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Shoji Y, Terashima Y, Ohkubo K, Ito H, Maruyama K, Fukuzumi S, Nakanishi I. Scandium Ion-Promoted Electron-Transfer Disproportionation of 2-Phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-Oxide (PTIO •) in Acetonitrile and Its Regeneration Induced by Water. Int J Mol Sci 2024; 25:4417. [PMID: 38674002 PMCID: PMC11050215 DOI: 10.3390/ijms25084417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Revised: 04/09/2024] [Accepted: 04/16/2024] [Indexed: 04/28/2024] Open
Abstract
2-Phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide (PTIO•), a persistent nitronyl nitroxide radical, has been used for the detection and trapping of nitric oxide, as a redox mediator for batteries, for the activity estimation of antioxidants, and so on. However, there is no report on the reactivity of PTIO• in the presence of redox-inactive metal ions. In this study, it is demonstrated that the addition of scandium triflate, Sc(OTf)3 (OTf = OSO2CF3), to an acetonitrile (MeCN) solution of PTIO• resulted in an electron-transfer disproportionation to generate the corresponding cation (PTIO+) and anion (PTIO-), the latter of which is suggested to be stabilized by Sc3+ to form [(PTIO)Sc]2+. The decay of the absorption band at 361 nm due to PTIO•, monitored using a stopped-flow technique, obeyed second-order kinetics. The second-order rate constant for the disproportionation, thus determined, increased with increasing the Sc(OTf)3 concentration to reach a constant value. A drastic change in the cyclic voltammogram recorded for PTIO• in deaerated MeCN containing 0.10 M Bu4NClO4 was also observed upon addition of Sc(OTf)3, suggesting that the large positive shift of the one-electron reduction potential of PTIO• (equivalent to the one-electron oxidation potential of PTIO-) in the presence of Sc(OTf)3 may result in the disproportionation. When H2O was added to the PTIO•-Sc(OTf)3 system in deaerated MeCN, PTIO• was completely regenerated. It is suggested that the complex formation of Sc3+ with H2O may weaken the interaction between PTIO- and Sc3+, leading to electron-transfer comproportionation to regenerate PTIO•. The reversible disproportionation of PTIO• was also confirmed by electron paramagnetic resonance (EPR) spectroscopy.
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Grants
- JP18K06620 Ministry of Education, Culture, Sports, Science and Technology
- JP20H02779 Ministry of Education, Culture, Sports, Science and Technology
- JP20H04819 Ministry of Education, Culture, Sports, Science and Technology
- JP18H04650 Ministry of Education, Culture, Sports, Science and Technology
- JP17H03010 Ministry of Education, Culture, Sports, Science and Technology
- JP16H02268 Ministry of Education, Culture, Sports, Science and Technology
- JP23K04686 Ministry of Education, Culture, Sports, Science and Technology
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Affiliation(s)
- Yoshimi Shoji
- Quantum RedOx Chemistry Team, Institute for Quantum Life Science (iQLS), Quantum Life and Medical Science Directorate (QLMS), National Institutes for Quantum Science and Technology (QST), Chiba-shi 263-8555, Chiba, Japan; (Y.S.); (H.I.)
| | - Yuri Terashima
- Environmental Radiation Effects Research Group, Department of Radiation Measurement and Dose Assessment, Institute for Radiological Science (NIRS), Quantum Life and Medical Science Directorate (QLMS), National Institutes for Quantum Science and Technology (QST), Chiba-shi 263-8555, Chiba, Japan; (Y.T.); (K.M.)
| | - Kei Ohkubo
- Institute for Advanced Co-Creation Studies, Open and Transdisciplinary Research Initiatives, Osaka University, Suita 565-0871, Osaka, Japan;
| | - Hiromu Ito
- Quantum RedOx Chemistry Team, Institute for Quantum Life Science (iQLS), Quantum Life and Medical Science Directorate (QLMS), National Institutes for Quantum Science and Technology (QST), Chiba-shi 263-8555, Chiba, Japan; (Y.S.); (H.I.)
| | - Kouichi Maruyama
- Environmental Radiation Effects Research Group, Department of Radiation Measurement and Dose Assessment, Institute for Radiological Science (NIRS), Quantum Life and Medical Science Directorate (QLMS), National Institutes for Quantum Science and Technology (QST), Chiba-shi 263-8555, Chiba, Japan; (Y.T.); (K.M.)
| | - Shunichi Fukuzumi
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Republic of Korea;
- Department of Chemistry, Faculty of Pure and Applied Sciences, University of Tsukuba, Tsukuba 305-8571, Ibaraki, Japan
| | - Ikuo Nakanishi
- Quantum RedOx Chemistry Team, Institute for Quantum Life Science (iQLS), Quantum Life and Medical Science Directorate (QLMS), National Institutes for Quantum Science and Technology (QST), Chiba-shi 263-8555, Chiba, Japan; (Y.S.); (H.I.)
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2
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Římal V, Bunyatova EI, Štěpánková H. Efficient Scavenging of TEMPOL Radical by Ascorbic Acid in Solution and Related Prolongation of 13C and 1H Nuclear Spin Relaxation Times of the Solute. Molecules 2024; 29:738. [PMID: 38338481 PMCID: PMC10856727 DOI: 10.3390/molecules29030738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 01/28/2024] [Accepted: 01/28/2024] [Indexed: 02/12/2024] Open
Abstract
Dynamic nuclear polarization for nuclear magnetic resonance (NMR) spectroscopy and imaging uses free radicals to strongly enhance the NMR signal of a compound under investigation. At the same time, the radicals shorten significantly its nuclear spin relaxation times which reduces the time window available for the experiments. Radical scavenging can overcome this drawback. Our work presents a detailed study of the reduction of the TEMPOL radical by ascorbic acid in solution by high-resolution NMR. Carbon-13 and hydrogen-1 nuclear spin relaxations are confirmed to be restored to their values without TEMPOL. Reaction mechanism, kinetics, and the influence of pD and viscosity are thoroughly discussed. The detailed investigation conducted in this work should help with choosing suitable concentrations in the samples for dynamic nuclear polarization and optimizing the measurement protocols.
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Affiliation(s)
- Václav Římal
- Faculty of Mathematics and Physics, Charles University, V Holešovičkách 2, 18000 Prague 8, Czech Republic;
| | | | - Helena Štěpánková
- Faculty of Mathematics and Physics, Charles University, V Holešovičkách 2, 18000 Prague 8, Czech Republic;
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3
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Gerken JB, Stamoulis A, MacDonnell ML, Stahl SS. Rate Equations for Reversible Disproportionation Reactions and Fitting to Time-Course Data. J Phys Chem A 2024; 128:328-332. [PMID: 38157490 DOI: 10.1021/acs.jpca.3c05232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2024]
Abstract
Integrated rate equations are straightforward to fit to experimental data to verify a proposed mechanism and to extract kinetic parameters. Such equations are derived for reversible disproportionation/comproportionation reactions with any set of initial concentrations. Extraction of forward and reverse rate constants from experimental data by fitting the rate law to the data is demonstrated for the disproportionation of 2,2,6,6-tetramethyl-1-piperidinyl-N-oxyl (TEMPO) under acidic conditions where the approach to equilibrium is observed.
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Affiliation(s)
- James B Gerken
- Department of Chemistry, University of Wisconsin─Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Alexios Stamoulis
- Department of Chemistry, University of Wisconsin─Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Madeline L MacDonnell
- Department of Chemistry, University of Wisconsin─Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Shannon S Stahl
- Department of Chemistry, University of Wisconsin─Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
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4
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Park J, Kim J, Jeong GY, Kim Y, Lee E. Uncovering Nitrosyl Reactivity at N-Heterocyclic Carbene Center. Angew Chem Int Ed Engl 2023:e202314978. [PMID: 37917039 DOI: 10.1002/anie.202314978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 10/31/2023] [Accepted: 11/02/2023] [Indexed: 11/03/2023]
Abstract
N-heterocyclic carbenes (NHCs) have garnered much attention due to their unique properties, such as strong σ-donating and π-accepting abilities, as well as their transition-metal-like reactivity toward small molecules. In 2015, we discovered that NHCs can react with nitric oxide (NO) gas to form radical adducts that resemble transition metal nitrosyl complexes. To elucidate the analogy between NHC and transition metal NO adducts, here we have undertaken a systematic investigation of the electron- and proton-transfer chemistry of [NHC-NO]⋅ (N-heterocyclic carbene nitric oxide radical) compounds. We have accessed a suite of compounds, comprised of [NHC-NO]+ , [NHC-NO]- , [NHC-NOH]0 , and [NHC-NHOH]+ species. In particular, [NHC-NO]- was isolated as potassium and lithium ion adducts. Most interestingly, a monomeric potassium [NHC-NO]- compound was isolated with the assistance of 18-crown-6, which is the first instance of a monomeric alkali N-oxyl compound to the best of our knowledge. Our results demonstrate that [NHC-NO]⋅ exhibits redox behavior broadly similar to metal nitrosyl complexes, which opens up more possibilities for utilizing NHCs to build on the known reactivity of metal complexes.
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Affiliation(s)
- Junbeom Park
- Department of Chemistry, Pohang University of Science and Technology, Pohang, 37673, Republic of Korea
| | - Jaelim Kim
- Department of Chemistry, Pohang University of Science and Technology, Pohang, 37673, Republic of Korea
| | - Gu Yoon Jeong
- Department of Chemistry, Pohang University of Science and Technology, Pohang, 37673, Republic of Korea
| | - Youngsuk Kim
- Department of Chemistry, Pusan National University, Busan, 46241, Republic of Korea
| | - Eunsung Lee
- Department of Chemistry, Pohang University of Science and Technology, Pohang, 37673, Republic of Korea
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5
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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: 8] [Impact Index Per Article: 8.0] [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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6
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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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Konopko A, Litwinienko G. Mutual Activation of Two Radical Trapping Agents: Unusual "Win-Win Synergy" of Resveratrol and TEMPO during Scavenging of dpph • Radical in Methanol. J Org Chem 2022; 87:15530-15538. [PMID: 36321638 PMCID: PMC9680031 DOI: 10.1021/acs.joc.2c02080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The reaction of the 2,2'-diphenyl-1-picrylhydrazyl radical (dpph•) with resveratrol in methanol (kMeOH = 192 M-1 s-1) is greatly accelerated in the presence of stable nitroxyl radical TEMPO• (kmixMeOH = 1.4 × 103 M-1 s-1). This synergistic effect is surprising because TEMPO• alone reacts with dpph• relatively slowly (kS = 31 M-1 s-1 in methanol and 0.03 M-1 s-1 in nonpolar ethyl acetate). We propose a putative mechanism in which a mutual activation occurs within the acid-base pair TEMPO•/RSV to the resveratrol (RSV) anion and TEMPOH•+ radical cation, both being extremely fast scavengers of the dpph• radical. The fast initial reaction is followed by a much slower but continuous decay of dpph• because a nitroxyl radical is recovered from the TEMPOnium cation, which is reduced directly by RSV/RSV- to TEMPO• or recovered indirectly via a reaction with methanol, producing TEMPOH subsequently oxidized by dpph• to TEMPO•.
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Affiliation(s)
- Adrian Konopko
- Faculty
of Chemistry, University of Warsaw, Pasteura 1, Warsaw02-093, Poland,Polish
Academy of Sciences, Nencki Institute of
Experimental Biology, Pasteura 3, Warsaw02-093, Poland
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8
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Song H, Pietrasiak E, Lee E. Persistent Radicals Derived from N-Heterocyclic Carbenes for Material Applications. Acc Chem Res 2022; 55:2213-2223. [PMID: 35849761 DOI: 10.1021/acs.accounts.2c00222] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Persistent radicals are potential building blocks of novel materials in many fields. Recently, highly stable persistent radicals are considered to be within reach, thanks to several radical stabilization strategies such as spin delocalization and steric protection. N-Heterocyclic carbene (NHC)-derived substituents can be attached to a radical center for these purposes, as illustrated by numerous NHC-stabilized radicals reported in the last two decades.This Account describes our recent work on developing NHC-derived persistent radicals, as well as their prospective applications. Considering that NHCs not only stabilize radicals but also reversibly interact with gas molecules, in 2015 our group reported NHC-nitric oxide (NHC-NO) radicals produced by reversibly trapping nitric oxide (NO) radical gas in NHCs. The resultant compounds were loaded into biocompatible poly(ethylene glycol)-block-poly(caprolactone) (PEG-b-PCL) micelles and injected into tumor-bearing mice. Then, NO release was triggered by high-intensity focused ultrasound irradiation of the tumor tissue. Furthermore, the NHC-NO radicals could also serve as a platform to generate other organic radicals such as oxime ether or iminyl radicals. Apart from medicine-related applications, radicals stabilized by NHCs can be used as energy storage materials. In this context, the triazenyl radical containing two NHC units reported by our laboratory could be a cathode active material in batteries, as an organic alternative to LiCoO2. The subsequently prepared unsymmetrical triazenyl radical derivatives were applied as anolytes in nonaqueous all-organic redox flow batteries. In addition, a ferrocene-based redox flow battery anolyte was obtained by introducing NHC-derived substituents that effectively stabilize the ferrocenate derivatives previously reported only at low temperatures. The batteries containing NHC-supported radicals exhibited high energy efficiency and insignificant radical decomposition over multiple cycles. Finally, toward developing air-persistent organic radicals for flexible devices and MRI contrasting agents, we also highlight our recent air- and physiologically stable organic radicals derived from NHCs. Coordination of tris(pentafluorophenyl)borane to the NHC-NO radical produced a new radical cation that is stable in an organic solvent under air for several months. The readily accessible 1,2-dicarbonyl radical cations generated by the reaction of NHCs with oxalyl chloride are remarkably persistent even in an aqueous solution for several months. They are also highly stable even under physiological conditions, making them particularly attractive potential candidates for organic MRI contrast agents. We hope that this Account will serve as a guide for the future development of stable NHC-derived organic radicals and draw the attention of the synthetic community to their potential applications in material science.
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Affiliation(s)
- Hayoung Song
- Department of Chemistry, Pohang University of Science and Technology. Pohang, 37673, Republic of Korea
| | - Ewa Pietrasiak
- Department of Chemistry, Pohang University of Science and Technology. Pohang, 37673, Republic of Korea
| | - Eunsung Lee
- Department of Chemistry, Pohang University of Science and Technology. Pohang, 37673, Republic of Korea
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9
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Oxazolidine Nitroxide Transformation in a Coordination Sphere of the Ln 3+ Ions. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27051626. [PMID: 35268728 PMCID: PMC8911955 DOI: 10.3390/molecules27051626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 01/31/2022] [Accepted: 02/02/2022] [Indexed: 11/17/2022]
Abstract
Upon the interaction of the hydrated lanthanide(III) salts found in acetonitrile solution with a tripodal paramagnetic compound, 4,4-dimethyl-2,2-bis(pyridin-2-yl)-1,3-oxazolidine-3-oxyl (Rad), functionalized by two pyridyl groups, three neutral, structurally characterized complexes with diamagnetic polydentate ligands—[Dy(RadH)(hbpm)Cl2], [Yb2(ipapm)2(NO3)4], and [Ce2(ipapm)2(NO3)4(EtOAc)2]—were obtained. These coordination compounds are minor uncolored crystalline products, which were formed in a reaction mixture due to the Rad transformation in a lanthanide coordination sphere, wherein the processes of its simultaneous disproportionation, hydrolysis, and condensation proceed differently than in the absence of Ln ions. The latter fact was confirmed by the formation of the structurally characterized product of the oxazolidine nitroxide transformation during its crystallization in toluene solution. Such a conversion in the presence of 4f elements ions is unique since no similar phenomenon was observed during the synthesis of the 3d-metal complexes with Rad.
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10
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Naas C, Scheler U, Lappan U. EPR Spectroscopy as an Efficient Tool for Investigations of Polyelectrolyte Multilayer Growth and Local Chain Dynamics. J Phys Chem B 2021; 125:6004-6011. [PMID: 34044535 DOI: 10.1021/acs.jpcb.1c02692] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The strong polycation poly(diallyldimethylammonium chloride) (PDADMAC) and the weak polyanion poly(ethylene-alt-maleic acid) (P(E-alt-MA)) were used to build polyelectrolyte multilayers (PEMs) up to 31 layers. A spin-label (SL) was covalently attached to the polyanion for studying the rotational dynamics of the polyacid backbone in a swollen state of the PEMs using continuous-wave (CW) electron paramagnetic resonance (EPR) spectroscopy. In the first step, the spin-labeled poly(ethylene-alt-maleic acid) (SL-P(E-alt-MA)) was used in every polyanion layer to monitor the PEMs growth by analyzing the integrated intensity of the spectra. The buildup was found to be pH-dependent resulting in PEM with different thicknesses. In the second step, SL-P(E-alt-MA) was selectively placed in a single polyanion layer to study the rotational dynamics of the polyacid backbone. The rotational diffusion coefficient of the polyacid backbone RS and the internal rotational diffusion coefficient of the SL attached to the polymer backbone RI were found to be higher at pH 5 than at pH 4, which is related to enhanced mobility.
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Affiliation(s)
- Carolin Naas
- Leibniz-Institut für Polymerforschung Dresden, e.V., Hohe Straße 6, 01069 Dresden, Germany
| | - Ulrich Scheler
- Leibniz-Institut für Polymerforschung Dresden, e.V., Hohe Straße 6, 01069 Dresden, Germany
| | - Uwe Lappan
- Leibniz-Institut für Polymerforschung Dresden, e.V., Hohe Straße 6, 01069 Dresden, Germany
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11
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The Hydrated Proton [H(H2O)n]+ as the Basis of Unified Complex Acidity Function Scale $$H_{{\text{o}}}^{{\text{w}}}$$ in Aqueous Solutions of Strong Acids With a Predominant Water Concentration. J SOLUTION CHEM 2021. [DOI: 10.1007/s10953-021-01066-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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12
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Naas C, Scheler U, Lappan U. Influence of pH on the Growth and the Local Dynamics of Polyelectrolyte Multilayers. Macromolecules 2021. [DOI: 10.1021/acs.macromol.0c01756] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Carolin Naas
- Leibniz-Institut für Polymerforschung Dresden e. V., Hohe Straße 6, 01069 Dresden, Germany
| | - Ulrich Scheler
- Leibniz-Institut für Polymerforschung Dresden e. V., Hohe Straße 6, 01069 Dresden, Germany
| | - Uwe Lappan
- Leibniz-Institut für Polymerforschung Dresden e. V., Hohe Straße 6, 01069 Dresden, Germany
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13
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Lee JW, Lim S, Maienshein DN, Liu P, Ngai MY. Redox-Neutral TEMPO Catalysis: Direct Radical (Hetero)Aryl C-H Di- and Trifluoromethoxylation. Angew Chem Int Ed Engl 2020; 59:21475-21480. [PMID: 32830430 PMCID: PMC7720849 DOI: 10.1002/anie.202009490] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 08/12/2020] [Indexed: 12/15/2022]
Abstract
Applications of TEMPO. catalysis for the development of redox-neutral transformations are rare. Reported here is the first TEMPO. -catalyzed, redox-neutral C-H di- and trifluoromethoxylation of (hetero)arenes. The reaction exhibits a broad substrate scope, has high functional-group tolerance, and can be employed for the late-stage functionalization of complex druglike molecules. Kinetic measurements, isolation and resubjection of catalytic intermediates, UV/Vis studies, and DFT calculations support the proposed oxidative TEMPO. /TEMPO+ redox catalytic cycle. Mechanistic studies also suggest that Li2 CO3 plays an important role in preventing catalyst deactivation. These findings will provide new insights into the design and development of novel reactions through redox-neutral TEMPO. catalysis.
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Affiliation(s)
- Johnny W Lee
- Department of Chemistry and Institute of Chemical Biology and Drug Discovery, State University of New York, Stony Brook, NY, 11794, USA
| | - Sanghyun Lim
- Department of Chemistry and Institute of Chemical Biology and Drug Discovery, State University of New York, Stony Brook, NY, 11794, USA
| | - Daniel N Maienshein
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - Peng Liu
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - Ming-Yu Ngai
- Department of Chemistry and Institute of Chemical Biology and Drug Discovery, State University of New York, Stony Brook, NY, 11794, USA
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14
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Lee JW, Lim S, Maienshein DN, Liu P, Ngai M. Redox‐Neutral TEMPO Catalysis: Direct Radical (Hetero)Aryl C−H Di‐ and Trifluoromethoxylation. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202009490] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Johnny W. Lee
- Department of Chemistry and Institute of Chemical Biology and Drug Discovery State University of New York Stony Brook NY 11794 USA
| | - Sanghyun Lim
- Department of Chemistry and Institute of Chemical Biology and Drug Discovery State University of New York Stony Brook NY 11794 USA
| | | | - Peng Liu
- Department of Chemistry University of Pittsburgh Pittsburgh PA 15260 USA
| | - Ming‐Yu Ngai
- Department of Chemistry and Institute of Chemical Biology and Drug Discovery State University of New York Stony Brook NY 11794 USA
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15
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Juliusson HY, Sigurdsson ST. Reduction Resistant and Rigid Nitroxide Spin-Labels for DNA and RNA. J Org Chem 2020; 85:4036-4046. [PMID: 32103670 DOI: 10.1021/acs.joc.9b02988] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Electron paramagnetic resonance (EPR) spectroscopy, coupled with site-directed spin labeling (SDSL), is a useful method for studying conformational changes of biomolecules in cells. To employ in-cell EPR using nitroxide-based spin labels, the structure of the nitroxides must confer reduction resistance to withstand the reductive environment within cells. Here, we report the synthesis of two new spin labels, EÇ and EÇm, both of which possess the rigidity and the reduction resistance needed for extracting detailed structural information by EPR spectroscopy. EÇ and EÇm were incorporated into DNA and RNA, respectively, by oligonucleotide synthesis. Both labels were shown to be nonperturbing of the duplex structure. The partial reduction of EÇm during RNA synthesis was circumvented by the protection of the nitroxide as a benzoylated hydroxylamine.
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Affiliation(s)
- Haraldur Y Juliusson
- Department of Chemistry, Science Institute, University of Iceland, Dunhaga 3, 107 Reykjavik, Iceland
| | - Snorri Th Sigurdsson
- Department of Chemistry, Science Institute, University of Iceland, Dunhaga 3, 107 Reykjavik, Iceland
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16
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Hafeez S, Khatri V, Kashyap HK, Nebhani L. Computational and experimental approach to evaluate the effect of initiator concentration, solvents, and enes on the TEMPO driven thiol–ene reaction. NEW J CHEM 2020. [DOI: 10.1039/d0nj02882g] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The fundamental mechanism and reaction kinetics of the TEMPO initiated thiol–ene reaction between benzyl mercaptan and variable enes in the presence of varying initiator concentration and varying solvents has been studied experimentally and computationally.
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Affiliation(s)
- Sumbul Hafeez
- Department of Materials Science and Engineering
- Indian Institute of Technology Delhi
- New Delhi-110016
- India
| | - Vikas Khatri
- Department of Chemistry
- Indian Institute of Technology Delhi
- New Delhi-110016
- India
| | - Hemant K. Kashyap
- Department of Chemistry
- Indian Institute of Technology Delhi
- New Delhi-110016
- India
| | - Leena Nebhani
- Department of Materials Science and Engineering
- Indian Institute of Technology Delhi
- New Delhi-110016
- India
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17
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Quirós MT, Gómez-Bengoa E, Muñoz MP. Unravelling mechanistic insights in the platinum-catalysed dihydroalkoxylation of allenes. PURE APPL CHEM 2019. [DOI: 10.1515/pac-2019-0214] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
The mechanism of the platinum-catalysed dihydroalkoxylation of allenes to give acetals has been studied experimentally and by computational methods. Our findings further explain divergent reactivity encountered for platinum- and gold-vinyl intermediates after the first nucleophilic attack onto the coordinated allene, as well as provide new details on the catalytic cycle with platinum, uncovering enol ethers as resting states of the catalytic cycle, a SEOx process via Pt(IV)–H as the final protodemetallation step after the second nucleophilic attack when neutral platinum complexes are used, and a fast acid promoted addition of methanol to enol ethers when cationic platinum complexes are employed.
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Affiliation(s)
- María Teresa Quirós
- School of Chemistry , University of East Anglia , Earlham Road , Norwich , NR4 7TJ , UK
| | - Enrique Gómez-Bengoa
- Departamento de Química Orgánica , Universidad del País Vasco , Apt. 1072 , 20080 San Sebastián , Spain
| | - María Paz Muñoz
- School of Chemistry , University of East Anglia , Earlham Road , Norwich , NR4 7TJ , UK
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18
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Feng Y, Shen M, Wang Z, Liu G. Transformation of atenolol by a laccase-mediator system: Efficiencies, effect of water constituents, and transformation pathways. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2019; 183:109555. [PMID: 31419699 DOI: 10.1016/j.ecoenv.2019.109555] [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: 04/26/2019] [Revised: 08/01/2019] [Accepted: 08/07/2019] [Indexed: 06/10/2023]
Abstract
In this study, we investigated the transformation of atenolol (ATL) by the naturally occurring laccase from Trametes versicolor in aqueous solution. Removal efficiency of ATL via laccase-catalyzed reaction in the presence of various laccase mediators was examined, and found that only the mediator 2, 2, 6, 6-tetramethyl-1-piperidinyloxy (TEMPO) was able to greatly promote ATL transformation. The influences of TEMPO concentration, laccase dosage, as well as solution pH and temperature on ATL transformation efficiency were tested. As TEMPO concentrations was increased from 0 to 2000 μM, ATL transformation efficiency first increased and then decreased, and the optimal TEMPO concentration was determined as 500 μM. ATL transformation efficiency was gradually increased with increasing laccase dosage. ATL transformation was highly pH-dependent with an optimum pH of 7.0, and it was almost constant over a temperature range of 25-50 °C. Humic acid inhibited ATL transformation through competition reaction with laccase. The presence of anions HCO3- and CO32- reduced ATL transformation due to both anions enhanced solution pHs, while Cl-, SO42-, and NO3- at 10 mM showed no obvious influence. The main transformation products were identified, and the potential transformation pathways were proposed. After enzymatic treatment, the toxicity of ATL and TEMPO mixtures was greatly reduced. The results of this study might present an alternative clean strategy for the remediation of ATL contaminated water matrix.
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Affiliation(s)
- Yiping Feng
- Guangzhou Key Laboratory Environmental Catalysis and Pollution Control, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou, 510006, China.
| | - Mengyao Shen
- Guangzhou Key Laboratory Environmental Catalysis and Pollution Control, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou, 510006, China
| | - Zhu Wang
- Research Institute of Environmental Studies at Greater Bay, Rural Non-point Source Pollution Comprehensive Management Technology Center of Guangdong Province, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, School of Environmental Science and Engineering, Guangzhou University, Guangzhou, 510006, China
| | - Guoguang Liu
- Guangzhou Key Laboratory Environmental Catalysis and Pollution Control, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou, 510006, China
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19
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Alonso JM, Muñoz MP. Platinum and Gold Catalysis: à la Carte Hydroamination of Terminal Activated Allenes with Azoles. Org Lett 2019; 21:7639-7644. [DOI: 10.1021/acs.orglett.9b02949] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- José Miguel Alonso
- School of Chemistry, University of East Anglia, Norwich NR4 7TJ, United Kingdom
| | - María Paz Muñoz
- School of Chemistry, University of East Anglia, Norwich NR4 7TJ, United Kingdom
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20
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Miller SA, Bisset KA, Leadbeater NE, Eddy NA. Catalytic Oxidation of Alcohols Using a 2,2,6,6-Tetramethylpiperidine-N
-hydroxyammonium Cation. European J Org Chem 2018. [DOI: 10.1002/ejoc.201801718] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Shelli A. Miller
- Department of Chemistry; University of Connecticut; 55 North Eagleville Road Storrs Connecticut 06269 USA
| | - Kathryn A. Bisset
- Department of Chemistry; University of Connecticut; 55 North Eagleville Road Storrs Connecticut 06269 USA
| | - Nicholas E. Leadbeater
- Department of Chemistry; University of Connecticut; 55 North Eagleville Road Storrs Connecticut 06269 USA
| | - Nicholas A. Eddy
- Department of Chemistry; University of Connecticut; 55 North Eagleville Road Storrs Connecticut 06269 USA
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21
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Navalpotro P, Sierra N, Trujillo C, Montes I, Palma J, Marcilla R. Exploring the Versatility of Membrane-Free Battery Concept Using Different Combinations of Immiscible Redox Electrolytes. ACS APPLIED MATERIALS & INTERFACES 2018; 10:41246-41256. [PMID: 30398052 DOI: 10.1021/acsami.8b11581] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Lately, the field of redox flow batteries is flourishing because of the emergence of new redox chemistries, including organic compounds, new electrolytes, and innovative designs. Recently, we reported an original membrane-free battery concept based on the mutual immiscibility of an aqueous catholyte containing hydroquinone and an ionic liquid anolyte containing para-benzoquinone as redox species. Here, we investigate the versatility of this concept exploring the electrochemical performance of 10 redox electrolytes based on different solvents, such as propylene carbonate, 2-butanone, or neutral-pH media, and containing different redox organic molecules, such as 2,2,6,6-tetramethylpiperidine-1-oxyl, 4-hydroxy-2,2,6,6-tetramethylpiperidine1-oxyl (OH-TEMPO), or substituted anthraquinones. The most representative electrolytes were paired and used as immiscible anolyte-catholyte in 5 different membrane-free batteries. Those batteries with substituted anthraquinones in the anolyte exhibited up to 50% improved open-circuit voltage (2.1 V), an operating voltage of 1.75 V, and 62% higher power density compared with our previous work. On the other hand, the partition coefficient of redox molecules between the two immiscible phases and the inherent self-discharge occurring at the interphase are revealed as intrinsic features affecting the performance of this type of membrane-free battery. It was successfully demonstrated that the functionalization of redox molecules is an interesting strategy to tune the partition coefficients mitigating the crossover that provokes low battery efficiency. As a result, the cycling life of a battery having OH-TEMPO as active species in the catholyte and containing propylene carbonate-based anolyte was evaluated over 300 cycles, achieving 85% capacity retention. These results demonstrated the huge versatility and countless possibilities of this new membrane-free battery concept.
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Affiliation(s)
- Paula Navalpotro
- Electrochemical Processes Unit , IMDEA Energy Institute , Avda. Ramón de la Sagra 3 , 28935 Móstoles , Spain
| | - Noemí Sierra
- Electrochemical Processes Unit , IMDEA Energy Institute , Avda. Ramón de la Sagra 3 , 28935 Móstoles , Spain
- Chemical and Environmental Engineering Group , Rey Juan Carlos University , C/Tulipán s/n , 28933 Móstoles , Madrid , Spain
| | - Carlos Trujillo
- Electrochemical Processes Unit , IMDEA Energy Institute , Avda. Ramón de la Sagra 3 , 28935 Móstoles , Spain
- Faculty of Chemical Science and Technology , University of Castilla-La Mancha , Avda. Camilo José Cela 10 , 13071 Ciudad Real , Spain
| | - Iciar Montes
- Electrochemical Processes Unit , IMDEA Energy Institute , Avda. Ramón de la Sagra 3 , 28935 Móstoles , Spain
| | - Jesus Palma
- Electrochemical Processes Unit , IMDEA Energy Institute , Avda. Ramón de la Sagra 3 , 28935 Móstoles , Spain
| | - Rebeca Marcilla
- Electrochemical Processes Unit , IMDEA Energy Institute , Avda. Ramón de la Sagra 3 , 28935 Móstoles , Spain
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22
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Liang K, Tong X, Li T, Shi B, Wang H, Yan P, Xia C. Enantioselective Radical Cyclization of Tryptamines by Visible Light-Excited Nitroxides. J Org Chem 2018; 83:10948-10958. [PMID: 30091607 DOI: 10.1021/acs.joc.8b01597] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Nitroxides can absorb both ultraviolet (UV) and visible light, and their electron can be excited from the π-bonding orbital to the antibonding π* orbital or the n-bonding orbital to the antibonding π* orbital, respectively. Despite the reported UV-induced hydrogen atom transfer (HAT) process, the potential of nitroxides for visible light-excited photosynthesis is underexplored. Here we demonstrate that nitroxide can convert indole to its radical through a visible light-induced HAT process. A chiral phosphoric acid-catalyzed cyclization of the in situ-formed imine radical, followed by trapping by another molecule of nitroxide, provides the product in high yield and enantioselectivity. To highlight the novelty and efficiency of this strategy, an asymmetric total synthesis of natural product (-)-verrupyrroloindoline was accomplished in 5 steps.
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Affiliation(s)
- Kangjiang Liang
- Key Laboratory of Medicinal Chemistry for Natural Resource (Ministry of Education and Yunnan Province), School of Chemical Science and Technology , Yunnan University , Kunming 650091 , China.,State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, University of Chinese Academy of Sciences , Chinese Academy of Sciences , Kunming 650201 , China
| | - Xiaogang Tong
- Key Laboratory of Medicinal Chemistry for Natural Resource (Ministry of Education and Yunnan Province), School of Chemical Science and Technology , Yunnan University , Kunming 650091 , China
| | - Tao Li
- Key Laboratory of Medicinal Chemistry for Natural Resource (Ministry of Education and Yunnan Province), School of Chemical Science and Technology , Yunnan University , Kunming 650091 , China
| | - Bingfei Shi
- Key Laboratory of Medicinal Chemistry for Natural Resource (Ministry of Education and Yunnan Province), School of Chemical Science and Technology , Yunnan University , Kunming 650091 , China
| | - Haiyang Wang
- Key Laboratory of Medicinal Chemistry for Natural Resource (Ministry of Education and Yunnan Province), School of Chemical Science and Technology , Yunnan University , Kunming 650091 , China
| | - Pengcheng Yan
- School of Pharmaceutical Sciences , Wenzhou Medical University , Wenzhou 325035 , China
| | - Chengfeng Xia
- Key Laboratory of Medicinal Chemistry for Natural Resource (Ministry of Education and Yunnan Province), School of Chemical Science and Technology , Yunnan University , Kunming 650091 , China
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23
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Song ZJ, Zhou G, Cohen R, Tan L. Preparation of ABNO on Scale and Analysis by Quantitative Paramagnetic NMR. Org Process Res Dev 2018. [DOI: 10.1021/acs.oprd.8b00191] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Zhiguo J. Song
- Department of Process R&D, Merck & Co. Inc., P.O. Box 2000, Rahway, New Jersey 07065, United States
| | - Guoyue Zhou
- Process R&D, WuXi AppTec Co., Ltd., 288 Fute Zhong Road, Shanghai 200131, China
| | - Ryan Cohen
- Department of Process R&D, Merck & Co. Inc., P.O. Box 2000, Rahway, New Jersey 07065, United States
| | - Lushi Tan
- Department of Process R&D, Merck & Co. Inc., P.O. Box 2000, Rahway, New Jersey 07065, United States
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24
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Hu L, Shi C, Guo K, Zhai T, Li H, Wang Y. Electrochemical Double‐Layer Capacitor Energized by Adding an Ambipolar Organic Redox Radical into the Electrolyte. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201804582] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Lintong Hu
- State Key Laboratory of Material Processing and Die & Mould TechnologySchool of Materials Science and EngineeringHuazhong University of Science and Technology Wuhan 430074 P. R. China
| | - Chao Shi
- State Key Laboratory of Material Processing and Die & Mould TechnologySchool of Materials Science and EngineeringHuazhong University of Science and Technology Wuhan 430074 P. R. China
| | - Kai Guo
- State Key Laboratory of Material Processing and Die & Mould TechnologySchool of Materials Science and EngineeringHuazhong University of Science and Technology Wuhan 430074 P. R. China
| | - Tianyou Zhai
- State Key Laboratory of Material Processing and Die & Mould TechnologySchool of Materials Science and EngineeringHuazhong University of Science and Technology Wuhan 430074 P. R. China
| | - Huiqiao Li
- State Key Laboratory of Material Processing and Die & Mould TechnologySchool of Materials Science and EngineeringHuazhong University of Science and Technology Wuhan 430074 P. R. China
| | - Yonggang Wang
- Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative MaterialsInstitute of New Energy, iChEM(Collaborative Innovation Center of Chemistry for Energy Materials)Fudan University Shanghai 200433 P. R. China
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25
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Hu L, Shi C, Guo K, Zhai T, Li H, Wang Y. Electrochemical Double‐Layer Capacitor Energized by Adding an Ambipolar Organic Redox Radical into the Electrolyte. Angew Chem Int Ed Engl 2018; 57:8214-8218. [DOI: 10.1002/anie.201804582] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Indexed: 01/21/2023]
Affiliation(s)
- Lintong Hu
- State Key Laboratory of Material Processing and Die & Mould TechnologySchool of Materials Science and EngineeringHuazhong University of Science and Technology Wuhan 430074 P. R. China
| | - Chao Shi
- State Key Laboratory of Material Processing and Die & Mould TechnologySchool of Materials Science and EngineeringHuazhong University of Science and Technology Wuhan 430074 P. R. China
| | - Kai Guo
- State Key Laboratory of Material Processing and Die & Mould TechnologySchool of Materials Science and EngineeringHuazhong University of Science and Technology Wuhan 430074 P. R. China
| | - Tianyou Zhai
- State Key Laboratory of Material Processing and Die & Mould TechnologySchool of Materials Science and EngineeringHuazhong University of Science and Technology Wuhan 430074 P. R. China
| | - Huiqiao Li
- State Key Laboratory of Material Processing and Die & Mould TechnologySchool of Materials Science and EngineeringHuazhong University of Science and Technology Wuhan 430074 P. R. China
| | - Yonggang Wang
- Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative MaterialsInstitute of New Energy, iChEM(Collaborative Innovation Center of Chemistry for Energy Materials)Fudan University Shanghai 200433 P. R. China
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26
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Nutting JE, Rafiee M, Stahl SS. Tetramethylpiperidine N-Oxyl (TEMPO), Phthalimide N-Oxyl (PINO), and Related N-Oxyl Species: Electrochemical Properties and Their Use in Electrocatalytic Reactions. Chem Rev 2018; 118:4834-4885. [PMID: 29707945 DOI: 10.1021/acs.chemrev.7b00763] [Citation(s) in RCA: 535] [Impact Index Per Article: 89.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
N-Oxyl compounds represent a diverse group of reagents that find widespread use as catalysts for the selective oxidation of organic molecules in both laboratory and industrial applications. While turnover of N-oxyl catalysts in oxidation reactions may be accomplished with a variety of stoichiometric oxidants, N-oxyl reagents have also been extensively used as catalysts under electrochemical conditions in the absence of chemical oxidants. Several classes of N-oxyl compounds undergo facile redox reactions at electrode surfaces, enabling them to mediate a wide range of electrosynthetic reactions. Electrochemical studies also provide insights into the structural properties and mechanisms of chemical and electrochemical catalysis by N-oxyl compounds. This review provides a comprehensive survey of the electrochemical properties and electrocatalytic applications of aminoxyls, imidoxyls, and related reagents, of which the two prototypical and widely used examples are 2,2,6,6-tetramethylpiperidine N-oxyl (TEMPO) and phthalimide N-oxyl (PINO).
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Affiliation(s)
- Jordan E Nutting
- Department of Chemistry , University of Wisconsin-Madison , 1101 University Avenue , Madison , Wisconsin 53706 , United States
| | - Mohammad Rafiee
- Department of Chemistry , University of Wisconsin-Madison , 1101 University Avenue , Madison , Wisconsin 53706 , United States
| | - Shannon S Stahl
- Department of Chemistry , University of Wisconsin-Madison , 1101 University Avenue , Madison , Wisconsin 53706 , United States
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27
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Pinto A, Kaiser D, Maryasin B, Di Mauro G, González L, Maulide N. Hydrative Aminoxylation of Ynamides: One Reaction, Two Mechanisms. Chemistry 2018; 24:2515-2519. [PMID: 29293283 PMCID: PMC5838720 DOI: 10.1002/chem.201706063] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Indexed: 11/08/2022]
Abstract
Organic synthesis boasts a wide array of reactions involving either radical species or ionic intermediates. The combination of radical and polar species, however, has not been explored to a comparable extent. Herein we present the hydrative aminoxylation of ynamides, a reaction which can proceed by either a polar-radical crossover mechanism or through a rare cationic activation. Common to both processes is the versatility of the persistent radical TEMPO and its oxidised oxoammonium derivative TEMPO+ . The unique mechanisms of these processes are elucidated experimentally and by in-depth DFT-calculations.
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Affiliation(s)
- Alexandre Pinto
- Institute of Organic Chemistry, University of Vienna, Währinger Strasse 38, 1090, Vienna, Austria
| | - Daniel Kaiser
- Institute of Organic Chemistry, University of Vienna, Währinger Strasse 38, 1090, Vienna, Austria
| | - Boris Maryasin
- Institute of Organic Chemistry, University of Vienna, Währinger Strasse 38, 1090, Vienna, Austria.,Institute of Theoretical Chemistry, University of Vienna, Währinger Strasse 17, 1090, Vienna, Austria
| | - Giovanni Di Mauro
- Institute of Organic Chemistry, University of Vienna, Währinger Strasse 38, 1090, Vienna, Austria
| | - Leticia González
- Institute of Theoretical Chemistry, University of Vienna, Währinger Strasse 17, 1090, Vienna, Austria
| | - Nuno Maulide
- Institute of Organic Chemistry, University of Vienna, Währinger Strasse 38, 1090, Vienna, Austria
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28
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Boase NRB, Torres MDT, Fletcher NL, de la Fuente-Nunez C, Fairfull-Smith KE. Polynitroxide copolymers to reduce biofilm fouling on surfaces. Polym Chem 2018. [DOI: 10.1039/c8py01101j] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Polynitroxide films – the first example of surface tethered nitroxides reducing biofilm fouling.
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Affiliation(s)
- Nathan R. B. Boase
- School of Chemistry
- Physics and Mechanical Engineering
- Queensland University of Technology (QUT)
- Brisbane
- Australia
| | - Marcelo D. T. Torres
- Synthetic Biology Group
- MIT Synthetic Biology Center
- Department of Biological Engineering and Electrical Engineering & Computer Science
- Research Laboratory of Electronics
- Massachusetts Institute of Technology
| | - Nicholas L. Fletcher
- Centre for Advanced Imaging
- University of Queensland
- St Lucia
- Australia
- Australian Institute for Bioengineering and Nanotechnology
| | - Cesar de la Fuente-Nunez
- Synthetic Biology Group
- MIT Synthetic Biology Center
- Department of Biological Engineering and Electrical Engineering & Computer Science
- Research Laboratory of Electronics
- Massachusetts Institute of Technology
| | - Kathryn E. Fairfull-Smith
- School of Chemistry
- Physics and Mechanical Engineering
- Queensland University of Technology (QUT)
- Brisbane
- Australia
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29
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Kim Y, Kim K, Lee E. Oxime Ether Radical Cations Stabilized by N-Heterocyclic Carbenes. Angew Chem Int Ed Engl 2017; 57:262-265. [DOI: 10.1002/anie.201710530] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Indexed: 02/03/2023]
Affiliation(s)
- Youngsuk Kim
- Center for Self-assembly and Complexity; Institute for Basic Science (IBS); Pohang 37673 Republic of Korea
- Department of Chemistry; Pohang University of Science and Technology; Pohang 37673 Republic of Korea
| | - Kimoon Kim
- Center for Self-assembly and Complexity; Institute for Basic Science (IBS); Pohang 37673 Republic of Korea
- Department of Chemistry; Pohang University of Science and Technology; Pohang 37673 Republic of Korea
- Division of Advanced Materials Science; Pohang University of Science and Technology; Pohang 37673 Republic of Korea
| | - Eunsung Lee
- Center for Self-assembly and Complexity; Institute for Basic Science (IBS); Pohang 37673 Republic of Korea
- Department of Chemistry; Pohang University of Science and Technology; Pohang 37673 Republic of Korea
- Division of Advanced Materials Science; Pohang University of Science and Technology; Pohang 37673 Republic of Korea
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30
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Kim Y, Kim K, Lee E. Oxime Ether Radical Cations Stabilized by N-Heterocyclic Carbenes. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201710530] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Youngsuk Kim
- Center for Self-assembly and Complexity; Institute for Basic Science (IBS); Pohang 37673 Republic of Korea
- Department of Chemistry; Pohang University of Science and Technology; Pohang 37673 Republic of Korea
| | - Kimoon Kim
- Center for Self-assembly and Complexity; Institute for Basic Science (IBS); Pohang 37673 Republic of Korea
- Department of Chemistry; Pohang University of Science and Technology; Pohang 37673 Republic of Korea
- Division of Advanced Materials Science; Pohang University of Science and Technology; Pohang 37673 Republic of Korea
| | - Eunsung Lee
- Center for Self-assembly and Complexity; Institute for Basic Science (IBS); Pohang 37673 Republic of Korea
- Department of Chemistry; Pohang University of Science and Technology; Pohang 37673 Republic of Korea
- Division of Advanced Materials Science; Pohang University of Science and Technology; Pohang 37673 Republic of Korea
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31
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Lagerblom K, Lagerspets E, Keskiväli J, Cook C, Ekholm F, Parviainen A, Repo T. Practical Aerobic Oxidation of Alcohols: A Ligand-Enhanced 2,2,6,6-Tetramethylpiperidine-1-oxy/Manganese Nitrate Catalyst System. ChemCatChem 2017. [DOI: 10.1002/cctc.201700710] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- Kalle Lagerblom
- Department of Chemistry; Faculty of Science, A. I. Virtasen aukio 1, 00014; University of Helsinki; P.O. Box 55 Finland
| | - Emi Lagerspets
- Department of Chemistry; Faculty of Science, A. I. Virtasen aukio 1, 00014; University of Helsinki; P.O. Box 55 Finland
| | - Juha Keskiväli
- Department of Chemistry; Faculty of Science, A. I. Virtasen aukio 1, 00014; University of Helsinki; P.O. Box 55 Finland
| | - Chris Cook
- Department of Chemistry; Faculty of Science, A. I. Virtasen aukio 1, 00014; University of Helsinki; P.O. Box 55 Finland
| | - Filip Ekholm
- Department of Chemistry; Faculty of Science, A. I. Virtasen aukio 1, 00014; University of Helsinki; P.O. Box 55 Finland
| | - Arno Parviainen
- Department of Chemistry; Faculty of Science, A. I. Virtasen aukio 1, 00014; University of Helsinki; P.O. Box 55 Finland
| | - Timo Repo
- Department of Chemistry; Faculty of Science, A. I. Virtasen aukio 1, 00014; University of Helsinki; P.O. Box 55 Finland
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32
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Kozlov VA, Ivanov SN, Koifman OI. Solvated proton as the main reagent and a catalyst in the single-stage aromatic sulfonation and protodesulfonation of sulfonic acids. J PHYS ORG CHEM 2017. [DOI: 10.1002/poc.3715] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Vladimir A. Kozlov
- Department of Chemistry and Technology of Macromolecular Compounds; Ivanovo State University of Chemistry and Technology; Ivanovo Russia
| | - Sergey N. Ivanov
- Department of Organic and Physical Chemistry; Ivanovo State University; Ivanovo Russia
| | - Oskar I. Koifman
- Department of Chemistry and Technology of Macromolecular Compounds; Ivanovo State University of Chemistry and Technology; Ivanovo Russia
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33
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Activation of TEMPO by ClO 2 for oxidation of cellulose by hypochlorite-Fundamental and practical aspects of the catalytic system. Carbohydr Polym 2017; 174:524-530. [PMID: 28821100 DOI: 10.1016/j.carbpol.2017.06.117] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 06/29/2017] [Accepted: 06/29/2017] [Indexed: 11/22/2022]
Abstract
Bromide-free TEMPO-catalyzed oxidation of the primary alcohols by sodium hypochlorite (NaOCl) does not proceed without a prior activation of the catalyst. Here were demonstrate an immediate in situ activation of the catalyst with an equimolar addition of chlorine dioxide (ClO2) relative to TEMPO. Sodium bromide (NaBr) had a similar role in activating the catalyst although NaBr was needed in excess and the activation took several minutes depending on the dosage of NaBr. The activation method, or the concentration of NaBr, did not affect the bulk oxidation rate. The selectivity of the ClO2 initiated oxidation remained high up to NaOCl addition of 3mol/kg bleached birch kraft pulp after which additional loss in yield and depolymerization of cellulose were emphasized with negligible increase in carboxylate content. A carboxylate content of 0.8-1mol/kg, sufficient for easy mechanical fibrillation of the pulp, was achieved under mild conditions with NaOCl addition of 2-2.5mol/kg pulp.
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Carbó López M, Chavant PY, Molton F, Royal G, Blandin V. Chiral Nitroxide/Copper-Catalyzed Aerobic Oxidation of Alcohols: Atroposelective Oxidative Desymmetrization. ChemistrySelect 2017. [DOI: 10.1002/slct.201601993] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Marta Carbó López
- Univ. Grenoble Alpes; DCM UMR-5250; F-38000 Grenoble France
- CNRS; DCM UMR-5250; F-38000 Grenoble France
| | - Pierre Y. Chavant
- Univ. Grenoble Alpes; DCM UMR-5250; F-38000 Grenoble France
- CNRS; DCM UMR-5250; F-38000 Grenoble France
| | - Florian Molton
- Univ. Grenoble Alpes; DCM UMR-5250; F-38000 Grenoble France
- CNRS; DCM UMR-5250; F-38000 Grenoble France
| | - Guy Royal
- Univ. Grenoble Alpes; DCM UMR-5250; F-38000 Grenoble France
- CNRS; DCM UMR-5250; F-38000 Grenoble France
| | - Véronique Blandin
- Univ. Grenoble Alpes; DCM UMR-5250; F-38000 Grenoble France
- CNRS; DCM UMR-5250; F-38000 Grenoble France
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Garmendia S, Mantione D, Alonso-de Castro S, Jehanno C, Lezama L, Hedrick JL, Mecerreyes D, Salassa L, Sardon H. Polyurethane based organic macromolecular contrast agents (PU-ORCAs) for magnetic resonance imaging. Polym Chem 2017. [DOI: 10.1039/c7py00166e] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Combination of its convenience for non-invasive application and high spatial resolution make Magnetic Resonance Imaging (MRI) one of the leading imaging modalities.
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Affiliation(s)
- Sofiem Garmendia
- POLYMAT
- University of the Basque Country UPV/EHU
- Joxe Mari Korta Center
- 20018 Donostia-San Sebastian
- Spain
| | - Daniele Mantione
- POLYMAT
- University of the Basque Country UPV/EHU
- Joxe Mari Korta Center
- 20018 Donostia-San Sebastian
- Spain
| | | | - Coralie Jehanno
- POLYMAT
- University of the Basque Country UPV/EHU
- Joxe Mari Korta Center
- 20018 Donostia-San Sebastian
- Spain
| | - Luis Lezama
- Department of Inorganic Chemistry and BC Materials
- University of the Basque Country UPV/EHU
- E-48080 Bilbao
- Spain
| | | | - David Mecerreyes
- POLYMAT
- University of the Basque Country UPV/EHU
- Joxe Mari Korta Center
- 20018 Donostia-San Sebastian
- Spain
| | - Luca Salassa
- CIC BiomaGUNE
- Donostia-San Sebastián
- Spain
- Ikerbasque
- Basque Foundation for Science
| | - Haritz Sardon
- POLYMAT
- University of the Basque Country UPV/EHU
- Joxe Mari Korta Center
- 20018 Donostia-San Sebastian
- Spain
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Tikhonov IV, Pliss EM, Borodin LI, Sen´ VD. Five-membered cyclic nitroxyl radicals as inhibitors of the oxidation of methyl linoleate in micelles. Russ Chem Bull 2016. [DOI: 10.1007/s11172-015-1240-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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37
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Stable nitroxyl radicals and hydroxylamines as inhibitors of methyl linoleate oxidation in micelles. Russ Chem Bull 2016. [DOI: 10.1007/s11172-015-1175-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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38
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Warnier C, Lemaire C, Becker G, Zaragoza G, Giacomelli F, Aerts J, Otabashi M, Bahri MA, Mercier J, Plenevaux A, Luxen A. Enabling Efficient Positron Emission Tomography (PET) Imaging of Synaptic Vesicle Glycoprotein 2A (SV2A) with a Robust and One-Step Radiosynthesis of a Highly Potent 18F-Labeled Ligand ([ 18F]UCB-H). J Med Chem 2016; 59:8955-8966. [PMID: 27598384 DOI: 10.1021/acs.jmedchem.6b00905] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We herein describe the straightforward synthesis of a stable pyridyl(4-methoxyphenyl)iodonium salt and its [18F] radiolabeling within a one-step, fully automated and cGMP compliant radiosynthesis of [18F]UCB-H ([18F]7), a PET tracer for the imaging of synaptic vesicle glycoprotein 2A (SV2A). Over the course of 1 year, 50 automated productions provided 34 ± 2% of injectable [18F]7 from up to 285 GBq (7.7 Ci) of [18F]fluoride in 50 min (uncorrected radiochemical yield, specific activity of 815 ± 185 GBq/μmol). The successful implementation of our synthetic strategy within routine, high-activity, and cGMP productions attests to its practicality and reliability for the production of large doses of [18F]7. In addition to enabling efficient and cost-effective clinical research on a range of neurological pathologies through the imaging of SV2A, this work further demonstrates the real value of iodonium salts for the cGMP 18F-PET tracer manufacturing industry, and their ability to fulfill practical and regulatory requirements in that field.
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Affiliation(s)
- Corentin Warnier
- GIGA Cyclotron Research Centre In Vivo Imaging, University of Liege , 4000 Liege, Belgium
| | - Christian Lemaire
- GIGA Cyclotron Research Centre In Vivo Imaging, University of Liege , 4000 Liege, Belgium
| | - Guillaume Becker
- GIGA Cyclotron Research Centre In Vivo Imaging, University of Liege , 4000 Liege, Belgium
| | - Guillermo Zaragoza
- Unidad de RX, Universidade de Santiago de Compostela , 15782 Santiago de Compostela, Spain
| | - Fabrice Giacomelli
- GIGA Cyclotron Research Centre In Vivo Imaging, University of Liege , 4000 Liege, Belgium
| | - Joël Aerts
- GIGA Cyclotron Research Centre In Vivo Imaging, University of Liege , 4000 Liege, Belgium.,INSERM U1148 , 75018 Paris, France
| | | | - Mohamed Ali Bahri
- GIGA Cyclotron Research Centre In Vivo Imaging, University of Liege , 4000 Liege, Belgium
| | | | - Alain Plenevaux
- GIGA Cyclotron Research Centre In Vivo Imaging, University of Liege , 4000 Liege, Belgium
| | - André Luxen
- GIGA Cyclotron Research Centre In Vivo Imaging, University of Liege , 4000 Liege, Belgium
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39
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Lagerblom K, Wrigstedt P, Keskiväli J, Parviainen A, Repo T. Iron-Catalysed Selective Aerobic Oxidation of Alcohols to Carbonyl and Carboxylic Compounds. Chempluschem 2016; 81:1160-1165. [DOI: 10.1002/cplu.201600240] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Revised: 07/04/2016] [Indexed: 12/13/2022]
Affiliation(s)
- Kalle Lagerblom
- Department of Chemistry; University of Helsinki; A.I. Virtasen aukio 1 P.O. Box 55 00014 Helsinki Finland
| | - Pauli Wrigstedt
- Department of Chemistry; University of Helsinki; A.I. Virtasen aukio 1 P.O. Box 55 00014 Helsinki Finland
| | - Juha Keskiväli
- Department of Chemistry; University of Helsinki; A.I. Virtasen aukio 1 P.O. Box 55 00014 Helsinki Finland
| | - Arno Parviainen
- Department of Chemistry; University of Helsinki; A.I. Virtasen aukio 1 P.O. Box 55 00014 Helsinki Finland
| | - Timo Repo
- Department of Chemistry; University of Helsinki; A.I. Virtasen aukio 1 P.O. Box 55 00014 Helsinki Finland
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40
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Tao X, Kehr G, Wang X, Daniliuc CG, Grimme S, Erker G. Rapid Dihydrogen Cleavage by Persistent Nitroxide Radicals under Frustrated Lewis Pair Conditions. Chemistry 2016; 22:9504-7. [DOI: 10.1002/chem.201602058] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Indexed: 11/09/2022]
Affiliation(s)
- Xin Tao
- Organisch-Chemisches Institut; Westfälische Wilhelm-Universität Münster; Corrensstraße 40 48149 Münster Germany
| | - Gerald Kehr
- Organisch-Chemisches Institut; Westfälische Wilhelm-Universität Münster; Corrensstraße 40 48149 Münster Germany
| | - Xiaowu Wang
- Organisch-Chemisches Institut; Westfälische Wilhelm-Universität Münster; Corrensstraße 40 48149 Münster Germany
| | - Constantin G. Daniliuc
- Organisch-Chemisches Institut; Westfälische Wilhelm-Universität Münster; Corrensstraße 40 48149 Münster Germany
| | - Stefan Grimme
- Mulliken Center for Theoretical Chemistry; Institut für Physikalische und Theoretische Chemie; Universität Bonn; Beringstraße 4 53115 Bonn Germany
| | - Gerhard Erker
- Organisch-Chemisches Institut; Westfälische Wilhelm-Universität Münster; Corrensstraße 40 48149 Münster Germany
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41
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Ahn SD, Fisher AC, Buchard A, Bull SD, Bond AM, Marken F. Hydrodynamic Rocking Disc Electrode Study of the TEMPO-mediated Catalytic Oxidation of Primary Alcohols. ELECTROANAL 2016. [DOI: 10.1002/elan.201600141] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Sunyhik D. Ahn
- Department of Chemistry; University of Bath; Claverton Down Bath BA2 7AY UK
| | - Adrian C. Fisher
- Department of Chemical Engineering; University of Cambridge, New Museums Site; Pembroke Street Cambridge CB2 3RA UK
| | - Antoine Buchard
- Department of Chemistry; University of Bath; Claverton Down Bath BA2 7AY UK
| | - Steven D. Bull
- Department of Chemistry; University of Bath; Claverton Down Bath BA2 7AY UK
| | - Alan M. Bond
- Monash University, School of Chemistry; Clayton Vic 3800 Australia
| | - Frank Marken
- Department of Chemistry; University of Bath; Claverton Down Bath BA2 7AY UK
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Lambert KM, Bobbitt JM, Eldirany SA, Kissane LE, Sheridan RK, Stempel ZD, Sternberg FH, Bailey WF. Metal-Free Oxidation of Primary Amines to Nitriles through Coupled Catalytic Cycles. Chemistry 2016; 22:5156-9. [DOI: 10.1002/chem.201600549] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Indexed: 01/27/2023]
Affiliation(s)
- Kyle M. Lambert
- Department of Chemistry; University of Connecticut; 55 North Eagleville Rd Storrs CT 06269-3060 USA
| | - James M. Bobbitt
- Department of Chemistry; University of Connecticut; 55 North Eagleville Rd Storrs CT 06269-3060 USA
| | - Sherif A. Eldirany
- Department of Chemistry; University of Connecticut; 55 North Eagleville Rd Storrs CT 06269-3060 USA
| | - Liam E. Kissane
- Department of Chemistry; University of Connecticut; 55 North Eagleville Rd Storrs CT 06269-3060 USA
| | - Rose K. Sheridan
- Department of Chemistry; University of Connecticut; 55 North Eagleville Rd Storrs CT 06269-3060 USA
| | - Zachary D. Stempel
- Department of Chemistry; University of Connecticut; 55 North Eagleville Rd Storrs CT 06269-3060 USA
| | - Francis H. Sternberg
- Department of Chemistry; University of Connecticut; 55 North Eagleville Rd Storrs CT 06269-3060 USA
| | - William F. Bailey
- Department of Chemistry; University of Connecticut; 55 North Eagleville Rd Storrs CT 06269-3060 USA
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Judith Percino M, Cerón M, Soriano-Moro G, Pacheco JA, Eugenia Castro M, Chapela VM, Bonilla-Cruz J, Saldivar-Guerra E. 2,2,6,6-Tetramethyl-1-oxopiperidinetribromide and two forms of 1-hydroxy-2,2,6,6-tetramethylpiperidinium bromide salt: Syntheses, crystal structures and theoretical calculations. J Mol Struct 2016. [DOI: 10.1016/j.molstruc.2015.09.020] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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44
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Interaction of Graphene Quantum Dots with 4-Acetamido-2,2,6,6-Tetramethylpiperidine-Oxyl Free Radicals: A Spectroscopic and Fluorimetric Study. J Fluoresc 2015; 26:283-95. [DOI: 10.1007/s10895-015-1712-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Accepted: 10/26/2015] [Indexed: 12/26/2022]
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45
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Pandit P, Yamamoto K, Nakamura T, Nishimura K, Kurashige Y, Yanai T, Nakamura G, Masaoka S, Furukawa K, Yakiyama Y, Kawano M, Higashibayashi S. Acid/base-regulated reversible electron transfer disproportionation of N-N linked bicarbazole and biacridine derivatives. Chem Sci 2015; 6:4160-4173. [PMID: 29218181 PMCID: PMC5707497 DOI: 10.1039/c5sc00946d] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Accepted: 04/15/2015] [Indexed: 11/24/2022] Open
Abstract
Regulation of electron transfer on organic substances by external stimuli is a fundamental issue in science and technology, which affects organic materials, chemical synthesis, and biological metabolism. Nevertheless, acid/base-responsive organic materials that exhibit reversible electron transfer have not been well studied and developed, owing to the difficulty in inventing a mechanism to associate acid/base stimuli and electron transfer. We discovered a new phenomenon in which N-N linked bicarbazole (BC) and tetramethylbiacridine (TBA) derivatives undergo electron transfer disproportionation by acid stimulus, forming their stable radical cations and reduced species. The reaction occurs through a biradical intermediate generated by the acid-triggered N-N bond cleavage reaction of BC or TBA, which acts as a two electron acceptor to undergo electron transfer reactions with two equivalents of BC or TBA. In addition, in the case of TBA the disproportionation reaction is highly reversible through neutralization with NEt3, which recovers TBA through back electron transfer and N-N bond formation reactions. This highly reversible electron transfer reaction is possible due to the association between the acid stimulus and electron transfer via the acid-regulated N-N bond cleavage/formation reactions which provide an efficient switching mechanism, the ability of the organic molecules to act as multi-electron donors and acceptors, the extraordinary stability of the radical species, the highly selective reactivity, and the balance of the redox potentials. This discovery provides new design concepts for acid/base-regulated organic electron transfer systems, chemical reagents, or organic materials.
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Affiliation(s)
- Palash Pandit
- Institute for Molecular Science , Myodaiji , Okazaki 444-8787 , Japan .
| | - Koji Yamamoto
- Institute for Molecular Science , Myodaiji , Okazaki 444-8787 , Japan .
| | - Toshikazu Nakamura
- Institute for Molecular Science , Myodaiji , Okazaki 444-8787 , Japan .
- School of Physical Sciences , The Graduate University for Advanced Studies , Myodaiji , Okazaki 444-8787 , Japan
| | - Katsuyuki Nishimura
- Institute for Molecular Science , Myodaiji , Okazaki 444-8787 , Japan .
- School of Physical Sciences , The Graduate University for Advanced Studies , Myodaiji , Okazaki 444-8787 , Japan
| | - Yuki Kurashige
- Institute for Molecular Science , Myodaiji , Okazaki 444-8787 , Japan .
- School of Physical Sciences , The Graduate University for Advanced Studies , Myodaiji , Okazaki 444-8787 , Japan
- Japan Science and Technology Agency , PRESTO, 4-1-8 Honcho , Kawaguchi , Saitama 332-0012 , Japan
| | - Takeshi Yanai
- Institute for Molecular Science , Myodaiji , Okazaki 444-8787 , Japan .
- School of Physical Sciences , The Graduate University for Advanced Studies , Myodaiji , Okazaki 444-8787 , Japan
| | - Go Nakamura
- Institute for Molecular Science , Myodaiji , Okazaki 444-8787 , Japan .
- School of Physical Sciences , The Graduate University for Advanced Studies , Myodaiji , Okazaki 444-8787 , Japan
| | - Shigeyuki Masaoka
- Institute for Molecular Science , Myodaiji , Okazaki 444-8787 , Japan .
- School of Physical Sciences , The Graduate University for Advanced Studies , Myodaiji , Okazaki 444-8787 , Japan
| | - Ko Furukawa
- Center for Instrumental Analysis , Institute for Research Promotion , Niigata University , Nishi-ku , Niigata 950-2181 , Japan
| | - Yumi Yakiyama
- Division of Advanced Materials Science , Pohang University of Science and Technology , San 31, Hyojadong , Pohang 790-784 , Korea
| | - Masaki Kawano
- Division of Advanced Materials Science , Pohang University of Science and Technology , San 31, Hyojadong , Pohang 790-784 , Korea
| | - Shuhei Higashibayashi
- Institute for Molecular Science , Myodaiji , Okazaki 444-8787 , Japan .
- School of Physical Sciences , The Graduate University for Advanced Studies , Myodaiji , Okazaki 444-8787 , Japan
- Japan Science and Technology Agency , ACT-C, 4-1-8 Honcho , Kawaguchi , Saitama 332-0012 , Japan
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46
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Zhang S, Miao C, Xia C, Sun W. 4-CH3CONH-TEMPO/Peracetic Acid System for a Shortened Electron-Transfer-Cycle-Controlled Oxidation of Secondary Alcohols. ChemCatChem 2015. [DOI: 10.1002/cctc.201500214] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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47
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Sen’ VD, Tikhonov IV, Borodin LI, Pliss EM, Golubev VA, Syroeshkin MA, Rusakov AI. Kinetics and thermodynamics of reversible disproportionation-comproportionation in redox triad oxoammonium cations - nitroxyl radicals - hydroxylamines. J PHYS ORG CHEM 2014. [DOI: 10.1002/poc.3392] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Vasily D. Sen’
- Institute of Problems of Chemical Physics; Russian Academy of Sciences; Chernogolovka 142432 Russian Federation
| | - Ivan V. Tikhonov
- P.G. Demidov Yaroslavl State University; Yaroslavl 150000 Russian Federation
| | - Leonid I. Borodin
- P.G. Demidov Yaroslavl State University; Yaroslavl 150000 Russian Federation
| | - Evgeny M. Pliss
- P.G. Demidov Yaroslavl State University; Yaroslavl 150000 Russian Federation
| | - Valery A. Golubev
- Institute of Problems of Chemical Physics; Russian Academy of Sciences; Chernogolovka 142432 Russian Federation
| | - Mikhail A. Syroeshkin
- N. D. Zelinsky Institute of Organic Chemistry; Russian Academy of Sciences; Moscow 119991 Russian Federation
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48
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A theoretical study of the thermodynamic and hydrogen-bond basicity of TEMPO radical and related nitroxides. Struct Chem 2014. [DOI: 10.1007/s11224-014-0484-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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49
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Green RA, Hill-Cousins JT, Brown RC, Pletcher D, Leach SG. A voltammetric study of the 2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO) mediated oxidation of benzyl alcohol in tert-butanol/water. Electrochim Acta 2013. [DOI: 10.1016/j.electacta.2013.09.070] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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50
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Tikhonov IV, Sen' VD, Borodin LI, Pliss EM, Golubev VA, Rusakov AI. Effect of the structure of nitroxyl radicals on the kinetics of their acid-catalyzed disproportionation. J PHYS ORG CHEM 2013. [DOI: 10.1002/poc.3247] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
| | - Vasily D. Sen'
- Institute of Problems of Chemical Physics; Russian Academy of Sciences; Chernogolovka Moscow Region Russia
| | | | | | - Valery A. Golubev
- Institute of Problems of Chemical Physics; Russian Academy of Sciences; Chernogolovka Moscow Region Russia
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