1
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Hatakeyama-Sato K, Oyaizu K. Redox: Organic Robust Radicals and Their Polymers for Energy Conversion/Storage Devices. Chem Rev 2023; 123:11336-11391. [PMID: 37695670 DOI: 10.1021/acs.chemrev.3c00172] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
Persistent radicals can hold their unpaired electrons even under conditions where they accumulate, leading to the unique characteristics of radical ensembles with open-shell structures and their molecular properties, such as magneticity, radical trapping, catalysis, charge storage, and electrical conductivity. The molecules also display fast, reversible redox reactions, which have attracted particular attention for energy conversion and storage devices. This paper reviews the electrochemical aspects of persistent radicals and the corresponding macromolecules, radical polymers. Radical structures and their redox reactions are introduced, focusing on redox potentials, bistability, and kinetic constants for electrode reactions and electron self-exchange reactions. Unique charge transport and storage properties are also observed with the accumulated form of redox sites in radical polymers. The radical molecules have potential electrochemical applications, including in rechargeable batteries, redox flow cells, photovoltaics, diodes, and transistors, and in catalysts, which are reviewed in the last part of this paper.
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Affiliation(s)
- Kan Hatakeyama-Sato
- School of Materials and Chemical Technology, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku Tokyo 152-8552, Japan
- Department of Applied Chemistry, Waseda University, Tokyo 169-8555, Japan
| | - Kenichi Oyaizu
- Department of Applied Chemistry, Waseda University, Tokyo 169-8555, Japan
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2
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Abstract
Nitroxides, also known as nitroxyl radicals, are long-lived or stable radicals with the general structure R1R2N-O•. The spin distribution over the nitroxide N and O atoms contributes to the thermodynamic stability of these radicals. The presence of bulky N-substituents R1 and R2 prevents nitroxide radical dimerization, ensuring their kinetic stability. Despite their reactivity toward various transient C radicals, some nitroxides can be easily stored under air at room temperature. Furthermore, nitroxides can be oxidized to oxoammonium salts (R1R2N═O+) or reduced to anions (R1R2N-O-), enabling them to act as valuable oxidants or reductants depending on their oxidation state. Therefore, they exhibit interesting reactivity across all three oxidation states. Due to these fascinating properties, nitroxides find extensive applications in diverse fields such as biochemistry, medicinal chemistry, materials science, and organic synthesis. This review focuses on the versatile applications of nitroxides in organic synthesis. For their use in other important fields, we will refer to several review articles. The introductory part provides a brief overview of the history of nitroxide chemistry. Subsequently, the key methods for preparing nitroxides are discussed, followed by an examination of their structural diversity and physical properties. The main portion of this review is dedicated to oxidation reactions, wherein parent nitroxides or their corresponding oxoammonium salts serve as active species. It will be demonstrated that various functional groups (such as alcohols, amines, enolates, and alkanes among others) can be efficiently oxidized. These oxidations can be carried out using nitroxides as catalysts in combination with various stoichiometric terminal oxidants. By reducing nitroxides to their corresponding anions, they become effective reducing reagents with intriguing applications in organic synthesis. Nitroxides possess the ability to selectively react with transient radicals, making them useful for terminating radical cascade reactions by forming alkoxyamines. Depending on their structure, alkoxyamines exhibit weak C-O bonds, allowing for the thermal generation of C radicals through reversible C-O bond cleavage. Such thermally generated C radicals can participate in various radical transformations, as discussed toward the end of this review. Furthermore, the application of this strategy in natural product synthesis will be presented.
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Affiliation(s)
- Dirk Leifert
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität, Corrensstrasse 40, 48149 Münster, Germany
| | - Armido Studer
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität, Corrensstrasse 40, 48149 Münster, Germany
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3
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Galazzo L, Bordignon E. Electron paramagnetic resonance spectroscopy in structural-dynamic studies of large protein complexes. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2023; 134-135:1-19. [PMID: 37321755 DOI: 10.1016/j.pnmrs.2022.11.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 11/11/2022] [Accepted: 11/17/2022] [Indexed: 06/17/2023]
Abstract
Macromolecular protein assemblies are of fundamental importance for many processes inside the cell, as they perform complex functions and constitute central hubs where reactions occur. Generally, these assemblies undergo large conformational changes and cycle through different states that ultimately are connected to specific functions further regulated by additional small ligands or proteins. Unveiling the 3D structural details of these assemblies at atomic resolution, identifying the flexible parts of the complexes, and monitoring with high temporal resolution the dynamic interplay between different protein regions under physiological conditions is key to fully understanding their properties and to fostering biomedical applications. In the last decade, we have seen remarkable advances in cryo-electron microscopy (EM) techniques, which deeply transformed our vision of structural biology, especially in the field of macromolecular assemblies. With cryo-EM, detailed 3D models of large macromolecular complexes in different conformational states became readily available at atomic resolution. Concomitantly, nuclear magnetic resonance (NMR) and electron paramagnetic resonance spectroscopy (EPR) have benefited from methodological innovations which also improved the quality of the information that can be achieved. Such enhanced sensitivity widened their applicability to macromolecular complexes in environments close to physiological conditions and opened a path towards in-cell applications. In this review we will focus on the advantages and challenges of EPR techniques with an integrative approach towards a complete understanding of macromolecular structures and functions.
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Affiliation(s)
- Laura Galazzo
- Department of Physical Chemistry, University of Geneva, Quai Ernest Ansermet 30, CH-1211 Genève 4, Switzerland.
| | - Enrica Bordignon
- Department of Physical Chemistry, University of Geneva, Quai Ernest Ansermet 30, CH-1211 Genève 4, Switzerland.
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4
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Verdhi LK, Fridman N, Szpilman AM. Copper- and Chiral Nitroxide-Catalyzed Oxidative Kinetic Resolution of Axially Chiral N-Arylpyrroles. Org Lett 2022; 24:5078-5083. [PMID: 35798692 DOI: 10.1021/acs.orglett.2c01860] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A readily prepared C2-symmetric, α-hydrogen-substituted chiral hydroxylamine serves as a precatalyst to generate a chiral nitroxide in situ. This chiral nitroxide catalyst in combination with a copper co-catalyst functions as an oxidant for an unprecedented enantioselective oxidative kinetic resolution (OKR) of racemic axially chiral N-arylpyrrole alcohols using atmospheric oxygen as an environmentally friendly terminal oxidant. The OKR process provides the axially chiral N-arylpyrroles in er up to 3.5:96.5 and with s factors up to 24.
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Affiliation(s)
- Lenin Kumar Verdhi
- Department of Chemical Sciences, Ariel University, Ariel 4070000, Israel
| | - Natalia Fridman
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa 3200009, Israel
| | - Alex M Szpilman
- Department of Chemical Sciences, Ariel University, Ariel 4070000, Israel
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5
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Cuatepotzo-Dı́az R, López-Méndez BL, López-Domı́nguez P, Albores-Velasco ME, Penlidis A, Vivaldo-Lima E. The Role of Nitroxide Degradation on the Efficiency of the Controller in Nitroxide-Mediated Radical Polymerization (NMP) of Styrene. Ind Eng Chem Res 2020. [DOI: 10.1021/acs.iecr.0c03547] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Rubén Cuatepotzo-Dı́az
- Ciencias de la Salud, Universidad del Valle de México, Campus Querétaro, Blvd. Juriquilla No. 1000, Santiago de Querétaro, 76230 Querétaro, México
| | - Brenda Larisa López-Méndez
- Facultad de Quı́mica, Departamento de Ingenierı́a Quı́mica, Universidad Nacional Autónoma de México, CU, 04510 México City, México
| | - Porfirio López-Domı́nguez
- Facultad de Quı́mica, Departamento de Ingenierı́a Quı́mica, Universidad Nacional Autónoma de México, CU, 04510 México City, México
| | - Martha Eugenia Albores-Velasco
- Facultad de Quı́mica, Departamento de Quı́mica Orgánica, Universidad Nacional Autónoma de México, CU, 04510 México City, México
| | - Alexander Penlidis
- Institute for Polymer Research, Department of Chemical Engineering, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Eduardo Vivaldo-Lima
- Facultad de Quı́mica, Departamento de Ingenierı́a Quı́mica, Universidad Nacional Autónoma de México, CU, 04510 México City, México
- Institute for Polymer Research, Department of Chemical Engineering, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
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6
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Toledo H, Tumanskii B, Sabirov DS, Kaushansky A, Fridman N, Szpilman AM. First α-deuterium nitroxides; synthesis and EPR study. Org Biomol Chem 2019; 17:7900-7906. [PMID: 31410426 DOI: 10.1039/c9ob01127g] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Herein is reported the first preparation of stable α-deuterium nitroxides of the IAPNO family. The confirmation and characteristics of the α-deuterium nitroxides and their α-hydrogen analogues are compared and analyzed. Such α-deuterium nitroxides may find use in biology, medicine and physical chemistry.
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Affiliation(s)
- Hila Toledo
- Department of Chemical Sciences, Ariel University, Israel.
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7
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Affiliation(s)
- F. Ruipérez
- POLYMAT, University of the Basque Country UPV/EHU, Donostia-San Sebastián, Spain
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8
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Lim S, McArdell CS, von Gunten U. Reactions of aliphatic amines with ozone: Kinetics and mechanisms. WATER RESEARCH 2019; 157:514-528. [PMID: 30986698 DOI: 10.1016/j.watres.2019.03.089] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 03/13/2019] [Accepted: 03/27/2019] [Indexed: 06/09/2023]
Abstract
Aliphatic amines are common constituents in micropollutants and dissolved organic matter and present in elevated concentrations in wastewater-impacted source waters. Due to high reactivity, reactions of aliphatic amines with ozone are likely to occur during ozonation in water and wastewater treatment. We investigated the kinetics and mechanisms of the reactions of ozone with ethylamine, diethylamine, and triethylamine as model nitrogenous compounds. Species-specific second-order rate constants for the neutral parent amines ranged from 9.3 × 104 to 2.2 × 106 M-1s-1 and the apparent second-order rate constants at pH 7 for potential or identified transformation products were 6.8 × 105 M-1s-1 for N,N-diethylhydroxylamine, ∼105 M-1s-1 for N-ethylhydroxylamine, 1.9 × 103 M-1s-1 for N-ethylethanimine oxide, and 3.4 M-1s-1 for nitroethane. Product analyses revealed that all amines were transformed to products containing a nitrogen-oxygen bond (e.g., triethylamine N-oxide and nitroethane) with high yields, i.e., 64-100% with regard to the abated target amines. These findings could be confirmed by measurements of singlet oxygen and hydroxyl radical which are formed during the amine-ozone reactions. Based on the high yields of nitroethane from ethylamine and diethylamine, a significant formation of nitroalkanes can be expected during ozonation of waters containing high levels of dissolved organic nitrogen, as expected in wastewaters or wastewater-impaired source waters. This may pose adverse effects on the aquatic environment and human health.
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Affiliation(s)
- Sungeun Lim
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, 8600, Duebendorf, Switzerland; School of Architecture, Civil and Environmental Engineering (ENAC), École Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland
| | - Christa S McArdell
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, 8600, Duebendorf, Switzerland
| | - Urs von Gunten
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, 8600, Duebendorf, Switzerland; School of Architecture, Civil and Environmental Engineering (ENAC), École Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland.
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9
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Prescott C, Bottle SE. Biological Relevance of Free Radicals and Nitroxides. Cell Biochem Biophys 2017; 75:227-240. [PMID: 27709467 DOI: 10.1007/s12013-016-0759-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 08/18/2016] [Indexed: 12/31/2022]
Abstract
Nitroxides are stable, kinetically-persistent free radicals which have been successfully used in the study and intervention of oxidative stress, a critical issue pertaining to cellular health which results from an imbalance in the levels of damaging free radicals and redox-active species in the cellular environment. This review gives an overview of some of the biological processes that produce radicals and other reactive oxygen species with relevance to oxidative stress, and then discusses interactions of nitroxides with these species in terms of the use of nitroxides as redox-sensitive probes and redox-active therapeutic agents.
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10
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McCann S, Lumb JP, Arndtsen BA, Stahl SS. Second-Order Biomimicry: In Situ Oxidative Self-Processing Converts Copper(I)/Diamine Precursor into a Highly Active Aerobic Oxidation Catalyst. ACS CENTRAL SCIENCE 2017; 3:314-321. [PMID: 28470049 PMCID: PMC5408333 DOI: 10.1021/acscentsci.7b00022] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2017] [Indexed: 05/11/2023]
Abstract
A homogeneous Cu-based catalyst system consisting of [Cu(MeCN)4]PF6, N,N'-di-tert-butylethylenediamine (DBED), and p-(N,N-dimethylamino)pyridine (DMAP) mediates efficient aerobic oxidation of alcohols. Mechanistic study of this reaction shows that the catalyst undergoes an in situ oxidative self-processing step, resulting in conversion of DBED into a nitroxyl that serves as an efficient cocatalyst for aerobic alcohol oxidation. Insights into this behavior are gained from kinetic studies, which reveal an induction period at the beginning of the reaction that correlates with the oxidative self-processing step, EPR spectroscopic analysis of the catalytic reaction mixture, which shows the buildup of the organic nitroxyl species during steady state turnover, and independent synthesis of oxygenated DBED derivatives, which are shown to serve as effective cocatalysts and eliminate the induction period in the reaction. The overall mechanism bears considerable resemblance to enzymatic reactivity. Most notable is the "oxygenase"-type self-processing step that mirrors generation of catalytic cofactors in enzymes via post-translational modification of amino acid side chains. This higher-order function within a synthetic catalyst system presents new opportunities for the discovery and development of biomimetic catalysts.
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Affiliation(s)
- Scott
D. McCann
- Department
of Chemistry, University of Wisconsin—Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Jean-Philip Lumb
- Department
of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, Quebec, H3A 0B8 Canada
- E-mail:
| | - Bruce A. Arndtsen
- Department
of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, Quebec, H3A 0B8 Canada
- E-mail:
| | - Shannon S. Stahl
- Department
of Chemistry, University of Wisconsin—Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
- E-mail:
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11
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Bi W, Bi Y, Gao X, Li P, Hou S, Zhang Y, Bammert C, Jockusch S, Legalley TD, Michael Gibson K, Bi L. Indole-TEMPO conjugates alleviate ischemia-reperfusion injury via attenuation of oxidative stress and preservation of mitochondrial function. Bioorg Med Chem 2017; 25:2545-2568. [PMID: 28359673 DOI: 10.1016/j.bmc.2017.03.033] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2016] [Revised: 03/14/2017] [Accepted: 03/16/2017] [Indexed: 01/13/2023]
Abstract
Mitochondrial oxidative damage contributes to a wide range of pathologies including ischemia/reperfusion injury. Accordingly, protecting mitochondria from oxidative damage should possess therapeutic relevance. In the present study, we have designed and synthesized a series of novel indole-TEMPO conjugates that manifested good anti-inflammatory properties in a murine model of xylene-induced ear edema. We have demonstrated that these compounds can protect cells from simulated ischemia/reperfusion (s-I/R)-induced reactive oxygen species (ROS) overproduction and mitochondrial dysfunction. Furthermore, we have demonstrated that indole-TEMPO conjugates can attenuate organ damage induced in rodents via intestinal I/R injury. We therefore propose that the pharmacological profile and mechanism of action of these indole-TEMPO conjugates involve convergent roles, including the ability to decrease free radical production via lipid peroxidation which couples to an associated decrease in ROS-mediated activation of the inflammatory process. We further hypothesize that the protective effects of indole-TEMPO conjugates partially reside in maintaining optimal mitochondrial function.
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Affiliation(s)
- Wei Bi
- Second Hospital of HeBei Medical University, Shijiazhuang 050000, PR China.
| | - Yue Bi
- Second Hospital of HeBei Medical University, Shijiazhuang 050000, PR China
| | - Xiang Gao
- Department of Chemistry and Biological Sciences, Michigan Technological University, Houghton, MI 49931, USA
| | - Pengfei Li
- Second Hospital of HeBei Medical University, Shijiazhuang 050000, PR China
| | - Shanshan Hou
- Department of Chemistry and Biological Sciences, Michigan Technological University, Houghton, MI 49931, USA
| | - Yanrong Zhang
- Second Hospital of HeBei Medical University, Shijiazhuang 050000, PR China
| | - Cathy Bammert
- Department of Chemistry and Biological Sciences, Michigan Technological University, Houghton, MI 49931, USA
| | - Steffen Jockusch
- Department of Chemistry, Columbia University, New York, NY 10027, USA
| | - Thomas D Legalley
- Marquette General Heart and Vascular Institute, Marquette General Hospital, Marquette, MI 49855, USA
| | - K Michael Gibson
- Department of Pharmacotherapy, College of Pharmacy, Washington State University, Spokane WA 99202, USA.
| | - Lanrong Bi
- Department of Chemistry and Biological Sciences, Michigan Technological University, Houghton, MI 49931, USA.
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12
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Iron MA, Szpilman AM. Mechanism of the Copper/TEMPO-Catalyzed Aerobic Oxidation of Alcohols. Chemistry 2016; 23:1368-1378. [DOI: 10.1002/chem.201604402] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2016] [Indexed: 11/08/2022]
Affiliation(s)
- Mark A. Iron
- Computational Chemistry Unit; Department of Chemical Research Support; Weizmann Institute of Science; 7610001 Rehovot Israel
| | - Alex M. Szpilman
- Department of Chemical Sciences; Ariel University; 40700 Ariel Israel
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13
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Thétiot-Laurent S, Gosset G, Clément JL, Cassien M, Mercier A, Siri D, Gaudel-Siri A, Rockenbauer A, Culcasi M, Pietri S. New Amino-Acid-Based β-Phosphorylated Nitroxides for Probing Acidic pH in Biological Systems by EPR Spectroscopy. Chembiochem 2016; 18:300-315. [DOI: 10.1002/cbic.201600550] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Indexed: 01/06/2023]
Affiliation(s)
- Sophie Thétiot-Laurent
- Aix Marseille Univ; CNRS; ICR; UMR 7273; Avenue Escadrile Normandie Niemen 13397 Marseille France
| | - Gaëlle Gosset
- Aix Marseille Univ; CNRS; ICR; UMR 7273; Avenue Escadrile Normandie Niemen 13397 Marseille France
| | - Jean-Louis Clément
- Aix Marseille Univ; CNRS; ICR; UMR 7273; Avenue Escadrile Normandie Niemen 13397 Marseille France
| | - Mathieu Cassien
- Aix Marseille Univ; CNRS; ICR; UMR 7273; Avenue Escadrile Normandie Niemen 13397 Marseille France
| | - Anne Mercier
- Aix Marseille Univ; CNRS; ICR; UMR 7273; Avenue Escadrile Normandie Niemen 13397 Marseille France
| | - Didier Siri
- Aix Marseille Univ; CNRS; ICR; UMR 7273; Avenue Escadrile Normandie Niemen 13397 Marseille France
| | - Anouk Gaudel-Siri
- Aix Marseille Univ; CNRS; ICR; UMR 7273; Avenue Escadrile Normandie Niemen 13397 Marseille France
| | - Antal Rockenbauer
- Research Centre for Natural Sciences of the Hungarian Academy of Sciences; Institute of Materials and Environmental Chemistry; Budapest University of Technology and Economics; 1117 Budapest Hungary
| | - Marcel Culcasi
- Aix Marseille Univ; CNRS; ICR; UMR 7273; Avenue Escadrile Normandie Niemen 13397 Marseille France
| | - Sylvia Pietri
- Aix Marseille Univ; CNRS; ICR; UMR 7273; Avenue Escadrile Normandie Niemen 13397 Marseille France
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14
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Scott MJ, Billiar TR, Stoyanovsky DA. N-tert-butylmethanimine N-oxide is an efficient spin-trapping probe for EPR analysis of glutathione thiyl radical. Sci Rep 2016; 6:38773. [PMID: 27941944 PMCID: PMC5150238 DOI: 10.1038/srep38773] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 11/10/2016] [Indexed: 12/29/2022] Open
Abstract
The electron spin resonance (EPR) spin-trapping technique allows detection of radical species with nanosecond half-lives. This technique is based on the high rates of addition of radicals to nitrones or nitroso compounds (spin traps; STs). The paramagnetic nitroxides (spin-adducts) formed as a result of reactions between STs and radical species are relatively stable compounds whose EPR spectra represent “structural fingerprints” of the parent radical species. Herein we report a novel protocol for the synthesis of N-tert-butylmethanimine N-oxide (EBN), which is the simplest nitrone containing an α-H and a tertiary α′-C atom. We present EPR spin-trapping proof that: (i) EBN is an efficient probe for the analysis of glutathione thiyl radical (GS•); (ii) β-cyclodextrins increase the kinetic stability of the spin-adduct EBN/•SG; and (iii) in aqueous solutions, EBN does not react with superoxide anion radical (O2−•) to form EBN/•OOH to any significant extent. The data presented complement previous studies within the context of synthetic accessibility to EBN and efficient spin-trapping analysis of GS•.
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Affiliation(s)
- Melanie J Scott
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Timothy R Billiar
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Detcho A Stoyanovsky
- Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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15
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Protonation-induced change in the conformation, crystal structure and property of triarylmethyl carbocation radical. Chem Phys Lett 2016. [DOI: 10.1016/j.cplett.2016.02.042] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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16
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Ljubić I, Kivimäki A, Coreno M. An experimental NEXAFS and computational TDDFT and ΔDFT study of the gas-phase core excitation spectra of nitroxide free radical TEMPO and its analogues. Phys Chem Chem Phys 2016; 18:10207-17. [DOI: 10.1039/c6cp00490c] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Core excitation (NEXAFS) C 1s, N 1s, and O 1s gas-phase spectra of stable nitroxide free radical TEMPO and two of its amide-substituted analogues are assigned from the onset of the absorptions to the vicinity of the core-ionization thresholds using the theoretical TDDFT and ΔDFT methods.
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Affiliation(s)
- Ivan Ljubić
- Department of Physical Chemistry
- Ruđer Bošković Institute
- HR-10000 Zagreb
- Croatia
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17
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Bottle SE, Clement JL, Fleige M, Simpson EM, Guillaneuf Y, Fairfull-Smith KE, Gigmes D, Blinco JP. Light-active azaphenalene alkoxyamines: fast and efficient mediators of a photo-induced persistent radical effect. RSC Adv 2016. [DOI: 10.1039/c6ra18500b] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Reported is the first example of an alkoxyamine that quantitatively yields a nitroxide upon light exposure. The alkoxyamine is used to generate a light driven persistent radical effect and applied to radical insertion, exchange and polymerization reactions.
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Affiliation(s)
- Steven E. Bottle
- School of Chemistry
- Physics and Mechanical Engineering
- Science and Engineering Faculty
- Queensland University of Technology
- Brisbane
| | | | - Mirco Fleige
- School of Chemistry
- Physics and Mechanical Engineering
- Science and Engineering Faculty
- Queensland University of Technology
- Brisbane
| | - Emily M. Simpson
- School of Chemistry
- Physics and Mechanical Engineering
- Science and Engineering Faculty
- Queensland University of Technology
- Brisbane
| | | | - Kathryn E. Fairfull-Smith
- School of Chemistry
- Physics and Mechanical Engineering
- Science and Engineering Faculty
- Queensland University of Technology
- Brisbane
| | - Didier Gigmes
- Aix Marseille Univ
- CNRS
- ICR UMR 7273
- 13397 Marseille
- France
| | - James P. Blinco
- School of Chemistry
- Physics and Mechanical Engineering
- Science and Engineering Faculty
- Queensland University of Technology
- Brisbane
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18
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Toledo H, Amar M, Bar S, Iron MA, Fridman N, Tumanskii B, Shimon LJW, Botoshansky M, Szpilman AM. Synthesis and stability of cyclic α-hydrogen nitroxides. Org Biomol Chem 2015; 13:10726-33. [PMID: 26356203 DOI: 10.1039/c5ob01443c] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Nitroxides (nitroxyl radicals) hold a unique place in science due to their stable radical nature. We have recently reported the first design concept providing a general solution to the problem of designing and preparing monocyclic α-hydrogen nitroxides. The initial studies were limited to aryl derivatives. We now report a wider study showing that alkyl substituents may be employed as well. In addition, we report several additional examples of aryl substituents and reveal some of the structural limitations with regard to nitroxide stability as a function of the α-carbon substituent.
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Affiliation(s)
- Hila Toledo
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, Israel.
| | - Michal Amar
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, Israel.
| | - Sukanta Bar
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, Israel.
| | - Mark A Iron
- Department of Chemical Research Support, Weizmann Institute of Science, Israel
| | - Natalia Fridman
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, Israel.
| | - Boris Tumanskii
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, Israel.
| | - Linda J W Shimon
- Department of Chemical Research Support, Weizmann Institute of Science, Israel
| | - Mark Botoshansky
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, Israel.
| | - Alex M Szpilman
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, Israel.
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19
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Zhang Z, Gao Y, Liu Y, Li J, Xie H, Li H, Wang W. Organocatalytic Aerobic Oxidation of Benzylic sp3 C–H Bonds of Ethers and Alkylarenes Promoted by a Recyclable TEMPO Catalyst. Org Lett 2015; 17:5492-5. [DOI: 10.1021/acs.orglett.5b02877] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Zhiguang Zhang
- Shanghai
Key Laboratory of New Drug Design, School of Pharmacy, and State Key
Laboratory of Bioengineering Reactor, East China University of Science and Technology, 130 Mei-long Road, Shanghai 200237, China
| | - Yuan Gao
- Shanghai
Key Laboratory of New Drug Design, School of Pharmacy, and State Key
Laboratory of Bioengineering Reactor, East China University of Science and Technology, 130 Mei-long Road, Shanghai 200237, China
| | - Yuan Liu
- Shanghai
Key Laboratory of New Drug Design, School of Pharmacy, and State Key
Laboratory of Bioengineering Reactor, East China University of Science and Technology, 130 Mei-long Road, Shanghai 200237, China
| | - Jianjun Li
- Shanghai
Key Laboratory of New Drug Design, School of Pharmacy, and State Key
Laboratory of Bioengineering Reactor, East China University of Science and Technology, 130 Mei-long Road, Shanghai 200237, China
| | - Hexin Xie
- Shanghai
Key Laboratory of New Drug Design, School of Pharmacy, and State Key
Laboratory of Bioengineering Reactor, East China University of Science and Technology, 130 Mei-long Road, Shanghai 200237, China
| | - Hao Li
- Shanghai
Key Laboratory of New Drug Design, School of Pharmacy, and State Key
Laboratory of Bioengineering Reactor, East China University of Science and Technology, 130 Mei-long Road, Shanghai 200237, China
| | - Wei Wang
- Shanghai
Key Laboratory of New Drug Design, School of Pharmacy, and State Key
Laboratory of Bioengineering Reactor, East China University of Science and Technology, 130 Mei-long Road, Shanghai 200237, China
- Department
of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131-0001, United States
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20
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Chatgilialoglu C, Ferreri C, Matyjaszewski K. Radicals and Dormant Species in Biology and Polymer Chemistry. Chempluschem 2015; 81:11-29. [DOI: 10.1002/cplu.201500271] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Indexed: 12/20/2022]
Affiliation(s)
| | - Carla Ferreri
- I.S.O.F.-BioFreeRadicals; Consiglio Nazionale delle Ricerche; Via P. Gobetti 101 Bologna 40129 Italy
| | - Krzysztof Matyjaszewski
- Department of Chemistry; Carnegie Mellon University; 4400 Fifth Avenue Pittsburgh PA 15213 USA
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21
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Bar S, Kumar JN, Amar M, Toledo H, Batrice RJ, Szpilman AM. Catalytic Aerobic Oxidation of Alcohols using Recoverable IAPNO α-Hydrogen Nitroxyl Radicals. ChemCatChem 2015. [DOI: 10.1002/cctc.201402985] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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