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Diphenylphosphino
Selected AbstractsRational Design of Chelating Phosphine Functionalized Os(II) Emitters and Fabrication of Orange Polymer Light-Emitting Diodes Using Solution Process,ADVANCED FUNCTIONAL MATERIALS, Issue 2 2008M. Cheng Abstract A new series of charge neutral Os(II) pyridyl azolate complexes with either bis(diphenylphosphino)methane (dppm) or cis -1,2-bis(diphenylphosphino)ethene (dppee) chelates were synthesized, and their structural, electrochemical, photophysical properties and thermodynamic relationship were established. For the dppm derivatives 3a and 4a, the pyridyl azolate chromophores adopt an eclipse orientation with both azolate segments aligned trans to each other, and with the pyridyl groups resided the sites that are opposite to the phosphorus atoms. In sharp contrast, the reactions with dppee ligand gave rise to the formation of two structural isomers for all three kind of azole chromophores, with both azolate or neutral heterocycles (i.e., pyridyl or isoquinolinyl fragments) located at the mutual trans -disposition around the Os metal (denoted as series of a and b complexes). These chelating phosphines Os(II) complexes show remarkably high thermal stability, among which and several exhibit nearly unitary phosphorescence yield in deaerated solution at RT. A polymer light-emitting device (PLED) prepared using 0.4 mol % of 5a as dopant in a blend of poly(vinylcarbazole) (PVK) and 30 wt % of 2- tert -butylphenyl-5-biphenyl-1,3,4-oxadiazole (PBD) exhibits yellow emission with brightness of 7208 cd m,2, an external quantum efficiency of 10.4 % and luminous efficiency of 36.1 cd A,1 at current density of 20 mA cm,2. Upon changing to 1.6 mol % of 6a, the result showed even better brightness of 9212 cd m,2, external quantum efficiency of 12.5 % and luminous efficiency of 46.1 cd A,1 at 20 mA cm,2, while the max. external quantum efficiency of both devices reaches as high as 11.7 % and 13.3 %, respectively. The high PL quantum efficiency, non-ionic nature, and short radiative lifetime are believed to be the determining factors for this unprecedented achievement. [source] Novel Heteroleptic CuI Complexes with Tunable Emission Color for Efficient Phosphorescent Light-Emitting Diodes,ADVANCED FUNCTIONAL MATERIALS, Issue 15 2007Q. Zhang Abstract A series of orange-red to red phosphorescent heteroleptic CuI complexes (the first ligand: 2,2,-biquinoline (bq), 4,4,-diphenyl-2,2,-biquinoline (dpbq) or 3,3,-methylen-4,4,-diphenyl-2,2,-biquinoline (mdpbq); the second ligand: triphenylphosphine or bis[2-(diphenylphosphino)phenyl]ether (DPEphos)) have been synthesized and fully characterized. With highly rigid bulky biquinoline-type ligands, complexes [Cu(mdpbq)(PPh3)2](BF4) and [Cu(mdpbq)(DPEphos)](BF4) emit efficiently in 20,wt,% PMMA films with photoluminescence quantum yield of 0.56 and 0.43 and emission maximum of 606,nm and 617,nm, respectively. By doping these complexes in poly(vinyl carbazole) (PVK) or N -(4-(carbazol-9-yl)phenyl)-3,6-bis(carbazol-9-yl) carbazole (TCCz), phosphorescent organic light-emitting diodes (OLEDs) were fabricated with various device structures. The complex [Cu(mdpbq)(DPEphos)](BF4) exhibits the best device performance. With the device structure of ITO/PEDOT/TCCz:[Cu(mdpbq)(DPEphos)](BF4) (15,wt,%)/TPBI/LiF/Al (III), a current efficiency up to 6.4,cd,A,1 with the Commission Internationale de L'Eclairage (CIE) coordinates of (0.61, 0.39) has been realized. To our best knowledge, this is the first report of efficient mononuclear CuI complexes with red emission. [source] New bis(diphenylphosphino)aniline derivatives: Synthesis and spectroscopic characterizationHETEROATOM CHEMISTRY, Issue 6 2007Nermin Biricik Six new multidentate bis(diphenyl-phosphino)amine [R,N(PPh2)2] ligands have been prepared from the reaction of aniline derivatives, R,NH2, with Ph2PCl in the presence of triethylamine. All of the compounds were obtained in good yields and were characterized by NMR, IR, and microanalysis. © 2007 Wiley Periodicals, Inc. Heteroatom Chem 18:613,616, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20362 [source] Novel Palladium-Catalysed Hydroamination of Myrcene and Catalyst Separation by Thermomorphic Solvent SystemsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 11-12 2010Arno Behr Abstract Hydroamination is an elegant and atom economical reaction to convert alkenes into amines. One of the few technical realisations of this reaction is the hydroamination of myrcene to diethylgeranylamine, an important precursor of (,)-menthol. However, this so-called "Takasago process" is catalysed by high amounts of alkali metals, especially lithium, which makes it a relatively expensive approach. In the present work, the hydroamination of myrcene with morpholine is catalysed by palladium complexes with bidentate ligands such as bis(diphenylphosphino)butane (DPPB) or bis(2-diphenylphosphinophenyl) ether (DPEphos). The systematic optimisation of the reaction parameters under single-phase conditions led to yields of the 1,4-adducts of higher than 90%. The only side products proved to be the telomers of myrcene, whose formation could be decreased by using appropriate reaction conditions. The method of temperature-dependent solvent systems was successfully applied to separate the palladium catalyst from the amines with a palladium leaching lower than 1.0%. [source] Scope and Limitations of Palladium-Catalyzed Cross-Coupling Reactions with Organogold CompoundsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 8 2010A. Stephen Abstract Five different alkenylgold(I) phosphane complexes were prepared and then investigated in [1,1,-bis(diphenylphosphino)ferrocene]palladium(II) dichloride-catalyzed cross-coupling reactions with different aryl halides, heterocyclic halides, an alkenyl halide, an alkynyl halide, allylic substrates, benzyl bromide and an acid chloride. With regard to the halides, the iodides were highly reactive, bromides or chlorides gave significantly reduced yields or failed, allylic acetates failed, too. The cross-coupling partners contained a number of different functional groups, while free carboxylic acids did not deliver cross-coupling products and o,o -disubstituted arenes failed as well, a broad range of other functional groups like nitro groups, nitrile groups, ester groups, ,,,-unsaturated ester groups and lactones, aldehydes, alkoxy groups, pyridyl groups, thienyl groups, unprotected phenols and anilines, even aryl azides were tolerated. The structures of one alkenylgold(I) species and of four of the cross-coupling products were proved by crystal structure analyses. [source] Highly Enantioselective Hydrogenation of Quinoline and Pyridine Derivatives with Iridium-(P-Phos) CatalystADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 6 2010Wei-Jun Tang Abstract The use of a chiral iridium catalyst generated in situ from the (cyclooctadiene)iridium chloride dimer, [Ir(COD)Cl]2, the P-Phos ligand [4,4,-bis(diphenylphosphino)-2,2,,6,6,-tetramethoxy-3,3,-bipyridine] and iodine (I2) for the asymmetric hydrogenation of 2,6-substituted quinolines and trisubstituted pyridines [2-substituted 7,8-dihydroquinolin-5(6H)-one derivatives] is reported. The catalyst worked efficiently to hydrogenate a series of quinoline derivatives to provide chiral 1,2,3,4-tetrahydroquinolines in high yields and up to 96% ee. The hydrogenation was carried out at high S/C (substrate to catalyst) ratios of 2000,50000, reaching up to 4000,h,1 TOF (turnover frequency) and up to 43000 TON (turnover number). The catalytic activity is found to be additive-controlled. At low catalyst loadings, decreasing the amount of additive I2 was necessary to maintain the good conversion. The same catalyst system could also enantioselectively hydrogenate trisubstituted pyridines, affording the chiral hexahydroquinolinone derivatives in nearly quantitative yields and up to 99% ee. Interestingly, increasing the amount of I2 favored high reactivity and enantioselectivity in this case. The high efficacy and enantioselectivity enable the present catalyst system of high practical potential. [source] Axially Chiral Phosphine-Oxazoline Ligands in Silver(I)- Catalyzed Asymmetric Mannich Reaction of Aldimines with TrimethylsiloxyfuranADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 17 2009Hong-Ping Deng Abstract A new asymmetric catalytic system for the Mannich reaction of aldimines with trimethylsiloxyfuran is described. The combination of an axially chiral phosphine-oxazoline ligand (S)-2-[(R)-2,-(diphenylphosphino)-1,1,-binaphthyl-2-yl]-4-phenyl-4,5-dihydrooxazole with silver acetate and 2,2,2-trifluoroacetic acid is a very effective catalytic system in the asymmetric Mannich reaction of various aldimines with trimethylsiloxyfuran in dichloromethane at ,78,°C, affording the corresponding adducts in up to 99% yield, 99:1 (dr) and 99% ee (major diastereoisomer) under mild conditions. [source] Continuous Hydrogen Generation from Formic Acid: Highly Active and Stable Ruthenium CatalystsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 14-15 2009Albert Boddien Abstract The ruthenium-catalyzed decomposition of formic acid was investigated with respect to continuous hydrogen generation and long-term stability of the catalytic systems. A highly active and stable system is presented, which was studied in batch and continuous modes for up to two months. The optimized catalyst system containing N,N -dimethyl- n -hexylamine with an in situ generated catalyst from (benzene)ruthenium dichloride dimer [RuCl2(benzene)]2 and 6 equivalents of 1,2-bis(diphenylphosphino)ethane (dppe) reached at room temperature a total turnover number (TON) of approximatly 260,000 with average turnover frequency (TOF) of about 900,h,1. Only hydrogen and carbon dioxide were detected in the produced gas mixture which makes this system applicable for direct use in fuel cells. [source] Synthesis of Trisubstituted Pyrroles from Rhodium-Catalyzed Alkyne Head-to-Tail Dimerization and Subsequent Gold- Catalyzed CyclizationADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 9 2009Hong Mei Peng Abstract Dimerization of N -protected propargylic amines in a rather rare head-to-tail mode has been achieved under mild conditions with high selectivity using rhodium catalysts. The N -protecting group could be a sulfonyl, carbamate, or carbonyl functionality and (cyclooctadiene)rhodium chloride dimer/1,1,-bis(diphenylphosphino)ferrocene {[Rh(COD)Cl]2/dppf} as well as tris(triphenylphosphine)rhodium chloride [Rh(PPh3)3Cl] proved to be active catalysts. In addition, these functionalized gem -enynes subsequently undergo selective gold(III)-catalyzed intramolecular hydroamination to give trisubstituted pyrroles under mild conditions. [source] Efficient, Nickel-Catalysed Kumada,Tamao,Corriu Cross- Coupling with a Calix[4]arene-Diphosphine LigandADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 9 2009Laure Monnereau Abstract The dynamic complex cis - P,P,-(,5 -cyclopentadienyl)-{5,17-bis(diphenylphosphino)-25,26,27, 28-tetrabenzyloxycalix[4]arene}nickel(II) tetrafluoroborate (2) in which the PNiP plane undergoes a rapid fanning motion was assessed in the cross-coupling reacting between phenylmagnesium bromide (PhMgBr) and aryl halides (ArX). TOFs, of up to 21250 mol(converted ArBr),mol(2),1,h,1, were obtained with electron-rich as well as congested bromoarenes using catalyst loadings as low as 1×10,3,mol%, provided that the reactions were carried out at 100,°C in dioxane with a PhMgBr/ArX ratio of 2:1. The high activities observed contrast with those observed for triphenylphosphine-based catalysts and furthermore, outperforms the fastest diphosphine-based catalysts reported, a behaviour which is likely to rely on a bite angle effect. [source] Copper-Catalyzed Conjugate Addition of Diboron Reagents to ,,,-Unsaturated Amides: Highly Reactive Copper-1,2- Bis(diphenylphosphino)benzene Catalyst SystemADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 6 2009Heesung Chea Abstract An efficient copper catalyst system for the ,-boration of ,,,-unsaturated amides has been developed. Copper-bisphosphine complexes with small bite angles generate efficient catalyst systems for the successful conjugate addition of bis(pinacolato)diboron to a variety ,,,-unsaturated amides under mild conditions. This method was utilized in the formal synthesis of (S)-fluoxetine. [source] Highly Efficient and Versatile Phosphine-Phosphoramidite Ligands for Asymmetric HydrogenationADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 5 2009Matthias Eggenstein Abstract A set of novel phosphine-phosphoramidite ligands possessing two elements of chirality have been prepared through a modular synthetic approach. The ligands (11bS)- N -[2-(diphenylphosphino)phenyl]- N -[(S)-1-phenylethyl]dinaphtho[2,1- d:1,,2,- f][1,3,2]dioxaphosphepin-4-amine [(Sa,Sc)- 1a] and (11bR)- N -[2-(diphenylphosphino)phenyl]- N -[(S)-1-(1-naphthyl)ethyl]dinaphtho[2,1- d:1,,2,- f][1,3,2]dioxaphosphepin-4-amine [(Sa,Sc)- 1b] are unique in providing enantioselectivities ,96% ee and ,94% ee, respectively, in mechanistically distinct hydrogenations of CC, CN and CO double bonds in combination with three different transition metals (rhodium, iridium, and ruthenium, respectively). Particularly remarkable are the enantiomeric excesses up to 97% achieved in the iridium-catalyzed hydrogenation of 2-substituted quinolines, where (11bS)- N -[2-(diphenylphosphino)phenyl]- N -[(S)-1-(naphthalen-1-yl)ethyl]-8,9,10,11, 12,13,14,15-octahydrodinaphtho[2,1- d:1,,2,- f][1,3,2]dioxaphosphepin-4-amine [(Sa,Sc)- 2] proved to be the most selective ligand. Substantially lower ees were obtained with the mismatched diastereomer (Ra,Sc)- 1b and with the N -phenyl-substituted ligand 1c, missing a second element of chirality. [source] Chemoselective Palladium-Catalyzed Reaction in Aqueous Media: Selectivity in the Reaction of Haloanilines with 1,1-Dimethylallyl AlcoholADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 4-5 2007Yuusaku Yokoyama Abstract Palladium-catalyzed reactions of various haloanilines with 1,1-dimethylallyl alcohol were carried out in the presence of a hydrophilic ligand, 3,3,,3,,-phosphinidyne tris(benzenesulfonic acid) trisodium salt (TPPTS), or a lipophilic phosphine ligand, 1,1,-bis(diphenylphosphino)ferrocene (DPPF). The reactions proceeded chemoselectively in aqueous solvent to give C -vinylated products under basic conditions or N -allylated products under neutral conditions in practical yields (up to 79,%). The use of an aqueous solvent played an important role in this chemoselectivity and allowed the development of a one-pot synthesis of 3-methylindole. This chemoselectivity is synthetically useful because the reactive position of haloanilines can be controlled simply by changing the basicity of the reaction medium, which eliminates the need to protect the amino group during the reaction. [source] A Combinatorial Approach to Heterogeneous Asymmetric Aquacatalysis with Amphiphilic Polymer-Supported Chiral Phosphine-Palladium ComplexesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 12-13 2006Yukinari Kobayashi Abstract A library of amphiphlic polystyrene-poly(ethylene glycol) (PS-PEG) resin-supported chiral phosphine ligands was prepared by the split method using porous miniature reactors. A polymeric (R)-2-(diphenylphosphino)binaphthyl (MOP) ligand anchored onto the PS-PEG resin by an (S)-alanine tether unit was identified through the library-based screening to be an effective chiral ligand for the asymmetric palladium-catalyzed ,-allylic substitution under heterogeneous aqueous conditions. [source] The Immobilization of Rhodium-4-(diphenylphosphino)-2- (diphenylphosphinomethyl)-pyrrolidine (Rh-PPM) Complexes: A Systematic StudyADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 12-13 2006Benoît Pugin Abstract A modular toolbox for the immobilization of homogeneous catalysts to various supports is described. It consists of functionalized chiral diphosphines and three different linkers based on isocyanate chemistry and it is used to attach the 4-(diphenylphosphino)-2-(diphenylphosphinomethyl)-pyrrolidine (PPM) ligand to a large variety of soluble, swellable and non-swellable solid organic polymers and to silica gels. As model reaction the hydrogenation of acetamidocinnamic acid derivatives, catalyzed with high enantioselectivity was chosen. Besides information on the usefulness of a particular type of support for synthetic applications, the experiments were also designed to address the question how parameters such as solubility, swellability, cage or pore size and solvent affect the rate and enantioselectivity of an immobilized catalyst. Rhodium complexes of ligands attached to soluble polymers and inorganic supports achieved ees up to 95,% and turnover frequencies between 700 and 1400,h,1, very close to the values of the homogeneous Rh catalyst (ee 95,%, TOF 1320,h,1). Insoluble or strongly cross-linked organic polymers led to catalysts with lower enantioselectivity and activity. PPM ligands attached to water soluble dendrimer fragments allowed hydrogenation in water solution with ees up to 94,%, albeit with much lower activity compared to reactions in methanol with the homogeneous catalyst. [source] Enhanced Hydrogenation Activity and Recycling of Cationic Rhodium Diphosphine Complexes through the Use of Highly Fluorous and Weakly-Coordinating Tetraphenylborate AnionsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 5 2003Broeke, Joep van Abstract The effect of the nature of the anion on the performance of ionic rhodium catalysts has received little attention. Herein it is shown that the use of highly fluorous tetraphenylborate anions can enhance catalyst activity in both conventional and fluorous media. For hydrogenation catalysts of the type [Rh(COD)(dppb)][X] {COD=1,5- cis,cis -cyclooctadiene; dppb=1,4-bis(diphenylphosphino)butane; X=BF4, (1a), [BPh4], (1b), [B{C6H4(SiMe3)-4}4], (1c), [B{C6H3(CF3)2 -3,5}4], (1d), [B{C6H4(SiMe2CH2CH2C6F13)-4}4], (1e), [B{C6H4(C6F13)-4}4], (1f) and [B{C6H3(C6F13)2 -3,5}4], (1,g)} the activity towards the hydrogenation of 1-octene in acetone increased in the order 1c <1b <1e <1a <1d ~ 1f <1g with 1g being twice as active as the commonly applied 1a. Despite the fluorophilic character introduced by the substituted tetraarylborate anions, the presence of some perfluoroalkyl-substituents in the cation was still required for achieving high partition coefficients. Therefore, [Rh(COD)(Ar2PCH2CH2PAr2)][X] {Ar=C6H4(SiMe2CH2CH2C6F13)-4, X=[B{C6H3(C6F13)2 -3,5}4], (3f); Ar=C6H4(SiMe(CH2CH2C6F13)2)-4 and X=[B{C6H4(C6F13)-4}4], (2g)} were prepared, which were active in the hydrogenation of 1-octene, 2g even more so than 3f. Both these highly fluorous catalysts could be recycled with 99% efficiency through fluorous biphasic separation, whereas the corresponding BF4, complex of 2g (2a) did not show any affinity for the fluorous phase. [source] Preparation of ethylene/1-octene copolymers from ethylene stock with tandem catalytic systemJOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2008Tao Jiang Abstract Tandem catalysis offers a novel synthetic route to the production of linear low-density polyethylene. This article reports the use of homogeneous tandem catalytic systems for the synthesis of ethylene/1-octene copolymers from ethylene stock as the sole monomer. The reported catalytic systems involving a highly selective, bis(diphenylphosphino)cyclohexylamine/Cr(acac)3/methylaluminoxane (MAO) catalytic systems for the synthesis of 1-hexene and 1-octene, and a copolymerization metallocene catalyst, rac -Et(Ind)2ZrCl2/MAO for the synthesis of ethylene/1-octene copolymer. Analysis by means of DSC, GPC, and 13C-NMR suggests that copolymers of 1-hexene and ethylene and copolymers of 1-octene and ethylene are produced with significant selectivity towards 1-hexene and 1-octene as comonomers incorporated into the polymer backbone respectively. We have demonstrated that, by the simple manipulation of the catalyst molar ratio and polymerization conditions, a series of branched polyethylenes with melting temperatures of 101.1,134.1°C and density of 0.922,0.950 g cm,3 can be efficiently produced. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Synthesis of [11C- carbonyl]hydroxyureas by a rhodium-mediated carbonylation reaction using [11C]carbon monoxideJOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 5 2006Julien Barletta Abstract [11C]Hydroxyurea has been successfully labelled using [11C]carbon monoxide at low concentration. The decay-corrected radiochemical yield was 38±3%, and the trapping efficiency of [11C]carbon monoxide in the order of 90±5%. This synthesis was performed by a rhodium-mediated carbonylation reaction starting with azidotrimethylsilane and the rhodium complex being made in situ by chloro(1,5-cyclooctadiene)rhodium(I) dimer ([Rh(cod)Cl]2) and 1,2- bis(diphenylphosphino)ethane (dppe). (13C)Hydroxyurea was synthesized using this method and the position of the labelling was confirmed by 13C-NMR. In order to perform accurate LC,MS identification, the derivative 1-hydroxy-3-phenyl[11C]urea was synthesized in a 35±4% decay-corrected radiochemical yield. After 13 µA h bombardment and 21 min synthesis, 1.6 GBq of pure 1-hydroxy-3-phenyl[11C]urea was collected starting from 6.75 GBq of [11C]carbon monoxide and the specific radioactivity of this compound was in the order of 686 GBq/µmol (3.47 nmol total mass). [11C]Hydroxyurea could be used in conjunction with PET to evaluate the uptake of this anticancer agent into tumour tissue in individual patients. Copyright © 2006 John Wiley & Sons, Ltd. [source] Evolution of iron catalysts for effective living radical polymerization: P,N chelate ligand for enhancement of catalytic performancesJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 20 2008Chihiro Uchiike Abstract Iron catalysts were evolved for more active transition metal-catalyzed living radical polymerization through design of the ligands. In situ introduction of P,N chelate-ligands, consisting of hetero-coordinating atoms [phosphine (P) and nitrogene (N)], onto FeBr2 effectively catalyzed living radical polymerization of methyl methacrylate (MMA) in conjunction with a bromide initiator, where the monomer-conversion reached over 90% without dropping the rates and the molecular weights of obtained PMMAs were well controlled. The benign effects of the "hetero-chelation" were demonstrated by comparative experiments with homo-chelate ligands (P,P, N,N), model compounds of the composed coordination site, and the combinations. We successfully achieved an isolation of iron complex with a P,N ligand [FeBr2(DMDPE); DMDPE: (R)- N,N -dimethyl-1-(2-(diphenylphosphino)phenyl)-ethanamine], which was superior to the conventional catalyst [FeBr2(Pn -Bu)2] with respect to controllability and activity, especially at the latter stage. The catalyst was almost quantitatively removed by water washing after polymerization. It was also effective for living polymerization of styrene. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 6819,6827, 2008 [source] Generation and interrogation of a pure nuclear spin state by parahydrogen-enhanced NMR spectroscopy: a defined initial state for quantum computationMAGNETIC RESONANCE IN CHEMISTRY, Issue 3 2005D. Blazina Abstract We describe a number of studies used to establish that parahydrogen can be used to prepare a two-spin system in a pure state, which is suitable for implementing NMR quantum computation. States are generated by pulsed and continuous-wave (CW) UV laser initiation of a chemical reaction between Ru(CO)3(L2) [where L2 = dppe = 1,2-bis(diphenylphosphino)ethane or L2 = dpae = 1,2-bis(diphenylarsino)ethane] with pure parahydrogen (generated at 18 K). This process forms Ru(CO)2(dppe)(H)2 and Ru(CO)2(dpae)(H)2 on a sub-microsecond time-scale. With the pulsed laser, the spin state of the hydride nuclei in Ru(CO)2(dppe)(H)2 has a purity of 89.8 ± 2.6% (from 12 measurements). To achieve comparable results by cooling would require a temperature of 6.6 mK, which is unmanageable in the liquid state, or an impractical magnetic field of 0.44 MT at room temperature. In the case of CW initiation, reduced state purities are observed due to natural signal relaxation even when a spin-lock is used to prevent dephasing. When Ru(CO)3(dpae) and pulsed laser excitation are utilized, the corresponding dihydride product spin state purity was determined as 106 ± 4% of the theoretical maximum. In other words, the state prepared using Ru(CO)3(dpae) as the precursor is indistinguishable from a pure state. Copyright © 2004 John Wiley & Sons, Ltd. [source] Preparation and use of polymer-supported chiral ruthenium complex catalystPOLYMERS FOR ADVANCED TECHNOLOGIES, Issue 11-12 2001Jing-Xing Gao Abstract The chiral diiminodiphosphine ligand, [(R,R)-P2N2],has been prepared by the condensation of o -(diphenylphosphino)benzaldehyde and 1,2-diaminocyclohexane. [(R,R)-P2N2] was reduced with excess NaBH4 in refluxing ethanol to afford the corresponding diaminodiphosphine 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 dicyclohexylcarbodiimine 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-phenylethanol in 95% yield and 96% ee. The catalyst was reused twice with some loss of activity and enantioselectivity. Copyright © 2001 John Wiley & Sons, Ltd. [source] Palladium-Catalyzed Coupling Reactions: Carbonylative Heck Reactions To Give Chalcones,ANGEWANDTE CHEMIE, Issue 31 2010Xiao-Feng Wu Chalkone leicht gemacht: Carbonylierende Heck-Reaktionen von Aryl- oder Alkenyltriflaten mit Kohlenmonoxid und aromatischen Olefinen gelingen in Gegenwart von Palladiumkatalysatoren (siehe Schema; dppp=1,3-Bis(diphenylphosphino)propan, Tf=Triflat; R=Aryl, Vinyl). Dieses Verfahren schließt eine Lücke zwischen carbonylierenden Suzuki- und Sonogashira-Reaktionen. [source] [,-4,5-Bis(diphenylphosphino)-9,9-dimethylxanthene]bis[(trifluoroacetato)gold(I)] and its dichloromethane 0.58-solvateACTA CRYSTALLOGRAPHICA SECTION C, Issue 5 2010Tünde Tunyogi The dinuclear AuI complex containing the 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (xantphos) ligand and trifluoroacetate anions exists in a solvent-free form, [,-4,5-bis(diphenylphosphino)-9,9-dimethylxanthene]bis[(trifluoroacetato)gold(I)], [Au2(C2F3O2)2(C39H32OP2)], (I), and as a dichloromethane solvate, [Au2(C2F3O2)2(C39H32OP2)]·0.58CH2Cl2, (II). The trifluoroacetate anions are coordinated to the AuI centres bridged by the xantphos ligand in both compounds. The AuI atoms are in distorted linear coordination environments in both compounds. The phosphine substituents are in a syn arrangement in the xantphos ligand, which facilitates the formation of short aurophilic Au...Au interactions of 2.8966,(8),Å in (I) and 2.9439,(6),Å in (II). [source] Different intermolecular interactions in azido[2-(diphenylphosphino)benzaldehyde semicarbazonato-,2P,N1,O]nickel(II)ACTA CRYSTALLOGRAPHICA SECTION C, Issue 7 2009Sladjana B. Novakovi The title compound, [Ni(C20H17N3OP)(N3)], is the first complex with a semicarbazide-based ligand having a P atom as one of the donors. The influence of the P atom on the deformation of the coordination geometry of the NiII ion is evident but less expressed than in the cases of complexes with analogous seleno- and thiosemicarbazide ligands. The torsion angles involving the two bonds formed by the P atom within the six-membered chelate ring have the largest values [C,P,Ni,N = 24.3,(2)° and C,C,P,Ni = ,24.2,(4)°], suggesting that the P atom considerably influences the conformation of the ring. Two types of N,H...N hydrogen bond connect the complex units into chains. [source] Synthesis and characterization of transition metal complexes of thiophene-2-methylamine: X-ray crystal structure of palladium (II) and platinum (II) complexes and use of palladium(II) complexes as pre-catalyst in Heck and Suzuki cross-coupling reactionsAPPLIED ORGANOMETALLIC CHEMISTRY, Issue 11 2009Murat Aydemir Abstract The reactions of thiophene-2-(N -diphenylphosphino)methylamine, Ph2PNHCH2 -C4H3S, 1 and thiophene-2-[N,N -bis(diphenylphosphino)methylamine], (Ph2P)2NCH2 -C4H3S, 2, with MCl2(cod) (M = Pd, Pt; cod = 1,5-cyclooctadiene) or [Cu(CH3CN)4]PF6 yields the new complexes [M(Ph2PNHCH2 -C4H3S)2Cl2], M = Pd 1a, Pt 1b, [Cu(Ph2PNHCH2 -C4H3S)4]PF6, 1c, and [M(Ph2P)2NCH2 -C4H3S)Cl2], M = Pd 2a, Pt 2b, {Cu[(Ph2P)2NCH2 -C4H3S]2}PF6, 2c, respectively. The new compounds were isolated as analytically pure crystalline solids and characterized by 31P-, 13C-, 1H-NMR and IR spectroscopy and elemental analysis. Furthermore, the solid-state molecular structures of representative palladium and platinum complexes of bis(phosphine)amine, 2a and 2b, respectively, were determined using single crystal X-ray diffraction analysis. The palladium complexes were tested as potential catalysts in the Heck and Suzuki cross-coupling reactions. Copyright © 2009 John Wiley & Sons, Ltd. [source] Synthesis and characterizations of N,N,-bis(diphenylphosphino)-2-(aminomethyl)aniline derivatives: application of a palladium(II) complex as pre-catalyst in Heck and Suzuki cross-coupling reactionsAPPLIED ORGANOMETALLIC CHEMISTRY, Issue 3 2009Murat Aydemir Abstract The reaction of 2-(aminomethyl)aniline with 2 equivalents of PPh2Cl in the presence of Et3N, proceeds in CH2Cl2 to give N,N,-bis(diphenylphosphino)-2-(aminomethyl)aniline 1 in good yield. Oxidation of 1 with aqueous H2O2, elemental sulfur or gray selenium gave the corresponding oxide, sulfide and selenide dichalcogenides [Ph2P(E)NHC6H4CH2NHP(E)Ph2] (E: O, 2a; S, 2b; Se, 2c), respectively. The reaction of [Ph2PNHC6H4CH2NHPPh2] with PdCl2(cod), PtCl2(cod) and [Cu(MeCN)4]PF6 gave the corresponding chelate complexes, PdCl21, PtCl21 and [Cu(1)2]PF6. The new compounds were fully characterized by NMR, IR spectroscopy and elemental analysis. The catalytic activity of the Pd(II) complex was tested in the Suzuki coupling and Heck reactions. The Pd(II) complex catalyzes the Suzuki coupling and Heck reaction, affording biphenyls and stilbenes respectively, in good yields. Copyright © 2009 John Wiley & Sons, Ltd. [source] Palladium,dppb,borate-catalyzed regioselective synthesis of cinnamate esters by alkoxycarbonylation of phenylacetyleneAPPLIED ORGANOMETALLIC CHEMISTRY, Issue 10 2008Jimoh Tijani Abstract The regioselective alkoxycarbonylation of phenylacetylene into various cinnamate esters was achieved with a catalyst system formed from palladium (II), 1,4-bis(diphenylphosphino) butane (dppb) and salicylborate complex in acetonitrile as a solvent. The influence of various parameters on the overall conversion of phenylacetylene and the selectivity of the reaction were studied systematically by varying the type of palladium complex, acids promoter, CO pressure, temperature and the reaction time. This investigation allowed us to obtain the predominant formation of cinnamate esters with excellent selectivity (90,96%). Copyright © 2008 John Wiley & Sons, Ltd. [source] Efficient palladium,ferrocenylphosphine catalytic systems for allylic amination of monoterpene derivativesAPPLIED ORGANOMETALLIC CHEMISTRY, Issue 12 2006Duc Hanh Nguyen Abstract Ferrocenylphosphines added to [Pd(µ-Cl)(,3 -C3H5)]2 dimeric precursor produce efficient catalysts to effect the allylic amination of terpenic allylacetates. Particularly convenient are tetrakis(diphenylphosphino)ferrocene and 1,1,-bis(diphenylphosphino)ferrocene, which allow the amination of allylacetates with good to excellent selectivity, and have turnover numbers as high as 80 000, for instance, for the formation of allylaniline. Herein, we report on reactions that selectively transform geranylacetate, nerylacetate, linalylacetate and perillylacetate into the corresponding allylic amines. These preparative methods give facile access to various products of great potential industrial interest. Copyright © 2006 John Wiley & Sons, Ltd. [source] (R,R)-Tricarbonyl{,6 -1-(diphenylphosphino)-2-[1-(diphenylphosphino)ethyl]benzene}chromium(0), (R,R)-tricarbonyl-1,3C -{,-1(,6):2,2P,P,-1-(diphenylphosphino)-2-[1-(diphenylphosphino)ethyl]benzene}[2(,4)-norbornadiene]chromium(0)rhodium(I) tetrafluoroborate methanol 0.75-solvate and (R,R)-tricarbonyl-1,3C -{,-1(,6):2,2P,P,-1-(diphenylphosphino)-2-[1-(diphenylphosphino)ethyl]benzene}[2(,4)-(Z,Z)-cycloocta-1,5-diene]chromium(0)rhodium(I) tetrafluoroborate methanol 1.5-solvateACTA CRYSTALLOGRAPHICA SECTION C, Issue 10 2004Wolfgang Braun The title mononuclear chromium compound, [Cr(C32H28P2)(CO)3], (I), and its rhodium complexes [CrRh(C7H8)(C32H28P2)(CO)3]BF4·0.75CH4O, (II), and [CrRh(C8H12)(C32H28P2)(CO)3]BF4·1.5CH4O, (III), prepared as a ligand and precatalysts, respectively, for application in asymmetric homogeneous hydrogenation, have been studied by single-crystal X-ray diffraction. The structures of the free and complexed ligand are compared. It was found that the backbone of the ligand remains rigid on coordination, while only minor conformational changes of its side chains are observed. Both elements of central and planar chirality seem to build a well defined chiral environment for stereoselective catalysis. [source] Crystallographic report: A synthetic precursor for hetero-binuclear metal complexes, [Ru(bpy)(dppy)2(CO)2](PF6)2 (bpy = 2,2,-bipyridine, dppy = 2-(diphenylphosphino)pyridine)APPLIED ORGANOMETALLIC CHEMISTRY, Issue 8 2004Dai Ooyama Abstract In the title complex, [Ru(bpy)(dppy)2(CO)2](PF6)2 (bpy = 2,2,-bipyridine, dppy = 2-(diphenylphosphino)pyridine), the ruthenium atom exhibits a slightly distorted octahedral coordination with the carbonyl ligands in cis positions. In addition, two dppy ligands coordinate to the ruthenium center through the phosphorus atoms in mutually trans positions and two pyridyl nitrogen atoms of the dppy direct toward two carbonyl ligands. Copyright © 2004 John Wiley & Sons, Ltd. 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