1
|
Gordon JB, Albert T, Yadav S, Thomas J, Siegler MA, Moënne-Loccoz P, Goldberg DP. Oxygen versus Sulfur Coordination in Cobalt Superoxo Complexes: Spectroscopic Properties, O 2 Binding, and H-Atom Abstraction Reactivity. Inorg Chem 2023; 62:392-400. [PMID: 36538786 PMCID: PMC10194424 DOI: 10.1021/acs.inorgchem.2c03484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
A five-coordinate, disiloxide-ligated cobalt(II) (S = 3/2) complex (1) was prepared as an oxygen-ligated analogue to the previously reported silanedithiolate-ligated CoII(Me3TACN)(S2SiMe2) (J. Am. Chem. Soc., 2019, 141, 3641-3653). The structural and spectroscopic properties of 1 were analyzed by single-crystal X-ray diffraction, electron paramagnetic resonance (EPR), and NMR spectroscopies. The reactivity of 1 with dioxygen was examined, and it was shown to bind O2 reversibly in a range of solvents at low temperatures. A cobalt(III)-superoxo complex, CoIII(O2·-)(Me3TACN)((OSi2Ph)2O) (2), was generated, and was analyzed by UV-vis, EPR, and resonance Raman spectroscopies. Unlike its sulfur-ligated analogue, complex 2 can thermally release O2 to regenerate 1. Vibrational assignments for selective 18O isotopic labeling of both O2 and disiloxide ligands in 2 are consistent with a 6-coordinate, Co(η1-O2·-)("end-on") complex. Complex 2 reacts with the O-H bond of 4-methoxy-2,2,6,6-tetramethylpiperidin-1-ol (4-MeO-TEMPOH) via H-atom abstraction with a rate of 0.58(2) M-1 s-1 at -105 °C, but it is unable to oxidize phenol substrates. This bracketed reactivity suggests that the O-H bond being formed in the putative CoIII(OOH) product has a relatively weak O-H bond strength (BDFE ∼66-74 kcal mol-1). These thermodynamic and kinetic parameters are similar to those seen for the sulfur-ligated Co(O2)(Me3TACN)(S2SiMe2), indicating that the differences in the electronic structure for O versus S ligation do not have a large impact on H-atom abstraction reactivity.
Collapse
Affiliation(s)
- Jesse B Gordon
- Department of Chemistry, The Johns Hopkins University, 3400 N. Charles Street, Baltimore, Maryland 21218, United States
| | - Therese Albert
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, Oregon 97239, United States
| | - Sudha Yadav
- Department of Chemistry, The Johns Hopkins University, 3400 N. Charles Street, Baltimore, Maryland 21218, United States
| | - Jithin Thomas
- Department of Chemistry, The Johns Hopkins University, 3400 N. Charles Street, Baltimore, Maryland 21218, United States
| | - Maxime A Siegler
- Department of Chemistry, The Johns Hopkins University, 3400 N. Charles Street, Baltimore, Maryland 21218, United States
| | - Pierre Moënne-Loccoz
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, Oregon 97239, United States
| | - David P Goldberg
- Department of Chemistry, The Johns Hopkins University, 3400 N. Charles Street, Baltimore, Maryland 21218, United States
| |
Collapse
|
2
|
Ghosh I, Chakraborty B, Bera A, Paul S, Paine TK. Selective oxygenation of C-H and CC bonds with H 2O 2 by high-spin cobalt(II)-carboxylate complexes. Dalton Trans 2022; 51:2480-2492. [PMID: 35050271 DOI: 10.1039/d1dt02235k] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Four cobalt(II)-carboxylate complexes [(6-Me3-TPA)CoII(benzoate)](BPh4) (1), [(6-Me3-TPA)CoII(benzilate)](ClO4) (2), [(6-Me3-TPA)CoII(mandelate)](BPh4) (3), and [(6-Me3-TPA)CoII(MPA)](BPh4) (4) (HMPA = 2-methoxy-2-phenylacetic acid) of the 6-Me3-TPA (tris((6-methylpyridin-2-yl)methyl)amine) ligand were isolated to investigate their ability in H2O2-dependent selective oxygenation of C-H and CC bonds. All six-coordinate complexes contain a high-spin cobalt(II) center. While the cobalt(II) complexes are inert toward dioxygen, each of these complexes reacts readily with hydrogen peroxide to form a diamagnetic cobalt(III) species, which decays with time leading to the oxidation of the methyl groups on the pyridine rings of the supporting ligand. Intramolecular ligand oxidation by the cobalt-based oxidant is partially inhibited in the presence of external substrates, and the substrates are converted to their corresponding oxidized products. Kinetic studies and labelling experiments indicate the involvement of a metal-based oxidant in affecting the chemo- and stereo-selective catalytic oxygenation of aliphatic C-H bonds and epoxidation of alkenes. An electrophilic cobalt-oxygen species that exhibits a kinetic isotope effect (KIE) value of 5.3 in toluene oxidation by 1 is proposed as the active oxidant. Among the complexes, the cobalt(II)-benzoate (1) and cobalt(II)-MPA (4) complexes display better catalytic activity compared to their α-hydroxy analogues (2 and 3). Catalytic studies with the cobalt(II)-acetonitrile complex [(6-Me3-TPA)CoII(CH3CN)2](ClO4)2 (5) in the presence and absence of externally added benzoate support the role of the carboxylate co-ligand in oxidation reactions. The proposed catalytic reaction involves a carboxylate-bridged dicobalt complex in the activation of H2O2 followed by the oxidation of substrates by a metal-based oxidant.
Collapse
Affiliation(s)
- Ivy Ghosh
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A & 2B Raja S. C. Mullick Road, Jadavpur, Kolkata 700 032, India.
| | - Biswarup Chakraborty
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A & 2B Raja S. C. Mullick Road, Jadavpur, Kolkata 700 032, India.
| | - Abhijit Bera
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A & 2B Raja S. C. Mullick Road, Jadavpur, Kolkata 700 032, India.
| | - Satadal Paul
- Department of Chemistry, Bangabasi Morning College, 19, Rajkumar Chakraborty Sarani, Kolkata - 700 009, India
| | - Tapan Kanti Paine
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A & 2B Raja S. C. Mullick Road, Jadavpur, Kolkata 700 032, India.
| |
Collapse
|
3
|
Zhang T, Yu M, Huang H. Fe-catalyzed Fukuyama-type indole synthesis triggered by hydrogen atom transfer. Chem Sci 2021; 12:10501-10505. [PMID: 34447542 PMCID: PMC8356753 DOI: 10.1039/d1sc03058b] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Accepted: 07/05/2021] [Indexed: 02/03/2023] Open
Abstract
Fe, Co, and Mn hydride-initiated radical olefin additions have enjoyed great success in modern synthesis, yet the extension of other hydrogen radicalophiles instead of olefins remains largely elusive. Herein, we report an efficient Fe-catalyzed intramolecular isonitrile-olefin coupling reaction delivering 3-substituted indoles, in which isonitrile was firstly applied as the hydrogen atom acceptor in the radical generation step by MHAT. The protocol features low catalyst loading, mild reaction conditions, and excellent functional group tolerance.
Collapse
Affiliation(s)
- Tianze Zhang
- Hefei National Laboratory for Physical Sciences at the Microscale, Department of Chemistry, Center for Excellence in Molecular Synthesis of CAS, University of Science and Technology of China Hefei 230026 P. R. China
| | - Min Yu
- Hefei National Laboratory for Physical Sciences at the Microscale, Department of Chemistry, Center for Excellence in Molecular Synthesis of CAS, University of Science and Technology of China Hefei 230026 P. R. China
| | - Hanmin Huang
- Hefei National Laboratory for Physical Sciences at the Microscale, Department of Chemistry, Center for Excellence in Molecular Synthesis of CAS, University of Science and Technology of China Hefei 230026 P. R. China
| |
Collapse
|
4
|
Huang Y, Li J, Li S, Ma J. Cobalt-Catalyzed Aerobic Oxidative Dearomatization of 2-Aryl Indoles and in situ [3+2] Annulation with Enamides. CHINESE J ORG CHEM 2021. [DOI: 10.6023/cjoc202104057] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
5
|
Shevick SL, Wilson CV, Kotesova S, Kim D, Holland PL, Shenvi RA. Catalytic hydrogen atom transfer to alkenes: a roadmap for metal hydrides and radicals. Chem Sci 2020; 11:12401-12422. [PMID: 33520153 PMCID: PMC7810138 DOI: 10.1039/d0sc04112b] [Citation(s) in RCA: 122] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 09/28/2020] [Indexed: 12/12/2022] Open
Abstract
Hydrogen atom transfer from metal hydrides to alkenes appears to underlie widely used catalytic methods – the mechanistic implications are fascinating.
Hydrogen atom transfer from a metal hydride (MHAT) has emerged as a powerful, if puzzling, technique in chemical synthesis. In catalytic MHAT reactions, earth-abundant metal complexes generate stabilized and unstabilized carbon-centered radicals from alkenes of various substitution patterns with robust chemoselectivity. This perspective combines organic and inorganic perspectives to outline challenges and opportunities, and to propose working models to assist further developments. We attempt to demystify the putative intermediates, the basic elementary steps, and the energetic implications, especially for cage pair formation, collapse and separation. Distinctions between catalysts with strong-field (SF) and weak-field (WF) ligand environments may explain some differences in reactivity and selectivity, and provide an organizing principle for kinetics that transcends the typical thermodynamic analysis. This blueprint should aid practitioners who hope to enter and expand this exciting area of chemistry.
Collapse
Affiliation(s)
- Sophia L Shevick
- Department of Chemistry , Scripps Research , 10550 North Torrey Pines Road , La Jolla , CA 92037 , USA
| | - Conner V Wilson
- Department of Chemistry , Yale University , 225 Prospect St. , New Haven , CT 06511 , USA
| | - Simona Kotesova
- Department of Chemistry , Scripps Research , 10550 North Torrey Pines Road , La Jolla , CA 92037 , USA
| | - Dongyoung Kim
- Department of Chemistry , Yale University , 225 Prospect St. , New Haven , CT 06511 , USA
| | - Patrick L Holland
- Department of Chemistry , Yale University , 225 Prospect St. , New Haven , CT 06511 , USA
| | - Ryan A Shenvi
- Department of Chemistry , Scripps Research , 10550 North Torrey Pines Road , La Jolla , CA 92037 , USA
| |
Collapse
|
6
|
Zuleta EC, Goenaga GA, Zawodzinski TA, Elder T, Bozell JJ. Deactivation of Co-Schiff base catalysts in the oxidation of para-substituted lignin models for the production of benzoquinones. Catal Sci Technol 2020. [DOI: 10.1039/c9cy02040c] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Those features which enhance the reactivity of Co-Schiff base oxidation catalysts can also contribute to their demise.
Collapse
Affiliation(s)
- Ernesto C. Zuleta
- Center for Renewable Carbon
- University of Tennessee
- Knoxville
- USA
- Bredesen Center for Interdisciplinary Research and Education
| | - Gabriel A. Goenaga
- Department of Chemical and Biomolecular Engineering
- University of Tennessee
- Knoxville
- USA
| | - Thomas A. Zawodzinski
- Bredesen Center for Interdisciplinary Research and Education
- Knoxville
- USA
- Department of Chemical and Biomolecular Engineering
- University of Tennessee
| | | | - Joseph J. Bozell
- Center for Renewable Carbon
- University of Tennessee
- Knoxville
- USA
- Bredesen Center for Interdisciplinary Research and Education
| |
Collapse
|
7
|
Reiss H, Shalit H, Vershinin V, More NY, Forckosh H, Pappo D. Cobalt(II)[salen]-Catalyzed Selective Aerobic Oxidative Cross-Coupling between Electron-Rich Phenols and 2-Naphthols. J Org Chem 2019; 84:7950-7960. [DOI: 10.1021/acs.joc.9b00822] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Hagai Reiss
- Department of Chemistry, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
| | - Hadas Shalit
- Department of Chemistry, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
| | - Vlada Vershinin
- Department of Chemistry, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
| | - Nagnath Yadav More
- Department of Chemistry, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
| | - Hagit Forckosh
- Department of Chemistry, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
| | - Doron Pappo
- Department of Chemistry, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
| |
Collapse
|
8
|
Gordon JB, Vilbert AC, Siegler MA, Lancaster KM, Moënne-Loccoz P, Goldberg DP. A Nonheme Thiolate-Ligated Cobalt Superoxo Complex: Synthesis and Spectroscopic Characterization, Computational Studies, and Hydrogen Atom Abstraction Reactivity. J Am Chem Soc 2019; 141:3641-3653. [PMID: 30776222 DOI: 10.1021/jacs.8b13134] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The synthesis and characterization of a Co(II) dithiolato complex Co(Me3TACN)(S2SiMe2) (1) are reported. Reaction of 1 with O2 generates a rare thiolate-ligated cobalt-superoxo species Co(O2)(Me3TACN)(S2SiMe2) (2) that was characterized spectroscopically and structurally by resonance Raman, EPR, and X-ray absorption spectroscopies as well as density functional theory. Metal-superoxo species are proposed to S-oxygenate metal-bound thiolate donors in nonheme thiol dioxygenases, but 2 does not lead to S-oxygenation of the intramolecular thiolate donors and does not react with exogenous sulfur donors. However, complex 2 is capable of oxidizing the O-H bonds of 2,2,6,6-tetramethylpiperidin-1-ol derivatives via H atom abstraction. Complementary proton-coupled electron-transfer reactivity is seen for 2 with separated proton/reductant pairs. The reactivity studies indicate that 2 can abstract H atoms from weak X-H bonds with bond dissociation free energy (BDFE) ≤ 70 kcal mol-1. DFT calculations predict that the putative Co(OOH) product has an O-H BDFE = 67 kcal mol-1, which matches the observed pattern of reactivity seen for 2. These data provide new information regarding the selectivity of S-oxygenation versus H atom abstraction in thiolate-ligated nonheme metalloenzymes that react with O2.
Collapse
Affiliation(s)
- Jesse B Gordon
- Department of Chemistry , The Johns Hopkins University , 3400 North Charles Street , Baltimore , Maryland 21218 , United States
| | - Avery C Vilbert
- Department of Chemistry and Chemical Biology, Baker Laboratory , Cornell University , Ithaca , New York 14853 , United States
| | - Maxime A Siegler
- Department of Chemistry , The Johns Hopkins University , 3400 North Charles Street , Baltimore , Maryland 21218 , United States
| | - Kyle M Lancaster
- Department of Chemistry and Chemical Biology, Baker Laboratory , Cornell University , Ithaca , New York 14853 , United States
| | - Pierre Moënne-Loccoz
- Department of Biochemistry & Molecular Biology , Oregon Health & Science University , Portland , Oregon 97239-3098 , United States
| | - David P Goldberg
- Department of Chemistry , The Johns Hopkins University , 3400 North Charles Street , Baltimore , Maryland 21218 , United States
| |
Collapse
|
9
|
Murphy LJ, Ruddy AJ, McDonald R, Ferguson MJ, Turculet L. Activation of Molecular Hydrogen and Oxygen by PSiP Complexes of Cobalt. Eur J Inorg Chem 2018. [DOI: 10.1002/ejic.201800915] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Luke J. Murphy
- Department of Chemistry Dalhousie University 6274 Coburg Road P.O. Box 15000 Halifax Nova Scotia Canada, B3H 4R 2
| | - Adam J. Ruddy
- Department of Chemistry Dalhousie University 6274 Coburg Road P.O. Box 15000 Halifax Nova Scotia Canada, B3H 4R 2
| | - Robert McDonald
- X‐ray Crystallography Laboratory Department of Chemistry University of Alberta Edmonton Alberta CanadaT6G 2G2
| | - Michael J. Ferguson
- X‐ray Crystallography Laboratory Department of Chemistry University of Alberta Edmonton Alberta CanadaT6G 2G2
| | - Laura Turculet
- Department of Chemistry Dalhousie University 6274 Coburg Road P.O. Box 15000 Halifax Nova Scotia Canada, B3H 4R 2
| |
Collapse
|
10
|
|
11
|
Oxygen activation by mononuclear Mn, Co, and Ni centers in biology and synthetic complexes. J Biol Inorg Chem 2016; 22:407-424. [PMID: 27853875 DOI: 10.1007/s00775-016-1402-7] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 10/21/2016] [Indexed: 10/20/2022]
Abstract
The active sites of metalloenzymes that catalyze O2-dependent reactions generally contain iron or copper ions. However, several enzymes are capable of activating O2 at manganese or nickel centers instead, and a handful of dioxygenases exhibit activity when substituted with cobalt. This minireview summarizes the catalytic properties of oxygenases and oxidases with mononuclear Mn, Co, or Ni active sites, including oxalate-degrading oxidases, catechol dioxygenases, and quercetin dioxygenase. In addition, recent developments in the O2 reactivity of synthetic Mn, Co, or Ni complexes are described, with an emphasis on the nature of reactive intermediates featuring superoxo-, peroxo-, or oxo-ligands. Collectively, the biochemical and synthetic studies discussed herein reveal the possibilities and limitations of O2 activation at these three "overlooked" metals.
Collapse
|
12
|
Shin B, Sutherlin KD, Ohta T, Ogura T, Solomon EI, Cho J. Reactivity of a Cobalt(III)-Hydroperoxo Complex in Electrophilic Reactions. Inorg Chem 2016; 55:12391-12399. [PMID: 27934432 DOI: 10.1021/acs.inorgchem.6b02288] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The reactivity of mononuclear metal-hydroperoxo adducts has fascinated researchers in many areas due to their diverse biological and catalytic processes. In this study, a mononuclear cobalt(III)-peroxo complex bearing a tetradentate macrocyclic ligand, [CoIII(Me3-TPADP)(O2)]+ (Me3-TPADP = 3,6,9-trimethyl-3,6,9-triaza-1(2,6)-pyridinacyclodecaphane), was prepared by reacting [CoII(Me3-TPADP)(CH3CN)2]2+ with H2O2 in the presence of triethylamine. Upon protonation, the cobalt(III)-peroxo intermediate was converted into a cobalt(III)-hydroperoxo complex, [CoIII(Me3-TPADP)(O2H)(CH3CN)]2+. The mononuclear cobalt(III)-peroxo and -hydroperoxo intermediates were characterized by a variety of physicochemical methods. Results of electrospray ionization mass spectrometry clearly show the transformation of the intermediates: the peak at m/z 339.2 assignable to the cobalt(III)-peroxo species disappears with concomitant growth of the peak at m/z 190.7 corresponding to the cobalt(III)-hydroperoxo complex (with bound CH3CN). Isotope labeling experiments further support the existence of the cobalt(III)-peroxo and -hydroperoxo complexes. In particular, the O-O bond stretching frequency of the cobalt(III)-hydroperoxo complex was determined to be 851 cm-1 for 16O2H samples (803 cm-1 for 18O2H samples), and its Co-O vibrational energy was observed at 571 cm-1 for 16O2H samples (551 cm-1 for 18O2H samples; 568 cm-1 for 16O22H samples) by resonance Raman spectroscopy. Reactivity studies performed with the cobalt(III)-peroxo and -hydroperoxo complexes in organic functionalizations reveal that the latter is capable of conducting oxygen atom transfer with an electrophilic character, whereas the former exhibits no oxygen atom transfer reactivity under the same reaction conditions. Alternatively, the cobalt(III)-hydroperoxo complex does not perform hydrogen atom transfer reactions, while analogous low-spin Fe(III)-hydroperoxo complexes are capable of this reactivity. Density functional theory calculations indicate that this lack of reactivity is due to the high free energy cost of O-O bond homolysis that would be required to produce the hypothetical Co(IV)-oxo product.
Collapse
Affiliation(s)
- Bongki Shin
- Department of Emerging Materials Science, DGIST , Daegu 42988, Korea
| | - Kyle D Sutherlin
- Department of Chemistry, Stanford University , Stanford, California 94305, United States
| | - Takehiro Ohta
- Picobiology Institute, Graduate School of Life Science, University of Hyogo , RSC-UH LP Center, Hyogo 679-5148, Japan
| | - Takashi Ogura
- Picobiology Institute, Graduate School of Life Science, University of Hyogo , RSC-UH LP Center, Hyogo 679-5148, Japan
| | - Edward I Solomon
- Department of Chemistry, Stanford University , Stanford, California 94305, United States.,Stanford Synchrotron Radiation Laboratory, Stanford Linear Accelerator Center , Menlo Park, California 94025, United States
| | - Jaeheung Cho
- Department of Emerging Materials Science, DGIST , Daegu 42988, Korea
| |
Collapse
|
13
|
Corcos AR, Villanueva O, Walroth RC, Sharma SK, Bacsa J, Lancaster KM, MacBeth CE, Berry JF. Oxygen Activation by Co(II) and a Redox Non-Innocent Ligand: Spectroscopic Characterization of a Radical–Co(II)–Superoxide Complex with Divergent Catalytic Reactivity. J Am Chem Soc 2016; 138:1796-9. [DOI: 10.1021/jacs.5b12643] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Amanda R. Corcos
- Department
of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, Wisconsin 53706, United States
| | - Omar Villanueva
- Department
of Chemistry, Emory University, 1515 Dickey Drive, Atlanta, Georgia 30322, United States
| | - Richard C. Walroth
- Department
of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853, United States
| | - Savita K. Sharma
- Department
of Chemistry, Emory University, 1515 Dickey Drive, Atlanta, Georgia 30322, United States
| | - John Bacsa
- Department
of Chemistry, Emory University, 1515 Dickey Drive, Atlanta, Georgia 30322, United States
| | - Kyle M. Lancaster
- Department
of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853, United States
| | - Cora E. MacBeth
- Department
of Chemistry, Emory University, 1515 Dickey Drive, Atlanta, Georgia 30322, United States
| | - John F. Berry
- Department
of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, Wisconsin 53706, United States
| |
Collapse
|
14
|
Recent advances in transition-metal-catalyzed selective oxidation of substituted phenols and methoxyarenes with environmentally benign oxidants. Coord Chem Rev 2016. [DOI: 10.1016/j.ccr.2015.07.019] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
15
|
Davila R, Farias N, Carolina Sañudo E, Vega A, Escuer A, Soler M, Manzur J. Dinuclear cobalt(iii) and mixed valence trinuclear MnIII–MnII–MnIII complexes with a tripodal bridging pyridylaminophenol ligand. NEW J CHEM 2016. [DOI: 10.1039/c5nj03670d] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Two new complexes with the tripodal N-(2-pyridyl-methyl)-N,N-bis-[2′-hydroxy-5′-methyl-benzyl]-amine, one CoIII dimer and a linear mixed valence MnIII–MnII–MnIII have been synthesized and characterized.
Collapse
Affiliation(s)
- Ruben Davila
- Deapartamento de Ciencia de los Materiales
- Facultad de Ciencias Físicas y Matemáticas
- Universidad de Chile
- Santiago
- Chile
| | - Nicolas Farias
- Deapartamento de Ciencia de los Materiales
- Facultad de Ciencias Físicas y Matemáticas
- Universidad de Chile
- Santiago
- Chile
| | - E. Carolina Sañudo
- Departament de Química Inorgánica
- Universitat de Barcelona
- 08028-Barcelona
- Spain
| | - Andrés Vega
- Departamento de Ciencias Químicas
- Facultad de Ciencias Exactas
- Universidad Andres Bello
- Viña del Mar
- Chile
| | - Albert Escuer
- Departament de Química Inorgánica
- Universitat de Barcelona
- 08028-Barcelona
- Spain
| | - Mónica Soler
- Deapartamento de Ciencia de los Materiales
- Facultad de Ciencias Físicas y Matemáticas
- Universidad de Chile
- Santiago
- Chile
| | - Jorge Manzur
- Deapartamento de Ciencia de los Materiales
- Facultad de Ciencias Físicas y Matemáticas
- Universidad de Chile
- Santiago
- Chile
| |
Collapse
|
16
|
Kochem A, Gellon G, Jarjayes O, Philouze C, Leconte N, van Gastel M, Bill E, Thomas F. A singlet ground state for a cobalt(II)-anilinosalen radical complex. Chem Commun (Camb) 2015; 50:4924-6. [PMID: 24700242 DOI: 10.1039/c4cc00952e] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The cobalt(II) anilinosalen complex [Co(II)(L)] was prepared and subsequently oxidized by one electron. The resulting cation comprises a square planar low spin Co(II) ion anti-ferromagnetically exchange coupled to an anilinyl radical.
Collapse
Affiliation(s)
- Amélie Kochem
- Département de Chimie Moléculaire - Chimie Inorganique Redox Biomimétique (CIRE) - UMR CNRS 5250, Université J. Fourier, B. P. 53, 38041 Grenoble cedex 9, France.
| | | | | | | | | | | | | | | |
Collapse
|
17
|
Soroceanu A, Cazacu M, Shova S, Turta C, Kožíšek J, Gall M, Breza M, Rapta P, Mac Leod TCO, Pombeiro AJL, Telser J, Dobrov AA, Arion VB. Copper(II) Complexes with Schiff Bases Containing a Disiloxane Unit: Synthesis, Structure, Bonding Features and Catalytic Activity for Aerobic Oxidation of Benzyl Alcohol. Eur J Inorg Chem 2013. [DOI: 10.1002/ejic.201201080] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
18
|
Kochem A, Kanso H, Baptiste B, Arora H, Philouze C, Jarjayes O, Vezin H, Luneau D, Orio M, Thomas F. Ligand contributions to the electronic structures of the oxidized cobalt(II) salen complexes. Inorg Chem 2012; 51:10557-71. [PMID: 23013360 DOI: 10.1021/ic300763t] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Square planar cobalt(II) complexes of salen ligands N,N'-bis(3-tert-butyl-5R-salicylidene)-1,2-cyclohexanediamine), where R = OMe (1) and tert-butyl (2), were prepared. 1 and 2 were electrochemically reversibly oxidized into cations [1-H(2)O](+) and [2-H(2)O](+) in CH(2)Cl(2). The chemically generated [1-H(2)O](SbF(6))·0.68 H(2)O·0.82CH(2)Cl(2) and [2-H(2)O](SbF(6))·0.3H(2)O·0.85CH(2)Cl(2) were characterized by X-ray diffraction and NIR spectroscopy. Both complexes are paramagnetic species containing a square pyramidal cobalt ion coordinated at the apical position by an exogenous water molecule. They exhibit remarkable NIR bands at 1220 (7370 M(-1) cm(-1)) and 1060 nm (5560 M(-1) cm(-1)), respectively, assigned to a CT transition. DFT calculations and magnetic measurements confirm the paramagnetic (S = 1) ground spin state of the cations. They show that more than 70% of the total spin density in [1-H(2)O](+) and [2-H(2)O](+) is localized on the metal, the remaining spin density being distributed over the aromatic rings (30% phenoxyl character). In the presence of N-methylimidazole 1 and 2 are irreversibly oxidized by air into the genuine octahedral cobalt(III) bis(phenolate) complexes [1-im(2)](+) and [2-im(2)](+), the former being structurally characterized. Neither [1-im(2)](+) nor [2-im(2)](+) exhibits a NIR feature in its electronic spectrum. 1 and 2 were electrochemically two-electron oxidized into [1](2+) and [2](2+). The cations were identified as Co(III)-phenoxyl species by their characteristic absorption band at ca. 400 nm in the UV-vis spectrum. Coordination of the phenoxyl radical to the cobalt(III) metal ion is evidenced by the EPR signal centered at g = 2.00.
Collapse
Affiliation(s)
- Amélie Kochem
- Equipe de Chimie Inorganique Redox Biomimétique, Département de Chimie Moléculaire, Université Joseph Fourier, 38041 Grenoble Cedex 9, France
| | | | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Juita, Dlugogorski BZ, Kennedy EM, Mackie JC. Low temperature oxidation of linseed oil: a review. ACTA ACUST UNITED AC 2012. [DOI: 10.1186/2193-0414-1-3] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Abstract
This review analyses and summarises the previous investigations on the oxidation of linseed oil and the self-heating of cotton and other materials impregnated with the oil. It discusses the composition and chemical structure of linseed oil, including its drying properties. The review describes several experimental methods used to test the propensity of the oil to induce spontaneous heating and ignition of lignocellulosic materials soaked with the oil. It covers the thermal ignition of the lignocellulosic substrates impregnated with the oil and it critically evaluates the analytical methods applied to investigate the oxidation reactions of linseed oil.
Initiation of radical chains by singlet oxygen (1Δg), and their propagation underpin the mechanism of oxidation of linseed oil, leading to the self-heating and formation of volatile organic species and higher molecular weight compounds. The review also discusses the role of metal complexes of cobalt, iron and manganese in catalysing the oxidative drying of linseed oil, summarising some kinetic parameters such as the rate constants of the peroxidation reactions.
With respect to fire safety, the classical theory of self-ignition does not account for radical and catalytic reactions and appears to offer limited insights into the autoignition of lignocellulosic materials soaked with linseed oil. New theoretical and numerical treatments of oxidation of such materials need to be developed. The self-ignition induced by linseed oil is predicated on the presence of both a metal catalyst and a lignocellulosic substrate, and the absence of any prior thermal treatment of the oil, which destroys both peroxy radicals and singlet O2 sensitisers. An overview of peroxyl chemistry included in the article will be useful to those working in areas of fire science, paint drying, indoor air quality, biofuels and lipid oxidation.
Collapse
|
20
|
Cho J, Sarangi R, Nam W. Mononuclear metal-O2 complexes bearing macrocyclic N-tetramethylated cyclam ligands. Acc Chem Res 2012; 45:1321-30. [PMID: 22612523 DOI: 10.1021/ar3000019] [Citation(s) in RCA: 167] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Metalloenzymes activate dioxygen to carry out a variety of biological reactions, including the biotransformation of naturally occurring molecules, oxidative metabolism of xenobiotics, and oxidative phosphorylation. The dioxygen activation at the catalytic sites of the enzymes occurs through several steps, such as the binding of O(2) at a reduced metal center, the generation of metal-superoxo and -peroxo species, and the O-O bond cleavage of metal-hydroperoxo complexes to form high-valent metal-oxo oxidants. Because these mononuclear metal-dioxygen (M-O(2)) adducts are implicated as key intermediates in dioxygen activation reactions catalyzed by metalloenzymes, studies of the structural and spectroscopic properties and reactivities of synthetic biomimetic analogues of these species have aided our understanding of their biological chemistry. One particularly versatile class of biomimetic coordination complexes for studying dioxygen activation by metal complexes is M-O(2) complexes bearing the macrocyclic N-tetramethylated cyclam (TMC) ligand. This Account describes the synthesis, structural and spectroscopic characterization, and reactivity studies of M-O(2) complexes bearing tetraazamacrocyclic n-TMC ligands, where M ═ Cr, Mn, Fe, Co, and Ni and n = 12, 13, and 14, based on recent results from our laboratory. We have used various spectroscopic techniques, including resonance Raman and X-ray absorption spectroscopy, and density functional theory (DFT) calculations to characterize several novel metal-O(2) complexes. Notably, X-ray crystal structures had shown that these complexes are end-on metal-superoxo and side-on metal-peroxo species. The metal ions and the ring size of the macrocyclic TMC ligands control the geometric and electronic structures of the metal-O(2) complexes, resulting in the end-on metal-superoxo versus side-on metal-peroxo structures. Reactivity studies performed with the isolated metal-superoxo complexes reveal that they can conduct electrophilic reactions such as oxygen atom transfer and C-H bond activation of organic substrates. The metal-peroxo complexes are active oxidants in nucleophilic reactions, such as aldehyde deformylation. We also demonstrate a complete intermolecular O(2)-transfer from metal(III)-peroxo complexes to a Mn(II) complex. The results presented in this Account show the significance of metal ions and supporting ligands in tuning the geometric and electronic structures and reactivities of the metal-O(2) intermediates that are relevant in biology and in biomimetic reactions.
Collapse
Affiliation(s)
- Jaeheung Cho
- Department of Bioinspired Science, Department of Chemistry and Nano Science, Ewha Womans University, Seoul 120-750, Korea
| | - Ritimukta Sarangi
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Wonwoo Nam
- Department of Bioinspired Science, Department of Chemistry and Nano Science, Ewha Womans University, Seoul 120-750, Korea
| |
Collapse
|
21
|
Siega P, Vrdoljak V, Tavagnacco C, Dreos R. Synthesis, characterization, and electrochemical properties of a new series of inorganic and organometallic Co(III) complexes with a Schiff base ligand derived from tyrosine. Inorganica Chim Acta 2012. [DOI: 10.1016/j.ica.2011.12.057] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
22
|
Sharma SK, May PS, Jones MB, Lense S, Hardcastle KI, MacBeth CE. Catalytic dioxygen activation by Co(ii) complexes employing a coordinatively versatile ligand scaffold. Chem Commun (Camb) 2011; 47:1827-9. [DOI: 10.1039/c0cc04671j] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
23
|
Sun Y, Chen K, Jia L, Li H. Toward understanding macrocycle specificity of iron on the dioxygen-binding ability: a theoretical study. Phys Chem Chem Phys 2011; 13:13800-8. [DOI: 10.1039/c0cp02715d] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
24
|
Cho J, Sarangi R, Kang HY, Lee JY, Kubo M, Ogura T, Solomon EI, Nam W. Synthesis, structural, and spectroscopic characterization and reactivities of mononuclear cobalt(III)-peroxo complexes. J Am Chem Soc 2010; 132:16977-86. [PMID: 21062059 PMCID: PMC2995300 DOI: 10.1021/ja107177m] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Metal-dioxygen adducts are key intermediates detected in the catalytic cycles of dioxygen activation by metalloenzymes and biomimetic compounds. In this study, mononuclear cobalt(III)-peroxo complexes bearing tetraazamacrocyclic ligands, [Co(12-TMC)(O(2))](+) and [Co(13-TMC)(O(2))](+), were synthesized by reacting [Co(12-TMC)(CH(3)CN)](2+) and [Co(13-TMC)(CH(3)CN)](2+), respectively, with H(2)O(2) in the presence of triethylamine. The mononuclear cobalt(III)-peroxo intermediates were isolated and characterized by various spectroscopic techniques and X-ray crystallography, and the structural and spectroscopic characterization demonstrated unambiguously that the peroxo ligand is bound in a side-on η(2) fashion. The O-O bond stretching frequency of [Co(12-TMC)(O(2))](+) and [Co(13-TMC)(O(2))](+) was determined to be 902 cm(-1) by resonance Raman spectroscopy. The structural properties of the CoO(2) core in both complexes are nearly identical; the O-O bond distances of [Co(12-TMC)(O(2))](+) and [Co(13-TMC)(O(2))](+) were 1.4389(17) Å and 1.438(6) Å, respectively. The cobalt(III)-peroxo complexes showed reactivities in the oxidation of aldehydes and O(2)-transfer reactions. In the aldehyde oxidation reactions, the nucleophilic reactivity of the cobalt-peroxo complexes was significantly dependent on the ring size of the macrocyclic ligands, with the reactivity of [Co(13-TMC)(O(2))](+) > [Co(12-TMC)(O(2))](+). In the O(2)-transfer reactions, the cobalt(III)-peroxo complexes transferred the bound peroxo group to a manganese(II) complex, affording the corresponding cobalt(II) and manganese(III)-peroxo complexes. The reactivity of the cobalt-peroxo complexes in O(2)-transfer was also significantly dependent on the ring size of tetraazamacrocycles, and the reactivity order in the O(2)-transfer reactions was the same as that observed in the aldehyde oxidation reactions.
Collapse
Affiliation(s)
- Jaeheung Cho
- Department of Bioinspired Science, Department of Chemistry and Nano Science, Center for Biomimetic Systems, Ewha Womans University, Seoul 120-750, Korea
| | - Ritimukta Sarangi
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Hye Yeon Kang
- Department of Bioinspired Science, Department of Chemistry and Nano Science, Center for Biomimetic Systems, Ewha Womans University, Seoul 120-750, Korea
| | - Jung Yoon Lee
- Department of Bioinspired Science, Department of Chemistry and Nano Science, Center for Biomimetic Systems, Ewha Womans University, Seoul 120-750, Korea
| | - Minoru Kubo
- Picobiology Institute, Graduate School of Life Science, University of Hyogo, Hyogo 678-1297, Japan
| | - Takashi Ogura
- Picobiology Institute, Graduate School of Life Science, University of Hyogo, Hyogo 678-1297, Japan
| | - Edward I. Solomon
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
- Department of Chemistry, Stanford University, Stanford, California 94305, USA
| | - Wonwoo Nam
- Department of Bioinspired Science, Department of Chemistry and Nano Science, Center for Biomimetic Systems, Ewha Womans University, Seoul 120-750, Korea
| |
Collapse
|
25
|
Jäger EG, Rost M, Rudolph M. Aktivierung von Sauerstoff an Eisen (II)-Komplexen Schiffscher Basen. ACTA ACUST UNITED AC 2010. [DOI: 10.1002/zfch.19890291113] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
26
|
Cobalt-catalyzed oxidation of terpenes: Co-MCM-41 as an efficient shape-selective heterogeneous catalyst for aerobic oxidation of isolongifolene under solvent-free conditions. J Catal 2009. [DOI: 10.1016/j.jcat.2009.04.012] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
27
|
Mechi L, Siega P, Dreos R, Zangrando E, Randaccio L. Crystal Structures and Solution Behavior of Paramagnetic, Trinuclear, Mixed‐Valent Cobalt Complexes with Salen‐Type Ligands. Eur J Inorg Chem 2009. [DOI: 10.1002/ejic.200900122] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Lassaad Mechi
- Dipartimento di Scienze Chimiche, Università di Trieste, Via Licio Giorgieri 1, 34127, Trieste, Italy, Fax: +39‐040‐5583903
| | - Patrizia Siega
- Dipartimento di Scienze Chimiche, Università di Trieste, Via Licio Giorgieri 1, 34127, Trieste, Italy, Fax: +39‐040‐5583903
| | - Renata Dreos
- Dipartimento di Scienze Chimiche, Università di Trieste, Via Licio Giorgieri 1, 34127, Trieste, Italy, Fax: +39‐040‐5583903
| | - Ennio Zangrando
- Dipartimento di Scienze Chimiche, Università di Trieste, Via Licio Giorgieri 1, 34127, Trieste, Italy, Fax: +39‐040‐5583903
| | - Lucio Randaccio
- Dipartimento di Scienze Chimiche, Università di Trieste, Via Licio Giorgieri 1, 34127, Trieste, Italy, Fax: +39‐040‐5583903
| |
Collapse
|
28
|
Simándi LI. Transition metal dioxygen complexes as intermediates in homogeneous catalytic oxidations. INT REV PHYS CHEM 2008. [DOI: 10.1080/01442358909353221] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
29
|
|
30
|
Robles-Dutenhefner PA, da Silva MJ, Sales LS, Sousa EM, Gusevskaya EV. Solvent-free liquid-phase autoxidation of monoterpenes catalyzed by sol–gel Co/SiO2. ACTA ACUST UNITED AC 2004. [DOI: 10.1016/j.molcata.2004.03.007] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
31
|
Abstract
Schiff base ligands are considered "privileged ligands" because they are easily prepared by the condensation between aldehydes and imines. Stereogenic centres or other elements of chirality (planes, axes) can be introduced in the synthetic design. Schiff base ligands are able to coordinate many different metals, and to stabilize them in various oxidation states, enabling the use of Schiff base metal complexes for a large variety of useful catalytic transformations. Practical guidelines for the preparation and use of different Schiff base metal complexes in the field of catalytic transformations are discussed in this tutorial review.
Collapse
Affiliation(s)
- Pier Giorgio Cozzi
- Dipartimento di Chimica "G. Ciamician", Vial Selmi 2, 40126 Bologna, Italy.
| |
Collapse
|
32
|
da Silva MJ, Robles-Dutenhefner P, Menini L, Gusevskaya EV. Cobalt catalyzed autoxidation of monoterpenes in acetic acid and acetonitrile solutions. ACTA ACUST UNITED AC 2003. [DOI: 10.1016/s1381-1169(03)00180-8] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
33
|
Bakac A. Hydrogen Atom Abstraction by Metal−Oxo and Metal−Superoxo Complexes: Kinetics and Thermodynamics. J Am Chem Soc 2000. [DOI: 10.1021/ja993371s] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Andreja Bakac
- Contribution from the Ames Laboratory, Iowa State University, Ames, Iowa 50011
| |
Collapse
|
34
|
Bakac A. Kinetics and Thermodynamics of Hydrogen Atom Transfer to Superoxometal Complexes. J Am Chem Soc 1997. [DOI: 10.1021/ja971987g] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Andreja Bakac
- Contribution from Ames Laboratory, Iowa State University, Ames, Iowa 50011
| |
Collapse
|
35
|
Sýkora J, Pado M, Tatarko M, Izakovič M. Homogeneous photo-oxidation of phenols: influence of metals. J Photochem Photobiol A Chem 1997. [DOI: 10.1016/s1010-6030(97)00182-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
36
|
|
37
|
Aerobic epoxidation via alkyl-2-oxocyclopentanecarboxylate co-oxidation with cobalt or manganese Jacobsen-type catalysts. ACTA ACUST UNITED AC 1997. [DOI: 10.1016/s1381-1169(96)00360-3] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
38
|
Simándi L, Simándi TL. Kinetics and mechanism of the cobaloxime(II) catalyzed oxidative dehydrogenation and double bond cleavage of 3,3′,5,5′-tetra-tert-butyl-4,4′-dihydroxystilbene by O2. ACTA ACUST UNITED AC 1997. [DOI: 10.1016/s1381-1169(96)00269-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
39
|
Simándi LI, Barna T, Németh S. Kinetics and mechanism of the cobaloxime(II)-catalysed oxidation of 2-aminophenol by dioxygen. A phenoxazinone synthase model involving free-radical intermediates. ACTA ACUST UNITED AC 1996. [DOI: 10.1039/dt9960000473] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
40
|
|
41
|
|
42
|
|
43
|
The Activation of Molecular Oxygen by Transition Metal Complexes. ACTA ACUST UNITED AC 1991. [DOI: 10.1016/s0167-2991(08)62822-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
|
44
|
|
45
|
Markó L. Transition metals in organic synthesis: Hydroformylation, reduction and oxidation. J Organomet Chem 1990. [DOI: 10.1016/0022-328x(90)80271-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
46
|
|
47
|
|