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Steen JD, Stepanovic S, Parvizian M, de Boer JW, Hage R, Chen J, Swart M, Gruden M, Browne WR. Lewis versus Brønsted Acid Activation of a Mn(IV) Catalyst for Alkene Oxidation. Inorg Chem 2019; 58:14924-14930. [PMID: 31625380 PMCID: PMC6832668 DOI: 10.1021/acs.inorgchem.9b02737] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
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Lewis acid (LA) activation
by coordination to metal oxido species
has emerged as a new strategy in catalytic oxidations. Despite the
many reports of enhancement of performance in oxidation catalysis,
direct evidence for LA-catalyst interactions under catalytically relevant
conditions is lacking. Here, we show, using the oxidation of alkenes
with H2O2 and the catalyst [Mn2(μ-O)3(tmtacn)2](PF6)2 (1), that Lewis acids commonly used to enhance catalytic activity,
e.g., Sc(OTf)3, in fact undergo hydrolysis with adventitious
water to release a strong Brønsted acid. The formation of Brønsted
acids in situ is demonstrated using a combination of resonance Raman,
UV/vis absorption spectroscopy, cyclic voltammetry, isotope labeling,
and DFT calculations. The involvement of Brønsted acids in LA
enhanced systems shown here holds implications for the conclusions
reached in regard to the relevance of direct LA-metal oxido interactions
under catalytic conditions. Lewis acid activation of oxidation
catalysts is proposed
to be through binding of the Lewis acids to metal-oxo species. The
activity of the catalyst [Mn2(μ-O)3(tmtacn)2](PF6)2 in the oxidation of alkenes
with H2O2 appears to correlate with the strength
of the Lewis acid used for its activation. We show that the correlation
arises from the relative propensity of the Lewis acids to generate
Brønsted acids in situ.
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Affiliation(s)
- Jorn D Steen
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of Science and Engineering , University of Groningen , Nijenborgh 4 , 9747 AG , Groningen , The Netherlands
| | - Stepan Stepanovic
- Faculty of Chemistry , University of Belgrade , Studentski trg 12-16 , 11000 Belgrade , Serbia
| | - Mahsa Parvizian
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of Science and Engineering , University of Groningen , Nijenborgh 4 , 9747 AG , Groningen , The Netherlands
| | - Johannes W de Boer
- Catexel B.V. , BioPartner Center Leiden , Galileiweg 8 , 2333 BD Leiden , The Netherlands
| | - Ronald Hage
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of Science and Engineering , University of Groningen , Nijenborgh 4 , 9747 AG , Groningen , The Netherlands.,Catexel B.V. , BioPartner Center Leiden , Galileiweg 8 , 2333 BD Leiden , The Netherlands
| | - Juan Chen
- Department of Applied Chemistry, School of Science , Northwestern Polytechnical University , Xi'an , Shaanxi 710072 , China
| | - Marcel Swart
- IQCC & Departament de Química , Universitat de Girona , Campus Montilivi (Ciències) , 17003 Girona , Spain.,ICREA , Pg. Lluís Companys 23 , 08010 Barcelona , Spain
| | - Maja Gruden
- Faculty of Chemistry , University of Belgrade , Studentski trg 12-16 , 11000 Belgrade , Serbia
| | - Wesley R Browne
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of Science and Engineering , University of Groningen , Nijenborgh 4 , 9747 AG , Groningen , The Netherlands
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2
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Abdolahzadeh S, Boyle NM, Hage R, de Boer JW, Browne WR. Metal-Catalyzed Photooxidation of Flavones in Aqueous Media. Eur J Inorg Chem 2018; 2018:2621-2630. [PMID: 31031566 PMCID: PMC6474262 DOI: 10.1002/ejic.201800288] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2018] [Indexed: 11/17/2022]
Abstract
Soluble model compounds, such as flavones, are frequently employed in initial and mechanistic studies under homogeneous conditions in the search for effective bleaching catalysts for raw cotton. The relevance of model substrates, such as morin and chrysin, and especially their reactivity with manganese catalysts [i.e. in combination with 1,4,7‐triazacyclononane (tacn) based ligands] applied in raw cotton bleaching with H2O2 in alkaline solutions is examined. We show that morin, used frequently as a model, is highly sensitive to oxidation with O2, by processes catalyzed by trace metal ions, that can be accelerated photochemically, although not involve generation of 1O2. The structurally related chrysin is not susceptible to such photo‐accelerated oxidation with O2. Furthermore, chrysin is oxidized by H2O2 only in the presence of a Mn‐tacn based catalyst, and does not undergo oxidation with O2 as terminal oxidant. Chrysin mimics the behavior of raw cotton's chromophores in their catalyzed oxidation with H2O2, and is likely a mechanistically relevant model compound for the study of transition metal catalysts for dye bleaching catalysts under homogeneous conditions.
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Affiliation(s)
- Shaghayegh Abdolahzadeh
- Stratingh Institute for Chemistry Faculty of Science and Engineering University of Groningen Nijenborgh 4 9747AG Groningen The Netherlands
| | - Nicola M Boyle
- Stratingh Institute for Chemistry Faculty of Science and Engineering University of Groningen Nijenborgh 4 9747AG Groningen The Netherlands
| | - Ronald Hage
- BioPartner Center Leiden Catexel Ltd Galileiweg 8 2333 BD Leiden The Netherlands
| | - Johannes W de Boer
- BioPartner Center Leiden Catexel Ltd Galileiweg 8 2333 BD Leiden The Netherlands
| | - Wesley R Browne
- Stratingh Institute for Chemistry Faculty of Science and Engineering University of Groningen Nijenborgh 4 9747AG Groningen The Netherlands
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3
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Nodzewska A, Watkinson M. Remarkable increase in the rate of the catalytic epoxidation of electron deficient styrenes through the addition of Sc(OTf)3 to the MnTMTACN catalyst. Chem Commun (Camb) 2018; 54:1461-1464. [DOI: 10.1039/c7cc09698d] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Sc(OTf)3 produces a remarkable enhancement in the activity of the MnTMTACN catalyst in the epoxidation of electron deficient styrenes.
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Affiliation(s)
- Aneta Nodzewska
- The Joseph Priestley Building
- School of Biological and Chemical Sciences
- Queen Mary University of London
- London
- UK
| | - Michael Watkinson
- The Joseph Priestley Building
- School of Biological and Chemical Sciences
- Queen Mary University of London
- London
- UK
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4
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Wegeberg C, Lauritsen FR, Frandsen C, Mørup S, Browne WR, McKenzie CJ. Directing a Non-Heme Iron(III)-Hydroperoxide Species on a Trifurcated Reactivity Pathway. Chemistry 2017; 24:5134-5145. [DOI: 10.1002/chem.201704615] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Indexed: 11/09/2022]
Affiliation(s)
- Christina Wegeberg
- Department of Physics, Chemistry and Pharmacy; University of Southern Denmark; Campusvej 55 5230 Odense M Denmark
| | - Frants R. Lauritsen
- Department of Physics, Chemistry and Pharmacy; University of Southern Denmark; Campusvej 55 5230 Odense M Denmark
| | - Cathrine Frandsen
- Department of Physics; Technical University of Denmark; 2800 Kongens Lyngby Denmark
| | - Steen Mørup
- Department of Physics; Technical University of Denmark; 2800 Kongens Lyngby Denmark
| | - Wesley R. Browne
- Molecular Inorganic Chemistry; Stratingh Institute for Chemistry; University of Groningen; Nijenborgh 4 9747 AG Groningen The Netherlands
| | - Christine J. McKenzie
- Department of Physics, Chemistry and Pharmacy; University of Southern Denmark; Campusvej 55 5230 Odense M Denmark
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5
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Padamati S, Angelone D, Draksharapu A, Primi G, Martin DJ, Tromp M, Swart M, Browne WR. Transient Formation and Reactivity of a High-Valent Nickel(IV) Oxido Complex. J Am Chem Soc 2017; 139:8718-8724. [PMID: 28581745 PMCID: PMC5492195 DOI: 10.1021/jacs.7b04158] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Indexed: 12/15/2022]
Abstract
A reactive high-valent dinuclear nickel(IV) oxido bridged complex is reported that can be formed at room temperature by reaction of [(L)2Ni(II)2(μ-X)3]X (X = Cl or Br) with NaOCl in methanol or acetonitrile (where L = 1,4,7-trimethyl-1,4,7-triazacyclononane). The unusual Ni(IV) oxido species is stabilized within a dinuclear tris-μ-oxido-bridged structure as [(L)2Ni(IV)2(μ-O)3]2+. Its structure and its reactivity with organic substrates are demonstrated through a combination of UV-vis absorption, resonance Raman, 1H NMR, EPR, and X-ray absorption (near-edge) spectroscopy, ESI mass spectrometry, and DFT methods. The identification of a Ni(IV)-O species opens opportunities to control the reactivity of NaOCl for selective oxidations.
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Affiliation(s)
- Sandeep
K. Padamati
- Molecular
Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of
Science and Engineering, University of Groningen, Nijenborgh 4, 9747AG, Groningen, The Netherlands
| | - Davide Angelone
- Molecular
Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of
Science and Engineering, University of Groningen, Nijenborgh 4, 9747AG, Groningen, The Netherlands
- IQCC
& Departament de Química, Universitat
de Girona, Campus Montilivi
(Ciències), 17003 Girona, Spain
| | - Apparao Draksharapu
- Molecular
Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of
Science and Engineering, University of Groningen, Nijenborgh 4, 9747AG, Groningen, The Netherlands
| | - Gloria Primi
- Molecular
Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of
Science and Engineering, University of Groningen, Nijenborgh 4, 9747AG, Groningen, The Netherlands
| | - David J. Martin
- Sustainable
Materials Characterisation, Van’t Hoff Institute for Molecular
Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Moniek Tromp
- Sustainable
Materials Characterisation, Van’t Hoff Institute for Molecular
Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Marcel Swart
- IQCC
& Departament de Química, Universitat
de Girona, Campus Montilivi
(Ciències), 17003 Girona, Spain
- ICREA, Pg. Lluís Companys 23, 08010 Barcelona, Spain
| | - Wesley R. Browne
- Molecular
Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of
Science and Engineering, University of Groningen, Nijenborgh 4, 9747AG, Groningen, The Netherlands
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