1
|
Mukherjee G, Velmurugan G, Kerscher M, Kumar Satpathy J, Sastri CV, Comba P. Mechanistic Insights into Amphoteric Reactivity of an Iron-Bispidine Complex. Chemistry 2024; 30:e202303127. [PMID: 37942658 DOI: 10.1002/chem.202303127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 11/08/2023] [Accepted: 11/09/2023] [Indexed: 11/10/2023]
Abstract
The reactivity of FeIII -alkylperoxido complexes has remained a riddle to inorganic chemists owing to their thermal instability and impotency towards organic substrates. These iron-oxygen adducts have been known as sluggish oxidants towards oxidative electrophilic and nucleophilic reactions. Herein, we report the synthesis and spectroscopic characterization of a relatively stable mononuclear high-spin FeIII -alkylperoxido complex supported by an engineered bispidine framework. Against the notion, this FeIII -alkylperoxido complex serves as a rare example of versatile reactivity in both electrophilic and nucleophilic reactions. Detailed mechanistic studies and computational calculations reveal a novel reaction mechanism, where a putative superoxido intermediate orchestrates the amphoteric property of the oxidant. The design of the backbone is pivotal to convey stability and reactivity to alkylperoxido and superoxido intermediates. Contrary to the well-known O-O bond cleavage that generates an FeIV -oxido species, the FeIII -alkylperoxido complex reported here undergoes O-C bond scission to generate a superoxido moiety that is responsible for the amphiphilic reactivity.
Collapse
Affiliation(s)
- Gourab Mukherjee
- Department of Catalysis & Fine Chemicals, CSIR-Indian Institute of Chemical Technology Tarnaka, Hyderabad, 500007, India
| | - Gunasekaran Velmurugan
- Anorganisch-Chemisches Institut and, Interdisciplinary Center for Scientific Computing (IWR), Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany)
| | - Marion Kerscher
- Anorganisch-Chemisches Institut and, Interdisciplinary Center for Scientific Computing (IWR), Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany)
| | - Jagnyesh Kumar Satpathy
- Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati, Assam, 781039, India
| | - Chivukula V Sastri
- Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati, Assam, 781039, India
| | - Peter Comba
- Anorganisch-Chemisches Institut and, Interdisciplinary Center for Scientific Computing (IWR), Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany)
| |
Collapse
|
2
|
Chen Y, Chen G, Man WL. Effect of Alkyl Group on Aerobic Peroxidation of Hydrocarbons Catalyzed by Cobalt(III) Alkylperoxo Complexes. Eur J Inorg Chem 2022. [DOI: 10.1002/ejic.202200346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Yunzhou Chen
- Hong Kong Baptist University Chemistry HONG KONG
| | - Gui Chen
- Dongguan University of Technology School of Environment and Civil Engineering HONG KONG
| | - Wai-Lun Man
- Hong Kong Baptist University Chemistry Waterloo RoadKowloong Tong 0000 Hong Kong HONG KONG
| |
Collapse
|
3
|
Liu X, Miao Y, Luo F, Tang H, Yuan B, Zhao Y, Xie Y, Shao D, Lu X. Microwave vitrification of Sr-contaminated soil: microstructure, mechanical properties and chemical durability. J Radioanal Nucl Chem 2021. [DOI: 10.1007/s10967-021-08111-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
4
|
Shin B, Park Y, Jeong D, Cho J. Nucleophilic reactivity of a mononuclear cobalt(iii)-bis(tert-butylperoxo) complex. Chem Commun (Camb) 2020; 56:9449-9452. [PMID: 32687135 DOI: 10.1039/d0cc03385e] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
A mononuclear cobalt(III)-bis(tert-butylperoxo) adduct (CoIII-(OOtBu)2) bearing a tetraazamacrocyclic ligand was synthesized and characterized using various physicochemical methods, such as X-ray, UV-vis, ESI-MS, EPR, and NMR analyses. The crystal structure of the CoIII-(OOtBu)2 complex clearly showed that two OOtBu ligands bound to the equatorial position of the cobalt(iii) center. Kinetic studies and product analyses indicate that the CoIII-(OOtBu)2 intermediate exhibits nucleophilic oxidative reactivity toward external organic substrates.
Collapse
Affiliation(s)
- Bongki Shin
- Department of Emerging Materials Science, DGIST, Daegu 42988, Korea.
| | - Younwoo Park
- Department of Emerging Materials Science, DGIST, Daegu 42988, Korea.
| | - Donghyun Jeong
- Department of Emerging Materials Science, DGIST, Daegu 42988, Korea.
| | - Jaeheung Cho
- Department of Emerging Materials Science, DGIST, Daegu 42988, Korea.
| |
Collapse
|
5
|
|
6
|
Parham JD, Wijeratne GB, Rice DB, Jackson TA. Spectroscopic and Structural Characterization of Mn(III)-Alkylperoxo Complexes Supported by Pentadentate Amide-Containing Ligands. Inorg Chem 2018; 57:2489-2502. [DOI: 10.1021/acs.inorgchem.7b02793] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Joshua D. Parham
- Department of Chemistry and Center for Environmentally Beneficial Catalysis, University of Kansas, Lawrence, Kansas 66045, United States
| | - Gayan B. Wijeratne
- Department of Chemistry and Center for Environmentally Beneficial Catalysis, University of Kansas, Lawrence, Kansas 66045, United States
| | - Derek B. Rice
- Department of Chemistry and Center for Environmentally Beneficial Catalysis, University of Kansas, Lawrence, Kansas 66045, United States
| | - Timothy A. Jackson
- Department of Chemistry and Center for Environmentally Beneficial Catalysis, University of Kansas, Lawrence, Kansas 66045, United States
| |
Collapse
|
7
|
Serrano-Plana J, Acuña-Parés F, Dantignana V, Oloo WN, Castillo E, Draksharapu A, Whiteoak CJ, Martin-Diaconescu V, Basallote MG, Luis JM, Que L, Costas M, Company A. Acid-Triggered O-O Bond Heterolysis of a Nonheme Fe III (OOH) Species for the Stereospecific Hydroxylation of Strong C-H Bonds. Chemistry 2018; 24:5331-5340. [PMID: 29193378 DOI: 10.1002/chem.201704851] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Indexed: 12/11/2022]
Abstract
A novel hydroperoxoiron(III) species [FeIII (OOH)(MeCN)(PyNMe3 )]2+ (3) has been generated by reaction of its ferrous precursor [FeII (CF3 SO3 )2 (PyNMe3 )] (1) with hydrogen peroxide at low temperatures. This species has been characterized by several spectroscopic techniques and cryospray mass spectrometry. Similar to most of the previously described low-spin hydroperoxoiron(III) compounds, 3 behaves as a sluggish oxidant and it is not kinetically competent for breaking weak C-H bonds. However, triflic acid addition to 3 causes its transformation into a much more reactive compound towards organic substrates that is capable of oxidizing unactivated C-H bonds with high stereospecificity. Stopped-flow kinetic analyses and theoretical studies provide a rationale for the observed chemistry, a triflic-acid-assisted heterolytic cleavage of the O-O bond to form a putative strongly oxidizing oxoiron(V) species. This mechanism is reminiscent to that observed in heme systems, where protonation of the hydroperoxo intermediate leads to the formation of the high-valent [(Porph. )FeIV (O)] (Compound I).
Collapse
Affiliation(s)
- Joan Serrano-Plana
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, C/ M. Aurèlia Capmany 69, 17003, Girona, Catalonia, Spain
| | - Ferran Acuña-Parés
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, C/ M. Aurèlia Capmany 69, 17003, Girona, Catalonia, Spain.,Institute of Chemical Research of Catalonia (ICIQ), Avinguda Països Catalans 16, 43007, Tarragona, Spain
| | - Valeria Dantignana
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, C/ M. Aurèlia Capmany 69, 17003, Girona, Catalonia, Spain
| | - Williamson N Oloo
- Department of Chemistry and Center for Metals in Biocatalysis, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Esther Castillo
- Departamento de Ciencia de los Materiales e Ingeniería MetalúrgicayQuímica Inorgánica, Universidad de Cádiz, Facultad de Ciencias, Apdo. 40, 11510, Puerto Real, Cádiz, Spain
| | - Apparao Draksharapu
- Department of Chemistry and Center for Metals in Biocatalysis, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Christopher J Whiteoak
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, C/ M. Aurèlia Capmany 69, 17003, Girona, Catalonia, Spain
| | - Vlad Martin-Diaconescu
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, C/ M. Aurèlia Capmany 69, 17003, Girona, Catalonia, Spain
| | - Manuel G Basallote
- Departamento de Ciencia de los Materiales e Ingeniería MetalúrgicayQuímica Inorgánica, Universidad de Cádiz, Facultad de Ciencias, Apdo. 40, 11510, Puerto Real, Cádiz, Spain
| | - Josep M Luis
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, C/ M. Aurèlia Capmany 69, 17003, Girona, Catalonia, Spain
| | - Lawrence Que
- Department of Chemistry and Center for Metals in Biocatalysis, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Miquel Costas
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, C/ M. Aurèlia Capmany 69, 17003, Girona, Catalonia, Spain
| | - Anna Company
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, C/ M. Aurèlia Capmany 69, 17003, Girona, Catalonia, Spain
| |
Collapse
|
8
|
Geometric effects on O O bond scission of copper(II)-alkylperoxide complexes. J Inorg Biochem 2017; 177:375-383. [DOI: 10.1016/j.jinorgbio.2017.08.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Revised: 08/01/2017] [Accepted: 08/21/2017] [Indexed: 11/20/2022]
|
9
|
Kim B, Jeong D, Cho J. Nucleophilic reactivity of copper(ii)–alkylperoxo complexes. Chem Commun (Camb) 2017; 53:9328-9331. [DOI: 10.1039/c7cc03965d] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Copper(ii)–alkylperoxo adducts, [Cu(CHDAP)(OOR)]+ (CHDAP = N,N′-dicyclohexyl-2,11-diaza[3,3](2,6)pyridinophane; R = C(CH3)2Ph and tBu), perform aldehyde deformylation (i.e., nucleophilic reactivity) under the stoichiometric reaction conditions.
Collapse
Affiliation(s)
- Bohee Kim
- Department of Emerging Materials Science
- DGIST
- Daegu 42988
- Korea
| | - Donghyun Jeong
- Department of Emerging Materials Science
- DGIST
- Daegu 42988
- Korea
| | - Jaeheung Cho
- Department of Emerging Materials Science
- DGIST
- Daegu 42988
- Korea
| |
Collapse
|
10
|
Zima AM, Lyakin OY, Ottenbacher RV, Bryliakov KP, Talsi EP. Iron-Catalyzed Enantioselective Epoxidations with Various Oxidants: Evidence for Different Active Species and Epoxidation Mechanisms. ACS Catal 2016. [DOI: 10.1021/acscatal.6b02851] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Alexandra M. Zima
- Novosibirsk State University, Pirogova 2, Novosibirsk 630090, Russian Federation
- Boreskov Institute of Catalysis, Pr. Lavrentieva 5, Novosibirsk 630090, Russian Federation
| | - Oleg Y. Lyakin
- Novosibirsk State University, Pirogova 2, Novosibirsk 630090, Russian Federation
- Boreskov Institute of Catalysis, Pr. Lavrentieva 5, Novosibirsk 630090, Russian Federation
| | - Roman V. Ottenbacher
- Novosibirsk State University, Pirogova 2, Novosibirsk 630090, Russian Federation
- Boreskov Institute of Catalysis, Pr. Lavrentieva 5, Novosibirsk 630090, Russian Federation
| | - Konstantin P. Bryliakov
- Novosibirsk State University, Pirogova 2, Novosibirsk 630090, Russian Federation
- Boreskov Institute of Catalysis, Pr. Lavrentieva 5, Novosibirsk 630090, Russian Federation
| | - Evgenii P. Talsi
- Novosibirsk State University, Pirogova 2, Novosibirsk 630090, Russian Federation
- Boreskov Institute of Catalysis, Pr. Lavrentieva 5, Novosibirsk 630090, Russian Federation
| |
Collapse
|
11
|
Bae JM, Lee MM, Lee SA, Lee SY, Bok KH, Kim J, Kim C. Nonheme iron complex-catalyzed efficient alcohol oxidation by t-BuOOH with N-hydroxyphthalimide (NHPI) as co-catalyst: Implication of high valent iron-oxo species. Inorganica Chim Acta 2016. [DOI: 10.1016/j.ica.2016.06.038] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
12
|
Rhine MA, Sanders BC, Patra AK, Harrop TC. Overview and New Insights into the Thiol Reactivity of Coordinated NO in {MNO}6/7/8 (M = Fe, Co) Complexes. Inorg Chem 2015; 54:9351-66. [DOI: 10.1021/acs.inorgchem.5b00883] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Melody A. Rhine
- Department of Chemistry
and Center for Metalloenzyme Studies, The University of Georgia, 140 Cedar Street, Athens, Georgia 30602, United States
| | - Brian C. Sanders
- Department of Chemistry
and Center for Metalloenzyme Studies, The University of Georgia, 140 Cedar Street, Athens, Georgia 30602, United States
| | - Ashis K. Patra
- Department of Chemistry
and Center for Metalloenzyme Studies, The University of Georgia, 140 Cedar Street, Athens, Georgia 30602, United States
| | - Todd C. Harrop
- Department of Chemistry
and Center for Metalloenzyme Studies, The University of Georgia, 140 Cedar Street, Athens, Georgia 30602, United States
| |
Collapse
|
13
|
Shin JW, Bae JM, Kim C, Min KS. Catalysis and molecular magnetism of dinuclear iron(III) complexes with N-(2-pyridylmethyl)-iminodiethanol/-ate. Dalton Trans 2014; 43:3999-4008. [PMID: 24452503 DOI: 10.1039/c3dt53376j] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The reaction of N-(2-pyridylmethyl)iminodiethanol (H2pmide) and Fe(NO3)3·9H2O in MeOH led to the formation of a dimeric iron(III) complex, [(Hpmide)Fe(NO3)]2(NO3)2·2CH3OH (1). Its anion-exchanged form, [(pmide)Fe(N3)]2 (2), was prepared by the reaction of 1and NaN3 in MeOH, during which the Hpmide ligand of 1 was also deprotonated. These compounds were investigated by single crystal X-ray diffraction and magnetochemistry. In complex 1, one iron(III) ion was bonded with a mono-deprotonated Hpmide ligand and a nitrate ion. The two iron(III) ions within the dinuclear unit were connected by two ethoxy groups with an inversion center. In 2, one iron(III) ion was coordinated with a deprotonated pmide ligand and an azide ion. The Fe(pmide)(N3) unit was related by symmetry through an inversion center. Both 1 and 2 efficiently catalyzed the oxidation of a variety of alcohols under mild conditions. The oxidation mechanism was proposed to involve an Fe(IV)=O intermediate as the major reactive species and an Fe(V)=O intermediate as a minor oxidant. Evidence for this proposal was derived from reactivity and Hammett studies, KIE (kH/kD) values, and the use of MPPH (2-methyl-1-phenylprop-2-yl hydroperoxide) as a mechanistic probe. Both compounds had significant antiferromagnetic interactions between the iron(III) ions via the oxygen atoms. 1 showed a strong antiferromagnetic interaction within the Fe(III) dimer, while 2 had a weak antiferromagnetic coupling within the Fe(III) dimer.
Collapse
Affiliation(s)
- Jong Won Shin
- Department of Chemistry and Green-Nano Materials Research Center, Kyungpook National University, Daegu, 702-701, Republic of Korea
| | | | | | | |
Collapse
|
14
|
Widger LR, Jiang Y, McQuilken AC, Yang T, Siegler MA, Matsumura H, Moënne-Loccoz P, Kumar D, de Visser SP, Goldberg DP. Thioether-ligated iron(II) and iron(III)-hydroperoxo/alkylperoxo complexes with an H-bond donor in the second coordination sphere. Dalton Trans 2014; 43:7522-32. [PMID: 24705907 PMCID: PMC4319814 DOI: 10.1039/c4dt00281d] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The non-heme iron complexes, [Fe(II)(N3PySR)(CH3CN)](BF4)2 () and [Fe(II)(N3Py(amide)SR)](BF4)2 (), afford rare examples of metastable Fe(iii)-OOH and Fe(iii)-OOtBu complexes containing equatorial thioether ligands and a single H-bond donor in the second coordination sphere. These peroxo complexes were characterized by a range of spectroscopic methods and density functional theory studies. The influence of a thioether ligand and of one H-bond donor on the stability and spectroscopic properties of these complexes was investigated.
Collapse
Affiliation(s)
- Leland R Widger
- Department of Chemistry, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, USA.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Peroxomanganese complexes as an aid to understanding redox-active manganese enzymes. J Biol Inorg Chem 2013; 19:1-15. [DOI: 10.1007/s00775-013-1067-4] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Accepted: 11/07/2013] [Indexed: 02/07/2023]
|
16
|
McDonald AR, Van Heuvelen KM, Guo Y, Li F, Bominaar EL, Münck E, Que L. Characterization of a thiolato iron(III) Peroxy dianion complex. Angew Chem Int Ed Engl 2012; 51:9132-6. [PMID: 22888066 PMCID: PMC3448492 DOI: 10.1002/anie.201203602] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2012] [Revised: 06/19/2012] [Indexed: 11/09/2022]
Abstract
Nucleophilic oxidant: The reaction between a thiolato iron(II) complex 1 and superoxide in aprotic solvent at -90 °C yields a novel thiolato iron(III) peroxide intermediate 2, which exhibits unusually high nucleophilic reactivity. Compound 2 is an isomer of the thiolato iron(II) superoxide intermediate that is invoked in the reaction between superoxide reductase and superoxide.
Collapse
Affiliation(s)
- Aidan R. McDonald
- Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, MN 55455, USA
| | - Katherine M. Van Heuvelen
- Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, MN 55455, USA
| | - Yisong Guo
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA 15213, USA
| | - Feifei Li
- Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, MN 55455, USA
| | - Emile L. Bominaar
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA 15213, USA
| | - Eckard Münck
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA 15213, USA
| | - Lawrence Que
- Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, MN 55455, USA
| |
Collapse
|
17
|
Tano T, Sugimoto H, Fujieda N, Itoh S. Heterolytic Alkyl Hydroperoxide O-O Bond Cleavage by Copper(I) Complexes. Eur J Inorg Chem 2012. [DOI: 10.1002/ejic.201200555] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
18
|
McDonald AR, Van Heuvelen KM, Guo Y, Li F, Bominaar EL, Münck E, Que L. Characterization of a Thiolato Iron(III) Peroxy Dianion Complex. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201203602] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
19
|
Gonzalez-Ovalle LE, Quesne MG, Kumar D, Goldberg DP, de Visser SP. Axial and equatorial ligand effects on biomimetic cysteine dioxygenase model complexes. Org Biomol Chem 2012; 10:5401-9. [PMID: 22714822 PMCID: PMC3454459 DOI: 10.1039/c2ob25406a] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Density functional theory (DFT) calculations are presented on biomimetic model complexes of cysteine dioxygenase and focus on the effect of axial and equatorial ligand placement. Recent studies by one of us [Y. M. Badiei, M. A. Siegler and D. P. Goldberg, J. Am. Chem. Soc. 2011, 133, 1274] gave evidence of a nonheme iron biomimetic model of cysteine dioxygenase using an i-propyl-bis(imino)pyridine, equatorial tridentate ligand. Addition of thiophenol, an anion - either chloride or triflate - and molecular oxygen, led to several possible stereoisomers of this cysteine dioxygenase biomimetic complex. Moreover, large differences in reactivity using chloride as compared to triflate as the binding anion were observed. Here we present a series of DFT calculations on the origin of these reactivity differences and show that it is caused by the preference of coordination site of anion versus thiophenol binding to the chemical system. Thus, stereochemical interactions of triflate and the bulky iso-propyl substituents of the ligand prevent binding of thiophenol in the trans position using triflate. By contrast, smaller anions, such as chloride, can bind in either cis or trans ligand positions and give isomers with similar stability. Our calculations help to explain the observance of thiophenol dioxygenation by this biomimetic system and gives details of the reactivity differences of ligated chloride versus triflate.
Collapse
Affiliation(s)
- Luis E. Gonzalez-Ovalle
- Manchester Interdisciplinary Biocenter and School of Chemical Engineering and Analytical Science, University of Manchester, 131 Princess Street, Manchester M1 7DN, UK. Fax: +44 161306 5201
| | - Matthew G. Quesne
- Manchester Interdisciplinary Biocenter and School of Chemical Engineering and Analytical Science, University of Manchester, 131 Princess Street, Manchester M1 7DN, UK. Fax: +44 161306 5201
| | - Devesh Kumar
- Department of Applied Physics, School of Physical Sciences, Babasaheb, Bhimrao Ambedkar University, Vidya Vihar, Rae Bareilly Road, Lucknow 226-025, India
| | - David P. Goldberg
- Department of Chemistry, Johns Hopkins University, 3400 N. Charles Street, Baltimore, Maryland 21218, USA
| | - Sam P. de Visser
- Manchester Interdisciplinary Biocenter and School of Chemical Engineering and Analytical Science, University of Manchester, 131 Princess Street, Manchester M1 7DN, UK. Fax: +44 161306 5201
| |
Collapse
|
20
|
Preparation of aluminum(III) (bis(amido)pyridine)(thiolate) complexes: unexpected transmetalation mediated by LiAlH(4). Inorganica Chim Acta 2012; 382:19-26. [PMID: 22345823 DOI: 10.1016/j.ica.2011.09.056] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Treatment of an unsymmetrical bis(imino)pyridyl-thiolate zinc(II) complex [Zn(II)(LN(3)S)(OTf)] (1) with LiAlH(4) results in the double reduction of the two imino groups in the ligand backbone, and at the same time causes a rare transmetalation reaction to occur. The products formed in this reaction are two novel aluminium(III) bis(amido)pyridyl-thiolate complexes [(R,S/S,R-[Al(III)(LH(2)N(3)S)(THF)] (2a) and [(R,R/S,S-[Al(III)(LH(2)N(3)S)(THF)] (2b), which are diastereomers of each other. These complexes have been characterized by single-crystal X-ray diffraction and (1)H NMR spectroscopy. Single crystal X-ray structure analysis shows that the Al(III) ion is bound in an almost idealized square pyramidal geometry in 2a, while being held in a more distorted square pyramidal geometry in 2b. The major difference between 2a and 2b arises in the orientation of the terminal methyl groups of the ligand backbone in relation to the Al(III)N(3)S plane. These two complexes are crystallized at different temperatures (room temperature vs -35 °C), allowing for their separate isolation. Structural analysis shows that these complexes are reduced by the formal addition of one hydride ion to each imino group, resulting in a deprotonated bis(amido)pyridyl-thiolate ligand. A detailed analysis of metrical parameters rules out the possibility of pure one- or two-electron reduction of the π-conjugated bis(imino)pyridine framework. (1)H NMR spectra reveal a rich pattern in solution indicating that the solution state structures for 2a and 2b match those observed in the solid-state crystal structures, and reveal that both complexes are severely conformationally restricted. Direct organic synthetic methods failed to produce the reduced bis(amino)pyridyl-thiol ligand in pure form, but during the course of these efforts an unusual unsymmetrical aminopyridyl ketone, 1-(6-(1-(2,6-diisopropylphenylamino)ethyl)pyridin-2-yl)ethanone was synthesized in good yield and can be used as a possible precursor for further ligand development.
Collapse
|
21
|
Tano T, Ertem MZ, Yamaguchi S, Kunishita A, Sugimoto H, Fujieda N, Ogura T, Cramer CJ, Itoh S. Reactivity of copper(II)-alkylperoxo complexes. Dalton Trans 2011; 40:10326-36. [PMID: 21808769 DOI: 10.1039/c1dt10656b] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Copper(II) complexes 1a and 1b, supported by tridentate ligand bpa [bis(2-pyridylmethyl)amine] and tetradentate ligand tpa [tris(2-pyridylmethyl)amine], respectively, react with cumene hydroperoxide (CmOOH) in the presence of triethylamine in CH(3)CN to provide the corresponding copper(II) cumylperoxo complexes 2a and 2b, the formation of which has been confirmed by resonance Raman and ESI-MS analyses using (18)O-labeled CmOOH. UV-vis and ESR spectra as well as DFT calculations indicate that 2a has a 5-coordinate square-pyramidal structure involving CmOO(-) at an equatorial position and one solvent molecule at an axial position at low temperature (-90 °C), whereas a 4-coordinate square-planar structure that has lost the axial solvent ligand is predominant at higher temperatures (above 0 °C). Complex 2b, on the other hand, has a typical trigonal bipyramidal structure with the tripodal tetradentate tpa ligand, where the cumylperoxo ligand occupies an axial position. Both cumylperoxo copper(II) complexes 2a and 2b are fairly stable at ambient temperature, but decompose at a higher temperature (60 °C) in CH(3)CN. Detailed product analyses and DFT studies indicate that the self-decomposition involves O-O bond homolytic cleavage of the peroxo moiety; concomitant hydrogen-atom abstraction from the solvent is partially involved. In the presence of 1,4-cyclohexadiene (CHD), the cumylperoxo complexes react smoothly at 30 °C to give benzene as one product. Detailed product analyses and DFT studies indicate that reaction with CHD involves concerted O-O bond homolytic cleavage and hydrogen-atom abstraction from the substrate, with the oxygen atom directly bonded to the copper(II) ion (proximal oxygen) involved in the C-H bond activation step.
Collapse
Affiliation(s)
- Tetsuro Tano
- Department of Material and Life Science, Division of Advanced Science and Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871, Japan
| | | | | | | | | | | | | | | | | |
Collapse
|
22
|
Coggins MK, Kovacs JA. Structural and spectroscopic characterization of metastable thiolate-ligated manganese(III)-alkylperoxo species. J Am Chem Soc 2011; 133:12470-3. [PMID: 21776951 DOI: 10.1021/ja205520u] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Metastable Mn-peroxo species are proposed to form as key intermediates in biological oxidation reactions involving O(2) and C-H bond activation. The majority of these have yet to be spectroscopically characterized, and their inherent instability, in most cases, precludes structural characterization. Cysteinate-ligated metal-peroxos have been shown to form as reactive intermediates in both heme and nonheme iron enzymes. Herein we report the only examples of isolable Mn(III)-alkylperoxo species, and the first two examples of structurally characterized synthetic thiolate-ligated metal-peroxos. Spectroscopic data, including electronic absorption and IR spectra, and ESI mass spectra for (16)O vs (18)O-labeled metastable Mn(III)-OOR (R = (t)Bu, Cm) are discussed, as well as preliminary reactivity.
Collapse
Affiliation(s)
- Michael K Coggins
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
| | | |
Collapse
|
23
|
|