@inbook {2453, title = {New Chemistry, Including Pulp Bleaching Processes, of the Golden-Aged, Water-Soluble Compound, Tris(hydroxymethyl)phosphine}, booktitle = {Catalysis of Organic Reactions}, series = {Chemical Industries}, volume = {123}, year = {2009}, note = {ISI Document Delivery No.: BLT07Times Cited: 0Cited Reference Count: 85James, Brian R.Proceedings Paper22nd Conference on Catalysis of Organic ReactionsMAR 30-APR 03, 2008Richmond, VAOrgan React Catalysis Soc, Avantium, BASF Catalysis LLC, Eli Lilly, Evonik Degussa Corp, WR Grace, Davison Catalysts, Parr Instrument, Air Prod, Amgen, Eastman, Umicore, Bristol Myers Squibb, DuPont, Headwaters, HEI, Lummus Technol, OMG, Seton Hall Univ, Sud Chem6000 BROKEN SOUND PARKWAY NW, STE 300, BOCA RATON, FL 33487-2742 USA}, pages = {1-14}, publisher = {Crc Press-Taylor \& Francis Group}, organization = {Crc Press-Taylor \& Francis Group}, address = {Boca Raton}, abstract = {Collaborative studies with the Pulp and Paper Institute of Canada (Paprican) have led serendipitously to development of a pulp bleaching process using tris(hydroxymethyl)phosphine, P(CH2OH)(3) (abbreviated THP), and this on-going work is reviewed. Work on hydrogenation of aromatic residues in lignin, using transition metal catalysts under homogeneous, aqueous-phase conditions, led to the discovery that commercially available THP, in the absence of any metal, bleached selected pulps. Use of THP or a related diphosphine 2 is competitive with the currently used bleaching agents, hydrosulfite (S2O42-) and alkaline peroxide. (Hydroxymethyl)phosphines react as strong nucleophiles and/or reductants toward unsaturated chromophore moieties of lignin, decreasing the degree of conjugation, and hence leading to bleaching. The resulting phosphorus-containing moieties in the lignin also give a more permanent brightening of the pulp. The organo-phosphorus chemistry realized is relevant to other processes catalyzed homogeneously by transition metal-phosphine systems. In situ metal-THP species can catalyze hydrogenation of C=C and/or C=O bonds in lignin chromophores, and investigations on such systems have unearthed new THP-promoted transition metal chemistry.}, keywords = {BIPHASIC CONDITIONS, BRIGHTNESS STABILIZING AGENTS, CATALYTIC-HYDROGENATION, CLUSTER CATALYSIS, HOMOGENEOUS CATALYST, LIGNIN MODEL COMPOUNDS, mechanical, PHOSPHORUS-COMPOUNDS, pulps, ruthenium complexes, TERTIARY PHOSPHINES}, isbn = {978-1-4200-7076-7}, url = {://000270967300001}, author = {James, Brian R.}, editor = {Prunier, M. L.} } @article {609, title = {Interaction of rhodium(I) bisphosphine complexes with semicarbazones to give orthometallated rhodium(III) complexes}, journal = {Russian Chemical Bulletin}, volume = {52}, number = {12}, year = {2003}, note = {ISI Document Delivery No.: 809IUTimes Cited: 7Cited Reference Count: 57International Memorial Symposium on Modern Trends in Organometallic and Catalytic Chemistry Dedicated to Mark Vol{\textquoteright}pinMAY 18-AUG 23, 2003Moscow, RUSSIA}, month = {Dec}, pages = {2707-2714}, type = {Proceedings Paper}, abstract = {Interaction of the cis-[Rh(PR3)(2)(Solv)(2)]PF6 complexes (R = Ar or R-3 = Ph2Me, Solv solvent) under Ar with semicarbazones bearing a phenyl group on the imine-C atom gives the rhodium(III)-hydrido-bis(phosphine)-orthometallated semicarbazone species [RhH(PR3)(2){(o-C6H4(R{\textquoteright})C=N-N(H)CONH2}]PF6 (R{\textquoteright} = Me or Et), which are characterized generally by elemental analysis, P-31{H-1} and H-1 NMR spectroscopy, and mass-spectrometry. The PPh3-containing complex with R{\textquoteright} = Me, structurally characterized by X-ray analysis, reveals coordination of the semicarbazone by the ortho-C atom, the imine-N atom, and the amide-carbonyl group. For a semicarbazone containing no Ph group, the rhodium(I) complex [Rh(PR3)(2)(Et(Me)C=N-N(H)CONH2)]PF6, containing the eta(2)-semicarbazone bonded via the imine-N and carbonyl, is formed. Attempts to hydrogenate the C=N moiety in the complexes or to catalytically hydrogenate the semicarbazones were unsuccessful.}, keywords = {ACTIVATION, ASYMMETRIC HYDROGENATION, BENZALDEHYDE SEMICARBAZONE, C-H, C-H BONDS, CATALYTIC-HYDROGENATION, COMPLEXES, CRYSTAL-STRUCTURE, FINE CHEMICALS, INTRAMOLECULAR ACTIVATION, molecular structure, orthometallation, phosphines, rhodium, SELECTIVE HYDROGENATION, semicarbazones, SYNTHESIS, TRANSITION-METAL-COMPLEXES, UNPRECEDENTED CHEMICAL TRANSFORMATION}, isbn = {1066-5285}, url = {://000220631200019}, author = {Ezhova, M. B. and Patrick, B. O. and James, Brian R. and Ford, M. E. and Waller, E. J.} } @article {408, title = {Bisphosphine ligands containing two o-N,N-dimethylanilinyl substituents at each phosphorus atom}, journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie}, volume = {80}, number = {11}, year = {2002}, note = {ISI Document Delivery No.: 623LDTimes Cited: 11Cited Reference Count: 35}, month = {Nov}, pages = {1600-1606}, type = {Article}, abstract = {The synthesis and complete characterization of the family of tetra(amine)bisphosphine ligands (o-NMe2C6H4)(2)P-(X)-P(o-NMe2C6H4)(2), where X = CH2 (dmapm), (CH2)(2) (dmape), and CH(CH2)(3)CH (dmapcp), are described. Crystal structure data are compared with known, analogous bisphosphines containing o-pyridyl or phenyl substituents in place of the o-dimethylanilinyl groups. Several short, intramolecular C-H...N distances in the anilinyl derivatives may represent the presence of weak hydrogen bonds.}, keywords = {ACID, amine, AMPHIPHILIC DIPHOSPHINES, CATALYTIC-HYDROGENATION, CHEMISTRY, DERIVATIVES, HYDROFORMYLATION, hydrogen-bonding to N atoms, phosphine, polydentate, RESOLUTION, RHODIUM COMPLEXES, RUTHENIUM(II), WATER-SOLUBLE PHOSPHINES}, isbn = {0008-4042}, url = {://000179703800030}, author = {Jones, N. D. and Meessen, P. and Smith, M. B. and Losehand, U. and Rettig, S. J. and Patrick, B. O. and James, Brian R.} } @article {4571, title = {Towards inhibition of yellowing of mechanical pulps. Part III. Hydrogenation of milled wood lignin}, journal = {Journal of Pulp and Paper Science}, volume = {25}, number = {9}, year = {1999}, note = {ISI Document Delivery No.: 235YETimes Cited: 10Cited Reference Count: 18}, month = {Sep}, pages = {312-317}, type = {Article}, abstract = {Oxygenation of hexadecacarbonylhexarhodium(0), Rh-6(CO)(16), in dimethylformamide (DMF) generates nn active catalyst, formulated as Rh-6(mu(3)-O)(4)(OH)(12) (DMF)(n), far the hydrogenation of the aromatic rings of milled wood lignin at similar to 20 degrees C under I atm H-2 in aqueous methyl cellosolve. Partial hydrogenation of the aromatic rings in lignin was confirmed by H-1 NMR spectroscopy. The ability of the catalyst to hydrogenate the lignin model compound 2-methoxy-4-propylphenol is critically dependent on the reaction medium: hydrogenation proceeds faster in aqueous ethanol than in aqueous dioxane, aqueous methyl cellosolve or anhydrous ethanol while no hydrogenation occurs in aqueous DMF.}, keywords = {aromatic compounds, CATALYSTS, CATALYTIC-HYDROGENATION, COMPOUNDS, HYDROGENATION, INHIBITION, lignin model, milled wood lignins, model compounds, OXYGENATION, rhodium compounds, yellowing}, isbn = {0826-6220}, url = {://000082570800002}, author = {Hu, Thomas Q. and James, Brian R. and Wang, Y.} } @article {4571, title = {Towards inhibition of yellowing of mechanical pulps. Part III. Hydrogenation of milled wood lignin}, journal = {Journal of Pulp and Paper Science}, volume = {25}, number = {9}, year = {1999}, note = {ISI Document Delivery No.: 235YETimes Cited: 10Cited Reference Count: 18}, month = {Sep}, pages = {312-317}, type = {Article}, abstract = {Oxygenation of hexadecacarbonylhexarhodium(0), Rh-6(CO)(16), in dimethylformamide (DMF) generates nn active catalyst, formulated as Rh-6(mu(3)-O)(4)(OH)(12) (DMF)(n), far the hydrogenation of the aromatic rings of milled wood lignin at similar to 20 degrees C under I atm H-2 in aqueous methyl cellosolve. Partial hydrogenation of the aromatic rings in lignin was confirmed by H-1 NMR spectroscopy. The ability of the catalyst to hydrogenate the lignin model compound 2-methoxy-4-propylphenol is critically dependent on the reaction medium: hydrogenation proceeds faster in aqueous ethanol than in aqueous dioxane, aqueous methyl cellosolve or anhydrous ethanol while no hydrogenation occurs in aqueous DMF.}, keywords = {aromatic compounds, CATALYSTS, CATALYTIC-HYDROGENATION, COMPOUNDS, HYDROGENATION, INHIBITION, lignin model, milled wood lignins, model compounds, OXYGENATION, rhodium compounds, yellowing}, isbn = {0826-6220}, url = {://000082570800002}, author = {Hu, Thomas Q. and James, Brian R. and Wang, Y.} } @article {4003, title = {Stereoselective hydrogenation of lignin degradation model compounds}, journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie}, volume = {75}, number = {9}, year = {1997}, note = {ISI Document Delivery No.: YE063Times Cited: 20Cited Reference Count: 29}, month = {Sep}, pages = {1234-1239}, type = {Article}, abstract = {Di-mu-chloro-bis(eta(4)-1,5-hexadiene)dirhodium(I) in a two-phase hexane-aqueous medium catalyzes the diastereoselective H-2-hydrogenation of lignin degradation model compounds 4-propylphenol, 2-methoxy-3-propylphenol, and 2,6-dimethoxy-3-propylphenol. The all-cis diastereomer is obtained selectively when the phenolic hydroxy group is protected as a methyl ether or when a model compound possessing two methoxy substituents adjacent to the phenolic hydroxy group is used. The relative stereochemistries of the hydrogenated products are established by X-ray crystal structure analysis and (or) H-1 NMR.}, keywords = {catalytic hydrogenation, CATALYTIC-HYDROGENATION, COMPOUNDS, diastereomer, lignin degradation model, STEREOSELECTIVE, X-ray crystal structure}, isbn = {0008-4042}, url = {://A1997YE06300011}, author = {Hu, Thomas Q. and James, Brian R. and Rettig, S. J. and Lee, C. L.} } @article {4003, title = {Stereoselective hydrogenation of lignin degradation model compounds}, journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie}, volume = {75}, number = {9}, year = {1997}, note = {ISI Document Delivery No.: YE063Times Cited: 20Cited Reference Count: 29}, month = {Sep}, pages = {1234-1239}, type = {Article}, abstract = {Di-mu-chloro-bis(eta(4)-1,5-hexadiene)dirhodium(I) in a two-phase hexane-aqueous medium catalyzes the diastereoselective H-2-hydrogenation of lignin degradation model compounds 4-propylphenol, 2-methoxy-3-propylphenol, and 2,6-dimethoxy-3-propylphenol. The all-cis diastereomer is obtained selectively when the phenolic hydroxy group is protected as a methyl ether or when a model compound possessing two methoxy substituents adjacent to the phenolic hydroxy group is used. The relative stereochemistries of the hydrogenated products are established by X-ray crystal structure analysis and (or) H-1 NMR.}, keywords = {catalytic hydrogenation, CATALYTIC-HYDROGENATION, COMPOUNDS, diastereomer, lignin degradation model, STEREOSELECTIVE, X-ray crystal structure}, isbn = {0008-4042}, url = {://A1997YE06300011}, author = {Hu, Thomas Q. and James, Brian R. and Rettig, S. J. and Lee, C. L.} } @article {4547, title = {SYNTHESIS, STRUCTURE AND HYDROGENATION OF ETA-3-BENZYL DIPHOSPHINE COMPLEXES OF RHODIUM AND IRIDIUM}, journal = {Journal of Organometallic Chemistry}, volume = {445}, number = {1-2}, year = {1993}, note = {ISI Document Delivery No.: KR221Times Cited: 30Cited Reference Count: 39}, month = {Feb}, pages = {245-256}, type = {Article}, abstract = {{The preparation of(COD)Rh(eta3-CH2Ph) is described starting from [(COD)Rh]2(mu-Cl)2 by the addition of either Zn(CH2Ph), or Mg(CH2Ph)2(THF)2. The addition of the bulky chelating diphosphines tBu2P(CH2)3PtBu2, iPr2P(CH2)3PiPr2, iPr2P(CH2)2PiPr2, iPr2PCH2PiPr2 and Cy2PCH2PCy2 to (COD)Rh(eta3-CH2Ph) yields the coordinatively unsaturated, four-coordinate rhodium complexes of the form P2Rh(eta3-CH2Ph). Iridium complexes of the form P2Ir(eta3-CH2Ph)(where P2 = tBu2P(CH2)3PtBu, and iPr2P(CH2)3PiPr2) can be prepared from [P2Ir]2(mu-Cl), and Zn(CH2Ph)2 or Mg(CHPh)2(THF)2. Reaction of the benzyl complexes with H-2 (1 atM) yields binuclear hydride derivatives of varying composition depending on the chelate ring size of the coordinated diphosphine. For the diphosphines with only a single methylene in the backbone, binuclear hexahydride complexes are formed in which the diphosphine is binucleating. The X-ray structure of {iPr2P(CH22)3PiPr2}Rh(eta3-CH2Ph) shows a square planar geometry about rhodium with alternating single and double bonds in the eta3-coordinated benzyl fragment. Crystals of (1,3-bis(diiso-propylphosphino)propane}rhodium(eta3-benzyl) are monoclinic}, keywords = {BINUCLEAR, BRIDGING ALKENYL, CATALYTIC-HYDROGENATION, CHEMISTRY, DIHYDROGEN, Hydrides, OXIDATIVE-ADDITION, RAY CRYSTAL-STRUCTURE, REACTIVITY, RHRE(CO)4(PH2PCH2PPH2)2}, isbn = {0022-328X}, url = {://A1993KR22100035}, author = {Fryzuk,Michael D. and McConville, D. H. and Rettig, S. J.} } @article {7235, title = {MONONUCLEAR AND DINUCLEAR RHODIUM CARBONYL SPECIES CONTAINING MONODENTATE OR BRIDGING 1,3-BIS(DIPHENYLPHOSPHINO)PROPANE}, journal = {Gazzetta Chimica Italiana}, volume = {122}, number = {8}, year = {1992}, note = {ISI Document Delivery No.: JW695Times Cited: 2Cited Reference Count: 50}, month = {Aug}, pages = {329-334}, type = {Article}, abstract = {The interaction of [Rh(CO)(dpp)]2(mu-CO)2 with H-2 in CH2Cl2 in the presence of varying amounts of dpp leads mainly to catalytically important species which include Rh(H)(CO)(dpp)(dpp*) and [RhH(CO)(dpp)]2(mu-dpp), these being formed also by treating RhH(dpp)2 with about 2 equivalents of CO; dpp and dpp* = bidentate and monodentate 1,3-bis(diphenylphosphino)propane, respectively. Mechanistic pathways involving a detected RhH(CO)2(dpp) and non-detected <> species are suggested.}, keywords = {ASYMMETRIC HYDROGENATION, CATALYSIS, CATALYTIC-HYDROGENATION, COMPLEXES, DIHYDROGEN, homogeneous, HYDROACYLATION, HYDROFORMYLATION, INSERTION, MONOXIDE, REACTIVITY}, isbn = {0016-5603}, url = {://A1992JW69500009}, author = {Fung, D. C. M. and James, Brian R.} } @article {7234, title = {REACTIONS OF NITRILES WITH BINUCLEAR RHODIUM HYDRIDES - THE STEPWISE REDUCTION OF A CARBON NITROGEN TRIPLE BOND AT 2 METAL CENTERS}, journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie}, volume = {70}, number = {9}, year = {1992}, note = {ISI Document Delivery No.: JW978Times Cited: 14Cited Reference Count: 29}, month = {Sep}, pages = {2381-2389}, type = {Article}, abstract = {{The reaction of simple nitriles, R{\textquoteright}CN (R{\textquoteright} = CH3, Ph, o-tol) with the electron-rich binuclear rhodium hydride derivatives [(R2PCH2CH2PR2)Rh]2(mu-H)2 (R = Pr(i): [(dippe) Rh]2(mu-H)2: R = OPri: [(dipope)Rh]2(mu-H)2) results in the formation of alkylideneimido derivatives [(R2PCH2CH2PR2)Rh]2(mu-H)(mu-N=CHR{\textquoteright}), apparently by insertion of the nitrile moiety into a bridging hydride bond: this was confirmed by the reaction of nitriles with the dideuteride [(dippe)Rh]2(mu-D)2, which resulted in the formation of [(dippe)Rh]2(mu-D)(mu-N=CHR{\textquoteright}). Further reduction can take place by addition of H-2 to generate the corresponding amide hydride derivatives [(dippe)Rh]2(mu-H)(mu-NHCH2R{\textquoteright}); this represents an overall stoichiometric reduction of a nitrile to a coordinated amide at a binuclear centre. These same amido-hydride complexes can be accessed by addition of amine to the starting binuclear rhodium hydride derivatives. The X-ray structure of [(Pri2PCH2CH2PPri2)Rh]2(mu-H)(mu-N=CHCH3) was undertaken to confirm the structure of these particular intermediates. Crystals of this material are monoclinic}, keywords = {ACIMIDOYL, CATALYTIC-HYDROGENATION, cluster complexes, CRYSTAL, LIGANDS, REACTIVITY}, isbn = {0008-4042}, url = {://A1992JW97800008}, author = {Fryzuk,Michael D. and Piers, W. E. and Rettig, S. J.} }