The interaction of Ru(OAc)2(Ph3P)2 with one equivalent of N,N'-bis[o-(di-phenylphosphino) benzylidene]ethylenediamine (P2NzC2) in refluxing dichloromethanc gave trans-Ru(OAc)2(PzN2C2)'2H20 (I) in moderate yield (63%); in refluxing-toluene, it gave a red solid which upon recrystallization in CHC13 gave trans-RuC12(P2NzC2)" 2H20 (II) in good yield (92%). Compound II could also be prepared in good yield (85%) via the interaction of RuCI2(DMSO)4 with one equivalent of P2NzC2 in refluxing toluene. The interaction of RuCI2(DMSO)4 with one equivalent of N,N'-bis[o-(diphenylphosphino) benzylidene]- 1,3-diaminopropane (P2N2C3), N,N'-bis[o-(diphenylphosphino)benzyl] ethylenediamine (P2N2C2H4) and N,N'-bis[o-(diphenylphosphino)benzamido]ethane (P2N2C2-amide) in refluxing toluene gave trans-RuCl2(P2N2C3) (Ⅲ), trans-RuC12(P2N2C2H4) (IV) and trans-RuC12(P2N2C2-amide) (V) in good yield, respectively. The interaction of Fe(C104)2" 6H20 with one equivalent of P2N2C2 and P2N2C2H4 in refluxing acetonitrile gave trans-[Fe(P2N2C2)(CH3CN)2](CI04)2 (VI) and trans-[Fe(P2N2C2H4) (CH3CN)2](CIO4)2 (VII), respectively. Interaction of FeC12-4H20 with one equivalent of N,N'-bis[o-(diphenylphosphino)benzylidene]-l,6-diaminohexane (P2N2C6) in refluxing gave trans-FeC12(P2N2C6) (VIII). Complexes I-VIII have been fully characterized by ana-lytical and spectroscopic methods. The structure of IV has been established by an X-ray diffraction study. Compound II could be reduced to compound IV with NaBH4 in ethanol and oxidized to V with aqueous H202 acetonitrile. Catalytic studies showed that both Ⅱ and IV were effected catalysts for the hydrogenation of acrylic acid to propionic acid.

The chiral diiminodiphosphine ligand, [(R,R)-P2N2], has been prepared by the condensation of o-(diphenyl-phosphino)benzaldehyde and 1,2-diaminoeyclohexane. [(R,R)-P2N2] was reduced with excess NaBH4 in refluxing ethanol to afford the corresponding diaminodi-phosphine ligand [(R,R)-P2(NH)2]. The interaction of [(R,R)-P2(NH)2] with trans-RuCl2(DMSO)4 gave the chiral ruthenium complex [(R,R)-RuP2(NH)2] in 84% yield. The reaction of [(R,R)-RuP2(NH)2] with poly-(acrylic acid) using dieyclohexylcarbodiimine as the coupling agent, gave water soluble poly(acrylic acid salt)-supported chiral ruthenium complex [PAA-(R,R)-RuP2(NH)2]. These chiral ligands and ruthenium complexes have been fully characterized by microanalysis and IR, NMR spectroscopic methods. The polymer-bound ruthenium complex [PAA-(R,R)-RuP2(NH)2] as catalyst was used in asymmetric transfer hydrogenation of acetophenone in 2-propanol, producing the 1-phenyl-ethanol in 95% yield and 96% ee. The catalyst was reused twice with some loss of activity and enantioselec-tivity. Copyright

Summary: The trans-RuIICl2 complexes with structurally similar N,N¢-bis[o-(diphenylphosphino)benzylidene]cyclohexane-1,2-diamine and N,N¢-bis[o-(diphenylphosphino)-benzyl]cyclohexane-1,2-diamine ligands have been synthesized, and their molecular structures have been determined. The C2-symmetric diphosphine/diaminebased Ru complex acts as an excellent catalyst precursor in asymmetric transfer hydrogenation of acetophenone in a 0.1 M 2-propanol solution, leading to 2-phenylethanol in 97% ee and in 93% yield after 7h at 45℃. This transfer hydrogenation is characterized by low reversibility under these conditions.

The new chiral ligands (S,S)-N,N%-bis[o-(diphenylphosphino)benzylidene]1,2-diiminocyclohexane, [(S,S)-1] and (S,S)-N,N%-bis[o-diphenylphosphino]benzyl-1,2-diaminocyclohexane, [(S,S)-2] have been prepared. The interaction of [(S,S)-1] and [(S,S)-2] with [Rh(COD)Cl]2 afforded the corresponding cationic rhodium complexes [(S,S)-3][X] and [(S,S)-4][X] (X PF6, BF4 or ClO4), respectively. [(S,S)-1], [(S,S)-2], [(S,S)-3][X] and [(S,S)-4][X] have been fully characterized by elemental analyses and spectroscopic methods. These chiral cationic rhodium complexes serve as catalytst precursors for the asymmetric transfer hydrogenation of acetophenone derivatives in 2-propanol and [(S,S)-4][PF6] acts as an excellent catalyst in the reduction of m-chloroacetophenone, giving the corresponding optical alcohols in 99% yield and up to 94% ee.

The interaction of [Ir(COD)Cl]2 with chiral tetradentate diaminodiphosphine ligands gave chiral diaminodiphosphine-Ir(I) complexes, which were characterized by IR, NMR and CD. The new chiral iridium(I) complex catalysts were applied to asymmetric transfer hydrogenation of various aromatic ketones using 2-propanol as a source of hydrogen. The results showed that the corresponding chiral alcohols could be obtained with high activity (up to 99.4% yield) and excellent enantioselectivities (up to 99.0% ee) under mild conditions. Propiophenone was a preferred substrate with respect to catalytic activity and enantioselectivity in the presence of base. The catalytic turnover reached 4780mol product/mol iridium and the turnover frequency was as high as 1593h−1 at 55℃.

The interaction of [Rh(COD)Cl]2 with two equivalents of (S)-N,NX-biswo-( diphenylphosphino) benzylidenexpropane-1, 2-diamine [(S)-1] or (S)-N, N'-bis [o-(diphenylphosphino) benzylxpropane-1, 2-diamine [(S)-2] in benzene/methanol mixture and then precipitation by the addition of a solution of NH4PF6 in water afforded cationic rhodium (I) complexes [Rh(S)-MeP2N2] [PF6] and [Rh(S)-MeP2 (NH)2] [PF6] in good yield, respectively. Complexes [Rh(R,R)-C6P2N2] [PF6] and [Rh(R,R)-C6P2(NH)2] [PF6] were also prepared by an analogous manner. All these rhodium complexes have been characterized by analytical and spectroscopic methods and their asymmetric catalytic properties for enantioselective transfer hydrogenation of acetophenone have been tested. [Rh(R,R)-C6P2(NH)2] [PF6] was used as an excellent catalyst precursor for enantioselective transfer reduction of acetophenone in 2-propanol, leading to 2-phenylathanol in 97% yield and in 91% ee after 7 h at 83℃.

The condensation of (S)-propane-1, 2-diamine with two equivalents of o- (diphenylphosphino) benzaldehyde gives (S)-N, N'-bis[o-(diphenylphosphino) benzylidenexpropane-1, 2-diaminew [(S)-1] ligand. The reduction of (S)-1 with excess NaBH4 is carried out in refluxing ethanol to afford corresponding (S)-N, N'-bis [o-(diphenylphosphino) benzylxpropane-1, 2-diamine [(S)-2]. The interaction of trans-RuCl2(DMSO)4 with one equivalent of (S)-1 or (S)-2 in refluxing toluene gives (S)-3 or (S)-4 in good yield, respectively. (S)-1, (S)-2, (S)-3 and (S)-4 have been fully characterized by analytical and spectroscopic methods. The structure of (R)-3 has been also established by an X-ray diffraction study. Catalytic studies showed that (S)-4 as an excellent catalyst precursor for the asymmetric transfer hydrogenation of acetophenone with 90% yield and up to 91% enantiomeric excess.

Water-soluble and air-stable triruthenium carbonyl cluster Ru3 CO.9 TPPMS.3 TPPMSssodium diphenylphosphi-nobenzene-m-sulphonate. was used as catalyst precursor to hydrogenated acrylic acid in good yield. The cluster also catalyzed the hydroformylation of propylene with syngas in water, the main product is n-butyraldehyde; side-products are iso-butyraldehyde and a small amount of 1-butyl and isobutyl alcohols. At 1208C and propylene, CO and H2 partial pressures of 0.7 MPa, 2.0 MPa and 2.0MPa, respectively, catalytic turnover of 61.2 mol productsrmol cluster h and product n:i ratio of 15.9 were obtained. For ethylene hydroformylation, the main product is propanal; side-products are 3-pentanone, 1-propanol and 2-methyl-pent-2-en-1-al. The catalyst was characterized before and after the reaction by IR and. X-ray photoelectron spectroscopy and the results were discussed as related to the possible catalytic active species. q1999 Elsevier Science B.V. All rights reserved.

The condensation of o-(diphenylphosphino)benzaldehyde and various chiral diamine gives a series of diimino-diphosphine tetradentate ligands, which are reduced with excess NaBH4 in refluxing ethanol to afford the corresponding diaminodiphosphine ligands in good yield. The reactivity of these ligands toward trans-RuCl2(DMSO)4 and [Rh(COD)Cl]2 had been investigated and a number of chiral Ru(II) and Rh(I) complexes with the PNNP-type ligands were synthesized and characterized by microanalysis and IR, NMR spectroscopic methods. The chiral Ru(II) and Rh(I) complexes have proved to be excellent catalyst precursors for the asymmetric transfer hydrogenation of aromatic ketones, leading to optically active alcohols in up to 97% ee. Chirality 12: 383-388, 2000.

The chiral Ru cluster-based catalyst systems generated in situ from Ru3(CO)12 and chiral iiminodiphosphine tetradentate ligands effected asymmetric transfer hydrogenation of propiophenone in 2-propanol, leading to 1-phenyl-1-propanol in 94% yield and with 96% ee.