101
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Sakthivel A, Raudaschl-Sieber G, Kühn FE. Heterogenization of an organorhenium(vii) oxide on a modified mesoporous molecular sieve. Dalton Trans 2006:468-72. [PMID: 16395446 DOI: 10.1039/b507742g] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A novel route to heterogenize an organorhenium(VII) oxide, derived from the well examined methyltrioxorhenium(VII) (MTO), on the surface of an iodosilane-modified MCM-41 is applied. The successful grafting of the -CH(2)-ReO3 moiety on the surface was evidenced by 1H CP MAS NMR, IR spectroscopy, TG-MS, and elemental analysis. XRD and TEM analyses confirm the retaining of long-range ordering throughout the grafting process. The rhenium loading of the mesoporous material after heterogenization of MTO is found to be 1.25 wt%. Despite containing formally a derivative of the very sensitive benzyltrioxorhenium(VII) the material is stable at room temperature and applicable as a heterogeneous catalyst for aldehyde olefination reactions.
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Affiliation(s)
- Ayyamperumal Sakthivel
- Lehrstuhl für Anorganische Chemie der Technischen Universität München, Lichtenbergstrasse 4, D-85747, Garching bei München, Germany
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102
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Saladino R, Fiani C, Belfiore MC, Gualandi G, Penna S, Mosesso P. Methyltrioxorhenium catalysed synthesis of highly oxidised aryltetralin lignans with anti-topoisomerase II and apoptogenic activities. Bioorg Med Chem 2005; 13:5949-60. [PMID: 16112581 DOI: 10.1016/j.bmc.2005.07.017] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2005] [Revised: 07/01/2005] [Accepted: 07/08/2005] [Indexed: 11/18/2022]
Abstract
A novel and efficient procedure to prepare highly oxidised aryltetralin lignans, such as isopodophyllotoxone and (-)-aristologone derivatives, by oxidation of podophyllotoxin and galbulin with methylrhenium trioxide (MTO) and novel MTO heterogeneous catalysts is reported. It is noteworthy that in the case of isopodophyllotoxone derivatives the functionalisation of the C-4 position of the C-ring and the ring-opening of the D-lactone moiety increased the activity against topoisomerase II while causing the undesired inhibition of tubulin polymerisation to disappear. The novel (-)-aristologone derivatives showed apoptogenic activity against resistant human lymphoma cell lines.
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Affiliation(s)
- Raffaele Saladino
- INFM, della Tuscia, via S.Camillo De Lellis, I-01100 Viterbo, Italy.
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103
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Du G, Espenson JH. Oxidation of vanadium(III) by hydrogen peroxide and the oxomonoperoxo vanadium(V) ion in acidic aqueous solutions: a kinetics and simulation study. Inorg Chem 2005; 44:5514-22. [PMID: 16022550 DOI: 10.1021/ic050502j] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The reaction between vanadium(III) and hydrogen peroxide in aqueous acidic solutions was investigated. The rate law shows first-order dependences on both vanadium(III) and hydrogen peroxide concentrations, with a rate constant, defined in terms of -d[H(2)O(2)]/dt, of 2.06 +/- 0.03 L mol(-)(1) s(-)(1) at 25 degrees C; the rate is independent of hydrogen ion concentration. The varying reaction stoichiometry, the appreciable evolution of dioxygen, the oxidation of 2-PrOH to acetone, and the inhibition of acetone formation by the hydroxyl radical scavengers, dimethyl sulfoxide and sodium benzoate, point to a Fenton mechanism as the predominant pathway in the reaction. Methyltrioxorhenium(VII) does not appear to catalyze this reaction. A second-order rate constant for the oxidation of V(3+) by OV(O(2))(+) was determined to be 11.3 +/- 0.3 L mol(-)(1) s(-)(1) at 25 degrees C. An overall reaction scheme consisting of over 20 reactions, in agreement with the experimental results and literature reports, was established by kinetic simulation studies.
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Affiliation(s)
- Guodong Du
- Department of Chemistry, Iowa State University, Ames, Iowa 50011, USA
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104
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Nabavizadeh SM, Rashidi M. Lewis Acidity of Methyltrioxorhenium(VII) (MTO) Based on the Relative Binding Strengths of N-Donors. J Am Chem Soc 2005; 128:351-7. [PMID: 16390165 DOI: 10.1021/ja056505c] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
This article presents a sigma acceptor strength scale for methyltrioxorhenium(VII) (MTO), one of the most versatile and useful high oxidation state organometallics ever described. The spectrophotometric titration of MTO with a series of N-donor bases in CCl(4) gives formation constants (K(f)) and enthalpies for the adduct formation reactions. An excellent linearity of log K(f) with respect to the Hammett sigma constants of the substituents on the ligands was observed. The resulting rho constant is proposed to be a good indication of the Lewis acidity of MTO. The enthalpies of adduct formation of N-donors with MTO also fit the ECW model to predict the values of E(A) and C(A) parameters for MTO. The parameters can be used to predict an acidity scale for MTO. These parameters also allow the chemists to predict and correlate quantitatively the enthalpies of MTO. Lewis base interactions. Significant chemical insights result from the fit of the data to the ECW model.
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Affiliation(s)
- S Masoud Nabavizadeh
- Department of Chemistry, College of Sciences, Shiraz University, Shiraz 71454, Iran.
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105
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González R. LM, Villa de P. AL, Montes de C. C, Gelbard G. Immobilization of methyltrioxorhenium onto tertiary amine and pyridine N-oxide resins. REACT FUNCT POLYM 2005. [DOI: 10.1016/j.reactfunctpolym.2005.01.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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106
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Chiral monomeric organorhenium(VII) and organomolybdenum(VI) compounds as catalysts for chiral olefin epoxidation reactions. ACTA ACUST UNITED AC 2005. [DOI: 10.1016/j.tetasy.2005.09.021] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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107
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Kirillov A, Haukka M, Kirillova M, Pombeiro A. Single-Pot Ethane Carboxylation Catalyzed by New Oxorhenium(V) Complexes with N,O Ligands. Adv Synth Catal 2005. [DOI: 10.1002/adsc.200505092] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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108
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109
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Kirillov AM, Haukka M, Guedes da Silva MFC, Pombeiro AJL. Preparation and Crystal Structures of Benzoylhydrazido- and-diazenidorhenium Complexes with N,O-Ligands and Their Catalytic Activity Towards Peroxidative Oxidation of Cycloalkanes. Eur J Inorg Chem 2005. [DOI: 10.1002/ejic.200400991] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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110
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Crestini C, Pro P, Neri V, Saladino R. Methyltrioxorhenium: a new catalyst for the activation of hydrogen peroxide to the oxidation of lignin and lignin model compounds. Bioorg Med Chem 2005; 13:2569-78. [DOI: 10.1016/j.bmc.2005.01.049] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2004] [Accepted: 01/21/2005] [Indexed: 10/25/2022]
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111
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Bianchini G, Crucianelli M, Angelis FD, Neri V, Saladino R. Highly efficient C–H insertion reactions of hydrogen peroxide catalyzed by homogeneous and heterogeneous methyltrioxorhenium systems in ionic liquids. Tetrahedron Lett 2005. [DOI: 10.1016/j.tetlet.2005.02.056] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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112
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Petrovski Ž, Braga SS, Santos AM, Rodrigues SS, Gonçalves IS, Pillinger M, Kühn FE, Romão CC. Synthesis and characterization of the inclusion compound of a ferrocenyldiimine dioxomolybdenum complex with heptakis-2,3,6-tri-O-methyl-β-cyclodextrin. Inorganica Chim Acta 2005. [DOI: 10.1016/j.ica.2004.11.032] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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113
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A novel and efficient catalytic epoxidation of olefins and monoterpenes with microencapsulated Lewis base adducts of methyltrioxorhenium. Tetrahedron 2005. [DOI: 10.1016/j.tet.2004.11.065] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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114
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Nabavizadeh SM, Akbari A, Rashidi M. Solvent effect on the adduct formation of methyltrioxorhenium (MTO) and pyridine: enthalpy and entropy contributions. Dalton Trans 2005:2423-7. [PMID: 15995752 DOI: 10.1039/b503870g] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
1:1 adduct formation between methyltrioxorhenium (MTO) and pyridine in different solvents (n-hexane, benzene, chloroform, ethyl acetate, dichloromethane and acetone) was studied using spectrophotometric techniques. The formation constants were determined from the absorbance change of the adduct versus pyridine concentration. The values of the formation constants vary from 114.5 to 752.5 L mol(-1) at T= 20 degrees C depending on the dielectric constant of the solvent (epsilon(r) = 1.89-20.7). Enthalpy and entropy changes during the adduct formation reactions were determined from van't Hoff plots. The measured enthalpy change of -37.0 to -22.2 kJ mol(-1) depends on epsilon(r), which is explained by Onsager's reaction field theory. The measured entropy change ranges from -71.2 to -36.6 J K(-1) mol(-1), and the dependence on the solvent is discussed in terms of the solvation effect.
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Affiliation(s)
- S Masoud Nabavizadeh
- Department of Chemistry, College of Sciences, Shiraz University, Shiraz, Iran 71454.
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115
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Nabavizadeh SM. Thermodynamic studies of the binding of bidentate nitrogen donors with methyltrioxorhenium (MTO) in CHCl3 solution. Dalton Trans 2005:1644-8. [PMID: 15852113 DOI: 10.1039/b502505b] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Methyltrioxorhenium (MTO) adduct formation with bidentate nitrogen donors 2,2'-bipyridine (bpy), 4,4'-dimethyl-2,2'-bipyridine (Me(2)bpy), 4,4'-di-tert-butyl-2,2'-bipyridine (tBu2bpy), 1,10-phenanthroline (phen), 5-methyl-1,10-phenanthroline (5-Mephen), 5-chloro-1,10-phenanthroline (5-Clphen), 4,7-dimethyl-1,10-phenanthroline (Me2phen) has been studied at different temperatures in CHCl3 solution. Spectrophotometeric measurements have been carried out to obtain the thermodynamic parameters. All complexes are enthalpy stabilized whereas the entropy changes counteract the adduct formation. The results are discussed in terms of different basicities of the bidentate N-donors.
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Affiliation(s)
- S Masoud Nabavizadeh
- Department of Chemistry, College of Sciences, Shiraz University, Shiraz, Iran 71454.
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116
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Kühn FE, Santos AM, Herrmann WA. Organorhenium(vii) and organomolybdenum(vi) oxides: syntheses and application in olefin epoxidation. Dalton Trans 2005:2483-91. [PMID: 16025165 DOI: 10.1039/b504523a] [Citation(s) in RCA: 136] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The first members of the classes of the organorhenium(VII) oxides and organomolybdenum(VI) oxides were described during the 1960s and 1970s. However, despite the fact that methyltrioxorhenium(VII)(MTO) is probably the best examined organometallic oxide known, many of its derivatives as well as the Mo congeners were not tested for any application. Nevertheless, it is known that several organomolybdenum oxides, particularly those of formula eta5-(C5R5)MoO2Cl and eta5-(C5R5)MoO2R' are powerful epoxidation catalysts if applied together with tert-butylhydroperoxide (TBHP). MTO catalyzes a broad variety of organic reactions, among them being olefin epoxidation--in this case with the "green" oxidant H2O2- the most thoroughly examined. The heterogenization of the molybdenum compounds as well as of MTO both on carrier materials and in ionic liquids has already been achieved and it is to be expected that a suitable modification of the organic ligands will lead to applications in chiral catalysis in the near future.
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Affiliation(s)
- Fritz E Kühn
- Lehrstuhl für Anorganische Chemie der Technischen Universität München, Lichtenbergstrasse 4, D-85747, Garching bei München, Germany.
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117
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Cai Y, Espenson JH. Catalysis by Methyltrioxorhenium(VII): Reduction of Hydronium Ions by Europium(II) and Reduction of Perchlorate Ions by Europium(II) and Chromium(II). Inorg Chem 2004; 44:489-95. [PMID: 15679376 DOI: 10.1021/ic048669k] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The title reactions occur stepwise, the first and fastest being MeReO3 + Eu2+ --> Re(VI) + Eu3+ (k298 = 2.7 x 10(4) L mol(-1) s(-1)), followed by rapid reduction of Re(VI) by Eu2+ to MeReO2. The latter species is reduced by a third Eu2+ to Re(IV), a metastable species characterized by an intense charge transfer band, epsilon410 = 910 L mol(-1) cm(-1) at pH 1; the rate constant for its formation is 61.3 L mol(-1) s(-1), independent of [H+]. Yet another reduction step occurs, during which hydrogen is evolved at a rate v = k[Re(IV)][Eu2+][H+](-1), with k = 2.56 s(-1) at mu = 0.33 mol L(-1). The 410 nm Re(IV) species bears no ionic charge on the basis of the kinetic salt effect. We attribute hydrogen evolution to a reaction between H-ReVO and H3O+, where the hydrido complex arises from the unimolecular rearrangement of Re(III)-OH in a reaction that cannot be detected directly. Chromium(II) ions do not evolve H2, despite E(Cr) degrees approximately E(EU) degrees. We attribute this lack of reactivity to the Re(IV) intermediate being captured as [Re(IV)-O-Cr(III)]2+, with both metals having substitutionally inert d3 electronic configurations. Hydrogen evolution occurs in chloride or triflate media; with perchlorate present, MeReO2 reduces perchlorate to chloride, as reported previously [Abu-Omar, M. M.; Espenson, J. H. Inorg. Chem. 1995, 34, 6239-6240].
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Affiliation(s)
- Yang Cai
- Ames Laboratory, Department of Chemistry, Iowa State University, Ames, Iowa 50011, USA
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118
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Lazzaro F, Crucianelli M, De Angelis F, Neri V, Saladino R. A novel oxidative side-chain transformation of α-amino acids and peptides by methyltrioxorhenium/H2O2 system. Tetrahedron Lett 2004. [DOI: 10.1016/j.tetlet.2004.10.074] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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119
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Molybdenum and tungsten complexes of composition (η5-C5R5)MR′(CO)3 and their use as olefin epoxidation catalyst precursors. ACTA ACUST UNITED AC 2004. [DOI: 10.1016/j.molcata.2004.07.023] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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120
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D’Accolti L, Fiorentino M, Fusco C, Crupi P, Curci R. Selective oxidation of acetylenic 1,4-diols with dioxiranes in comparison with the methyltrioxorhenium–hydrogen peroxide oxidant. Tetrahedron Lett 2004. [DOI: 10.1016/j.tetlet.2004.09.110] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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121
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Kühn FE, Scherbaum A, Herrmann WA. Methyltrioxorhenium and its applications in olefin oxidation, metathesis and aldehyde olefination. J Organomet Chem 2004. [DOI: 10.1016/j.jorganchem.2004.08.018] [Citation(s) in RCA: 171] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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122
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Bianchini G, Crucianelli M, De Angelis F, Neri V, Saladino R. A novel catalyzed C–H insertion reactions of hydrogen peroxide by poly(4-vinylpyridine)/methyltrioxorhenium systems. Tetrahedron Lett 2004. [DOI: 10.1016/j.tetlet.2004.01.083] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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123
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Methyltrioxorhenium catalyzed oxidation of 1,2-diols to 1,2-diketones using hydrogen peroxide as oxidant. Tetrahedron Lett 2004. [DOI: 10.1016/j.tetlet.2003.11.131] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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124
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Jain SL, Sharma VB, Sain B. Methyltrioxorhenium Catalyzed Oxidative Cleavage of α-Hydroxycarbonyl Compounds to Carboxylic Acids with Hydrogen Peroxide. SYNTHETIC COMMUN 2003. [DOI: 10.1081/scc-120026309] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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125
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Koshino N, Espenson JH. Kinetics and mechanism of oxygen atom transfer from methyl phenyl sulfoxide to triarylphosphines catalyzed by an oxorhenium(V) dimer. Inorg Chem 2003; 42:5735-42. [PMID: 12950224 DOI: 10.1021/ic034322q] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
An oxorhenium(V) dimer, [PMeReO(mtp)](2), D, where mtpH(2) is 2-(mercaptomethyl)thiophenol, catalyzes oxygen atom transfer reaction from methyl phenyl sulfoxide to triarylphosphines. Kinetic studies in benzene-d(6) at 23 degrees C indicate that the reaction takes place through the formation of an adduct between D and sulfoxide. The equilibrium constants, K(DL), for adduct formation were determined by spectrophotometric titration, and the values of K(DL) for MeS(O)C(6)H(4)-4-R were obtained as 14.1(2), 5.7(1), and 2.1(1) for R = Me, H, and Br, respectively. Following sulfoxide binding, oxygen atom transfer occurs with either internal or external nucleophilic assistance. Because [MeReO(mtp)](2) is a much more reactive catalyst than its monomerized form, MeReO(mtp)PPh(3), loss of the active catalyst during the time course of the reaction must be taken into account as a part of the kinetic analysis. As it happens, sulfoxide catalyzes monomerization. Monomerization by triarylphosphines was also studied in the presence of sulfoxide, and a mechanism for that reaction was also proposed. Both the phosphine-assisted monomerization and the phosphine-assisted pathway for oxygen atom transfer involve transition states with ternary components, D, sulfoxide, and phosphine, which we suggest are structural isomers of one another.
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Affiliation(s)
- Nobuyoshi Koshino
- Ames Laboratory and Department of Chemistry, Iowa State University of Science and Technology, Ames, Iowa 50011, USA
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126
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127
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Nabavizadeh SM. Adduct formation of methyltrioxorhenium with mono- and bidentate nitrogen donors: formation constants. Inorg Chem 2003; 42:4204-8. [PMID: 12817981 DOI: 10.1021/ic0343408] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The coordination of N-donor ligands to MTO (methyltrioxorhenium) is governed by both electronic and steric effects. For example, the binding constant of pyridine to MTO is 196.6 L mol(-)(1), whereas that of the better donor 4-picoline is 732 L mol(-)(1) and that of the sterically encumbered 2,6-di-tert-butyl-4-methylpyridine is <1 L mol(-)(1). Equilibrium constants have been evaluated for this reaction, MTO + L = MTO.L, where L comprises mono- and bidentate N-donor ligands. The values of log K for monodentate ligands range from <0 for 2-substituted pyridines to 3.3 for 1-butylimidazole and for bidentate ligands from 2.2 for 2,2'-bipyridine to 5.27 for 4,7-dimethyl-1,10-phenanthroline at 25 degrees C in chloroform. A successful correlation of log K with pK(a) of L was realized except in the case of 2-substituted ligands, where steric effects make K smaller than expected from the proton basicity of L.
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Affiliation(s)
- S Masoud Nabavizadeh
- Department of Chemistry, College of Sciences, Shiraz University, Shiraz, Iran 71454.
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128
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Abrantes M, Santos AM, Mink J, Kühn FE, Romão CC. A Simple Entry to (η5-C5R5)chlorodioxomolybdenum(VI) Complexes (R = H, CH3, CH2Ph) and Their Use as Olefin Epoxidation Catalysts. Organometallics 2003. [DOI: 10.1021/om0300023] [Citation(s) in RCA: 136] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Marta Abrantes
- Instituto de Tecnologia Química e Biológica da Universidade Nova de Lisboa, Quinta do Marquês, EAN, Apt 127, 2781-901 Oeiras, Portugal, Anorganisch-chemisches Institut der Technischen Universität München, Lichtenberstrasse 4, D-85747 Garching bei München, Germany, Institute of Isotope and Surface Chemistry, Chemical Research Center of the Hungarian Academy of Sciences, PO Box 77, H-1525 Budapest, Hungary, Vezprém University, PO Box 158, H-8201 Vezprém, Hungary
| | - Ana M. Santos
- Instituto de Tecnologia Química e Biológica da Universidade Nova de Lisboa, Quinta do Marquês, EAN, Apt 127, 2781-901 Oeiras, Portugal, Anorganisch-chemisches Institut der Technischen Universität München, Lichtenberstrasse 4, D-85747 Garching bei München, Germany, Institute of Isotope and Surface Chemistry, Chemical Research Center of the Hungarian Academy of Sciences, PO Box 77, H-1525 Budapest, Hungary, Vezprém University, PO Box 158, H-8201 Vezprém, Hungary
| | - Janos Mink
- Instituto de Tecnologia Química e Biológica da Universidade Nova de Lisboa, Quinta do Marquês, EAN, Apt 127, 2781-901 Oeiras, Portugal, Anorganisch-chemisches Institut der Technischen Universität München, Lichtenberstrasse 4, D-85747 Garching bei München, Germany, Institute of Isotope and Surface Chemistry, Chemical Research Center of the Hungarian Academy of Sciences, PO Box 77, H-1525 Budapest, Hungary, Vezprém University, PO Box 158, H-8201 Vezprém, Hungary
| | - Fritz E. Kühn
- Instituto de Tecnologia Química e Biológica da Universidade Nova de Lisboa, Quinta do Marquês, EAN, Apt 127, 2781-901 Oeiras, Portugal, Anorganisch-chemisches Institut der Technischen Universität München, Lichtenberstrasse 4, D-85747 Garching bei München, Germany, Institute of Isotope and Surface Chemistry, Chemical Research Center of the Hungarian Academy of Sciences, PO Box 77, H-1525 Budapest, Hungary, Vezprém University, PO Box 158, H-8201 Vezprém, Hungary
| | - Carlos C. Romão
- Instituto de Tecnologia Química e Biológica da Universidade Nova de Lisboa, Quinta do Marquês, EAN, Apt 127, 2781-901 Oeiras, Portugal, Anorganisch-chemisches Institut der Technischen Universität München, Lichtenberstrasse 4, D-85747 Garching bei München, Germany, Institute of Isotope and Surface Chemistry, Chemical Research Center of the Hungarian Academy of Sciences, PO Box 77, H-1525 Budapest, Hungary, Vezprém University, PO Box 158, H-8201 Vezprém, Hungary
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129
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Sharma VB, Jain SL, Sain B. Methyltrioxorhenium catalyzed aerobic oxidation of organonitrogen compounds. Tetrahedron Lett 2003. [DOI: 10.1016/s0040-4039(03)00639-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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130
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Santos AM, Romão CC, Kühn FE. (Eta2-alkyne)methyl(dioxo)rhenium complexes as aldehyde-olefination catalysts. J Am Chem Soc 2003; 125:2414-5. [PMID: 12603128 DOI: 10.1021/ja021315c] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Complexes CH3ReO2L (L = 2-butyne, 3-hexyne, diphenylacetylene) are catalysts for the olefination of aldehydes, using 4-nitrobenzaldehyde (4-nba) as the standard aldehyde and ethyldiazoacetate (eda) as the diazo compound. Spectroscopic studies including in situ 31P, 17O, 13C, and 1H NMR spectroscopy are used to elucidate the mechanism and the nature of the active species. One of the key steps of the mechanism is the rapid formation of phosphazine at the beginning of the cycle and its subsequent reaction with the metal dioxide complex to form the catalytically active carbene species.
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Affiliation(s)
- Ana M Santos
- Instituto de Tecnologia Química e Biológica da Universidade Nova de Lisboa, Quinta do Marquês, EAN, Apt 127, 2781-901 Oeiras, Portugal
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Armstrong A. 2 Synthetic methods : Part (ii) Oxidation and reduction methods. ACTA ACUST UNITED AC 2003. [DOI: 10.1039/b212010k] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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133
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Kühn FE, Xue WM, Al-Ajlouni A, Santos AM, Zang S, Romão CC, Eickerling G, Herdtweck E. Synthesis and catalytic application of octahedral lewis base adducts of dichloro and dialkyl dioxotungsten(VI). Inorg Chem 2002; 41:4468-77. [PMID: 12184764 DOI: 10.1021/ic0200085] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Complexes of the composition W(O)(2)(Cl)(2)L(2) and W(O)(2)(R)(2)L(2) (R = Me, Et; L(2) = bidentate Lewis base ligand) have been prepared and are fully characterized (including an exemplary X-ray crystal structure of W(O)(2)(Cl)(2)(4,4'-di-tert-butyl-2,2'-bipyridine)). This latter compound crystallizes in the orthorhombic space group P2(1)2(1)2(1) with a = 8.3198(1) A, b = 13.3224(2) A, c = 18.0415(2) A, and Z = 4. The title complexes are applied as catalysts in olefin epoxidation catalysis with tert-butyl hydroperoxide (TBHP) as the oxidizing agent. The W(VI) complexes display only moderate turnover frequencies but can be reused several times without loss of catalytic activity. The highest activity can be achieved at reaction temperatures of ca. 90 degrees C. Chloro derivatives are somewhat more active than alkyl complexes, and sterically less crowded complexes show also higher activities than their congeners with bulky ligands L(2). Kinetic examinations show that the catalyst formation is the rate determining step and it is observed that tert-butyl alcohol, the byproduct of the epoxidation reaction, acts as a competitor for TBHP, thus lowering the reaction velocity during the course of the reaction but not irreversibly destroying the catalyst.
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Affiliation(s)
- Fritz E Kühn
- Anorganisch-Chemisches Institut, Technischen Universität München, Lichtenbergstrasse 4, D-85747 Garching bei München, Germany.
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Nunes C, Pillinger M, Valente A, Gonçalves I, Rocha J, Ferreira P, Kühn F. Synthesis and Characterization of Methyltrioxorhenium(VII) Immobilized in Bipyridyl-Functionalized Mesoporous Silica. Eur J Inorg Chem 2002. [DOI: 10.1002/1099-0682(200205)2002:5<1100::aid-ejic1100>3.0.co;2-b] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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135
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Yuan Y, Iwasawa Y. Performance and Characterization of Supported Rhenium Oxide Catalysts for Selective Oxidation of Methanol to Methylal. J Phys Chem B 2002. [DOI: 10.1021/jp013770l] [Citation(s) in RCA: 106] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Youzhu Yuan
- Department of Chemistry, Graduate School of Science, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Yasuhiro Iwasawa
- Department of Chemistry, Graduate School of Science, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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136
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Béreau VM, Khan SI, Abu-Omar MM. Synthesis of enantiopure oxorhenium(V) and arylimidorhenium(V) "3 + 2" Schiff base complexes. X-ray diffraction, cyclic voltammetry, UV-vis, and circular dichroism characterizations. Inorg Chem 2001; 40:6767-73. [PMID: 11735489 DOI: 10.1021/ic0108033] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Two new oxorhenium(V) and two new arylimidorhenium(V) complexes of the Schiff base ligands 2-hydroxybenzaldehyde-((1R,2S)-1-amino-2-indanol)imine (1) (H(2)L(1)) and 3-(1-adamantyl)-2-hydroxy-5-methylbenzaldehyde-((1R,2S)-1-amino- 2-indanol)imine (2) (H(2)L(2)) have been prepared from the reaction of the precursor Re(O)(PPh(3))(2)Cl(3), Re(NC(6)H(5))(PPh(3))(2)Cl(3), or Re(NC(6)H(4)OCH(3))(PPh(3))(2)Cl(3) and the free ligands H(2)L(1,2). The complexes Re(O)(HL(1))(L(1)) (3), Re(O)(HL(2))(L(2)) (4), Re(NC(6)H(5))(HL(1))(L(1)) (5), and Re(NC(6)H(4)OCH(3))(HL(1))(L(1)) (6) have been isolated and fully characterized by IR, (1)H NMR, circular dichroism, LRMS-FAB, and elemental analysis. All the complexes have a chiral center at rhenium. A single enantiomer is obtained in all cases. Suitable crystals of 3 and 5 were used in X-ray structural determinations. Crystal data: (3) C(32)H(27)N(2)O(5)Re.CH(2)Cl(2), orthorhombic, P2(1)2(1)2(1), a = 9.5599(16) A, b = 9.9579(16) A, c = 31.712(5) A, V = 3018.9(9) A(3), T = 100(2) K, Z = 4. (5) C(40)H(38)N(3)O(5)Re, monoclinic, P2(1), a = 9.286(3) A, b = 18.759(6) A, c = 9.957(3) A, beta = 102.817(6) degrees, V = 1691.3(10) A(3), T = 100(2) K, Z = 2. The major characteristic of these complexes is the presence of two coordination modes for the Schiff base ligands on rhenium, a tridentate ligand (noted L(1,2)) and another bidentate ligand (noted HL(1,2)). In the latter, the -OH group of the indanol is free and tilts away from the coordination sphere. X-ray structural analyses in conjunction with circular dichroism were used to assign the absolute configuration at rhenium (C). Cyclic voltammetry, UV-vis, and circular dichroism data are presented and discussed. The complexes were found to be highly stable and to resist reduction even when treated with organic phosphanes.
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Affiliation(s)
- V M Béreau
- Department of Chemistry and Biochemistry, University of California, 405 Hilgard Avenue, Los Angeles, California 90095-1569, USA
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137
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Arias J, Newlands CR, Abu-Omar MM. Kinetics and mechanisms of catalytic oxygen atom transfer with oxorhenium(V) oxazoline complexes. Inorg Chem 2001; 40:2185-92. [PMID: 11304165 DOI: 10.1021/ic000917z] [Citation(s) in RCA: 112] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The rhenium(V) monooxo complexes (hoz)2Re(O)Cl (1) and [(hoz)2Re(O)(OH2)][OTf] (2) have been synthesized and fully characterized (hoz = 2-(2'-hydroxyphenyl)-2-oxazoline). A single-crystal X-ray structure of 2 has been solved: space group = P1, a = 13.61(2) A, b = 14.76(2) A, c = 11.871(14) A, alpha = 93.69(4) degrees, beta = 99.43(4) degrees, gamma = 108.44(4) degrees, Z = 4; the structure was refined to final residuals R = 0.0455 and Rw = 0.1055. 1 and 2 catalyze oxygen atom transfer from aryl sulfoxides to alkyl sulfides and oxygen-scrambling between sulfoxides to yield sulfone and sulfide. Superior catalytic activity has been observed for 2 due to the availability of a coordination site on the rhenium. The active form of the catalyst is a dioxo rhenium(VII) intermediate, [Re(O)2(hoz)2]+ (3). In the presence of sulfide, 3 is rapidly reduced to [Re(O)(hoz)2]+ with sulfoxide as the sole organic product. The transition state is very sensitive to electronic influences. A Hammett correlation plot with para-substituted thioanisole derivatives gave a reaction constant rho of -4.6 +/- 0.4, in agreement with an electrophilic oxygen transfer from rhenium. The catalytic reaction features inhibition by sulfides at high concentrations. The equilibrium constants for sulfide binding to complex 2 (cause of inhibition), K2 (L x mol(-1)), were determined for a few sulfides: Me2S (22 +/- 3), Et2S (14 +/- 2), and tBu2S (8 +/- 2). Thermodynamic data, obtained from equilibrium measurements in solution, show that the S=O bond in alkyl sulfoxides is stronger than in aryl sulfoxides. The Re=O bond strength in 3 was estimated to be about 20 kcal x mol(-1). The high activity and oxygen electrophilicity of complex 3 are discussed and related to analogous molybdenum systems.
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Affiliation(s)
- J Arias
- Department of Chemistry and Biochemistry, University of California, Los Angeles, 405 Hilgard Avenue, Los Angeles, California 90095-1569, USA
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138
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Huang R, Espenson JH. Mechanistic Study of Oxygen-Transfer Reaction Catalyzed by an Oxorhenium(V) Compound. Inorg Chem 2001. [DOI: 10.1021/ic000854k] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ruili Huang
- Ames Laboratory and the Department of Chemistry, Iowa State University of Science and Technology, Ames, Iowa 50011
| | - James H. Espenson
- Ames Laboratory and the Department of Chemistry, Iowa State University of Science and Technology, Ames, Iowa 50011
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