe2Ph 10, PMePh2 11) and [Ru(eta(6)-p-cymene)X(kappa(2)-P,S-Ph2PCH2P{ =NP(=S)(OEt)(2)}Ph-2)][SbF6] (X=Br 12, I 13, N-3 14), respectively. The catalytic activity of complexes 2-7a,b in transfer hydrogenation of ketones by propan-2-ol has been also studied.