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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 Ph 2 PCH 2 P{NP(S)(OR) 2 }Ph 2 (R = Et, Ph)

2003; Royal Society of Chemistry; Issue: 16 Linguagem: Inglês

10.1039/b305520e

1477-9234

Victorio Cadierno, Pascale Crochet, Josefina Dı́ez, Joaquín García‐Álvarez, Sergio E. Garcı́a-Garrido, Santiago García‐Granda, José Gimeno, Miguel A. Rodrı́guez,

Carbon dioxide utilization in catalysis

Iminophosphorane-phosphines Ph2PCH2P{NP(S)(OR)2}Ph2 (R = Et 1a, Ph 1b) have been prepared by treatment of bis(diphenylphosphino)methane with an equimolar amount of thiophosphorylated azides (RO)2P(S)N3. Dimers [{Ru(η6-p-cymene)(μ-Cl)Cl}2] and [{Ru(η3:η3-C10H16)(μ-Cl)Cl}2] react with a two-fold excess of 1a,b yielding the neutral complexes [Ru(η6-p-cymene)Cl2(κ1-P-Ph2PCH2P{NP(S)(OR)2}Ph2)] (R = Et 2a, Ph 2b) and [Ru(η3:η3-C10H16)Cl2(κ1-P-Ph2PCH2P{NP(S)(OR)2}Ph2)] (R = Et 5a, Ph 5b), respectively. Treatment of 2a,b and 5a,b with one equivalent of AgSbF6 affords the cationic species [Ru(η6-p-cymene)Cl(κ2-P,S-Ph2PCH2P{NP(S)(OR)2}Ph2)][SbF6] (R = Et 3a, Ph 3b) and [Ru(η3:η3-C10H16)Cl(κ2-P,S-Ph2PCH2P{NP(S)(OR)2}Ph2)][SbF6] (R = Et 6a, Ph 6b), respectively. The structure of the cation of complex 6a has been confirmed by X-ray crystallography. The preference observed for the κ2-P,S- vs. κ2-P,N- coordination of 1a,b seems to be sterically controlled since theoretical calculations on the models [Ru(η6-C6H6)Cl(κ2-P,N-H2PCH2P{NP(S)(OH)2}H2)]+A and [Ru(η6-C6H6)Cl(κ2-P,S-H2PCH2P{NP(S)(OH)2}H2)]+B show that isomer A is ca. 5.0 kcal mol−1 more stable than B. Dicationic complexes [Ru(η6-p-cymene)(κ3-P,N,S-Ph2PCH2P{NP(S)(OR)2}Ph2)][SbF6]2 (R = Et 4a, Ph 4b) and [Ru(η3:η3-C10H16)(κ3-P,N,S-Ph2PCH2P{NP(S)(OR)2}Ph2)][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(η6-p-cymene)(κ3-P,N,S-Ph2PCH2P{NP(S)(OEt)2}Ph2)][SbF6]24a towards neutral and anionic ligands has been explored allowing the synthesis of complexes [Ru(η6-p-cymene)(L)(κ2-P,S-Ph2PCH2P{NP(S)(OEt)2}Ph2)][SbF6]2 (L = NCMe 8, PMe39, PMe2Ph 10, PMePh211) and [Ru(η6-p-cymene)X(κ2-P,S-Ph2PCH2P{NP(S)(OEt)2}Ph2)][SbF6] (X = Br 12, I 13, N314), respectively. The catalytic activity of complexes 2–7a,b in transfer hydrogenation of ketones by propan-2-ol has been also studied.