1
|
Fagnano A, Frateloreto F, Paoloni R, Sappino C, Lanzalunga O, Costas M, Di Stefano S, Olivo G. Proximity Effects on the Reactivity of a Nonheme Iron (IV) Oxo Complex in C-H Oxidation. Angew Chem Int Ed Engl 2024; 63:e202401694. [PMID: 38478739 DOI: 10.1002/anie.202401694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Indexed: 04/05/2024]
Abstract
Precise control of substrate positioning and orientation (its proximity to the reactive unit) is often invoked to rationalize the superior enzymatic reaction rates and selectivities when compared to synthetic models. Artificial nonheme iron (IV) oxo (Fe(IV)=O) complexes react with C(sp3)-H bonds via a biomimetic Hydrogen Atom Transfer/Hydroxyl Rebound mechanism, but rates, site-selectivity and even hydroxyl rebound efficiency (ligand rebound versus substrate radical diffusion) are smaller than in oxygenases. Herein, we quantitatively analyze how substrate binding modulates nonheme Fe(IV)=O reactivity by comparing rates and outcomes of C-H oxidation by a pair of Fe(IV)=O complexes that share the same first coordination sphere but only one contains a crown ether receptor that recognizes the substrate. Substrate binding makes the reaction intramolecular, exhibiting Michaelis-Menten kinetics and increased reaction rates. In addition, C-H oxidation occurs with high site selectivity for remote sites. Analysis of Effective Molarity reveals that the system operates at its maximal theoretical capability for the oxidation of these remote sites. Remarkably, substrate positioning also affects Hydroxyl Rebound, whose efficiency only increases on the sites placed in proximity by recognition. Overall, these observations provide evidence that supramolecular control of substrate positioning can effectively modulate the reactivity of oxygenases and its models.
Collapse
Affiliation(s)
- Alessandro Fagnano
- Dipartimento di Chimica and Istituto CNR per i Sistemi Biologici (ISB-CNR), Sezione Meccanismi di Reazione, c/o Dipartimento di Chimica, Università di Roma "La Sapienza", P.le A. Moro, 5 I-00185, Rome, Italy
| | - Federico Frateloreto
- Dipartimento di Chimica and Istituto CNR per i Sistemi Biologici (ISB-CNR), Sezione Meccanismi di Reazione, c/o Dipartimento di Chimica, Università di Roma "La Sapienza", P.le A. Moro, 5 I-00185, Rome, Italy
| | - Roberta Paoloni
- Dipartimento di Chimica and Istituto CNR per i Sistemi Biologici (ISB-CNR), Sezione Meccanismi di Reazione, c/o Dipartimento di Chimica, Università di Roma "La Sapienza", P.le A. Moro, 5 I-00185, Rome, Italy
| | - Carla Sappino
- Dipartimento di Chimica and Istituto CNR per i Sistemi Biologici (ISB-CNR), Sezione Meccanismi di Reazione, c/o Dipartimento di Chimica, Università di Roma "La Sapienza", P.le A. Moro, 5 I-00185, Rome, Italy
| | - Osvaldo Lanzalunga
- Dipartimento di Chimica and Istituto CNR per i Sistemi Biologici (ISB-CNR), Sezione Meccanismi di Reazione, c/o Dipartimento di Chimica, Università di Roma "La Sapienza", P.le A. Moro, 5 I-00185, Rome, Italy
| | - Miquel Costas
- QBIS-Cat, Institut de Química Computacional i Catàlisi (IQCC), Departament de Quimica, Universitat de Girona Campus Montilivi, 17071, Girona, Catalonia, Spain
| | - Stefano Di Stefano
- Dipartimento di Chimica and Istituto CNR per i Sistemi Biologici (ISB-CNR), Sezione Meccanismi di Reazione, c/o Dipartimento di Chimica, Università di Roma "La Sapienza", P.le A. Moro, 5 I-00185, Rome, Italy
| | - Giorgio Olivo
- Dipartimento di Chimica and Istituto CNR per i Sistemi Biologici (ISB-CNR), Sezione Meccanismi di Reazione, c/o Dipartimento di Chimica, Università di Roma "La Sapienza", P.le A. Moro, 5 I-00185, Rome, Italy
| |
Collapse
|
2
|
Yu K, Zhang K, Jakob RP, Maier T, Ward TR. An artificial nickel chlorinase based on the biotin-streptavidin technology. Chem Commun (Camb) 2024; 60:1944-1947. [PMID: 38277163 PMCID: PMC10863421 DOI: 10.1039/d3cc05847f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Accepted: 01/17/2024] [Indexed: 01/27/2024]
Abstract
Herein, we report on an artificial nickel chlorinase (ANCase) resulting from anchoring a biotinylated nickel-based cofactor within streptavidin (Sav). The resulting ANCase was efficient for the chlorination of diverse C(sp3)-H bonds. Guided by the X-ray analysis of the ANCase, the activity of the artificial chlorinase could be significantly improved. This approach opens interesting perspectives for late-stage functionalization of organic intermediates as it complements biocatalytic chlorination strategies.
Collapse
Affiliation(s)
- Kun Yu
- Department of Chemistry, University of Basel, Mattenstrasse 22, Basel, CH-4058, Switzerland.
| | - Kailin Zhang
- Department of Chemistry, University of Basel, Mattenstrasse 22, Basel, CH-4058, Switzerland.
| | - Roman P Jakob
- Biozentrum, University of Basel, Spitalstrasse 41, Basel, CH-4056, Switzerland
| | - Timm Maier
- Biozentrum, University of Basel, Spitalstrasse 41, Basel, CH-4056, Switzerland
| | - Thomas R Ward
- Department of Chemistry, University of Basel, Mattenstrasse 22, Basel, CH-4058, Switzerland.
| |
Collapse
|
3
|
Yadav V, Wen L, Yadav S, Siegler MA, Goldberg DP. Selective Radical Transfer in a Series of Nonheme Iron(III) Complexes. Inorg Chem 2023; 62:17830-17842. [PMID: 37857315 DOI: 10.1021/acs.inorgchem.3c02617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2023]
Abstract
A series of nonheme iron complexes, FeIII(BNPAPh2O)(Lax)(Leq) (Lax/eq = N3-, NCS-, NCO-, and Cl-) have been synthesized using the previously reported BNPAPh2O- ligand. The ferrous analogs FeII(BNPAPh2O)(Lax) (Lax = N3-, NCS-, and NCO-) were also prepared. The complexes were structurally characterized using single crystal X-ray diffraction, which shows that all the FeIII complexes are six-coordinate, with one anionic ligand (Lax) in the H-bonding axial site and the other anionic ligand (Leq) in the equatorial plane, cis to the Lax ligand. The reaction of FeIII(BNPAPh2O-)(Lax)(Leq) with Ph3C• shows that one ligand is selectively transferred in each case. A selectivity trend emerges that shows •N3 is the most favored for transfer in each case to the carbon radical, whereas Cl• is the least favored. The NCO and NCS ligands showed an intermediate propensity for radical transfer, with NCS > NCO. The overall order of selectivity is N3 > NCS > NCO > Cl. In addition, we also demonstrated that H-bonding has a small effect on governing product selectivity by using a non-H-bonded ligand (DPAPh2O-). This study demonstrates the inherent radical transfer selectivity of nonhydroxo-ligated nonheme iron(III) complexes, which could be useful for efforts in synthetic and (bio)catalytic C-H functionalization.
Collapse
Affiliation(s)
- Vishal Yadav
- Department of Chemistry, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
| | - Lyupeng Wen
- Department of Chemistry, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
| | - Sudha Yadav
- Department of Chemistry, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
| | - Maxime A Siegler
- Department of Chemistry, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
| | - David P Goldberg
- Department of Chemistry, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
| |
Collapse
|
4
|
Joy J, Ess DH. Direct Dynamics Trajectories Demonstrate Dynamic Matching and Nonstatistical Radical Pair Intermediates during Fe-Oxo-Mediated C-H Functionalization Reactions. J Am Chem Soc 2023; 145:7628-7637. [PMID: 36952628 DOI: 10.1021/jacs.3c01196] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/25/2023]
Abstract
The generally proposed mechanism for the reaction between non-heme Fe-oxo complexes and alkane C-H bonds involves a hydrogen atom transfer (HAT) reaction step with a radical pair intermediate that then has competitive radical rebound, dissociation, or desaturation pathways. Here, we report density functional theory-based quasiclassical direct dynamics trajectories that examine post-HAT reaction dynamics. Trajectories revealed that the radical pair intermediate can be a nonstatistical type intermediate without complete internal vibrational redistribution and post-HAT selectivity is generally determined by dynamic effects. Fast rebound trajectories occur through dynamic matching between the rotational motion of the newly formed Fe-OH bond and collision with the alkane radical, and all of this occurs through a nonsynchronous dynamically concerted process that circumvents the radical pair intermediate structure. For radical pair dissociation, trajectories proceeded to the radical pair intermediate for a very brief time, followed by complete dissociation. These trajectories provide a new viewpoint and model to understand the inherent reaction pathway selectivity for non-heme Fe-oxo-mediated C-H functionalization reactions.
Collapse
Affiliation(s)
- Jyothish Joy
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602, United States
| | - Daniel H Ess
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602, United States
| |
Collapse
|
5
|
Schlachta TP, Kühn FE. Cyclic iron tetra N-heterocyclic carbenes: synthesis, properties, reactivity, and catalysis. Chem Soc Rev 2023; 52:2238-2277. [PMID: 36852959 DOI: 10.1039/d2cs01064j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/01/2023]
Abstract
Cyclic iron tetracarbenes are an emerging class of macrocyclic iron N-heterocyclic carbene (NHC) complexes. They can be considered as an organometallic compound class inspired by their heme analogs, however, their electronic properties differ, e.g. due to the very strong σ-donation of the four combined NHCs in equatorial coordination. The ligand framework of iron tetracarbenes can be readily modified, allowing fine-tuning of the structural and electronic properties of the complexes. The properties of iron tetracarbene complexes are discussed quantitatively and correlations are established. The electronic nature of the tetracarbene ligand allows the isolation of uncommon iron(III) and iron(IV) species and reveals a unique reactivity. Iron tetracarbenes are successfully applied in C-H activation, CO2 reduction, aziridination and epoxidation catalysis and mechanisms as well as decomposition pathways are described. This review will help researchers evaluate the structural and electronic properties of their complexes and target their catalyst properties through ligand design.
Collapse
Affiliation(s)
- Tim P Schlachta
- Technical University of Munich, School of Natural Sciences, Department of Chemistry and Catalysis Research Center, Molecular Catalysis, Lichtenbergstraße 4, 85748 Garching, Germany.
| | - Fritz E Kühn
- Technical University of Munich, School of Natural Sciences, Department of Chemistry and Catalysis Research Center, Molecular Catalysis, Lichtenbergstraße 4, 85748 Garching, Germany.
| |
Collapse
|
6
|
Yang M, Chen X, Su X, She YB, Yang YF. Mechanistic Study of Chemoselectivity for Carbon Radical Hydroxylation versus Chlorination with Fe III (OH)(Cl) Complexes. Chem Asian J 2023; 18:e202201311. [PMID: 36705485 DOI: 10.1002/asia.202201311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 01/21/2023] [Accepted: 01/23/2023] [Indexed: 01/28/2023]
Abstract
The FeIII (OH)(Cl) complex resembles the key intermediate proposed for the non-heme iron halogenases. Goldberg and co-workers reported that the FeIII (OH)(Cl) RC reacts with triphenylmethyl radical 1 to give an exclusive hydroxylation product. To understand the chemoselectivity of the reaction of RC with 1, density functional theory (DFT) calculations have been conducted. From RC, the competing pathways were identified as the OH-transfer, Cl-transfer, and isomerization pathways. The direct Cl-transfer is more favorable than direct OH-transfer by 2.8 kcal/mol. The hydrogen bonding interactions between the hydroxyl group and the pendent amine ligand impede the direct OH-transfer from RC. Compared with the direct Cl-transfer pathway, the isomerization pathways require lower barriers. In isomer RCiso2 , the equatorial hydroxyl group, which has smaller diabatic bond dissociation energy, prefers to transfer to form the hydroxylation product. In FeIII (Cl)2 RC2 and RC2iso , the equatorial chloride group also prefers to transfer to give the chlorination product.
Collapse
Affiliation(s)
- Miao Yang
- College of Chemical Engineering, Zhejiang University of Technology, Hangzhou, Zhejiang, 310014, P. R. China
| | - Xiahe Chen
- College of Chemical Engineering, Zhejiang University of Technology, Hangzhou, Zhejiang, 310014, P. R. China
| | - Xingxing Su
- College of Chemical Engineering, Zhejiang University of Technology, Hangzhou, Zhejiang, 310014, P. R. China
| | - Yuan-Bin She
- College of Chemical Engineering, Zhejiang University of Technology, Hangzhou, Zhejiang, 310014, P. R. China
| | - Yun-Fang Yang
- College of Chemical Engineering, Zhejiang University of Technology, Hangzhou, Zhejiang, 310014, P. R. China
| |
Collapse
|
7
|
Shen C, Dagnaw WM, Fong CW, Lau KC, Chow CF. Selective functionalization of C(sp 3)-H bonds: catalytic chlorination and bromination by Iron III-acacen-halide under ambient condition. Chem Commun (Camb) 2022; 58:10627-10630. [PMID: 36069398 DOI: 10.1039/d2cc02924c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The oxidative catalytic halogenations of the C(sp3)-H bond of alkanes promoted by FeIII(acacen)Cl (1III-Cl) and FeIII(acacen)Br (1III-Br) in the presence of trifluoroacetic acid (TFA) were investigated. Four major steps were involved: (i) formation of [FeV(acacen)(oxo)X] species (X = Cl or Br), (ii) hydrogen-atom transfer, (iii) halogen atom rebound, and (iv) regeneration of 1III-Cl or 1III-Br. TFA played a significant role in (i) forming the high-valent iron-oxo intermediate and (ii) generating the reaction selectivity.
Collapse
Affiliation(s)
- Chang Shen
- Department of Science and Environmental Studies, The Education University of Hong Kong, 10 Lo Ping Road, Tai Po, Hong Kong SAR, China.
| | - Wasihun Menberu Dagnaw
- Department of Chemistry, The City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, SAR, China.
| | - Ching Wai Fong
- Department of Science and Environmental Studies, The Education University of Hong Kong, 10 Lo Ping Road, Tai Po, Hong Kong SAR, China.
| | - Kai Chung Lau
- Department of Chemistry, The City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, SAR, China.
| | - Cheuk-Fai Chow
- Department of Science and Environmental Studies, The Education University of Hong Kong, 10 Lo Ping Road, Tai Po, Hong Kong SAR, China.
| |
Collapse
|
8
|
Han J, Tan L, Wan Y, Li G, Anderson SN. C(sp 3)-H oxidation and chlorination catalysed by a bioinspired pincer iron(III) complex. Dalton Trans 2022; 51:11620-11624. [PMID: 35895115 DOI: 10.1039/d2dt02005j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A pincer iron(III) catalyst for the oxidation and chlorination of C(sp3)-H bonds was developed. Oxidation of a diagnostic substrate cis-decalin implies that a long-lived carbon-centred radical is involved. Mechanistic studies suggest that an Fe-oxo species could be responsible for the rate-determining C-H activation step. This report expands the scope of non-heme catalysts for C-H functionalisation.
Collapse
Affiliation(s)
- Jian Han
- Department of Chemistry and Biochemistry, Utah State University, Logan, Utah, 84322, USA.
| | - Liming Tan
- Department of Chemistry and Biochemistry, Utah State University, Logan, Utah, 84322, USA.
| | - Yanjun Wan
- Department of Chemistry and Biochemistry, Utah State University, Logan, Utah, 84322, USA.
| | - Gang Li
- Department of Chemistry and Biochemistry, Utah State University, Logan, Utah, 84322, USA.
| | - Stephen N Anderson
- Department of Chemistry and Biochemistry, Utah State University, Logan, Utah, 84322, USA.
| |
Collapse
|
9
|
Gérard EF, Yadav V, Goldberg DP, de Visser SP. What Drives Radical Halogenation versus Hydroxylation in Mononuclear Nonheme Iron Complexes? A Combined Experimental and Computational Study. J Am Chem Soc 2022; 144:10752-10767. [PMID: 35537044 PMCID: PMC9228086 DOI: 10.1021/jacs.2c01375] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
![]()
Nonheme iron halogenases
are unique enzymes in nature that selectively
activate an aliphatic C–H bond of a substrate to convert it
into C–X (X = Cl/Br, but not F/I). It is proposed that they
generate an FeIII(OH)(X) intermediate in their catalytic
cycle. The analogous FeIII(OH) intermediate in nonheme
iron hydroxylases transfers OH• to give alcohol
product, whereas the halogenases transfer X• to
the carbon radical substrate. There remains significant debate regarding
what factors control their remarkable selectivity of the halogenases.
The reactivity of the complexes FeIII(BNPAPh2O)(OH)(X) (X = Cl, Br) with a secondary carbon radical (R•) is described. It is found that X• transfer occurs
with a secondary carbon radical, as opposed to OH• transfer with tertiary radicals. Comprehensive computational studies
involving density functional theory were carried out to examine the
possible origins of this selectivity. The calculations reproduce the
experimental findings, which indicate that halogen transfer is not
observed for the tertiary radicals because of a nonproductive equilibrium
that results from the endergonic nature of these reactions, despite
a potentially lower reaction barrier for the halogenation pathway.
In contrast, halogen transfer is favored for secondary carbon radicals,
for which the halogenated product complex is thermodynamically more
stable than the reactant complex. These results are rationalized by
considering the relative strengths of the C–X bonds that are
formed for tertiary versus secondary carbon centers. The computational
analysis also shows that the reaction barrier for halogen transfer
is significantly dependent on secondary coordination sphere effects,
including steric and H-bonding interactions.
Collapse
Affiliation(s)
- Emilie F Gérard
- Manchester Institute of Biotechnology, The University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom.,Department of Chemical Engineering, The University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Vishal Yadav
- Department of Chemistry, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
| | - David P Goldberg
- Department of Chemistry, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
| | - Sam P de Visser
- Manchester Institute of Biotechnology, The University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom.,Department of Chemical Engineering, The University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| |
Collapse
|
10
|
Tao Y, Li Z, Zhang Y, Sun K, Liu Z. Determining the inherent selectivity for carbon radical hydroxylation versus halogenation with high-spin oxoiron(iv)-halide complexes: a concerted rebound step. RSC Adv 2022; 12:9891-9897. [PMID: 35424943 PMCID: PMC8963258 DOI: 10.1039/d2ra01384c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 03/22/2022] [Indexed: 11/23/2022] Open
Abstract
A synthetic iron model can process both halogenation and hydroxylation with vague selectivity, which is different from halogenase even though these structures are used for the simulation of halogenase. The key factor of the synthetic oxo-iron model mediated hydroxylation or the halogenation is still under debate. Herein density functional theory calculation is used to investigate the hydroxylation versus halogenation of propylene by the complex [FeIV(O)(TQA)(X)]+ (X = F, Cl, Br). Our results suggest that a concerted rebound mechanism (between the -X and the hydroxyl ligands after the hydrogen abstraction) leads to the formation of two different kinds of products. DFT calculation for the hydroxylation versus halogenation of propylene by [FeIV(O)(TQA)X]+ (X = F, Cl and Br) reveals that after hydrogen abstraction, halogen and oxygen rebound reactions are a synergistic process.![]()
Collapse
Affiliation(s)
- Yaping Tao
- College of Physics and Electronic Information & Henan Key Laboratory of Electromagnetic Transformation and Detection, Luoyang Normal University Luoyang 471934 China
| | - Zixian Li
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology Beijing 100029 China
| | - Yiman Zhang
- College of Physics and Electronic Information & Henan Key Laboratory of Electromagnetic Transformation and Detection, Luoyang Normal University Luoyang 471934 China
| | - Kexi Sun
- College of Physics and Electronic Information & Henan Key Laboratory of Electromagnetic Transformation and Detection, Luoyang Normal University Luoyang 471934 China
| | - Zhaojun Liu
- College of Physics and Electronic Information & Henan Key Laboratory of Electromagnetic Transformation and Detection, Luoyang Normal University Luoyang 471934 China
| |
Collapse
|
11
|
Abstract
Ni(II)-tetradentate amido-quinoline complexes effectively catalysed C-H chlorination of a series of hydrocarbons in the presence of NaOCl and acetic acid. The bond dissociation energy of the C(sp3)-H bond of the substrates varies from 99.3 kcal mol-1 (cyclohexane) to 87 kcal mol-1 (ethyl benzene). Exclusively chlorinated products (TON: 220 for cyclohexane) were obtained without any hydroxylated products, thus mimicking the activity of the halogenase enzyme.
Collapse
Affiliation(s)
- Sanjay Adhikari
- Department of Chemistry Shiv Nadar University, U.P. 201314, India.
| | - Aniruddha Sarkar
- Department of Chemical Sciences, Indian Institute of Science, Education and Research Kolkata, Mohanpur 741246, India
| | | |
Collapse
|
12
|
Paik A, Paul S, Bhowmik S, Das R, Naveen T, Rana S. Recent Advances in First Row Transition Metal Mediated C‐H Halogenation of (Hetero)arenes and Alkanes. ASIAN J ORG CHEM 2022. [DOI: 10.1002/ajoc.202200060] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Aniruddha Paik
- University of North Bengal Department of Chemistry Raja Rammohunpur, DarjeelingWest Bengal, India - 734013 734013 Siliguri INDIA
| | - Sabarni Paul
- University of North Bengal Department of Chemistry Raja Rammohunpur, DarjeelingWest Bengal, India - 734013 734013 Siliguri INDIA
| | - Sabyasachi Bhowmik
- University of North Bengal Department of Chemistry Raja Rammohunpur, DarjeelingWest Bengal, India - 734013 734013 Siliguri INDIA
| | - Rahul Das
- University of North Bengal Department of Chemistry Raja Rammohunpur, DarjeelingWest Bengal, India - 734013 734013 Siliguri INDIA
| | - Togati Naveen
- Sardar Vallabhbhai National Institute of Technology Department of Chemistry 395007 Surat INDIA
| | - Sujoy Rana
- University of North Bengal Chemistry Raja Rammohunpur, DarjeelingWest Bengal, India, 734013 734013 Siliguri INDIA
| |
Collapse
|
13
|
Bleher K, Comba P, Faltermeier D, Gupta A, Kerscher M, Krieg S, Martin B, Velmurugan G, Yang S. Non-Heme-Iron-Mediated Selective Halogenation of Unactivated Carbon-Hydrogen Bonds. Chemistry 2021; 28:e202103452. [PMID: 34792224 PMCID: PMC9300152 DOI: 10.1002/chem.202103452] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Indexed: 12/23/2022]
Abstract
Oxidation of the iron(II) precursor [(L1)FeIICl2], where L1 is a tetradentate bispidine, with soluble iodosylbenzene (sPhIO) leads to the extremely reactive ferryl oxidant [(L1)(Cl)FeIV=O]+ with a cis disposition of the chlorido and oxido coligands, as observed in non‐heme halogenase enzymes. Experimental data indicate that, with cyclohexane as substrate, there is selective formation of chlorocyclohexane, the halogenation being initiated by C−H abstraction and the result of a rebound of the ensuing radical to an iron‐bound Cl−. The time‐resolved formation of the halogenation product indicates that this primarily results from sPhIO oxidation of an initially formed oxido‐bridged diiron(III) resting state. The high yield of up to >70 % (stoichiometric reaction) as well as the differing reactivities of free Fe2+ and Fe3+ in comparison with [(L1)FeIICl2] indicate a high complex stability of the bispidine‐iron complexes. DFT analysis shows that, due to a large driving force and small triplet‐quintet gap, [(L1)(Cl)FeIV=O]+ is the most reactive small‐molecule halogenase model, that the FeIII/radical rebound intermediate has a relatively long lifetime (as supported by experimentally observed cage escape), and that this intermediate has, as observed experimentally, a lower energy barrier to the halogenation than the hydroxylation product; this is shown to primarily be due to steric effects.
Collapse
Affiliation(s)
- Katharina Bleher
- Universität Heidelberg, Anorganisch-Chemisches Institut und Interdisziplinäres Zentrum für Wissenschaftliches Rechnen (IWR), INF 270, 69120, Heidelberg, Germany
| | - Peter Comba
- Universität Heidelberg, Anorganisch-Chemisches Institut und Interdisziplinäres Zentrum für Wissenschaftliches Rechnen (IWR), INF 270, 69120, Heidelberg, Germany
| | - Dieter Faltermeier
- Universität Heidelberg, Anorganisch-Chemisches Institut und Interdisziplinäres Zentrum für Wissenschaftliches Rechnen (IWR), INF 270, 69120, Heidelberg, Germany
| | - Ashutosh Gupta
- Universität Heidelberg, Anorganisch-Chemisches Institut und Interdisziplinäres Zentrum für Wissenschaftliches Rechnen (IWR), INF 270, 69120, Heidelberg, Germany
| | - Marion Kerscher
- Universität Heidelberg, Anorganisch-Chemisches Institut und Interdisziplinäres Zentrum für Wissenschaftliches Rechnen (IWR), INF 270, 69120, Heidelberg, Germany
| | - Saskia Krieg
- Universität Heidelberg, Anorganisch-Chemisches Institut und Interdisziplinäres Zentrum für Wissenschaftliches Rechnen (IWR), INF 270, 69120, Heidelberg, Germany
| | - Bodo Martin
- Universität Heidelberg, Anorganisch-Chemisches Institut und Interdisziplinäres Zentrum für Wissenschaftliches Rechnen (IWR), INF 270, 69120, Heidelberg, Germany
| | - Gunasekaran Velmurugan
- Universität Heidelberg, Anorganisch-Chemisches Institut und Interdisziplinäres Zentrum für Wissenschaftliches Rechnen (IWR), INF 270, 69120, Heidelberg, Germany
| | - Shuyi Yang
- Universität Heidelberg, Anorganisch-Chemisches Institut und Interdisziplinäres Zentrum für Wissenschaftliches Rechnen (IWR), INF 270, 69120, Heidelberg, Germany
| |
Collapse
|
14
|
Abu‐Odeh M, Bleher K, Johnee Britto N, Comba P, Gast M, Jaccob M, Kerscher M, Krieg S, Kurth M. Pathways of the Extremely Reactive Iron(IV)-oxido complexes with Tetradentate Bispidine Ligands. Chemistry 2021; 27:11377-11390. [PMID: 34121233 PMCID: PMC8456976 DOI: 10.1002/chem.202101045] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Indexed: 11/07/2022]
Abstract
The nonheme iron(IV)-oxido complex trans-N3-[(L1 )FeIV =O(Cl)]+ , where L1 is a derivative of the tetradentate bispidine 2,4-di(pyridine-2-yl)-3,7-diazabicyclo[3.3.1]nonane-1-one, is known to have an S=1 electronic ground state and to be an extremely reactive oxidant for oxygen atom transfer (OAT) and hydrogen atom abstraction (HAA) processes. Here we show that, in spite of this ferryl oxidant having the "wrong" spin ground state, it is the most reactive nonheme iron model system known so far and of a similar order of reactivity as nonheme iron enzymes (C-H abstraction of cyclohexane, -90 °C (propionitrile), t1/2 =3.5 sec). Discussed are spectroscopic and kinetic data, supported by a DFT-based theoretical analysis, which indicate that substrate oxidation is significantly faster than self-decay processes due to an intramolecular demethylation pathway and formation of an oxido-bridged diiron(III) intermediate. It is also shown that the iron(III)-chlorido-hydroxido/cyclohexyl radical intermediate, resulting from C-H abstraction, selectively produces chlorocyclohexane in a rebound process. However, the life-time of the intermediate is so long that other reaction channels (known as cage escape) become important, and much of the C-H abstraction therefore is unproductive. In bulk reactions at ambient temperature and at longer time scales, there is formation of significant amounts of oxidation product - selectively of chlorocyclohexane - and it is shown that this originates from oxidation of the oxido-bridged diiron(III) resting state.
Collapse
Affiliation(s)
- Mahmud Abu‐Odeh
- Anorganisch-Chemisches InstitutUniversität HeidelbergINF 27069120HeidelbergGermany
| | - Katharina Bleher
- Anorganisch-Chemisches InstitutUniversität HeidelbergINF 27069120HeidelbergGermany
| | | | - Peter Comba
- Anorganisch-Chemisches InstitutUniversität HeidelbergINF 27069120HeidelbergGermany
- Interdisziplinäres Zentrum für Wissenschaftliches Rechnen (IWR) MathematikonIm Neuenheimer Feld 20569120HeidelbergGermany
| | - Michael Gast
- Anorganisch-Chemisches InstitutUniversität HeidelbergINF 27069120HeidelbergGermany
| | | | - Marion Kerscher
- Anorganisch-Chemisches InstitutUniversität HeidelbergINF 27069120HeidelbergGermany
| | - Saskia Krieg
- Anorganisch-Chemisches InstitutUniversität HeidelbergINF 27069120HeidelbergGermany
| | - Marius Kurth
- Anorganisch-Chemisches InstitutUniversität HeidelbergINF 27069120HeidelbergGermany
| |
Collapse
|
15
|
Tripodi GL, Dekker MMJ, Roithová J, Que L. Tuning the H-Atom Transfer Reactivity of Iron(IV)-Oxo Complexes as Probed by Infrared Photodissociation Spectroscopy. Angew Chem Int Ed Engl 2021; 60:7126-7131. [PMID: 33393186 PMCID: PMC8048595 DOI: 10.1002/anie.202016695] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Indexed: 01/14/2023]
Abstract
Reactivities of non-heme iron(IV)-oxo complexes are mostly controlled by the ligands. Complexes with tetradentate ligands such as [(TPA)FeO]2+ (TPA=tris(2-pyridylmethyl)amine) belong to the most reactive ones. Here, we show a fine-tuning of the reactivity of [(TPA)FeO]2+ by an additional ligand X (X=CH3 CN, CF3 SO3- , ArI, and ArIO; ArI=2-(t BuSO2 )C6 H4 I) attached in solution and reveal a thus far unknown role of the ArIO oxidant. The HAT reactivity of [(TPA)FeO(X)]+/2+ decreases in the order of X: ArIO > MeCN > ArI ≈ TfO- . Hence, ArIO is not just a mere oxidant of the iron(II) complex, but it can also increase the reactivity of the iron(IV)-oxo complex as a labile ligand. The detected HAT reactivities of the [(TPA)FeO(X)]+/2+ complexes correlate with the Fe=O and FeO-H stretching vibrations of the reactants and the respective products as determined by infrared photodissociation spectroscopy. Hence, the most reactive [(TPA)FeO(ArIO)]2+ adduct in the series has the weakest Fe=O bond and forms the strongest FeO-H bond in the HAT reaction.
Collapse
Affiliation(s)
- Guilherme L. Tripodi
- Department of spectroscopy and CatalysisInstitute for Molecules and MaterialsRadboud University NijmegenHeyendaalseweg 1356525AJNijmegenThe Netherlands
| | - Magda M. J. Dekker
- Department of spectroscopy and CatalysisInstitute for Molecules and MaterialsRadboud University NijmegenHeyendaalseweg 1356525AJNijmegenThe Netherlands
| | - Jana Roithová
- Department of spectroscopy and CatalysisInstitute for Molecules and MaterialsRadboud University NijmegenHeyendaalseweg 1356525AJNijmegenThe Netherlands
| | - Lawrence Que
- Department of ChemistryUniversity of MinnesotaMinneapolisTwin Cities 207 Pleasant Street SE55455MNUSA
| |
Collapse
|
16
|
Tripodi GL, Dekker MMJ, Roithová J, Que L. Tuning the H‐Atom Transfer Reactivity of Iron(IV)‐Oxo Complexes as Probed by Infrared Photodissociation Spectroscopy. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202016695] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Guilherme L. Tripodi
- Department of spectroscopy and Catalysis Institute for Molecules and Materials Radboud University Nijmegen Heyendaalseweg 135 6525 AJ Nijmegen The Netherlands
| | - Magda M. J. Dekker
- Department of spectroscopy and Catalysis Institute for Molecules and Materials Radboud University Nijmegen Heyendaalseweg 135 6525 AJ Nijmegen The Netherlands
| | - Jana Roithová
- Department of spectroscopy and Catalysis Institute for Molecules and Materials Radboud University Nijmegen Heyendaalseweg 135 6525 AJ Nijmegen The Netherlands
| | - Lawrence Que
- Department of Chemistry University of Minnesota Twin Cities, 207 Pleasant Street SE Minneapolis MN 55455 USA
| |
Collapse
|
17
|
Castillo CE, Gamba I, Vicens L, Clémancey M, Latour JM, Costas M, Basallote MG. Spin State Tunes Oxygen Atom Transfer towards Fe IV O Formation in Fe II Complexes. Chemistry 2021; 27:4946-4954. [PMID: 33350013 DOI: 10.1002/chem.202004921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Indexed: 11/08/2022]
Abstract
Oxoiron(IV) complexes bearing tetradentate ligands have been extensively studied as models for the active oxidants in non-heme iron-dependent enzymes. These species are commonly generated by oxidation of their ferrous precursors. The mechanisms of these reactions have seldom been investigated. In this work, the reaction kinetics of complexes [FeII (CH3 CN)2 L](SbF6 )2 ([1](SbF6 )2 and [2](SbF6 )2 ) and [FeII (CF3 SO3 )2 L] ([1](OTf)2 and [2](OTf)2 (1, L=Me,H Pytacn; 2, L=nP,H Pytacn; R,R' Pytacn=1-[(6-R'-2-pyridyl)methyl]-4,7- di-R-1,4,7-triazacyclononane) with Bu4 NIO4 to form the corresponding [FeIV (O)(CH3 CN)L]2+ (3, L=Me,H Pytacn; 4, L=nP,H Pytacn) species was studied in acetonitrile/acetone at low temperatures. The reactions occur in a single kinetic step with activation parameters independent of the nature of the anion and similar to those obtained for the substitution reaction with Cl- as entering ligand, which indicates that formation of [FeIV (O)(CH3 CN)L]2+ is kinetically controlled by substitution in the starting complex to form [FeII (IO4 )(CH3 CN)L]+ intermediates that are converted rapidly to oxo complexes 3 and 4. The kinetics of the reaction is strongly dependent on the spin state of the starting complex. A detailed analysis of the magnetic susceptibility and kinetic data for the triflate complexes reveals that the experimental values of the activation parameters for both complexes are the result of partial compensation of the contributions from the thermodynamic parameters for the spin-crossover equilibrium and the activation parameters for substitution. The observation of these opposite and compensating effects by modifying the steric hindrance at the ligand illustrates so far unconsidered factors governing the mechanism of oxygen atom transfer leading to high-valent iron oxo species.
Collapse
Affiliation(s)
- Carmen E Castillo
- Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica, y Química Inorgánica, Facultad de Ciencias, Instituto de Biomoléculas (INBIO), Universidad de Cádiz, Puerto Real, Cádiz, 11510, Spain
| | - Ilaria Gamba
- Grup de Química Bioinspirada, Supramolecular i Catàlisi (QBIS-CAT), Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, Campus de Montilivi, Girona, 17071, Catalonia, Spain
| | - Laia Vicens
- Grup de Química Bioinspirada, Supramolecular i Catàlisi (QBIS-CAT), Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, Campus de Montilivi, Girona, 17071, Catalonia, Spain
| | - Martin Clémancey
- CEA, CNRS, IRIG, DIESE, LCBM, Université Grenoble Alpes, pmb, 38000, Grenoble, France
| | - Jean-Marc Latour
- CEA, CNRS, IRIG, DIESE, LCBM, Université Grenoble Alpes, pmb, 38000, Grenoble, France
| | - Miquel Costas
- Grup de Química Bioinspirada, Supramolecular i Catàlisi (QBIS-CAT), Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, Campus de Montilivi, Girona, 17071, Catalonia, Spain
| | - Manuel G Basallote
- Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica, y Química Inorgánica, Facultad de Ciencias, Instituto de Biomoléculas (INBIO), Universidad de Cádiz, Puerto Real, Cádiz, 11510, Spain
| |
Collapse
|
18
|
Schneider JE, Goetz MK, Anderson JS. Statistical analysis of C-H activation by oxo complexes supports diverse thermodynamic control over reactivity. Chem Sci 2021; 12:4173-4183. [PMID: 34163690 PMCID: PMC8179456 DOI: 10.1039/d0sc06058e] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 01/28/2021] [Indexed: 01/29/2023] Open
Abstract
Transition metal oxo species are key intermediates for the activation of strong C-H bonds. As such, there has been interest in understanding which structural or electronic parameters of metal oxo complexes determine their reactivity. Factors such as ground state thermodynamics, spin state, steric environment, oxygen radical character, and asynchronicity have all been cited as key contributors, yet there is no consensus on when each of these parameters is significant or the relative magnitude of their effects. Herein, we present a thorough statistical analysis of parameters that have been proposed to influence transition metal oxo mediated C-H activation. We used density functional theory (DFT) to compute parameters for transition metal oxo complexes and analyzed their ability to explain and predict an extensive data set of experimentally determined reaction barriers. We found that, in general, only thermodynamic parameters play a statistically significant role. Notably, however, there are independent and significant contributions from the oxidation potential and basicity of the oxo complexes which suggest a more complicated thermodynamic picture than what has been shown previously.
Collapse
Affiliation(s)
| | - McKenna K Goetz
- Department of Chemistry, University of Chicago Chicago IL 60637 USA
| | - John S Anderson
- Department of Chemistry, University of Chicago Chicago IL 60637 USA
| |
Collapse
|
19
|
Rana S, Biswas JP, Paul S, Paik A, Maiti D. Organic synthesis with the most abundant transition metal–iron: from rust to multitasking catalysts. Chem Soc Rev 2021; 50:243-472. [DOI: 10.1039/d0cs00688b] [Citation(s) in RCA: 85] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The promising aspects of iron in synthetic chemistry are being explored for three-four decades as a green and eco-friendly alternative to late transition metals. This present review unveils these rich iron-chemistry towards different transformations.
Collapse
Affiliation(s)
- Sujoy Rana
- Department of Chemistry
- University of North Bengal
- Darjeeling
- India
| | | | - Sabarni Paul
- Department of Chemistry
- University of North Bengal
- Darjeeling
- India
| | - Aniruddha Paik
- Department of Chemistry
- University of North Bengal
- Darjeeling
- India
| | - Debabrata Maiti
- Department of Chemistry
- IIT Bombay
- Mumbai-400076
- India
- Tokyo Tech World Research Hub Initiative (WRHI)
| |
Collapse
|
20
|
Sánchez-Eguía BN, Serrano-Plana J, Company A, Costas M. Catalytic O 2 activation with synthetic models of α-ketoglutarate dependent oxygenases. Chem Commun (Camb) 2020; 56:14369-14372. [PMID: 33150337 DOI: 10.1039/d0cc05942k] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An iron complex bearing the facially capping tridentate 1,4,7-triazacyclononane ligand mimics structural and functional features of alpha-ketoglutarate (α-KG) dependent enzymes, and engages in enzyme-like catalytic O2 activation coupled to α-ketoacid decarboxylation, oxygenating sulfides. This system constitutes a rare case of non-enzymatic catalytic O2 activation, cycling between FeII and FeIV(O).
Collapse
Affiliation(s)
- Brenda N Sánchez-Eguía
- Grup de Química Bioinspirada, Supramolecular i Catàlisi (QBIS-CAT), Institut de Química Computacional i Catàlisi (IQCC), Universitat de Girona. Facultat de Ciències, Campus de Montilivi, 17003, Girona, Spain.
| | | | | | | |
Collapse
|
21
|
Abstract
Metal-halides that perform proton coupled electron-transfer (PCET) oxidation are an important new class of high-valent oxidant. In investigating metal-dihalides, we reacted [FeIII(Cl)(T(OMe)PP)] (1, T(OMe)PP = meso-tetra(4-methoxyphenyl)porphyrinyl) with (dichloroiodo)benzene. An FeIII-meso-chloro-isoporphyrin complex [FeIII(Cl)2(T(OMe)PP-Cl)] (2) was obtained. 2 was characterized by electronic absorption, 1H NMR, EPR, and X-ray absorption spectroscopies and mass spectrometry with support from computational analyses. 2 was reacted with a series of hydrocarbon substrates. The measured kinetic data exhibited a nonlinear behavior, whereby the oxidation followed a hydrogen-atom-transfer (HAT) PCET mechanism. The meso-chlorine atom was identified as the HAT agent. In one case, a halogenated product was identified by mass spectrometry. Our findings demonstrate that oxo-free hydrocarbon oxidation with heme systems is possible and show the potential for iron-dihalides in oxidative hydrocarbon halogenation.
Collapse
Affiliation(s)
- Robert Gericke
- School of Chemistry, College Green, Trinity College Dublin, The University of Dublin, Dublin 2 D02 PN40, Ireland
| | - Lorna M Doyle
- School of Chemistry, College Green, Trinity College Dublin, The University of Dublin, Dublin 2 D02 PN40, Ireland
| | - Erik R Farquhar
- National Synchrotron Light Source II, Brookhaven National Laboratory, Case Western Reserve University Center for Synchrotron Biosciences, Upton, New York 11973, United States
| | - Aidan R McDonald
- School of Chemistry, College Green, Trinity College Dublin, The University of Dublin, Dublin 2 D02 PN40, Ireland
| |
Collapse
|
22
|
Affiliation(s)
- Prasenjit Mondal
- School of Chemistry Trinity College Dublin The University of Dublin College Green Dublin 2 Ireland
| | - Marta Lovisari
- School of Chemistry Trinity College Dublin The University of Dublin College Green Dublin 2 Ireland
| | - Brendan Twamley
- School of Chemistry Trinity College Dublin The University of Dublin College Green Dublin 2 Ireland
| | - Aidan R. McDonald
- School of Chemistry Trinity College Dublin The University of Dublin College Green Dublin 2 Ireland
| |
Collapse
|
23
|
Mondal P, Lovisari M, Twamley B, McDonald AR. Fast Hydrocarbon Oxidation by a High‐Valent Nickel–Fluoride Complex. Angew Chem Int Ed Engl 2020; 59:13044-13050. [DOI: 10.1002/anie.202004639] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Indexed: 11/11/2022]
Affiliation(s)
- Prasenjit Mondal
- School of Chemistry Trinity College Dublin The University of Dublin College Green Dublin 2 Ireland
| | - Marta Lovisari
- School of Chemistry Trinity College Dublin The University of Dublin College Green Dublin 2 Ireland
| | - Brendan Twamley
- School of Chemistry Trinity College Dublin The University of Dublin College Green Dublin 2 Ireland
| | - Aidan R. McDonald
- School of Chemistry Trinity College Dublin The University of Dublin College Green Dublin 2 Ireland
| |
Collapse
|
24
|
Yadav V, Rodriguez RJ, Siegler MA, Goldberg DP. Determining the Inherent Selectivity for Carbon Radical Hydroxylation versus Halogenation with Fe III(OH)(X) Complexes: Relevance to the Rebound Step in Non-heme Iron Halogenases. J Am Chem Soc 2020; 142:7259-7264. [PMID: 32281794 DOI: 10.1021/jacs.0c00493] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The first structural models of the proposed cis-FeIII(OH)(halide) intermediate in the non-heme iron halogenases were synthesized and examined for their inherent reactivity with tertiary carbon radicals. Selective hydroxylation occurs for these cis-FeIII(OH)(X) (X = Cl, Br) complexes in a radical rebound-like process. In contrast, a cis-FeIII(Cl)2 complex reacts with carbon radicals to give halogenation. These results are discussed in terms of the inherent reactivity of the analogous rebound intermediate in both enzymes and related catalysts.
Collapse
Affiliation(s)
- Vishal Yadav
- Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Rodolfo J Rodriguez
- Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Maxime A Siegler
- Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - David P Goldberg
- Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, United States
| |
Collapse
|
25
|
|
26
|
Sabenya G, Gamba I, Gómez L, Clémancey M, Frisch JR, Klinker EJ, Blondin G, Torelli S, Que L, Martin-Diaconescu V, Latour JM, Lloret-Fillol J, Costas M. Octahedral iron(iv)-tosylimido complexes exhibiting single electron-oxidation reactivity. Chem Sci 2019; 10:9513-9529. [PMID: 32055323 PMCID: PMC6979323 DOI: 10.1039/c9sc02526j] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 08/17/2019] [Indexed: 11/28/2022] Open
Abstract
High valent iron species are very reactive molecules involved in oxidation reactions of relevance to biology and chemical synthesis. Herein we describe iron(iv)-tosylimido complexes [FeIV(NTs)(MePy2tacn)](OTf)2 (1(IV)[double bond, length as m-dash]NTs) and [FeIV(NTs)(Me2(CHPy2)tacn)](OTf)2 (2(IV)[double bond, length as m-dash]NTs), (MePy2tacn = N-methyl-N,N-bis(2-picolyl)-1,4,7-triazacyclononane, and Me2(CHPy2)tacn = 1-(di(2-pyridyl)methyl)-4,7-dimethyl-1,4,7-triazacyclononane, Ts = Tosyl). 1(IV)[double bond, length as m-dash]NTs and 2(IV)[double bond, length as m-dash]NTs are rare examples of octahedral iron(iv)-imido complexes and are isoelectronic analogues of the recently described iron(iv)-oxo complexes [FeIV(O)(L)]2+ (L = MePy2tacn and Me2(CHPy2)tacn, respectively). 1(IV)[double bond, length as m-dash]NTs and 2(IV)[double bond, length as m-dash]NTs are metastable and have been spectroscopically characterized by HR-MS, UV-vis, 1H-NMR, resonance Raman, Mössbauer, and X-ray absorption (XAS) spectroscopy as well as by DFT computational methods. Ferric complexes [FeIII(HNTs)(L)]2+, 1(III)-NHTs (L = MePy2tacn) and 2(III)-NHTs (L = Me2(CHPy2)tacn) have been isolated after the decay of 1(IV)[double bond, length as m-dash]NTs and 2(IV)[double bond, length as m-dash]NTs in solution, spectroscopically characterized, and the molecular structure of [FeIII(HNTs)(MePy2tacn)](SbF6)2 determined by single crystal X-ray diffraction. Reaction of 1(IV)[double bond, length as m-dash]NTs and 2(IV)[double bond, length as m-dash]NTs with different p-substituted thioanisoles results in the transfer of the tosylimido moiety to the sulphur atom producing sulfilimine products. In these reactions, 1(IV)[double bond, length as m-dash]NTs and 2(IV)[double bond, length as m-dash]NTs behave as single electron oxidants and Hammett analyses of reaction rates evidence that tosylimido transfer is more sensitive than oxo transfer to charge effects. In addition, reaction of 1(IV)[double bond, length as m-dash]NTs and 2(IV)[double bond, length as m-dash]NTs with hydrocarbons containing weak C-H bonds results in the formation of 1(III)-NHTs and 2(III)-NHTs respectively, along with the oxidized substrate. Kinetic analyses indicate that reactions proceed via a mechanistically unusual HAT reaction, where an association complex precedes hydrogen abstraction.
Collapse
Affiliation(s)
- Gerard Sabenya
- Institut de Química Computacional i Catàlisi (IQCC) , Departament de Química , Universitat de Girona , Campus Montilivi , E17071 Girona , Spain .
| | - Ilaria Gamba
- Institut de Química Computacional i Catàlisi (IQCC) , Departament de Química , Universitat de Girona , Campus Montilivi , E17071 Girona , Spain .
| | - Laura Gómez
- Institut de Química Computacional i Catàlisi (IQCC) , Departament de Química , Universitat de Girona , Campus Montilivi , E17071 Girona , Spain .
| | - Martin Clémancey
- Univ. Grenoble-Alpes , CNRS , CEA , IRIG , DIESE , CBM , Grenoble 38000 , France
| | - Jonathan R Frisch
- Department of Chemistry , University of Minnesota , Pleasant Str 207 , Minneapolis , Minnesota , USA
| | - Eric J Klinker
- Department of Chemistry , University of Minnesota , Pleasant Str 207 , Minneapolis , Minnesota , USA
| | - Geneviève Blondin
- Univ. Grenoble-Alpes , CNRS , CEA , IRIG , DIESE , CBM , Grenoble 38000 , France
| | - Stéphane Torelli
- Univ. Grenoble-Alpes , CNRS , CEA , IRIG , DIESE , CBM , Grenoble 38000 , France
| | - Lawrence Que
- Department of Chemistry , University of Minnesota , Pleasant Str 207 , Minneapolis , Minnesota , USA
| | - Vlad Martin-Diaconescu
- Institut de Química Computacional i Catàlisi (IQCC) , Departament de Química , Universitat de Girona , Campus Montilivi , E17071 Girona , Spain .
- Institute of Chemical Research of Catalonia (ICIQ) , The Barcelona Institute of Science and Technology , Avinguda Països Catalans 16 , 43007 Tarragona , Spain .
| | - Jean-Marc Latour
- Univ. Grenoble-Alpes , CNRS , CEA , IRIG , DIESE , CBM , Grenoble 38000 , France
| | - Julio Lloret-Fillol
- Institut de Química Computacional i Catàlisi (IQCC) , Departament de Química , Universitat de Girona , Campus Montilivi , E17071 Girona , Spain .
- Institute of Chemical Research of Catalonia (ICIQ) , The Barcelona Institute of Science and Technology , Avinguda Països Catalans 16 , 43007 Tarragona , Spain .
- Catalan Institution for Research and Advanced Studies (ICREA) , Passeig Lluïs Companys, 23 , 08010 , Barcelona , Spain
| | - Miquel Costas
- Institut de Química Computacional i Catàlisi (IQCC) , Departament de Química , Universitat de Girona , Campus Montilivi , E17071 Girona , Spain .
| |
Collapse
|
27
|
Sharma N, Lee YM, Li XX, Nam W, Fukuzumi S. Regioselective Oxybromination of Benzene and Its Derivatives by Bromide Anion with a Mononuclear Nonheme Mn(IV)–Oxo Complex. Inorg Chem 2019; 58:14299-14303. [DOI: 10.1021/acs.inorgchem.9b02410] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Namita Sharma
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Yong-Min Lee
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Xiao-Xi Li
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Wonwoo Nam
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
- School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi’an 710119, China
| | - Shunichi Fukuzumi
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
- Faculty of Science and Engineering, Meijo University, Nagoya, Aichi 468-8502, Japan
| |
Collapse
|
28
|
Terencio T, Andris E, Gamba I, Srnec M, Costas M, Roithová J. Chemoselectivity in the Oxidation of Cycloalkenes with a Non-Heme Iron(IV)-Oxo-Chloride Complex: Epoxidation vs. Hydroxylation Selectivity. J Am Soc Mass Spectrom 2019; 30:1923-1933. [PMID: 31399940 PMCID: PMC6805805 DOI: 10.1007/s13361-019-02251-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 05/15/2019] [Accepted: 05/15/2019] [Indexed: 06/10/2023]
Abstract
We report and analyze chemoselectivity in the gas phase reactions of cycloalkenes (cyclohexene, cycloheptene, cis-cyclooctene, 1,4-cyclohexadiene) with a non-heme iron(IV)-oxo complex [(PyTACN)Fe(O)(Cl)]+, which models the active species in iron-dependent halogenases. Unlike in the halogenases, we did not observe any chlorination of the substrate. However, we observed two other reaction pathways: allylic hydrogen atom transfer (HAT) and alkene epoxidation. The HAT is clearly preferred in the case of 1,4-cyclohexadiene, both pathways have comparable reaction rates in reaction with cyclohexene, and epoxidation is strongly favored in reactions with cycloheptene and cis-cyclooctene. This preference for epoxidation differs from the reactivity of iron(IV)-oxo complexes in the condensed phase, where HAT usually prevails. To understand the observed selectivity, we analyze effects of the substrate, spin state, and solvation. Our DFT and CASPT2 calculations suggest that all the reactions occur on the quintet potential energy surface. The DFT-calculated energies of the transition states for the epoxidation and hydroxylation pathways explain the observed chemoselectivity. The SMD implicit solvation model predicts the relative increase of the epoxidation barriers with solvent polarity, which explains the clear preference of HAT in the condensed phase.
Collapse
Affiliation(s)
- Thibault Terencio
- Department of Organic Chemistry, Faculty of Science, Charles University, Hlavova 2030/8, 128 43, Prague 2, Czech Republic
- School of Chemical Science and Engineering, Yachay Tech University, 100650, Yachay City of Knowledge, Urcuqui, Ecuador
| | - Erik Andris
- Department of Organic Chemistry, Faculty of Science, Charles University, Hlavova 2030/8, 128 43, Prague 2, Czech Republic
| | - Ilaria Gamba
- Departament de Quimica and Institute of Computational Chemistry and Catalysis (IQCC), University of Girona, Campus Montilivi, 17071, Girona, Spain
| | - Martin Srnec
- J. Heyrovsky Institute of Physical Chemistry of the CAS, v. v. i., Dolejškova 2155/3, 182 23, Prague 8, Czech Republic.
| | - Miquel Costas
- Departament de Quimica and Institute of Computational Chemistry and Catalysis (IQCC), University of Girona, Campus Montilivi, 17071, Girona, Spain.
| | - Jana Roithová
- Department of Organic Chemistry, Faculty of Science, Charles University, Hlavova 2030/8, 128 43, Prague 2, Czech Republic.
- Institute for Molecules and Materials, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ, Nijmegen, Netherlands.
| |
Collapse
|
29
|
Pangia TM, Yadav V, Gérard EF, Lin YT, de Visser SP, Jameson GNL, Goldberg DP. Mechanistic Investigation of Oxygen Rebound in a Mononuclear Nonheme Iron Complex. Inorg Chem 2019; 58:9557-9561. [PMID: 31313577 DOI: 10.1021/acs.inorgchem.9b01208] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
An iron(III) methoxide complex reacts with para-substituted triarylmethyl radicals to give iron(II) and methoxyether products. Second-order rate constants for the radical derivatives were obtained. Hammett and Marcus plots suggest the radical transfer reactions proceed via a concerted process. Calculations support the concerted nature of these reactions involving a single transition state with no initial charge transfer. These findings have implications for the radical "rebound" step invoked in nonheme iron oxygenases, halogenases, and related synthetic catalysts.
Collapse
Affiliation(s)
- Thomas M Pangia
- Department of Chemistry , The Johns Hopkins University , 3400 North Charles Street , Baltimore , Maryland 21218 , United States
| | - Vishal Yadav
- Department of Chemistry , The Johns Hopkins University , 3400 North Charles Street , Baltimore , Maryland 21218 , United States
| | - Emilie F Gérard
- Manchester Institute of Biotechnology and School of Chemical Engineering and Analytical Science , The University of Manchester , 131 Princess Street , Manchester M1 7DN , United Kingdom
| | - Yen-Ting Lin
- Manchester Institute of Biotechnology and School of Chemical Engineering and Analytical Science , The University of Manchester , 131 Princess Street , Manchester M1 7DN , United Kingdom
| | - Sam P de Visser
- Manchester Institute of Biotechnology and School of Chemical Engineering and Analytical Science , The University of Manchester , 131 Princess Street , Manchester M1 7DN , United Kingdom
| | - Guy N L Jameson
- School of Chemistry, Bio21 Molecular Science and Biotechnology Institute , The University of Melbourne , 30 Flemington Road , Parkville , Victoria 3010 , Australia
| | - David P Goldberg
- Department of Chemistry , The Johns Hopkins University , 3400 North Charles Street , Baltimore , Maryland 21218 , United States
| |
Collapse
|
30
|
Yadav V, Gordon JB, Siegler MA, Goldberg DP. Dioxygen-Derived Nonheme Mononuclear Fe III(OH) Complex and Its Reactivity with Carbon Radicals. J Am Chem Soc 2019; 141:10148-10153. [PMID: 31244183 DOI: 10.1021/jacs.9b03329] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
A new tetradentate, monoanionic, mixed N/O donor ligand (BNPAPh2O-) with second coordination sphere H-bonding groups has been synthesized for stabilization of a terminal FeIII(OH) complex. The complex FeII(BNPAPh2O)(OTf) (1) reacts with O2 to give a mononuclear terminal FeIII(OH) complex, FeIII(OH)(BNPAPh2O)(OTf) (2), both of which were characterized by X-ray diffraction, electrospray ionization mass spectrometry, UV-vis, 1H and 19F nuclear magnetic resonance, 57Fe Mössbauer, and electron paramagnetic resonance spectroscopies. Treatment of 2 with carbon radicals (Ar3C·) gives Ar3COH and the FeII complex 1, in direct analogy with the elusive radical "rebound" process proposed for nonheme iron enzymes.
Collapse
Affiliation(s)
- Vishal Yadav
- Department of Chemistry , The Johns Hopkins University , Baltimore , Maryland 21218 , United States
| | - Jesse B Gordon
- Department of Chemistry , The Johns Hopkins University , Baltimore , Maryland 21218 , United States
| | - Maxime A Siegler
- Department of Chemistry , The Johns Hopkins University , Baltimore , Maryland 21218 , United States
| | - David P Goldberg
- Department of Chemistry , The Johns Hopkins University , Baltimore , Maryland 21218 , United States
| |
Collapse
|
31
|
Rana S, Biswas JP, Sen A, Clémancey M, Blondin G, Latour JM, Rajaraman G, Maiti D. Selective C-H halogenation over hydroxylation by non-heme iron(iv)-oxo. Chem Sci 2018; 9:7843-7858. [PMID: 30429994 PMCID: PMC6194801 DOI: 10.1039/c8sc02053a] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 08/14/2018] [Indexed: 12/26/2022] Open
Abstract
Non-heme iron based halogenase enzymes promote selective halogenation of the sp3-C-H bond through iron(iv)-oxo-halide active species. During halogenation, competitive hydroxylation can be prevented completely in enzymatic systems. However, synthetic iron(iv)-oxo-halide intermediates often result in a mixture of halogenation and hydroxylation products. In this report, we have developed a new synthetic strategy by employing non-heme iron based complexes for selective sp3-C-H halogenation by overriding hydroxylation. A room temperature stable, iron(iv)-oxo complex, [Fe(2PyN2Q)(O)]2+ was directed for hydrogen atom abstraction (HAA) from aliphatic substrates and the iron(ii)-halide [FeII(2PyN2Q)(X)]+ (X, halogen) was exploited in conjunction to deliver the halogen atom to the ensuing carbon centered radical. Despite iron(iv)-oxo being an effective promoter of hydroxylation of aliphatic substrates, the perfect interplay of HAA and halogen atom transfer in this work leads to the halogenation product selectively by diverting the hydroxylation pathway. Experimental studies outline the mechanistic details of the iron(iv)-oxo mediated halogenation reactions. A kinetic isotope study between PhCH3 and C6D5CD3 showed a value of 13.5 that supports the initial HAA step as the RDS during halogenation. Successful implementation of this new strategy led to the establishment of a functional mimic of non-heme halogenase enzymes with an excellent selectivity for halogenation over hydroxylation. Detailed theoretical studies based on density functional methods reveal how the small difference in the ligand design leads to a large difference in the electronic structure of the [Fe(2PyN2Q)(O)]2+ species. Both experimental and computational studies suggest that the halide rebound process of the cage escaped radical with iron(iii)-halide is energetically favorable compared to iron(iii)-hydroxide and it brings in selective formation of halogenation products over hydroxylation.
Collapse
Affiliation(s)
- Sujoy Rana
- Department of Chemistry , IIT Bombay , Powai , Mumbai-400076 , India
| | | | - Asmita Sen
- Department of Chemistry , IIT Bombay , Powai , Mumbai-400076 , India
| | - Martin Clémancey
- University of Grenoble Alpes , LCBM/PMB and CEA , IRTSV/CBM/PMB and CNRS , LCBM UMR 5249, PMB , 38000 Grenoble , France
| | - Geneviève Blondin
- University of Grenoble Alpes , LCBM/PMB and CEA , IRTSV/CBM/PMB and CNRS , LCBM UMR 5249, PMB , 38000 Grenoble , France
| | - Jean-Marc Latour
- University of Grenoble Alpes , LCBM/PMB and CEA , IRTSV/CBM/PMB and CNRS , LCBM UMR 5249, PMB , 38000 Grenoble , France
| | - Gopalan Rajaraman
- Department of Chemistry , IIT Bombay , Powai , Mumbai-400076 , India
| | - Debabrata Maiti
- Department of Chemistry , IIT Bombay , Powai , Mumbai-400076 , India
| |
Collapse
|
32
|
Jana RD, Sheet D, Chatterjee S, Paine TK. Aliphatic C–H Bond Halogenation by Iron(II)-α-Keto Acid Complexes and O2: Functional Mimicking of Nonheme Iron Halogenases. Inorg Chem 2018; 57:8769-8777. [DOI: 10.1021/acs.inorgchem.8b00421] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Rahul Dev Jana
- Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, 2A & 2B Raja S. C. Mullick Road, Jadavpur, Kolkata 700032, India
| | - Debobrata Sheet
- Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, 2A & 2B Raja S. C. Mullick Road, Jadavpur, Kolkata 700032, India
| | - Sayanti Chatterjee
- Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, 2A & 2B Raja S. C. Mullick Road, Jadavpur, Kolkata 700032, India
| | - Tapan Kanti Paine
- Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, 2A & 2B Raja S. C. Mullick Road, Jadavpur, Kolkata 700032, India
| |
Collapse
|
33
|
Pangia TM, Davies CG, Prendergast JR, Gordon JB, Siegler MA, Jameson GNL, Goldberg DP. Observation of Radical Rebound in a Mononuclear Nonheme Iron Model Complex. J Am Chem Soc 2018; 140:4191-4194. [PMID: 29537258 PMCID: PMC6047074 DOI: 10.1021/jacs.7b12707] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A nonheme iron(III) terminal methoxide complex, [FeIII(N3PyO2Ph)(OCH3)]ClO4, was synthesized. Reaction of this complex with the triphenylmethyl radical (Ph3C•) leads to formation of Ph3COCH3 and the one-electron-reduced iron(II) center, as seen by UV-vis, EPR, 1H NMR, and Mössbauer spectroscopy. These results indicate that homolytic Fe-O bond cleavage occurs together with C-O bond formation, providing a direct observation of the "radical rebound" process proposed for both biological and synthetic nonheme iron centers.
Collapse
Affiliation(s)
- Thomas M. Pangia
- Department of Chemistry, The Johns Hopkins University, Baltimore Maryland, 21218
| | - Casey G. Davies
- Department of Chemistry and MacDiarmid Institute for Advanced Materials and Nanotechnology, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand
| | - Joshua R. Prendergast
- Department of Chemistry and MacDiarmid Institute for Advanced Materials and Nanotechnology, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand
- School of Chemistry, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, 30 Flemington Road, Parkville, Victoria 3010, Australia
| | - Jesse B. Gordon
- Department of Chemistry, The Johns Hopkins University, Baltimore Maryland, 21218
| | - Maxime A. Siegler
- Department of Chemistry, The Johns Hopkins University, Baltimore Maryland, 21218
| | - Guy N. L. Jameson
- Department of Chemistry and MacDiarmid Institute for Advanced Materials and Nanotechnology, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand
- School of Chemistry, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, 30 Flemington Road, Parkville, Victoria 3010, Australia
| | - David P. Goldberg
- Department of Chemistry, The Johns Hopkins University, Baltimore Maryland, 21218
| |
Collapse
|
34
|
Affiliation(s)
- Prasenjit Mondal
- School
of Chemistry and CRANN/AMBER Nanoscience Institute, Trinity College Dublin, The University of Dublin, College Green, Dublin 2, Ireland
| | - Paolo Pirovano
- School
of Chemistry and CRANN/AMBER Nanoscience Institute, Trinity College Dublin, The University of Dublin, College Green, Dublin 2, Ireland
| | - Ankita Das
- School
of Chemistry and CRANN/AMBER Nanoscience Institute, Trinity College Dublin, The University of Dublin, College Green, Dublin 2, Ireland
| | - Erik R. Farquhar
- Case
Western Reserve University Center for Synchrotron Biosciences, National Synchrotron Light Source II, Brookhaven National Laboratory II, Upton, New York 11973, United States
| | - Aidan R. McDonald
- School
of Chemistry and CRANN/AMBER Nanoscience Institute, Trinity College Dublin, The University of Dublin, College Green, Dublin 2, Ireland
| |
Collapse
|
35
|
Du J, Zhang J, Zhu J, Xia C, Sun W. Synthesis, characterization, and reactivity of a chiral Fe(iv)–oxo complex bearing an l-proline-derived aminopyridine ligand. NEW J CHEM 2018. [DOI: 10.1039/c8nj00964c] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A chiral nonheme Fe(iv)–oxo complex was synthesized and spectroscopically characterized. Its reactivity in C–H activation as well as in asymmetric sulfoxidation and C–H hydroxylation was investigated.
Collapse
Affiliation(s)
- Junyi Du
- State Key Laboratory for Oxo Synthesis and Selective Oxidation, Center for Excellence in Molecular Synthesis, Suzhou Research Institute of LICP, Lanzhou Institute of Chemical Physics (LICP), Chinese Academy of Sciences
- Lanzhou
- P. R. China
- University of Chinese Academy of Sciences
- Beijing 100049
| | - Jisheng Zhang
- State Key Laboratory for Oxo Synthesis and Selective Oxidation, Center for Excellence in Molecular Synthesis, Suzhou Research Institute of LICP, Lanzhou Institute of Chemical Physics (LICP), Chinese Academy of Sciences
- Lanzhou
- P. R. China
| | - Jianhua Zhu
- State Key Laboratory for Oxo Synthesis and Selective Oxidation, Center for Excellence in Molecular Synthesis, Suzhou Research Institute of LICP, Lanzhou Institute of Chemical Physics (LICP), Chinese Academy of Sciences
- Lanzhou
- P. R. China
| | - Chungu Xia
- State Key Laboratory for Oxo Synthesis and Selective Oxidation, Center for Excellence in Molecular Synthesis, Suzhou Research Institute of LICP, Lanzhou Institute of Chemical Physics (LICP), Chinese Academy of Sciences
- Lanzhou
- P. R. China
| | - Wei Sun
- State Key Laboratory for Oxo Synthesis and Selective Oxidation, Center for Excellence in Molecular Synthesis, Suzhou Research Institute of LICP, Lanzhou Institute of Chemical Physics (LICP), Chinese Academy of Sciences
- Lanzhou
- P. R. China
| |
Collapse
|
36
|
de Sousa DP, Miller CJ, Chang Y, Waite TD, McKenzie CJ. Electrochemically Generated cis-Carboxylato-Coordinated Iron(IV) Oxo Acid-Base Congeners as Promiscuous Oxidants of Water Pollutants. Inorg Chem 2017; 56:14936-14947. [PMID: 29039183 DOI: 10.1021/acs.inorgchem.7b02208] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The nonheme iron(IV) oxo complex [FeIV(O)(tpenaH)]2+ and its conjugate base [FeIV(O)(tpena)]+ [tpena- = N,N,N'-tris(2-pyridylmethyl)ethylenediamine-N'-acetate] have been prepared electrochemically in water by bulk electrolysis of solutions prepared from [FeIII2(μ-O)(tpenaH)2](ClO4)4 at potentials over 1.3 V (vs NHE) using inexpensive and commercially available carbon-based electrodes. Once generated, these iron(IV) oxo complexes persist at room temperature for minutes to half an hour over a wide range of pH values. They are capable of rapidly decomposing aliphatic and aromatic alcohols, alkanes, formic acid, phenols, and the xanthene dye rhodamine B. The oxidation of formic acid to carbon dioxide demonstrates the capacity for total mineralization of organic compounds. A radical hydrogen-atom-abstraction mechanism is proposed with a reactivity profile for the series that is reminiscent of oxidations by the hydroxyl radical. Facile regeneration of [FeIV(O)(tpenaH)]2+/ [FeIV(O)(tpena)]+ and catalytic turnover in the oxidation of cyclohexanol under continuous electrolysis demonstrates the potential of the application of [FeIII(tpena)]2+ as an electrocatalyst. The promiscuity of the electrochemically generated iron(IV) oxo complexes, in terms of the broad range of substrates examined, represents an important step toward the goal of cost-effective electrocatalytic water purification.
Collapse
Affiliation(s)
- David P de Sousa
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark , Campusvej 55, 5320 Odense, Denmark
| | - Christopher J Miller
- Water Research Centre, School of Civil and Environmental Engineering, University of New South Wales , Sydney, New South Wales 2052, Australia
| | - Yingyue Chang
- Water Research Centre, School of Civil and Environmental Engineering, University of New South Wales , Sydney, New South Wales 2052, Australia
| | - T David Waite
- Water Research Centre, School of Civil and Environmental Engineering, University of New South Wales , Sydney, New South Wales 2052, Australia
| | - Christine J McKenzie
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark , Campusvej 55, 5320 Odense, Denmark
| |
Collapse
|
37
|
Affiliation(s)
- Olaf Cussó
- QBIS Research Group, Institut de Química
Computacional i Catàlisi (IQCC) and Departament de Química, Universitat de Girona, Campus Montilivi, Girona E-17071, Catalonia, Spain
| | - Joan Serrano-Plana
- QBIS Research Group, Institut de Química
Computacional i Catàlisi (IQCC) and Departament de Química, Universitat de Girona, Campus Montilivi, Girona E-17071, Catalonia, Spain
| | - Miquel Costas
- QBIS Research Group, Institut de Química
Computacional i Catàlisi (IQCC) and Departament de Química, Universitat de Girona, Campus Montilivi, Girona E-17071, Catalonia, Spain
| |
Collapse
|
38
|
Kupper C, Mondal B, Serrano-Plana J, Klawitter I, Neese F, Costas M, Ye S, Meyer F. Nonclassical Single-State Reactivity of an Oxo-Iron(IV) Complex Confined to Triplet Pathways. J Am Chem Soc 2017; 139:8939-8949. [PMID: 28557448 DOI: 10.1021/jacs.7b03255] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
C-H bond activation mediated by oxo-iron (IV) species represents the key step of many heme and nonheme O2-activating enzymes. Of crucial interest is the effect of spin state of the FeIV(O) unit. Here we report the C-H activation kinetics and corresponding theoretical investigations of an exclusive tetracarbene ligated oxo-iron(IV) complex, [LNHCFeIV(O)(MeCN)]2+ (1). Kinetic traces using substrates with bond dissociation energies (BDEs) up to 80 kcal mol-1 show pseudo-first-order behavior and large but temperature-dependent kinetic isotope effects (KIE 32 at -40 °C). When compared with a topologically related oxo-iron(IV) complex bearing an equatorial N-donor ligand, [LTMCFeIV(O) (MeCN)]2+ (A), the tetracarbene complex 1 is significantly more reactive with second order rate constants k'2 that are 2-3 orders of magnitude higher. UV-vis experiments in tandem with cryospray mass spectrometry evidence that the reaction occurs via formation of a hydroxo-iron(III) complex (4) after the initial H atom transfer (HAT). An extensive computational study using a wave function based multireference approach, viz. complete active space self-consistent field (CASSCF) followed by N-electron valence perturbation theory up to second order (NEVPT2), provided insight into the HAT trajectories of 1 and A. Calculated free energy barriers for 1 reasonably agree with experimental values. Because the strongly donating equatorial tetracarbene pushes the Fe-dx2-y2 orbital above dz2, 1 features a dramatically large quintet-triplet gap of ∼18 kcal/mol compared to ∼2-3 kcal/mol computed for A. Consequently, the HAT process performed by 1 occurs on the triplet surface only, in contrast to complex A reported to feature two-state-reactivity with contributions from both triplet and quintet states. Despite this, the reactive FeIV(O) units in 1 and A undergo the same electronic-structure changes during HAT. Thus, the unique complex 1 represents a pure "triplet-only" ferryl model.
Collapse
Affiliation(s)
- Claudia Kupper
- Universität Göttingen , Institut für Anorganische Chemie, Tammannstrasse 4, 37077 Göttingen, Germany
| | - Bhaskar Mondal
- Max-Planck Institut für Chemische Energiekonversion , Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Joan Serrano-Plana
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Quimica, Universitat de Girona , Campus Montilivi, E17071 Girona, Catalonia, Spain
| | - Iris Klawitter
- Universität Göttingen , Institut für Anorganische Chemie, Tammannstrasse 4, 37077 Göttingen, Germany
| | - Frank Neese
- Max-Planck Institut für Chemische Energiekonversion , Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Miquel Costas
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Quimica, Universitat de Girona , Campus Montilivi, E17071 Girona, Catalonia, Spain
| | - Shengfa Ye
- Max-Planck Institut für Chemische Energiekonversion , Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Franc Meyer
- Universität Göttingen , Institut für Anorganische Chemie, Tammannstrasse 4, 37077 Göttingen, Germany
| |
Collapse
|
39
|
Andris E, Navrátil R, Jašík J, Terencio T, Srnec M, Costas M, Roithová J. Chasing the Evasive Fe═O Stretch and the Spin State of the Iron(IV)-Oxo Complexes by Photodissociation Spectroscopy. J Am Chem Soc 2017; 139:2757-2765. [PMID: 28125220 DOI: 10.1021/jacs.6b12291] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
We demonstrate the application of infrared photodissocation spectroscopy for determination of the Fe═O stretching frequencies of high-valent iron(IV)-oxo complexes [(L)Fe(O)(X)]2+/+ (L = TMC, N4Py, PyTACN, and X = CH3CN, CF3SO3, ClO4, CF3COO, NO3, N3). We show that the values determined by resonance Raman spectroscopy in acetonitrile solutions are on average 9 cm-1 red-shifted with respect to unbiased gas-phase values. Furthermore, we show the assignment of the spin state of the complexes based on the vibrational modes of a coordinated anion and compare reactivities of various iron(IV)-oxo complexes generated as dications or monocations (bearing an anionic ligand). The coordinated anions can drastically affect the reactivity of the complex and should be taken into account when comparing reactivities of complexes bearing different ligands. Comparison of reactivities of [(PyTACN)Fe(O)(X)]+ generated in different spin states and bearing different anionic ligands X revealed that the nature of anion influences the reactivity more than the spin state. The triflate and perchlorate ligands tend to stabilize the quintet state of [(PyTACN)Fe(O)(X)]+, whereas trifluoroacetate and nitrate stabilize the triplet state of the complex.
Collapse
Affiliation(s)
- Erik Andris
- Department of Organic Chemistry, Faculty of Science, Charles University , Hlavova 2030/8, 12843 Prague 2, Czech Republic
| | - Rafael Navrátil
- Department of Organic Chemistry, Faculty of Science, Charles University , Hlavova 2030/8, 12843 Prague 2, Czech Republic
| | - Juraj Jašík
- Department of Organic Chemistry, Faculty of Science, Charles University , Hlavova 2030/8, 12843 Prague 2, Czech Republic
| | - Thibault Terencio
- Department of Organic Chemistry, Faculty of Science, Charles University , Hlavova 2030/8, 12843 Prague 2, Czech Republic
| | - Martin Srnec
- J. Heyrovsky Institute of Physical Chemistry of the CAS , v.v i., Dolejškova 2155/3, 182 23 Prague 8, Czech Republic
| | - Miquel Costas
- Departament de Quimica and Institute of Computational Chemistry and Catalysis (IQCC), University of Girona , Campus Montilivi, Girona 17071, Spain
| | - Jana Roithová
- Department of Organic Chemistry, Faculty of Science, Charles University , Hlavova 2030/8, 12843 Prague 2, Czech Republic
| |
Collapse
|
40
|
Huang X, Groves JT. Beyond ferryl-mediated hydroxylation: 40 years of the rebound mechanism and C-H activation. J Biol Inorg Chem 2016; 22:185-207. [PMID: 27909920 PMCID: PMC5350257 DOI: 10.1007/s00775-016-1414-3] [Citation(s) in RCA: 195] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Accepted: 11/03/2016] [Indexed: 11/24/2022]
Abstract
Since our initial report in 1976, the oxygen rebound mechanism has become the consensus mechanistic feature for an expanding variety of enzymatic C-H functionalization reactions and small molecule biomimetic catalysts. For both the biotransformations and models, an initial hydrogen atom abstraction from the substrate (R-H) by high-valent iron-oxo species (Fen=O) generates a substrate radical and a reduced iron hydroxide, [Fen-1-OH ·R]. This caged radical pair then evolves on a complicated energy landscape through a number of reaction pathways, such as oxygen rebound to form R-OH, rebound to a non-oxygen atom affording R-X, electron transfer of the incipient radical to yield a carbocation, R+, desaturation to form olefins, and radical cage escape. These various flavors of the rebound process, often in competition with each other, give rise to the wide range of C-H functionalization reactions performed by iron-containing oxygenases. In this review, we first recount the history of radical rebound mechanisms, their general features, and key intermediates involved. We will discuss in detail the factors that affect the behavior of the initial caged radical pair and the lifetimes of the incipient substrate radicals. Several representative examples of enzymatic C-H transformations are selected to illustrate how the behaviors of the radical pair [Fen-1-OH ·R] determine the eventual reaction outcome. Finally, we discuss the powerful potential of "radical rebound" processes as a general paradigm for developing novel C-H functionalization reactions with synthetic, biomimetic catalysts. We envision that new chemistry will continue to arise by bridging enzymatic "radical rebound" with synthetic organic chemistry.
Collapse
|
41
|
Leto DF, Massie AA, Rice DB, Jackson TA. Spectroscopic and Computational Investigations of a Mononuclear Manganese(IV)-Oxo Complex Reveal Electronic Structure Contributions to Reactivity. J Am Chem Soc 2016; 138:15413-15424. [PMID: 27802057 DOI: 10.1021/jacs.6b08661] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The mononuclear Mn(IV)-oxo complex [MnIV(O)(N4py)]2+, where N4py is the pentadentate ligand N,N-bis(2-pyridylmethyl)-N-bis(2-pyridyl)methylamine, has been proposed to attack C-H bonds by an excited-state reactivity pattern [ Cho, K.-B.; Shaik, S.; Nam, W. J. Phys. Chem. Lett. 2012 , 3 , 2851 - 2856 (DOI: 10.1021/jz301241z )]. In this model, a 4E excited state is utilized to provide a lower-energy barrier for hydrogen-atom transfer. This proposal is intriguing, as it offers both a rationale for the relatively high hydrogen-atom-transfer reactivity of [MnIV(O)(N4py)]2+ and a guideline for creating more reactive complexes through ligand modification. Here we employ a combination of electronic absorption and variable-temperature magnetic circular dichroism (MCD) spectroscopy to experimentally evaluate this excited-state reactivity model. Using these spectroscopic methods, in conjunction with time-dependent density functional theory (TD-DFT) and complete-active space self-consistent-field calculations (CASSCF), we define the ligand-field and charge-transfer excited states of [MnIV(O)(N4py)]2+. Through a graphical analysis of the signs of the experimental C-term MCD signals, we unambiguously assign a low-energy MCD feature of [MnIV(O)(N4py)]2+ as the 4E excited state predicted to be involved in hydrogen-atom-transfer reactivity. The CASSCF calculations predict enhanced MnIII-oxyl character on the excited-state 4E surface, consistent with previous DFT calculations. Potential-energy surfaces, developed using the CASSCF methods, are used to determine how the energies and wave functions of the ground and excited states evolved as a function of Mn═O distance. The unique insights into ground- and excited-state electronic structure offered by these spectroscopic and computational studies are harmonized with a thermodynamic model of hydrogen-atom-transfer reactivity, which predicts a correlation between transition-state barriers and driving force.
Collapse
Affiliation(s)
- Domenick F Leto
- Department of Chemistry and Center for Environmentally Beneficial Catalysis, University of Kansas , Lawrence, Kansas 66045, United States
| | - Allyssa A Massie
- 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
|
42
|
Puri M, Company A, Sabenya G, Costas M, Que L. Oxygen Atom Exchange between H2O and Non-Heme Oxoiron(IV) Complexes: Ligand Dependence and Mechanism. Inorg Chem 2016; 55:5818-27. [DOI: 10.1021/acs.inorgchem.6b00023] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Mayank Puri
- Department of Chemistry and Center for
Metals in Biocatalysis, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
| | - Anna Company
- Grup de
Química Bioinspirada, Supramolecular i Catàlisi (QBIS-CAT),
Institut de Química Computacional i Catàlisi (IQCC),
Departament de Química, Universitat de Girona, Campus de
Montilivi, E17071, Girona, Catalonia Spain
| | - Gerard Sabenya
- Grup de
Química Bioinspirada, Supramolecular i Catàlisi (QBIS-CAT),
Institut de Química Computacional i Catàlisi (IQCC),
Departament de Química, Universitat de Girona, Campus de
Montilivi, E17071, Girona, Catalonia Spain
| | - Miquel Costas
- Grup de
Química Bioinspirada, Supramolecular i Catàlisi (QBIS-CAT),
Institut de Química Computacional i Catàlisi (IQCC),
Departament de Química, Universitat de Girona, Campus de
Montilivi, E17071, Girona, Catalonia Spain
| | - Lawrence Que
- Department of Chemistry and Center for
Metals in Biocatalysis, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
| |
Collapse
|
43
|
Srnec M, Wong SD, Matthews ML, Krebs C, Bollinger JM, Solomon EI. Electronic Structure of the Ferryl Intermediate in the α-Ketoglutarate Dependent Non-Heme Iron Halogenase SyrB2: Contributions to H Atom Abstraction Reactivity. J Am Chem Soc 2016; 138:5110-22. [PMID: 27021969 DOI: 10.1021/jacs.6b01151] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Low temperature magnetic circular dichroism (LT MCD) spectroscopy in combination with quantum-chemical calculations are used to define the electronic structure associated with the geometric structure of the Fe(IV)═O intermediate in SyrB2 that was previously determined by nuclear resonance vibrational spectroscopy. These studies elucidate key frontier molecular orbitals (FMOs) and their contribution to H atom abstraction reactivity. The VT MCD spectra of the enzymatic S = 2 Fe(IV)═O intermediate with Br(-) ligation contain information-rich features that largely parallel the corresponding spectra of the S = 2 model complex (TMG3tren)Fe(IV)═O (Srnec, M.; Wong, S. D.; England, J; Que, L; Solomon, E. I. Proc. Natl. Acad. Sci. USA 2012, 109, 14326-14331). However, quantitative differences are observed that correlate with π-anisotropy and oxo donor strength that perturb FMOs and affect reactivity. Due to π-anisotropy, the Fe(IV)═O active site exhibits enhanced reactivity in the direction of the substrate cavity that proceeds through a π-channel that is controlled by perpendicular orientation of the substrate C-H bond relative to the halide-Fe(IV)═O plane. Also, the increased intrinsic reactivity of the SyrB2 intermediate relative to the ferryl model complex is correlated to a higher oxyl character of the Fe(IV)═O at the transition states resulting from the weaker ligand field of the halogenase.
Collapse
Affiliation(s)
- Martin Srnec
- Department of Chemistry, Stanford University , Stanford, California 94305-5080, United States .,J. Heyrovský Institute of Physical Chemistry, The Czech Academy of Sciences , Dolejškova 2155/3, 182 23 Prague 8, Czech Republic
| | - Shaun D Wong
- Department of Chemistry, Stanford University , Stanford, California 94305-5080, United States
| | - Megan L Matthews
- Department of Chemistry, Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Carsten Krebs
- Department of Chemistry, Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - J Martin Bollinger
- Department of Chemistry, Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Edward I Solomon
- Department of Chemistry, Stanford University , Stanford, California 94305-5080, United States
| |
Collapse
|
44
|
Puri M, Biswas AN, Fan R, Guo Y, Que L. Modeling Non-Heme Iron Halogenases: High-Spin Oxoiron(IV)-Halide Complexes That Halogenate C-H Bonds. J Am Chem Soc 2016; 138:2484-7. [PMID: 26875530 DOI: 10.1021/jacs.5b11511] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The non-heme iron halogenases CytC3 and SyrB2 catalyze C-H bond halogenation in the biosynthesis of some natural products via S = 2 oxoiron(IV)-halide intermediates. These oxidants abstract a hydrogen atom from a substrate C-H bond to generate an alkyl radical that reacts with the bound halide to form a C-X bond chemoselectively. The origin of this selectivity has been explored in biological systems but has not yet been investigated with synthetic models. Here we report the characterization of S = 2 [Fe(IV)(O)(TQA)(Cl/Br)](+) (TQA = tris(quinolyl-2-methyl)amine) complexes that can preferentially halogenate cyclohexane. These are the first synthetic oxoiron(IV)-halide complexes that serve as spectroscopic and functional models for the halogenase intermediates. Interestingly, the nascent substrate radicals generated by these synthetic complexes are not as short-lived as those obtained from heme-based oxidants and can be intercepted by O2 to prevent halogenation, supporting an emerging notion that rapid rebound may not necessarily occur in non-heme oxoiron(IV) oxidations.
Collapse
Affiliation(s)
- Mayank Puri
- Department of Chemistry and Center for Metals in Biocatalysis, University of Minnesota , Minneapolis, Minnesota 55455, United States
| | - Achintesh N Biswas
- Department of Chemistry and Center for Metals in Biocatalysis, University of Minnesota , Minneapolis, Minnesota 55455, United States
| | - Ruixi Fan
- Department of Chemistry, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States
| | - Yisong Guo
- Department of Chemistry, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States
| | - Lawrence Que
- Department of Chemistry and Center for Metals in Biocatalysis, University of Minnesota , Minneapolis, Minnesota 55455, United States
| |
Collapse
|
45
|
Chatterjee S, Paine TK. Hydroxylation versus Halogenation of Aliphatic C−H Bonds by a Dioxygen-Derived Iron-Oxygen Oxidant: Functional Mimicking of Iron Halogenases. Angew Chem Int Ed Engl 2016; 128:7848-53. [DOI: 10.1002/ange.201509914] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
46
|
Chatterjee S, Paine TK. Hydroxylation versus Halogenation of Aliphatic C-H Bonds by a Dioxygen-Derived Iron-Oxygen Oxidant: Functional Mimicking of Iron Halogenases. Angew Chem Int Ed Engl 2016; 55:7717-22. [PMID: 26822989 DOI: 10.1002/anie.201509914] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Indexed: 11/10/2022]
Abstract
An iron-oxygen intermediate species generated in situ in the reductive activation of dioxygen by an iron(II)-benzilate complex of a monoanionic facial N3 ligand, promoted the halogenation of aliphatic C-H bonds in the presence of a protic acid and a halide anion. An electrophilic iron(IV)-oxo oxidant with a coordinated halide is proposed as the active oxidant. The halogenation reaction with dioxygen and the iron complex mimics the activity of non-heme iron halogenases.
Collapse
Affiliation(s)
- Sayanti Chatterjee
- Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, 2A & 2B Raja S. C. Mullick Road, Jadavpur, Kolkata-, 700032, India
| | - Tapan Kanti Paine
- Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, 2A & 2B Raja S. C. Mullick Road, Jadavpur, Kolkata-, 700032, India.
| |
Collapse
|
47
|
Abstract
![]()
2003 marked a banner year in the bioinorganic chemistry of mononuclear
non-heme iron enzymes. The first non-heme oxoiron(IV) intermediate
(called J) was trapped and characterized
by Bollinger and Krebs in the catalytic cycle of taurine dioxygenase
(TauD), and the first crystal structure of a synthetic non-heme oxoiron(IV)
complex was reported by Münck, Nam, and Que. These results
stimulated inorganic chemists to synthesize related oxoiron(IV) complexes
to shed light on the electronic structures and spectroscopic properties
of these novel intermediates and gain mechanistic insights into their
function in biology. All of the biological oxoiron(IV) intermediates
discovered since 2003 have an S = 2 ground spin state,
while over 90% of the 60 or so synthetic oxoiron(IV) complexes reported
to date have an S = 1 ground spin state. This difference
in electronic structure has fueled an interest to more accurately
model these enzymatic intermediates and synthesize S = 2 oxoiron(IV) complexes. This Account follows up on a previous
Account (Acc. Chem.
Res. 2007, 40, 493) that provided
a perspective on the early developments in this field up to 2007 and
details our group’s efforts in the development of synthetic
strategies to obtain oxoiron(IV) complexes with an S = 2 ground state. Upon inspection of a qualitative d-orbital splitting
diagram for a d4 metal–oxo center, it becomes evident
that the key to achieving an S = 2 ground state is
to decrease the energy gap between the dx2–y2 and
dxy orbitals. Described below are two
different synthetic strategies we used to accomplish this goal. The first strategy took advantage of the realization that the dx2–y2 and dxy orbitals become
degenerate in a C3-symmetric ligand environment.
Thus, by employing bulky tripodal ligands, trigonal-bipyramidal S = 2 oxoiron(IV) complexes were obtained. However, substrate
access to the oxoiron(IV) center was hindered by the bulky ligands,
and the complexes showed limited ability to cleave substrate C–H
bonds. The second strategy entailed introducing weaker-field equatorial
ligands in six-coordinate oxoiron(IV) complexes to decrease the dx2–y2/dxy energy gap to
the point where the S = 2 ground state is favored.
These pseudo-octahedral S = 2 oxoiron(IV) complexes
exhibit high H-atom transfer reactivity relative to their S = 1 counterparts and shed light on the role that the spin
state may play in these reactions. Among these complexes is a highly
reactive species that to date represents the closest electronic and
functional model of the enzymatic intermediate, TauD-J.
Collapse
Affiliation(s)
- Mayank Puri
- Department
of Chemistry and
Center for Metals in Biocatalysis, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Lawrence Que
- Department
of Chemistry and
Center for Metals in Biocatalysis, University of Minnesota, Minneapolis, Minnesota 55455, United States
| |
Collapse
|
48
|
Draksharapu A, Angelone D, Quesne MG, Padamati SK, Gómez L, Hage R, Costas M, Browne WR, de Visser SP. Identification and spectroscopic characterization of nonheme iron(III) hypochlorite intermediates. Angew Chem Int Ed Engl 2015; 54:4357-61. [PMID: 25663379 PMCID: PMC4670478 DOI: 10.1002/anie.201411995] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2014] [Revised: 01/10/2015] [Indexed: 11/18/2022]
Abstract
Fe(III)-hypohalite complexes have been implicated in a wide range of important enzyme-catalyzed halogenation reactions including the biosynthesis of natural products and antibiotics and post-translational modification of proteins. The absence of spectroscopic data on such species precludes their identification. Herein, we report the generation and spectroscopic characterization of nonheme Fe(III)-hypohalite intermediates of possible relevance to iron halogenases. We show that Fe(III)-OCl polypyridylamine complexes can be sufficiently stable at room temperature to be characterized by UV/Vis absorption, resonance Raman and EPR spectroscopies, and cryo-ESIMS. DFT methods rationalize the pathways to the formation of the Fe(III)-OCl, and ultimately Fe(IV)=O, species and provide indirect evidence for a short-lived Fe(II)-OCl intermediate. The species observed and the pathways involved offer insight into and, importantly, a spectroscopic database for the investigation of iron halogenases.
Collapse
Affiliation(s)
- Apparao Draksharapu
- Stratingh Institute for Chemistry, Faculty of Mathematics and Natural Sciences, University of GroningenNijenborgh 4, 9747 AG Groningen (The Netherlands) E-mail:
| | - Davide Angelone
- Stratingh Institute for Chemistry, Faculty of Mathematics and Natural Sciences, University of GroningenNijenborgh 4, 9747 AG Groningen (The Netherlands) E-mail:
| | - Matthew G Quesne
- Manchester Institute of Biotechnology and School of Chemical Engineering and Analytical Science, The University of Manchester131 Princess Street, Manchester M1 7DN (UK) E-mail:
| | - Sandeep K Padamati
- Stratingh Institute for Chemistry, Faculty of Mathematics and Natural Sciences, University of GroningenNijenborgh 4, 9747 AG Groningen (The Netherlands) E-mail:
| | - Laura Gómez
- Departament de Química and Institute of Computational Chemistry and Catalysis (IQCC), University of GironaCampus de Montilivi, Girona 17071 (Spain)
- Serveis Tècnics de Recerca (STR), Universitat de GironaParc Científic i Tecnològic, E-17003 Girona, Spain
| | - Ronald Hage
- Catexel Ltd., BioPartner Center LeidenGalileiweg 8, 2333 BD Leiden (The Netherlands)
| | - Miquel Costas
- Departament de Química and Institute of Computational Chemistry and Catalysis (IQCC), University of GironaCampus de Montilivi, Girona 17071 (Spain)
| | - Wesley R Browne
- Stratingh Institute for Chemistry, Faculty of Mathematics and Natural Sciences, University of GroningenNijenborgh 4, 9747 AG Groningen (The Netherlands) E-mail:
| | - Sam P de Visser
- Manchester Institute of Biotechnology and School of Chemical Engineering and Analytical Science, The University of Manchester131 Princess Street, Manchester M1 7DN (UK) E-mail:
| |
Collapse
|
49
|
Draksharapu A, Angelone D, Quesne MG, Padamati SK, Gómez L, Hage R, Costas M, Browne WR, de Visser SP. Identification and Spectroscopic Characterization of Nonheme Iron(III) Hypochlorite Intermediates. Angew Chem Weinheim Bergstr Ger 2015; 127:4431-4435. [PMID: 27478260 PMCID: PMC4955228 DOI: 10.1002/ange.201411995] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/14/2014] [Revised: 01/10/2015] [Indexed: 11/07/2022]
Abstract
FeIII-hypohalite complexes have been implicated in a wide range of important enzyme-catalyzed halogenation reactions including the biosynthesis of natural products and antibiotics and post-translational modification of proteins. The absence of spectroscopic data on such species precludes their identification. Herein, we report the generation and spectroscopic characterization of nonheme FeIII-hypohalite intermediates of possible relevance to iron halogenases. We show that FeIII-OCl polypyridylamine complexes can be sufficiently stable at room temperature to be characterized by UV/Vis absorption, resonance Raman and EPR spectroscopies, and cryo-ESIMS. DFT methods rationalize the pathways to the formation of the FeIII-OCl, and ultimately FeIV=O, species and provide indirect evidence for a short-lived FeII-OCl intermediate. The species observed and the pathways involved offer insight into and, importantly, a spectroscopic database for the investigation of iron halogenases.
Collapse
Affiliation(s)
- Apparao Draksharapu
- Stratingh Institute for Chemistry, Faculty of Mathematics and Natural Sciences, University of Groningen, Nijenborgh 4, 9747 AG Groningen (The Netherlands)
| | - Davide Angelone
- Stratingh Institute for Chemistry, Faculty of Mathematics and Natural Sciences, University of Groningen, Nijenborgh 4, 9747 AG Groningen (The Netherlands)
| | - Matthew G. Quesne
- Manchester Institute of Biotechnology and School of Chemical Engineering and Analytical Science, The University of Manchester, 131 Princess Street, Manchester M1 7DN (UK)
| | - Sandeep K. Padamati
- Stratingh Institute for Chemistry, Faculty of Mathematics and Natural Sciences, University of Groningen, Nijenborgh 4, 9747 AG Groningen (The Netherlands)
| | - Laura Gómez
- Departament de Química and Institute of Computational Chemistry and Catalysis (IQCC), University of Girona, Campus de Montilivi, Girona 17071 (Spain)
- Serveis Tècnics de Recerca (STR), Universitat de Girona, Parc Científic i Tecnològic, E‐17003 Girona, Spain
| | - Ronald Hage
- Catexel Ltd., BioPartner Center Leiden, Galileiweg 8, 2333 BD Leiden (The Netherlands)
| | - Miquel Costas
- Departament de Química and Institute of Computational Chemistry and Catalysis (IQCC), University of Girona, Campus de Montilivi, Girona 17071 (Spain)
| | - Wesley R. Browne
- Stratingh Institute for Chemistry, Faculty of Mathematics and Natural Sciences, University of Groningen, Nijenborgh 4, 9747 AG Groningen (The Netherlands)
| | - Sam P. de Visser
- Manchester Institute of Biotechnology and School of Chemical Engineering and Analytical Science, The University of Manchester, 131 Princess Street, Manchester M1 7DN (UK)
| |
Collapse
|
50
|
Kleespies ST, Oloo WN, Mukherjee A, Que L. C-H Bond Cleavage by Bioinspired Nonheme Oxoiron(IV) Complexes, Including Hydroxylation of n-Butane. Inorg Chem 2015; 54:5053-64. [PMID: 25751610 DOI: 10.1021/ic502786y] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The development of efficient and selective hydrocarbon oxidation processes with low environmental impact remains a major challenge of the 21st century because of the strong and apolar nature of the C-H bond. Naturally occurring iron-containing metalloenzymes can, however, selectively functionalize strong C-H bonds on substrates under mild and environmentally benign conditions. The key oxidant in a number of these transformations is postulated to possess an S = 2 Fe(IV)═O unit in a nonheme ligand environment. This oxidant has been trapped and spectroscopically characterized and its reactivity toward C-H bonds demonstrated for several nonheme iron enzyme classes. In order to obtain insight into the structure-activity relationships of these reactive intermediates, over 60 synthetic nonheme Fe(IV)(O) complexes have been prepared in various laboratories and their reactivities investigated. This Forum Article summarizes the current status of efforts in the characterization of the C-H bond cleavage reactivity of synthetic Fe(IV)(O) complexes and provides a snapshot of the current understanding of factors that control this reactivity, such as the properties of the supporting ligands and the spin state of the iron center. In addition, new results on the oxidation of strong C-H bonds such as those of cyclohexane and n-butane by a putative S = 2 synthetic Fe(IV)(O) species that is generated in situ using dioxygen at ambient conditions are presented.
Collapse
Affiliation(s)
- Scott T Kleespies
- Department of Chemistry and Center for Metals in Biocatalysis, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Williamson N Oloo
- Department of Chemistry and Center for Metals in Biocatalysis, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Anusree Mukherjee
- Department of Chemistry and Center for Metals in Biocatalysis, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Lawrence Que
- Department of Chemistry and Center for Metals in Biocatalysis, University of Minnesota, Minneapolis, Minnesota 55455, United States
| |
Collapse
|