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Prukała D, Zubova E, Svobodová E, Šimková L, Varma N, Chudoba J, Ludvík J, Burdzinski G, Gulaczyk I, Sikorski M, Cibulka R. Introduction of flavin anions into photoredox catalysis: acid-base equilibria of lumichrome allow photoreductions with an anion of an elusive 10-unsubstituted isoalloxazine. Chem Sci 2025:d5sc01630d. [PMID: 40406213 PMCID: PMC12094105 DOI: 10.1039/d5sc01630d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2025] [Accepted: 05/12/2025] [Indexed: 05/26/2025] Open
Abstract
Flavins have been established as effective catalysts in oxidative photoredox catalysis. Conversely, their use in reductive photocatalysis remains limited, mainly due to the relatively low stability of the transient flavin radicals (semiquinones), which are used in photoreductions. The fully reduced forms of flavins are also disadvantaged in photocatalysis because they absorb light in the UV rather than in the visible region. In this work, we present a new approach for reductive flavin photocatalysis that utilises a flavin (isoalloxazine) anion derived from the elusive 10-unsubstituted 3,7,8-trimethylisoalloxazine, an unstable tautomer of 3-methyllumichrome. We found the conditions under which this isoalloxazine anion is formed by in situ deprotonation/isomerisation from the readily available 3-methyllumichrome and we subsequently used it as a photoredox catalyst in the reductive dehalogenation of activated bromoarenes and their C-P coupling reaction with trimethyl phosphite to form an arylphosphonate. Steady-state and transient absorption spectroscopy, NMR and cyclic voltammetry investigations, together with quantum chemical calculations, showed that the anion of oxidised isoalloxazine has several advantages, compared to other forms of flavins used in photoreductions, such as high stability, even in the presence of oxygen, an absorption maximum in the visible region, thereby allowing the use of excitation light between 470 and 505 nm, and a relatively long-lived singlet excited-state.
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Affiliation(s)
- Dorota Prukała
- Faculty of Chemistry, Adam Mickiewicz University 61-614 Poznań Poland
| | - Ekaterina Zubova
- Department of Organic Chemistry, University of Chemistry and Technology, Prague 16628 Prague Czech Republic
| | - Eva Svobodová
- Department of Organic Chemistry, University of Chemistry and Technology, Prague 16628 Prague Czech Republic
| | - Ludmila Šimková
- Department of Molecular Electrochemistry and Catalysis, J. Heyrovský Institute of Physical Chemistry, Czech Academy of Sciences 18223 Prague Czech Republic
| | - Naisargi Varma
- Faculty of Chemistry, Adam Mickiewicz University 61-614 Poznań Poland
| | - Josef Chudoba
- Central Laboratories, University of Chemistry and Technology, Prague 16628 Prague Czech Republic
| | - Jiří Ludvík
- Department of Molecular Electrochemistry and Catalysis, J. Heyrovský Institute of Physical Chemistry, Czech Academy of Sciences 18223 Prague Czech Republic
| | - Gotard Burdzinski
- Faculty of Physics and Astronomy, Adam Mickiewicz University 61-614 Poznań Poland
| | - Iwona Gulaczyk
- Faculty of Chemistry, Adam Mickiewicz University 61-614 Poznań Poland
| | - Marek Sikorski
- Faculty of Chemistry, Adam Mickiewicz University 61-614 Poznań Poland
| | - Radek Cibulka
- Department of Organic Chemistry, University of Chemistry and Technology, Prague 16628 Prague Czech Republic
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2
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Seo D, Kwon S, Yoon G, Son T, Won C, Singh N, Kim D, Baek Y. Expanding the chemical space of flavins with pentacyclic architecture. Nat Commun 2025; 16:3561. [PMID: 40234447 PMCID: PMC12000593 DOI: 10.1038/s41467-025-58957-2] [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: 02/20/2025] [Accepted: 04/07/2025] [Indexed: 04/17/2025] Open
Abstract
Inspired by the prominent redox and optical properties of natural flavins, synthetic flavins have found broad applications in organic, photochemical, and biochemical research. Tailoring these properties of flavins, however, remains a challenge. In this work, we present three pentacyclic flavins (C-PF, O-PF, and S-PF) that leverage a strategic molecular design to modify the flavin's electronic structure. Notably, the oxygen- and sulfur-linked pentacyclic flavins (O-PF and S-PF) exhibit deep-red and NIR emission, respectively, driven by enhanced π-conjugation, substituent effects, and charge separation upon excitation. These heteroatom-incorporated pentacyclic flavins exhibit unusual quasi-reversible oxidation, expanding both optical and redox limits of synthetic flavins. Comprehensive spectroscopic, structural, and computational analyses reveal how heteroatom incorporation within this five-ring-fused system unlocks redox and optical properties of flavin-derived chromophores.
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Affiliation(s)
- Dayeong Seo
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Seongyeon Kwon
- Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science, Daejeon, Republic of Korea
| | - Gahye Yoon
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Taeil Son
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Changhyeon Won
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Neetu Singh
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Dongwook Kim
- Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science, Daejeon, Republic of Korea
| | - Yunjung Baek
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea.
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3
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Müller L, Poll J, Nuernberger P, Ghosh I, König B. Quinones as Multifunctional Scaffolds for Oxidative, Reductive, and HAT Photocatalysis. Chemistry 2025; 31:e202404707. [PMID: 39961015 PMCID: PMC11973854 DOI: 10.1002/chem.202404707] [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: 12/22/2024] [Accepted: 02/17/2025] [Indexed: 03/04/2025]
Abstract
Photoredox catalysis, which enables both electron and hydrogen atom transfer, has become a powerful tool for activating chemical bonds and synthesizing complex molecules under mild conditions. Typically, photocatalysts are optimized either for oxidative or reductive reactions within a limited redox window (less than 3.1 V) and for hydrogen atom transfer (HAT) reactions, with few frameworks capable of mediating both pathways for high redox-demanding reactions (covering more than a 5 V redox window) without requiring special conditions. Herein, we report the use of quinones as multifunctional scaffolds in light-driven redox transformations, offering access to a redox window of approximately 5 V using visible light. The quinone scaffold's versatility facilitates a wide range of radical and ionic processes under both oxidative and reductive conditions, in addition to enabling HAT reactions. By keeping the parameters, i. e. the reaction partners, constant, such transformations can be carried out under just two reaction conditions. Oxidative transformations and HAT reactions occur under ambient air, while activation of the chromophore for reductive transformations can be achieved using an inorganic base (Cs2CO3) via a simple acid-base deprotonation event. This dual capability highlights the potential of quinones as scaffolds to extend their utility in photoredox catalysis.
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Affiliation(s)
- Lea Müller
- Fakultät für Chemie und PharmazieUniversität Regensburg93053RegensburgGermany
| | - Jonas Poll
- Institut für Physikalische und Theoretische ChemieUniversität Regensburg93053RegensburgGermany
| | - Patrick Nuernberger
- Institut für Physikalische und Theoretische ChemieUniversität Regensburg93053RegensburgGermany
| | - Indrajit Ghosh
- Fakultät für Chemie und PharmazieUniversität Regensburg93053RegensburgGermany
- Nanotechnology CentreCentre for Energy and Environmental TechnologiesVSB - Technical University of Ostrava708 00Ostrava-PorubaCzech Republic
| | - Burkhard König
- Fakultät für Chemie und PharmazieUniversität Regensburg93053RegensburgGermany
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4
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Shaikh AC, Hossain MM, Moutet J, Kumar A, Thompson B, Huxter VM, Gianetti TL. Isolated Neutral Organic Radical Unveiled Solvent-Radical Interaction in Highly Reducing Photocatalysis. Angew Chem Int Ed Engl 2025; 64:e202420483. [PMID: 39753513 DOI: 10.1002/anie.202420483] [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: 10/27/2024] [Revised: 01/02/2025] [Accepted: 01/03/2025] [Indexed: 01/21/2025]
Abstract
Diffusion-limited kinetics is a key mechanistic debate when consecutive photoelectron transfer (conPET) is discussed in photoredox catalysis. In situ generated organic photoactive radicals can access catalytic systems as reducing as alkaline metals that can activate remarkably stable bonds. However, in many cases, the extremely short-lived transient nature of these doublet state open-shell species has led to debatable mechanistic studies, hindering adoption and development. Herein, we document the use of an isolated and stable neutral organic nPrDMQA radical as a highly photoreducing species. The isolated radical offers a unique platform to investigate the mechanism behind the photocatalytic activity of organic photocatalyst radicals. The involvement of reduced solvent is observed, formed by single electron transfer (SET) between the short-lived excited state nPrDMQA radical and the solvent. In our detailed mechanistic studies, spectroscopic and chemical affirmation of solvent reduction is strongly evident. Reduction of aryl halides, including difluoroarenes is presented as a model study of the conPET method. Further, the activation of N2O, a greenhouse gas that is yet to be activated by photoredox catalysis, is showcased in the absence of a transition metal.
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Affiliation(s)
- Aslam C Shaikh
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, 85721, United States
- Department of Chemistry, Indian Institute of Technology Ropar, Rupnagar, Punjab, 140001, India
| | - Md Mubarak Hossain
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, 85721, United States
| | - Jules Moutet
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, 85721, United States
| | - Anshu Kumar
- Department of Physics, University of Arizona, Tucson, AZ, 85721, United States
| | - Benjamin Thompson
- Department of Optical Sciences, University of Arizona, Tucson, AZ, 85721, United States
| | - Vanessa M Huxter
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, 85721, United States
- Department of Physics, University of Arizona, Tucson, AZ, 85721, United States
| | - Thomas L Gianetti
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, 85721, United States
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5
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Wei D, Bu J, Zhang S, Chen S, Yue L, Li X, Liang K, Xia C. Light-Driven Stepwise Reduction of Aliphatic Carboxylic Esters to Aldehydes and Alcohols. Angew Chem Int Ed Engl 2025; 64:e202420084. [PMID: 39837787 DOI: 10.1002/anie.202420084] [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: 10/17/2024] [Revised: 01/03/2025] [Accepted: 01/21/2025] [Indexed: 01/23/2025]
Abstract
The reduction of carboxylic esters to aldehydes and alcohols is a fundamental functional group transformation in chemistry. However, the inertness of carbonyl group and the instability of ketyl radical anion intermediate impede the reduction of carboxylic esters via photochemical strategy. Herein, we described the reduction of aliphatic carboxylic esters with synergistic dual photocatalysis via phenolate-catalyzed single electron transfer process and thiol-catalyzed hydrogen atom transfer process. The competitive back electron transfer process was effectively inhibited by protonation of the ketyl-type radical anion. This protocol enabled the efficient reduction of carboxylic esters to alcohols under mild conditions. By interruption of the reduction with prolinol, the step-controlled reduction of carboxylic esters to aldehydes was accomplished. The developed process was also successfully applied to the preparation of deuterated alcohols and aldehydes from esters with D2O as the deuterium source.
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Affiliation(s)
- Delian Wei
- Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education, Yunnan Key Laboratory of Research and Development for Natural Products, School of Pharmacy, Yunnan University, Kunming, 650500, China
| | - Jiawei Bu
- Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education, Yunnan Key Laboratory of Research and Development for Natural Products, School of Pharmacy, Yunnan University, Kunming, 650500, China
| | - Shengfu Zhang
- Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education, Yunnan Key Laboratory of Research and Development for Natural Products, School of Pharmacy, Yunnan University, Kunming, 650500, China
| | - Shiyu Chen
- Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education, Yunnan Key Laboratory of Research and Development for Natural Products, School of Pharmacy, Yunnan University, Kunming, 650500, China
| | - Ling Yue
- Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education, Yunnan Key Laboratory of Research and Development for Natural Products, School of Pharmacy, Yunnan University, Kunming, 650500, China
| | - Xipan Li
- Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education, Yunnan Key Laboratory of Research and Development for Natural Products, School of Pharmacy, Yunnan University, Kunming, 650500, China
| | - Kangjiang Liang
- Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education, Yunnan Key Laboratory of Research and Development for Natural Products, School of Pharmacy, Yunnan University, Kunming, 650500, China
| | - Chengfeng Xia
- Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education, Yunnan Key Laboratory of Research and Development for Natural Products, School of Pharmacy, Yunnan University, Kunming, 650500, China
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6
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Zhu X, Chen H, Wang J, Migliore A, Li X, Li Y, Wang B, Yang C, Jiao Y, Cao J, Yang C, Gao C, He S, Houk KN, Yang J, Stoddart JF, Jia C, Guo X. Single-Electron Catalysis of Reversible Cycloadditions under Nanoconfinement. J Am Chem Soc 2025; 147:6203-6213. [PMID: 39912303 DOI: 10.1021/jacs.4c18064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2025]
Abstract
Electron transfer (ET) is crucial in many chemical reactions, but its mechanism and role are hardly understood in nanobiotechnology due to the complexity of reaction species and pathways involved. By modulating and monitoring electron behavior at the single-molecule level, we can better understand the fundamental mechanisms and ways to control them for technological use. Here, we unravel a mechanism of single-electron catalysis under positively charged nanoconfinement. We demonstrate that both (2 + 2) and (4 + 4) cycloadditions can be catalyzed reversibly by a single electron. Key reaction pathways are discovered by monitoring sequential electrical signals in the cycloadditions through advanced single-molecule detection platforms. Experimental and theoretical results consistently demonstrate that combining single ET processes with nanoconfinement involving cucurbit[8]uril can lower the reaction energy barrier and promote reversible cycloaddition. Moreover, we show that the bias voltage can fine-tune ET processes and chemical equilibria in bond formation and cleavage. Our results provide a novel approach to elucidate, modulate, and design electron-involved reactions and functionalized devices.
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Affiliation(s)
- Xin Zhu
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, P.R. China
- Beijing National Laboratory for Molecular Sciences, National Biomedical Imaging Center, College of Chemistry and Molecular Engineering, Peking University, 292 Chengfu Road, Haidian District, Beijing 100871, P.R. China
| | - Hongliang Chen
- Stoddart Institute of Molecular Science, Department of Chemistry, Zhejiang University, Hangzhou 310021, P.R. China
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou 311215, P.R. China
| | - Jinying Wang
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, P.R. China
| | - Agostino Migliore
- Department of Chemical Sciences, University of Padova, Via Marzolo 1, Padova 35131, Italy
| | - Xingxing Li
- Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei, Anhui 230026, P.R. China
| | - Yanwei Li
- Environment Research Institute, Shandong University, Qingdao 266237, P.R. China
- Shenzhen Research Institute, Shandong University, Shenzhen 518057, P.R. China
| | - Boyu Wang
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, P.R. China
| | - Chen Yang
- Beijing National Laboratory for Molecular Sciences, National Biomedical Imaging Center, College of Chemistry and Molecular Engineering, Peking University, 292 Chengfu Road, Haidian District, Beijing 100871, P.R. China
| | - Yang Jiao
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Jiawen Cao
- Beijing National Laboratory for Molecular Sciences, National Biomedical Imaging Center, College of Chemistry and Molecular Engineering, Peking University, 292 Chengfu Road, Haidian District, Beijing 100871, P.R. China
| | - Caiyao Yang
- Beijing National Laboratory for Molecular Sciences, National Biomedical Imaging Center, College of Chemistry and Molecular Engineering, Peking University, 292 Chengfu Road, Haidian District, Beijing 100871, P.R. China
| | - Chunyan Gao
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, P.R. China
| | - Suhang He
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, P.R. China
| | - Kendall N Houk
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
| | - Jinlong Yang
- Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei, Anhui 230026, P.R. China
| | - J Fraser Stoddart
- Stoddart Institute of Molecular Science, Department of Chemistry, Zhejiang University, Hangzhou 310021, P.R. China
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou 311215, P.R. China
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong SAR 999077, P.R. China
- School of Chemistry, University of New South Wales, Sydney, NSW 2052, Australia
| | - Chuancheng Jia
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, P.R. China
| | - Xuefeng Guo
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, P.R. China
- Beijing National Laboratory for Molecular Sciences, National Biomedical Imaging Center, College of Chemistry and Molecular Engineering, Peking University, 292 Chengfu Road, Haidian District, Beijing 100871, P.R. China
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7
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Biswas A, Kolb S, Röttger SH, Das A, Patalag LJ, Dey PP, Sil S, Maji S, Chakraborty S, Wenger OS, Bhunia A, Werz DB, Mandal SK. A BOIMPY Dye Enables Multi-Photoinduced Electron Transfer Catalysis: Reaching Super-Reducing Properties. Angew Chem Int Ed Engl 2025; 64:e202416472. [PMID: 39655963 DOI: 10.1002/anie.202416472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2024] [Revised: 10/17/2024] [Accepted: 12/10/2024] [Indexed: 01/11/2025]
Abstract
An established concept to create radical intermediates is photoexcitation of a catalyst to a higher energy intermediate, subsequently leading to a photoinduced electron transfer (PET) with a reaction partner. The known concept of consecutive photoinduced electron transfer (con-PET) leads to catalytically active species even higher in energy by the uptake of two photons. Generally speaking, increased photon uptake leads to a more potent reductant. Here, we report the concept of multi-photoinduced electron transfer catalysis (>2 photons), termed multi-PET, which is enabled by photoinduced one-electron reductions of an organic dye. Further irradiation of the doubly reduced species leads to a photoexcited dianionic super-reductant, which is more potent than Li metal - one of the strongest chemical reductants known. This multi-photon process which is enabled by 390 nm LEDs allows the cleavage of strong carbon-fluorine bonds and reduction of other halides even in very electron-rich substrates. The resulting radicals are quenched by hydrogen atoms or engaged in carbon-carbon and carbon-phosphorus bond formations, highlighting the utility of multi-PET for organic chemistry. In addition, multi-PET enabled Birch-type reductions. Spectroscopic, chemical and computational investigations are presented to gain mechanistic insights.
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Affiliation(s)
- Amit Biswas
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, 741246, India
| | - Simon Kolb
- DFG Cluster of Excellence livMatS @ FIT - Freiburg Center for Interactive Materials and Bioinspired Technologies, University of Freiburg, Freiburg, 79110, Germany
- Institute of Organic Chemistry, University of Freiburg, Albertstr. 21, 79104, Freiburg, Germany
| | - Sebastian H Röttger
- DFG Cluster of Excellence livMatS @ FIT - Freiburg Center for Interactive Materials and Bioinspired Technologies, University of Freiburg, Freiburg, 79110, Germany
- Institute of Organic Chemistry, University of Freiburg, Albertstr. 21, 79104, Freiburg, Germany
| | - Arpan Das
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, 741246, India
| | - Lukas J Patalag
- DFG Cluster of Excellence livMatS @ FIT - Freiburg Center for Interactive Materials and Bioinspired Technologies, University of Freiburg, Freiburg, 79110, Germany
- Institute of Organic Chemistry, University of Freiburg, Albertstr. 21, 79104, Freiburg, Germany
| | - Partha P Dey
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, 741246, India
| | - Swagata Sil
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, 741246, India
| | - Subir Maji
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, 741246, India
| | - Soumi Chakraborty
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, 741246, India
| | - Oliver S Wenger
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056, Basel, Switzerland
| | - Anup Bhunia
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, 741246, India
| | - Daniel B Werz
- DFG Cluster of Excellence livMatS @ FIT - Freiburg Center for Interactive Materials and Bioinspired Technologies, University of Freiburg, Freiburg, 79110, Germany
- Institute of Organic Chemistry, University of Freiburg, Albertstr. 21, 79104, Freiburg, Germany
| | - Swadhin K Mandal
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, 741246, India
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8
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Langschwager T, Storch G. Flavin-Catalyzed, Photochemical Conversion of Dehydroalanine into 4,5-Dihydroxynorvaline. Angew Chem Int Ed Engl 2025; 64:e202414679. [PMID: 39305229 DOI: 10.1002/anie.202414679] [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: 08/02/2024] [Indexed: 11/06/2024]
Abstract
The chemical synthesis of unnatural amino acids (UAA) is a key strategy for preparing designed peptides, including pharmaceutically active compounds. Alterations of existing amino acid residues such as dehydroalanine (Dha) are particularly important since selected positions can be addressed without the necessity of a complete de novo synthesis. The intriguing UAA 4,5-dihydroxynorvaline (Dnv) is found in a variety of naturally occurring peptides and biologically active compounds. However, no method is currently available to modify an existing peptide with this residue. We report the use of flavin catalysts and visible light irradiation for this challenge, which serves as a versatile strategy for converting Dha into Dnv. Our study shows that excited flavins are competent hydrogen atom abstraction catalysts for ethers and acetals, which allows masked 1,2-dihydroxyethylene functionalization from 2,2-dimethyl-1,3-dioxolane. The masked diol was successfully coupled to Dha residues, and a series of Dnv-containing products is reported. A mild and orthogonal protocol for deprotection of the acetal group was also identified, allowing free Dnv-modified peptides to be obtained. This method provides a straightforward strategy for Dnv functionalization, which is envisioned to be crucial for accessing natural products and synthetic analogues with pharmaceutical activity.
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Affiliation(s)
- Tim Langschwager
- School of Natural Sciences and Catalysis Research Center (CRC), Technical University of Munich (TUM), Lichtenbergstr. 4, 85747, Garching, Germany
| | - Golo Storch
- School of Natural Sciences and Catalysis Research Center (CRC), Technical University of Munich (TUM), Lichtenbergstr. 4, 85747, Garching, Germany
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9
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Grudzień K, Szeptuch Z, Kubiszewski H, Chaładaj W, Rybicka-Jasińska K. NHC-Cu Three-Coordinate Complex as a Promising Photocatalyst for Energy and Electron Transfer Reactions. J Org Chem 2024; 89:8546-8550. [PMID: 38830237 PMCID: PMC11197101 DOI: 10.1021/acs.joc.4c00450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Revised: 05/10/2024] [Accepted: 05/17/2024] [Indexed: 06/05/2024]
Abstract
Herein, we describe a simple three-coordinate complex of Cu(I) with an NHC and 1,10-phenanthroline ligands as an effective photocatalyst for energy (e.g., olefin E/Z isomerization) and electron transfer (e.g., aryl halide dehalogenation) reactions under blue-light irradiation. This complex can be obtained in a one-pot procedure starting from commercially available reagents and green solvents (EtOH, water). We hereby present a study of its activity and mechanistic insight into its mode of operation.
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Affiliation(s)
- Krzysztof Grudzień
- Institute
of Organic Chemistry, Polish Academy of
Sciences, Kasprzaka 44/52, Warsaw 01-224, Poland
| | - Zuzanna Szeptuch
- Institute
of Organic Chemistry, Polish Academy of
Sciences, Kasprzaka 44/52, Warsaw 01-224, Poland
- Faculty
of Chemistry, Warsaw University of Technology, Noakowskiego 3, Warsaw 00-664, Poland
| | - Hubert Kubiszewski
- Institute
of Organic Chemistry, Polish Academy of
Sciences, Kasprzaka 44/52, Warsaw 01-224, Poland
- Faculty
of Medicine, Medical University of Warsaw, Żwirki i Wigury 61, Warsaw 02-091, Poland
| | - Wojciech Chaładaj
- Institute
of Organic Chemistry, Polish Academy of
Sciences, Kasprzaka 44/52, Warsaw 01-224, Poland
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10
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Das A, Charpentier O, Hessin C, Schleinitz J, Pianca D, Le Breton N, Choua S, Grimaud L, Gourlaouen C, Desage-El Murr M. Site-Selective Radical Aromatic C-H Functionalization of Alloxazine and Flavin through Ground-State Single Electron Transfer. Angew Chem Int Ed Engl 2024; 63:e202403417. [PMID: 38627209 DOI: 10.1002/anie.202403417] [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: 02/18/2024] [Indexed: 06/11/2024]
Abstract
Flavins and their alloxazine isomers are key chemical scaffolds for bioinspired electron transfer strategies. Their properties can be fine-tuned by functional groups, which must be introduced at an early stage of the synthesis as their aromatic ring is inert towards post-functionalization. We show that the introduction of a remote metal-binding redox site on alloxazine and flavin activates their aromatic ring towards direct C-H functionalization. Mechanistic studies are consistent with a synthetic sequence involving ground-state single electron transfer (SET) with an electrophilic source followed by radical-radical coupling. This unprecedented reactivity opens new opportunities in molecular editing of flavins by direct aromatic post-functionalization and the utility of the method is demonstrated with the site-selective C6 functionalization of alloxazine and flavin with a CF3 group, Br or Cl, that can be further elaborated into OH and aryl for chemical diversification.
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Affiliation(s)
- Agnideep Das
- Université de Strasbourg, Institut de Chimie, CNRS UMR7177, 4, rue Blaise Pascal, 67000, Strasbourg, France
| | - Oscar Charpentier
- Université de Strasbourg, Institut de Chimie, CNRS UMR7177, 4, rue Blaise Pascal, 67000, Strasbourg, France
| | - Cheriehan Hessin
- Université de Strasbourg, Institut de Chimie, CNRS UMR7177, 4, rue Blaise Pascal, 67000, Strasbourg, France
| | - Jules Schleinitz
- Laboratoire des biomolécules, LBM, Chemistry department École Normale Supérieure, PSL University, Sorbonne Université, CNRS, 75005, Paris, France
| | - David Pianca
- Université de Strasbourg, Institut de Chimie, CNRS UMR7177, 4, rue Blaise Pascal, 67000, Strasbourg, France
| | - Nolwenn Le Breton
- Université de Strasbourg, Institut de Chimie, CNRS UMR7177, 4, rue Blaise Pascal, 67000, Strasbourg, France
| | - Sylvie Choua
- Université de Strasbourg, Institut de Chimie, CNRS UMR7177, 4, rue Blaise Pascal, 67000, Strasbourg, France
| | - Laurence Grimaud
- Laboratoire des biomolécules, LBM, Chemistry department École Normale Supérieure, PSL University, Sorbonne Université, CNRS, 75005, Paris, France
| | - Christophe Gourlaouen
- Université de Strasbourg, Institut de Chimie, CNRS UMR7177, 4, rue Blaise Pascal, 67000, Strasbourg, France
| | - Marine Desage-El Murr
- Université de Strasbourg, Institut de Chimie, CNRS UMR7177, 4, rue Blaise Pascal, 67000, Strasbourg, France
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11
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Shiogai Y, Oka M, Miyake H, Iida H. Aerobic oxidative synthesis of benzimidazoles by flavin photocatalysis. Org Biomol Chem 2024; 22:4450-4454. [PMID: 38753213 DOI: 10.1039/d4ob00360h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2024]
Abstract
Flavin photocatalysis were utilised for an aerobic oxidative reaction between arylamines and o-phenylenediamine. This metal-free reaction proceeded in methanol under visible light irradiation and consumed only atmospheric molecular oxygen, providing a novel eco-friendly method for the synthesis of benzimidazoles.
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Affiliation(s)
- Yuta Shiogai
- Department of Chemistry, Graduate School of Natural Science and Technology, Shimane University, 1060 Nishikawatsu, Matsue, 690-8504 Japan.
| | - Marina Oka
- Department of Chemistry, Graduate School of Natural Science and Technology, Shimane University, 1060 Nishikawatsu, Matsue, 690-8504 Japan.
| | - Hazuki Miyake
- Department of Chemistry, Graduate School of Natural Science and Technology, Shimane University, 1060 Nishikawatsu, Matsue, 690-8504 Japan.
| | - Hiroki Iida
- Department of Chemistry, Graduate School of Natural Science and Technology, Shimane University, 1060 Nishikawatsu, Matsue, 690-8504 Japan.
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12
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Rehpenn A, Hindelang S, Truong KN, Pöthig A, Storch G. Enhancing Flavins Photochemical Activity in Hydrogen Atom Abstraction and Triplet Sensitization through Ring-Contraction. Angew Chem Int Ed Engl 2024; 63:e202318590. [PMID: 38339882 DOI: 10.1002/anie.202318590] [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: 12/04/2023] [Revised: 01/30/2024] [Accepted: 02/01/2024] [Indexed: 02/12/2024]
Abstract
The isoalloxazine heterocycle of flavin cofactors reacts with various nucleophiles to form covalent adducts with important functions in enzymes. Molecular flavin models allow for the characterization of such adducts and the study of their properties. A fascinating set of reactions occurs when flavins react with hydroxide base, which leads to imidazolonequinoxalines, ring-contracted flavins, with so far unexplored activity. We report a systematic study of the photophysical properties of this new chromophore by absorption and emission spectroscopy as well as cyclic voltammetry. Excited, ring-contracted flavins are significantly stronger hydrogen atom abstractors when compared to the parent flavins, which allowed the direct trifluoromethylthiolation of aliphatic methine positions (bond dissociation energy (BDE) of 400.8 kJ mol-1). In an orthogonal activity, their increased triplet energy (E(S0←T1)=244 kJ mol-1) made sensitized reactions possible which exceeded the power of standard flavins. Combining both properties, ring-contracted flavin catalysts enabled the one-pot, five-step transformation of α-tropolone into trans-3,4-disubstituted cyclopentanones. We envision this new class of flavin-derived chromophores to open up new modes of reactivity that are currently impossible with unmodified flavins.
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Affiliation(s)
- Andreas Rehpenn
- Technical University of Munich (TUM), School of Natural Sciences and Catalysis Research Center (CRC), Lichtenbergstr. 4, 85747, Garching, Germany
| | - Stephan Hindelang
- Technical University of Munich (TUM), School of Natural Sciences and Catalysis Research Center (CRC), Lichtenbergstr. 4, 85747, Garching, Germany
| | - Khai-Nghi Truong
- Rigaku Europe SE, Hugenottenallee 167, 63263, Neu-Isenburg, Germany
| | - Alexander Pöthig
- Technical University of Munich (TUM), School of Natural Sciences and Catalysis Research Center (CRC), Lichtenbergstr. 4, 85747, Garching, Germany
| | - Golo Storch
- Technical University of Munich (TUM), School of Natural Sciences and Catalysis Research Center (CRC), Lichtenbergstr. 4, 85747, Garching, Germany
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13
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Panter S, Ayekoi A, Tesche J, Chen J, Illarionov B, Bacher A, Fischer M, Weber S. Shining a Spotlight on Methyl Groups: Photochemically Induced Dynamic Nuclear Polarization Spectroscopy of 5-Deazariboflavin and Its Nor Analogs. Int J Mol Sci 2024; 25:848. [PMID: 38255921 PMCID: PMC10815406 DOI: 10.3390/ijms25020848] [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: 12/08/2023] [Revised: 01/07/2024] [Accepted: 01/08/2024] [Indexed: 01/24/2024] Open
Abstract
5-Deazaflavins are analogs of naturally occurring flavin cofactors. They serve as substitutes for natural flavin cofactors to investigate and modify the reaction pathways of flavoproteins. Demethylated 5-deazaflavins are potential candidates for artificial cofactors, allowing us to fine-tune the reaction kinetics and absorption characteristics of flavoproteins. In this contribution, demethylated 5-deazariboflavin radicals are investigated (1) to assess the influence of the methyl groups on the electronic structure of the 5-deazaflavin radical and (2) to explore their photophysical properties with regard to their potential as artificial cofactors. We determined the proton hyperfine structure of demethylated 5-deazariboflavins using photochemically induced dynamic nuclear polarization (photo-CIDNP) spectroscopy, as well as density functional theory (DFT). To provide context, we compare our findings to a study of flavin mononucleotide (FMN) derivatives. We found a significant influence of the methylation pattern on the absorption properties, as well as on the proton hyperfine coupling ratios of the xylene moiety, which appears to be solvent-dependent. This effect is enhanced by the replacement of N5 by C5-H in 5-deazaflavin derivatives compared to their respective flavin counterparts.
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Affiliation(s)
- Sabrina Panter
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstr. 21, 79104 Freiburg, Germany; (S.P.); (A.A.)
| | - Audrey Ayekoi
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstr. 21, 79104 Freiburg, Germany; (S.P.); (A.A.)
| | - Jannis Tesche
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstr. 21, 79104 Freiburg, Germany; (S.P.); (A.A.)
| | - Jing Chen
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstr. 21, 79104 Freiburg, Germany; (S.P.); (A.A.)
| | - Boris Illarionov
- Institut für Lebensmittelchemie, Universität Hamburg, Grindelallee 117, 20146 Hamburg, Germany; (B.I.); (M.F.)
| | - Adelbert Bacher
- TUM School of Natural Sciences, Technische Universität München, Lichtenbergstr. 4, 85747 Garching, Germany;
| | - Markus Fischer
- Institut für Lebensmittelchemie, Universität Hamburg, Grindelallee 117, 20146 Hamburg, Germany; (B.I.); (M.F.)
| | - Stefan Weber
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstr. 21, 79104 Freiburg, Germany; (S.P.); (A.A.)
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14
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Tian X, Liu Y, Yakubov S, Schütte J, Chiba S, Barham JP. Photo- and electro-chemical strategies for the activations of strong chemical bonds. Chem Soc Rev 2024; 53:263-316. [PMID: 38059728 DOI: 10.1039/d2cs00581f] [Citation(s) in RCA: 28] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/08/2023]
Abstract
The employment of light and/or electricity - alternatively to conventional thermal energy - unlocks new reactivity paradigms as tools for chemical substrate activations. This leads to the development of new synthetic reactions and a vast expansion of chemical spaces. This review summarizes recent developments in photo- and/or electrochemical activation strategies for the functionalization of strong bonds - particularly carbon-heteroatom (C-X) bonds - via: (1) direct photoexcitation by high energy UV light; (2) activation via photoredox catalysis under irradiation with relatively lower energy UVA or blue light; (3) electrochemical reduction; (4) combination of photocatalysis and electrochemistry. Based on the types of the targeted C-X bonds, various transformations ranging from hydrodefunctionalization to cross-coupling are covered with detailed discussions of their reaction mechanisms.
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Affiliation(s)
- Xianhai Tian
- Fakultät für Chemie und Pharmazie, Universität Regensburg, 93040 Regensburg, Germany.
| | - Yuliang Liu
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore 637371, Singapore.
| | - Shahboz Yakubov
- Fakultät für Chemie und Pharmazie, Universität Regensburg, 93040 Regensburg, Germany.
| | - Jonathan Schütte
- Fakultät für Chemie und Pharmazie, Universität Regensburg, 93040 Regensburg, Germany.
| | - Shunsuke Chiba
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore 637371, Singapore.
| | - Joshua P Barham
- Fakultät für Chemie und Pharmazie, Universität Regensburg, 93040 Regensburg, Germany.
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15
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Wörner J, Panter S, Illarionov B, Bacher A, Fischer M, Weber S. Expanding Reaction Horizons: Evidence of the 5-Deazaflavin Radical Through Photochemically Induced Dynamic Nuclear Polarization. Angew Chem Int Ed Engl 2023; 62:e202309334. [PMID: 37571931 DOI: 10.1002/anie.202309334] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 08/09/2023] [Accepted: 08/10/2023] [Indexed: 08/13/2023]
Abstract
Deazaflavins are important analogues of the naturally occurring flavins: riboflavin, flavin mononucleotide (FMN), and flavin adenine dinucleotide (FAD). The use of 5-deazaflavin as a replacement coenzyme in a number of flavoproteins has proven particularly valuable in unraveling and manipulating their reaction mechanisms. It was frequently reported that one-electron-transfer reactions in flavoproteins are impeded with 5-deazaflavin as the cofactor. Based on these findings, it was concluded that the 5-deazaflavin radical is significantly less stable compared to the respective flavin semiquinone and quickly re-oxidizes or undergoes disproportionation. The long-standing paradigm of 5-deazaflavin being solely a two-electron/hydride acceptor/donor-"a nicotinamide in flavin clothing"-needs to be re-evaluated now with the indirect observation of a one-electron-reduced (paramagnetic) species using photochemically induced dynamic nuclear polarization (photo-CIDNP) 1 H nuclear magnetic resonance (NMR) under biologically relevant conditions.
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Affiliation(s)
- Jakob Wörner
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstraße 21, 79104, Freiburg, Germany
| | - Sabrina Panter
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstraße 21, 79104, Freiburg, Germany
| | - Boris Illarionov
- Institut für Lebensmittelchemie, Universität Hamburg, Grindelallee 117, 20146, Hamburg, Germany
| | - Adelbert Bacher
- TUM School of Natural Sciences, Technische Universität München, Lichtenbergstraße 4, 85747, Garching, Germany
| | - Markus Fischer
- Institut für Lebensmittelchemie, Universität Hamburg, Grindelallee 117, 20146, Hamburg, Germany
| | - Stefan Weber
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstraße 21, 79104, Freiburg, Germany
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16
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Takeda A, Oka M, Iida H. Atom-Economical Syntheses of Dihydropyrroles Using Flavin-Iodine-Catalyzed Aerobic Multistep and Multicomponent Reactions. J Org Chem 2023. [PMID: 37183405 DOI: 10.1021/acs.joc.3c00444] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Herein, we report facile, atom-economical syntheses of multisubstituted 2,3-dihydropyrroles using flavin-iodine-catalyzed aerobic oxidative multistep transformations of chalcones with β-enamine ketones or 1,3-dicarbonyl compounds and amines. Exploiting coupled flavin-iodine catalysis, the multistep reaction, including C-C and C-N bond formation, is promoted only by the consumption of O2 (1 atm), thus allowing aerobic oxidative synthesis that generates green H2O as the only waste.
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Affiliation(s)
- Aki Takeda
- Department of Chemistry, Graduate School of Natural Science and Technology, Shimane University, 1060 Nishikawatsu, Matsue 690-8504, Japan
| | - Marina Oka
- Department of Chemistry, Graduate School of Natural Science and Technology, Shimane University, 1060 Nishikawatsu, Matsue 690-8504, Japan
| | - Hiroki Iida
- Department of Chemistry, Graduate School of Natural Science and Technology, Shimane University, 1060 Nishikawatsu, Matsue 690-8504, Japan
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17
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Matysik J, Gerhards L, Theiss T, Timmermann L, Kurle-Tucholski P, Musabirova G, Qin R, Ortmann F, Solov'yov IA, Gulder T. Spin Dynamics of Flavoproteins. Int J Mol Sci 2023; 24:ijms24098218. [PMID: 37175925 PMCID: PMC10179055 DOI: 10.3390/ijms24098218] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 04/19/2023] [Accepted: 04/27/2023] [Indexed: 05/15/2023] Open
Abstract
This short review reports the surprising phenomenon of nuclear hyperpolarization occurring in chemical reactions, which is called CIDNP (chemically induced dynamic nuclear polarization) or photo-CIDNP if the chemical reaction is light-driven. The phenomenon occurs in both liquid and solid-state, and electron transfer systems, often carrying flavins as electron acceptors, are involved. Here, we explain the physical and chemical properties of flavins, their occurrence in spin-correlated radical pairs (SCRP) and the possible involvement of flavin-carrying SCRPs in animal magneto-reception at earth's magnetic field.
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Affiliation(s)
- Jörg Matysik
- Institut für Analytische Chemie, Universität Leipzig, Linnéstr. 3, 04103 Leipzig, Germany
| | - Luca Gerhards
- Institut für Physik, Carl von Ossietzky Universität Oldenburg, Carl-von Ossietzky-Str. 9-11, 26129 Oldenburg, Germany
| | - Tobias Theiss
- Institut für Organische Chemie, Universität Leipzig, Johannisallee 29, 04103 Leipzig, Germany
| | - Lisa Timmermann
- Institut für Organische Chemie, Universität Leipzig, Johannisallee 29, 04103 Leipzig, Germany
| | | | - Guzel Musabirova
- Institut für Analytische Chemie, Universität Leipzig, Linnéstr. 3, 04103 Leipzig, Germany
| | - Ruonan Qin
- Institut für Analytische Chemie, Universität Leipzig, Linnéstr. 3, 04103 Leipzig, Germany
| | - Frank Ortmann
- TUM School of Natural Sciences, Technische Universität München, Lichtenbergstr. 4, 85748 Garching, Germany
| | - Ilia A Solov'yov
- Institut für Physik, Carl von Ossietzky Universität Oldenburg, Carl-von Ossietzky-Str. 9-11, 26129 Oldenburg, Germany
- Research Center for Neurosensory Science, Carl von Ossietzky Universität Oldenburg, Carl-von-Ossietzky-Str. 9-11, 26129 Oldenburg, Germany
- Center for Nanoscale Dynamics (CENAD), Carl von Ossietzky Universität Oldenburg, Carl-von-Ossietzky-Str. 9-11, 26129 Oldenburg, Germany
| | - Tanja Gulder
- Institut für Organische Chemie, Universität Leipzig, Johannisallee 29, 04103 Leipzig, Germany
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18
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Insińska-Rak M, Golczak A, Gierszewski M, Anwar Z, Cherkas V, Kwiatek D, Sikorska E, Khmelinskii I, Burdziński G, Cibulka R, Mrówczyńska L, Kolanowski JL, Sikorski M. 5-Deazaalloxazine as photosensitizer of singlet oxygen and potential redox-sensitive agent. Photochem Photobiol Sci 2023:10.1007/s43630-023-00401-9. [PMID: 36934363 DOI: 10.1007/s43630-023-00401-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Accepted: 02/28/2023] [Indexed: 03/20/2023]
Abstract
Flavins are a unique class of compounds that combine the features of singlet oxygen generators and redox-dependent fluorophores. From a broad family of flavin derivatives, deazaalloxazines are significantly underdeveloped from the point of view of photophysical properties. Herein, we report photophysics of 5-deazaalloxazine (1a) in water, acetonitrile, and some other solvents. In particular, triplet excited states of 1a in water and in acetonitrile were investigated using ultraviolet-visible (UV-Vis) transient absorption spectroscopy. The measured triplet lifetimes for 1a were all on the microsecond time scale (≈ 60 μs) in deoxygenated solutions. The quantum yield of S1 → T1 intersystem crossing for 1a in water was 0.43 based on T1 energy transfer from 1a to indicaxanthin (5) acting as acceptor and on comparative actinometric measurements using benzophenone (6). 1a was an efficient photosensitizer for singlet oxygen in aerated solutions, with quantum yields of singlet oxygen in methanol of about 0.76, compared to acetonitrile ~ 0.74, dichloromethane ~ 0.64 and 1,2-dichloroethane ~ 0.54. Significantly lower singlet oxygen quantum yields were obtained in water and deuterated water (ФΔ ~ 0.42 and 0.44, respectively). Human red blood cells (RBC) were used as a cell model to study the antioxidant capacity in vitro and cytotoxic activity of 1a. Fluorescence-lifetime imaging microscopy (FLIM) data were analyzed by fluorescence lifetime parameters and distribution for different parts of the emission spectrum. Comparison of multidimensional fluorescent properties of RBC under physiological-like and oxidative-stress conditions in the presence and absence of 1a suggests its dual activity as probe and singlet-oxygen generator and opens up a pathway for using FLIM to analyze complex intracellular behavior of flavin-like compounds. These new data on structure-property relationship contribute to the body of information required for a rational design of flavin-based tools for future biological and biochemical applications.
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Affiliation(s)
- Małgorzata Insińska-Rak
- Faculty of Chemistry, Adam Mickiewicz University, Uniwersytetu Poznańskiego 8, 61-614, Poznań, Poland
| | - Anna Golczak
- Faculty of Chemistry, Adam Mickiewicz University, Uniwersytetu Poznańskiego 8, 61-614, Poznań, Poland
| | - Mateusz Gierszewski
- Faculty of Physics, Adam Mickiewicz University, Uniwersytetu Poznańskiego 2, 61-614, Poznań, Poland
| | - Zubair Anwar
- Faculty of Chemistry, Adam Mickiewicz University, Uniwersytetu Poznańskiego 8, 61-614, Poznań, Poland
| | - Volodymyr Cherkas
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12-14, 61-704, Poznań, Poland
| | - Dorota Kwiatek
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12-14, 61-704, Poznań, Poland
| | - Ewa Sikorska
- Poznań University of Economics and Business, Al. Niepodległości 10, 61-875, Poznań, Poland
| | - Igor Khmelinskii
- Department of Chemistry and Pharmacy, Faculty of Sciences and Technology, and Centre for Electronics, Optoelectronics and Telecommunications, University of the Algarve, 8005-139, Faro, Portugal
| | - Gotard Burdziński
- Faculty of Physics, Adam Mickiewicz University, Uniwersytetu Poznańskiego 2, 61-614, Poznań, Poland
| | - Radek Cibulka
- Department of Organic Chemistry, University of Chemistry and Technology, Prague, Technicka 5, Prague 6, 16628, Prague, Czech Republic.
| | - Lucyna Mrówczyńska
- Faculty of Biology, Adam Mickiewicz University, Uniwersytetu Poznańskiego 6, 61-614, Poznań, Poland.
| | - Jacek Lukasz Kolanowski
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12-14, 61-704, Poznań, Poland.
| | - Marek Sikorski
- Faculty of Chemistry, Adam Mickiewicz University, Uniwersytetu Poznańskiego 8, 61-614, Poznań, Poland.
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19
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Shiogai Y, Oka M, Iida H. Aerobic cross-dehydrogenative coupling of toluenes and o-phenylenediamines by flavin photocatalysis for the facile synthesis of benzimidazoles. Org Biomol Chem 2023; 21:2081-2085. [PMID: 36804653 DOI: 10.1039/d3ob00113j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
Herein, we demonstrate a green atom-economical synthesis of benzimidazoles via the flavin-photocatalysed aerobic oxidative cross-dehydrogenative coupling of toluenes and o-phenylenediamines. The proposed metal-free reaction proceeds in methanol/H2O under visible light irradiation by consuming only molecular oxygen from atmospheric air and produces only water as waste.
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Affiliation(s)
- Yuta Shiogai
- Department of Chemistry, Graduate School of Natural Science and Technology, Shimane University, 1060 Nishikawatsu, Matsue, 690-8504 Japan.
| | - Marina Oka
- Department of Chemistry, Graduate School of Natural Science and Technology, Shimane University, 1060 Nishikawatsu, Matsue, 690-8504 Japan.
| | - Hiroki Iida
- Department of Chemistry, Graduate School of Natural Science and Technology, Shimane University, 1060 Nishikawatsu, Matsue, 690-8504 Japan.
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20
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Priyanka U, Lens PNL. Enhanced production of amylase, pyruvate and phenolic compounds from glucose by light-driven Aspergillus niger-CuS nanobiohybrids. JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY (OXFORD, OXFORDSHIRE : 1986) 2023; 98:602-614. [PMID: 37066082 PMCID: PMC10087041 DOI: 10.1002/jctb.7153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 05/29/2022] [Accepted: 06/08/2022] [Indexed: 06/19/2023]
Abstract
BACKGROUND The demand for value-added compounds such as amylase, pyruvate and phenolic compounds produced by biological methods has prompted the rapid development of advanced technologies for their enhanced production. Nanobiohybrids (NBs) make use of both the microbial properties of whole-cell microorganisms and the light-harvesting efficiency of semiconductors. Photosynthetic NBs were constructed that link the biosynthetic pathways of Aspergillus niger with CuS nanoparticles. RESULTS In this work, NB formation was confirmed by negative values of the interaction energy, i.e., 2.31 × 108 to -5.52 × 108 kJ mol-1 for CuS-Che NBs, whereas for CuS-Bio NBs the values were -2.31 × 108 to -4.62 × 108 kJ mol-1 for CuS-Bio NBs with spherical nanoparticle interaction. For CuS-Bio NBs with nanorod interaction, it ranged from -2.3 × 107 to -3.47 × 107 kJ mol-1 . Further, the morphological changes observed by scanning electron microscopy showed the presence of the elements Cu and S in the energy-dispersive X-ray spectra and the presence of CuS bonds in Fourier transform infrared spectroscopy indicate NB formation. In addition, the quenching effect in photoluminescence studies confirmed NB formation. Production yields of amylase, phenolic compounds and pyruvate amounted to 11.2 μmol L-1, 52.5 μmol L-1 and 28 nmol μL-1, respectively, in A. niger-CuS Bio NBs on the third day of incubation in the bioreactor. Moreover, A niger cells-CuS Bio NBs had amino acids and lipid yields of 6.2 mg mL-1 and 26.5 mg L-1, respectively. Furthermore, probable mechanisms for the enhanced production of amylase, pyruvate and phenolic compounds are proposed. CONCLUSION Aspergillus niger-CuS NBs were used for the production of the amylase enzyme and value-added compounds such as pyruvate and phenolic compounds. Aspergillus niger-CuS Bio NBs showed a greater efficiency compared to A. niger-CuS Che NBs as the biologically produced CuS nanoparticles had a higher compatibility with A. niger cells. © 2022 The Authors. Journal of Chemical Technology and Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry (SCI).
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Affiliation(s)
- Uddandarao Priyanka
- Department of Microbiology and Ryan InstituteNational University of IrelandGalwayIreland
| | - Piet NL Lens
- Department of Microbiology and Ryan InstituteNational University of IrelandGalwayIreland
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21
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Čubiňák M, Varma N, Oeser P, Pokluda A, Pavlovska T, Cibulka R, Sikorski M, Tobrman T. Tuning the Photophysical Properties of Flavins by Attaching an Aryl Moiety via Direct C-C Bond Coupling. J Org Chem 2023; 88:218-229. [PMID: 36525315 DOI: 10.1021/acs.joc.2c02168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Palladium-catalyzed Suzuki reactions of brominated flavin derivatives (5-deazaflavins, alloxazines, and isoalloxazines) with boronic acids or boronic acid esters that occur readily under mild conditions were shown to be an effective tool for the synthesis of a broad range of 7/8-arylflavins. In general, the introduction of an aryl/heteroaryl group by means of a direct C-C bond has been shown to be a promising approach to tuning the photophysical properties of flavin derivatives. The aryl substituents caused a bathochromic shift in the absorption spectra of up to 52 nm and prolonged the fluorescence lifetime by up to 1 order of magnitude. Moreover, arylation of flavin derivatives decreased their ability to generate singlet oxygen.
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Affiliation(s)
- Marek Čubiňák
- Department of Organic Chemistry, University of Chemistry and Technology, Prague, Technická 5, 166 28Prague 6, Czech Republic
| | - Naisargi Varma
- Faculty of Chemistry, Adam Mickiewicz University, Uniwersytetu Poznańskiego 8, 61-614Poznań, Poland
| | - Petr Oeser
- Department of Organic Chemistry, University of Chemistry and Technology, Prague, Technická 5, 166 28Prague 6, Czech Republic
| | - Adam Pokluda
- Department of Organic Chemistry, University of Chemistry and Technology, Prague, Technická 5, 166 28Prague 6, Czech Republic
| | - Tetiana Pavlovska
- Department of Organic Chemistry, University of Chemistry and Technology, Prague, Technická 5, 166 28Prague 6, Czech Republic
| | - Radek Cibulka
- Department of Organic Chemistry, University of Chemistry and Technology, Prague, Technická 5, 166 28Prague 6, Czech Republic
| | - Marek Sikorski
- Faculty of Chemistry, Adam Mickiewicz University, Uniwersytetu Poznańskiego 8, 61-614Poznań, Poland
| | - Tomáš Tobrman
- Department of Organic Chemistry, University of Chemistry and Technology, Prague, Technická 5, 166 28Prague 6, Czech Republic
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22
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Multielectron Transfer Sensitization of Flavin Cofactor Recycling. INORG CHEM COMMUN 2023. [DOI: 10.1016/j.inoche.2023.110444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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23
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Pavlovska T, Král Lesný D, Svobodová E, Hoskovcová I, Archipowa N, Kutta RJ, Cibulka R. Tuning Deazaflavins Towards Highly Potent Reducing Photocatalysts Guided by Mechanistic Understanding - Enhancement of the Key Step by the Internal Heavy Atom Effect. Chemistry 2022; 28:e202200768. [PMID: 35538649 PMCID: PMC9541856 DOI: 10.1002/chem.202200768] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Indexed: 11/11/2022]
Abstract
Deazaflavins are well suited for reductive chemistry acting via a consecutive photo-induced electron transfer, in which their triplet state and semiquinone - the latter is formed from the former after electron transfer from a sacrificial electron donor - are key intermediates. Guided by mechanistic investigations aiming to increase intersystem crossing by the internal heavy atom effect and optimising the concentration conditions to avoid unproductive excited singlet reactions, we synthesised 5-aryldeazaflavins with Br or Cl substituents on different structural positions via a three-component reaction. Bromination of the deazaisoalloxazine core leads to almost 100 % triplet yield but causes photo-instability and enhances unproductive side reactions. Bromine on the 5-phenyl group in ortho position does not affect the photostability, increases the triplet yield, and allows its efficient usage in the photocatalytic dehalogenation of bromo- and chloroarenes with electron-donating methoxy and alkyl groups even under aerobic conditions. Reductive powers comparable to lithium are achieved.
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Affiliation(s)
- Tetiana Pavlovska
- Department of Organic ChemistryUniversity of Chemistry and Technology, PragueTechnická 5166 28Prague 6Czech Republic
| | - David Král Lesný
- Department of Organic ChemistryUniversity of Chemistry and Technology, PragueTechnická 5166 28Prague 6Czech Republic
| | - Eva Svobodová
- Department of Organic ChemistryUniversity of Chemistry and Technology, PragueTechnická 5166 28Prague 6Czech Republic
| | - Irena Hoskovcová
- Department of Inorganic ChemistryUniversity of Chemistry and Technology, PragueTechnická 5166 28Prague 6Czech Republic
| | - Nataliya Archipowa
- Institute for Biophysics and Physical BiochemistryUniversity of RegensburgD-93053RegensburgGermany
| | - Roger Jan Kutta
- Institute of Physical and Theoretical ChemistryUniversity of RegensburgD-93053RegensburgGermany
| | - Radek Cibulka
- Department of Organic ChemistryUniversity of Chemistry and Technology, PragueTechnická 5166 28Prague 6Czech Republic
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24
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Mizushima T, Oka M, Imada Y, Iida H. Low‐Voltage‐Driven Electrochemical Aerobic Oxygenation with Flavin Catalysis: Chemoselective Synthesis of Sulfoxides from Sulfides. Adv Synth Catal 2022. [DOI: 10.1002/adsc.202200351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Taiga Mizushima
- Department of Chemistry Graduate School of Natural Science and Technology Shimane University 1060 Nishikawatsu Matsue Shimane 690-8504 Japan
| | - Marina Oka
- Department of Chemistry Graduate School of Natural Science and Technology Shimane University 1060 Nishikawatsu Matsue Shimane 690-8504 Japan
| | - Yasushi Imada
- Department of Applied Chemistry Tokushima University Minamijosanjima Tokushima 770-8506 Japan
| | - Hiroki Iida
- Department of Chemistry Graduate School of Natural Science and Technology Shimane University 1060 Nishikawatsu Matsue Shimane 690-8504 Japan
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25
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Crocker LB, Lee JH, Mital S, Mills GC, Schack S, Bistrović-Popov A, Franck CO, Mela I, Kaminski CF, Christie G, Fruk L. Tuning riboflavin derivatives for photodynamic inactivation of pathogens. Sci Rep 2022; 12:6580. [PMID: 35449377 PMCID: PMC9022420 DOI: 10.1038/s41598-022-10394-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Accepted: 03/28/2022] [Indexed: 11/14/2022] Open
Abstract
The development of effective pathogen reduction strategies is required due to the rise in antibiotic-resistant bacteria and zoonotic viral pandemics. Photodynamic inactivation (PDI) of bacteria and viruses is a potent reduction strategy that bypasses typical resistance mechanisms. Naturally occurring riboflavin has been widely used in PDI applications due to efficient light-induced reactive oxygen species (ROS) release. By rational design of its core structure to alter (photo)physical properties, we obtained derivatives capable of outperforming riboflavin's visible light-induced PDI against E. coli and a SARS-CoV-2 surrogate, revealing functional group dependency for each pathogen. Bacterial PDI was influenced mainly by guanidino substitution, whereas viral PDI increased through bromination of the flavin. These observations were related to enhanced uptake and ROS-specific nucleic acid cleavage mechanisms. Trends in the derivatives' toxicity towards human fibroblast cells were also investigated to assess viable therapeutic derivatives and help guide further design of PDI agents to combat pathogenic organisms.
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Affiliation(s)
- Leander B Crocker
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge, CB3 0AS, UK
| | - Ju Hyun Lee
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge, CB3 0AS, UK
| | - Suraj Mital
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge, CB3 0AS, UK
| | - Gabrielle C Mills
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge, CB3 0AS, UK
| | - Sina Schack
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge, CB3 0AS, UK
| | - Andrea Bistrović-Popov
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge, CB3 0AS, UK
| | - Christoph O Franck
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge, CB3 0AS, UK
| | - Ioanna Mela
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge, CB3 0AS, UK
| | - Clemens F Kaminski
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge, CB3 0AS, UK
| | - Graham Christie
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge, CB3 0AS, UK
| | - Ljiljana Fruk
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge, CB3 0AS, UK.
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26
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Liao LL, Song L, Yan SS, Ye JH, Yu DG. Highly reductive photocatalytic systems in organic synthesis. TRENDS IN CHEMISTRY 2022. [DOI: 10.1016/j.trechm.2022.03.008] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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27
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Zhao Z, Niu F, Li P, Wang H, Zhang Z, Meyer GJ, Hu K. Visible Light Generation of a Microsecond Long-Lived Potent Reducing Agent. J Am Chem Soc 2022; 144:7043-7047. [PMID: 35271254 DOI: 10.1021/jacs.2c00422] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Photoexcitation of molecular radicals can produce strong reducing agents; however, the limited lifetimes of the doublet excited states preclude many applications. Herein, we propose and demonstrate a general strategy to translate a highly energetic electron from a doublet excited state to a ZrO2 insulator, thereby increasing the lifetime by about 6 orders of magnitude while maintaining a reducing potential less than -2.4 V vs SCE. Specifically, red light excitation of a salicylic acid modified perylene diimide radical anion PDI•- anchored to a ZrO2 insulator yields a ZrO2(e-)|PDI charge separated state with an ∼10 μs lifetime in 23% yield. The ZrO2(e-)s were shown to drive CO2 → CO reduction with a Re catalyst present in micromolar concentrations. More broadly, this strategy provides new opportunities to reduce important reagents and catalysts at low concentrations through diffusional electron transfer.
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Affiliation(s)
- Zijian Zhao
- Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, 220 Handan Road, Shanghai 200433, PR China
| | - Fushuang Niu
- Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, 220 Handan Road, Shanghai 200433, PR China
| | - Pengju Li
- Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, 220 Handan Road, Shanghai 200433, PR China
| | - Hanqi Wang
- Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, 220 Handan Road, Shanghai 200433, PR China
| | - Zhenghao Zhang
- Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, 220 Handan Road, Shanghai 200433, PR China
| | - Gerald J Meyer
- Department of Chemistry, University of North Carolina at Chapel Hill, Murray Hall 2202B, Chapel Hill, North Carolina 27599-3290, United States
| | - Ke Hu
- Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, 220 Handan Road, Shanghai 200433, PR China
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28
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Foja R, Walter A, Jandl C, Thyrhaug E, Hauer J, Storch G. Reduced Molecular Flavins as Single-Electron Reductants after Photoexcitation. J Am Chem Soc 2022; 144:4721-4726. [PMID: 35259294 DOI: 10.1021/jacs.1c13285] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Flavoenzymes mediate a multitude of chemical reactions and are catalytically active both in different oxidation states and in covalent adducts with reagents. The transfer of such reactivity to the organic laboratory using simplified molecular flavins is highly desirable, and such applications in (photo)oxidation reactions are already established. However, molecular flavins have not been used for the reduction of organic substrates yet, although this activity is known and well-studied for DNA photolyase enzymes. We report a catalytic method using reduced molecular flavins as photoreductants and γ-terpinene as a sacrificial reductant. Additionally, we present our design for air-stable, reduced flavin catalysts, which is based on a conformational bias strategy and circumvents the otherwise rapid reduction of O2 from air. Using our catalytic strategy, we were able to replace superstoichiometric amounts of the rare-earth reductant SmI2 in a 5-exo-trig cyclization of substituted barbituric acid derivatives. Such flavin-catalyzed reductions are anticipated to be beneficial for other transformations as well and their straightforward synthesis indicates future use in stereo- as well as site-selective transformations.
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Affiliation(s)
- Richard Foja
- Department of Chemistry, Technical University of Munich, Lichtenbergstrasse 4, 85747 Garching, Germany
| | - Alexandra Walter
- Department of Chemistry, Technical University of Munich, Lichtenbergstrasse 4, 85747 Garching, Germany
| | - Christian Jandl
- Department of Chemistry, Technical University of Munich, Lichtenbergstrasse 4, 85747 Garching, Germany
| | - Erling Thyrhaug
- Department of Chemistry, Technical University of Munich, Lichtenbergstrasse 4, 85747 Garching, Germany
| | - Jürgen Hauer
- Department of Chemistry, Technical University of Munich, Lichtenbergstrasse 4, 85747 Garching, Germany
| | - Golo Storch
- Department of Chemistry, Technical University of Munich, Lichtenbergstrasse 4, 85747 Garching, Germany
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29
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Recent advances of visible-light photocatalysis in the functionalization of organic compounds. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY C: PHOTOCHEMISTRY REVIEWS 2022. [DOI: 10.1016/j.jphotochemrev.2022.100488] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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30
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Liu Q, Huo CD, Du Z, Fu Y. Recent Progress in Organophotoredox Reaction. Org Biomol Chem 2022; 20:6721-6740. [DOI: 10.1039/d2ob00807f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In the past decade, visible light photoredox catalysis has been established as a gentle and powerful strategy for the activation of organic molecules. As an important part of it, organic...
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31
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Ilic A, Schwarz J, Johnson C, de Groot LHM, Kaufhold S, Lomoth R, Wärnmark K. Photoredox Catalysis via Consecutive 2LMCT- and 3MLCT-Excitation of an Fe(III/II)- N-Heterocyclic Carbene Complex. Chem Sci 2022; 13:9165-9175. [PMID: 36093023 PMCID: PMC9383194 DOI: 10.1039/d2sc02122f] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 07/09/2022] [Indexed: 11/21/2022] Open
Abstract
Fe-N-heterocyclic carbene (NHC) complexes attract increasing attention as photosensitisers and photoredox catalysts. Such applications generally rely on sufficiently long excited state lifetimes and efficient bimolecular quenching, which leads to there...
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Affiliation(s)
- Aleksandra Ilic
- Centre for Analysis and Synthesis (CAS), Department of Chemistry, Lund University SE-22100 Lund Sweden
| | - Jesper Schwarz
- Centre for Analysis and Synthesis (CAS), Department of Chemistry, Lund University SE-22100 Lund Sweden
| | - Catherine Johnson
- Department of Chemistry-Ångström Laboratory, Uppsala University SE-75120 Uppsala Sweden
| | - Lisa H M de Groot
- Centre for Analysis and Synthesis (CAS), Department of Chemistry, Lund University SE-22100 Lund Sweden
| | - Simon Kaufhold
- Centre for Analysis and Synthesis (CAS), Department of Chemistry, Lund University SE-22100 Lund Sweden
| | - Reiner Lomoth
- Department of Chemistry-Ångström Laboratory, Uppsala University SE-75120 Uppsala Sweden
| | - Kenneth Wärnmark
- Centre for Analysis and Synthesis (CAS), Department of Chemistry, Lund University SE-22100 Lund Sweden
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32
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Pezzetta C, Folli A, Matuszewska O, Murphy D, Davidson RWM, Bonifazi D. peri
‐Xanthenoxanthene (PXX): a Versatile Organic Photocatalyst in Organic Synthesis. Adv Synth Catal 2021. [DOI: 10.1002/adsc.202100030] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Cristofer Pezzetta
- School of Chemistry Cardiff University Park Place Cardiff CF10 3AT United Kingdom
- Dr. Reddy's Laboratories (EU) 410 Science Park, Milton Road Cambridge CB4 0PE United Kingdom
| | - Andrea Folli
- School of Chemistry Cardiff University Park Place Cardiff CF10 3AT United Kingdom
| | - Oliwia Matuszewska
- School of Chemistry Cardiff University Park Place Cardiff CF10 3AT United Kingdom
| | - Damien Murphy
- School of Chemistry Cardiff University Park Place Cardiff CF10 3AT United Kingdom
| | - Robert W. M. Davidson
- Dr. Reddy's Laboratories (EU) 410 Science Park, Milton Road Cambridge CB4 0PE United Kingdom
| | - Davide Bonifazi
- School of Chemistry Cardiff University Park Place Cardiff CF10 3AT United Kingdom
- Institute of Organic Chemistry Faculty of Chemistry University of Vienna Währinger Strasse 38 1090 Vienna Austria
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33
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Rehpenn A, Walter A, Storch G. Molecular Editing of Flavins for Catalysis. SYNTHESIS-STUTTGART 2021. [DOI: 10.1055/a-1458-2419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
AbstractThe diverse activity of flavoenzymes in organic transformations has fascinated researchers for a long time. However, when applied outside an enzyme environment, the isolated flavin cofactor only shows largely reduced activity. This highlights the importance of embedding the reactive isoalloxazine core of flavins in defined surroundings. The latter include crucial non-covalent interactions with amino acid side chains or backbone as well as controlled access to reactants such as molecular oxygen. Nevertheless, molecular flavins are increasingly applied in the organic laboratory as valuable organocatalysts. Chemical modification of the parent isoalloxazine structure is of particular interest in this context in order to achieve reactivity and selectivity in transformations, which are so far only known with flavoenzymes or even unprecedented. This review aims to give a systematic overview of the reported designed flavin catalysts and highlights the impact of each structural alteration. It is intended to serve as a source of information when comparing the performance of known catalysts, but also when designing new flavins. Over the last few decades, molecular flavin catalysis has emerged from proof-of-concept reactions to increasingly sophisticated transformations. This stimulates anticipating new flavin catalyst designs for solving contemporary challenges in organic synthesis.1 Introduction2 N1-Modification3 N3-Modification4 N5-Modification5 C6–C9-Modification6 N10-Modification7 Conclusion
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34
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Bertrams MS, Kerzig C. Converting p-terphenyl into a novel organo-catalyst for LED-driven energy and electron transfer photoreactions in water. Chem Commun (Camb) 2021; 57:6752-6755. [PMID: 34143166 DOI: 10.1039/d1cc01947c] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
p-Terphenyl is a potent photoredox catalyst under UV-irradiation. Aiming for more sustainable reaction conditions, we added two sulfonate groups to this key structure to achieve water solubility and incorporated an SO2-bridge thereby shifting the absorption spectrum towards the visible. The resulting photocatalyst shows unexpected triplet reactivity in several test reactions.
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Affiliation(s)
- Maria-Sophie Bertrams
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128 Mainz, Germany.
| | - Christoph Kerzig
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128 Mainz, Germany.
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35
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Tanimoto K, Okai H, Oka M, Ohkado R, Iida H. Aerobic Oxidative C-H Azolation of Indoles and One-Pot Synthesis of Azolyl Thioindoles by Flavin-Iodine-Coupled Organocatalysis. Org Lett 2021; 23:2084-2088. [PMID: 33656903 DOI: 10.1021/acs.orglett.1c00241] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The aerobic oxidative cross-coupling of indoles with azoles driven by flavin-iodine-coupled organocatalysis has been developed for the green synthesis of 2-(azol-1-yl)indoles. The coupled organocatalytic system enabled the one-pot three-component synthesis of 2-azolyl-3-thioindoles from indoles, azoles, and thiols in an atom-economical manner by utilizing molecular oxygen as the only sacrificial reagent.
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Affiliation(s)
- Kazumasa Tanimoto
- Department of Chemistry, Graduate School of Natural Science and Technology, Shimane University, 1060 Nishikawatsu, Matsue, 690-8504, Japan
| | - Hayaki Okai
- Department of Chemistry, Graduate School of Natural Science and Technology, Shimane University, 1060 Nishikawatsu, Matsue, 690-8504, Japan
| | - Marina Oka
- Department of Chemistry, Graduate School of Natural Science and Technology, Shimane University, 1060 Nishikawatsu, Matsue, 690-8504, Japan
| | - Ryoma Ohkado
- Department of Chemistry, Graduate School of Natural Science and Technology, Shimane University, 1060 Nishikawatsu, Matsue, 690-8504, Japan
| | - Hiroki Iida
- Department of Chemistry, Graduate School of Natural Science and Technology, Shimane University, 1060 Nishikawatsu, Matsue, 690-8504, Japan
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36
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Hartman T, Reisnerová M, Chudoba J, Svobodová E, Archipowa N, Kutta RJ, Cibulka R. Photocatalytic Oxidative [2+2] Cycloelimination Reactions with Flavinium Salts: Mechanistic Study and Influence of the Catalyst Structure. Chempluschem 2021; 86:373-386. [DOI: 10.1002/cplu.202000767] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 12/22/2020] [Indexed: 01/19/2023]
Affiliation(s)
- Tomáš Hartman
- Department of Organic Chemistry University of Chemistry and Technology, Prague Technická 5 166 28 Prague 6 Czech Republic
| | - Martina Reisnerová
- Department of Organic Chemistry University of Chemistry and Technology, Prague Technická 5 166 28 Prague 6 Czech Republic
| | - Josef Chudoba
- Central Laboratories University of Chemistry and Technology, Prague Technická 5 166 28 Prague 6 Czech Republic
| | - Eva Svobodová
- Department of Organic Chemistry University of Chemistry and Technology, Prague Technická 5 166 28 Prague 6 Czech Republic
| | - Nataliya Archipowa
- Manchester Institute of Biotechnology and School of Chemistry The University of Manchester Manchester M1 7DN United Kingdom
| | - Roger Jan Kutta
- Institute of Physical and Theoretical Chemistry University of Regensburg 93040 Regensburg Germany
| | - Radek Cibulka
- Department of Organic Chemistry University of Chemistry and Technology, Prague Technická 5 166 28 Prague 6 Czech Republic
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37
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Gui J, Cai X, Chen L, Zhou Y, Zhu W, Jiang Y, Hu M, Chen X, Hu Y, Zhang S. Facile and practical hydrodehalogenations of organic halides enabled by calcium hydride and palladium chloride. Org Chem Front 2021. [DOI: 10.1039/d1qo00758k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
For the first time, calcium hydride and palladium chloride were used to reduce a wide range of organic halides including aromatic bromides, aromatic chlorides, aromatic triflates, aliphatic bromides, aliphatic chlorides and trihalomethyl compounds.
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Affiliation(s)
- Jingjing Gui
- Jiangsu Key Laboratory of Neuropsychiatric Diseases & College of Pharmaceutical Sciences, Soochow University, Suzhou, 215123, P.R. China
| | - Xin Cai
- Jiangsu Key Laboratory of Neuropsychiatric Diseases & College of Pharmaceutical Sciences, Soochow University, Suzhou, 215123, P.R. China
| | - Lingyun Chen
- Jiangsu Key Laboratory of Neuropsychiatric Diseases & College of Pharmaceutical Sciences, Soochow University, Suzhou, 215123, P.R. China
| | - Yuxin Zhou
- Jiangsu Key Laboratory of Neuropsychiatric Diseases & College of Pharmaceutical Sciences, Soochow University, Suzhou, 215123, P.R. China
| | - Wenjing Zhu
- Jiangsu Key Laboratory of Neuropsychiatric Diseases & College of Pharmaceutical Sciences, Soochow University, Suzhou, 215123, P.R. China
| | - Yuanrui Jiang
- Jiangsu Key Laboratory of Neuropsychiatric Diseases & College of Pharmaceutical Sciences, Soochow University, Suzhou, 215123, P.R. China
| | - Min Hu
- Jiangsu Key Laboratory of Neuropsychiatric Diseases & College of Pharmaceutical Sciences, Soochow University, Suzhou, 215123, P.R. China
| | - Xiaobei Chen
- State Key Laboratory of Bioreactor Engineering, and Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science & Technology, Shanghai, 200237, P.R. China
| | - Yanwei Hu
- Jiangsu Key Laboratory of Neuropsychiatric Diseases & College of Pharmaceutical Sciences, Soochow University, Suzhou, 215123, P.R. China
| | - Shilei Zhang
- Jiangsu Key Laboratory of Neuropsychiatric Diseases & College of Pharmaceutical Sciences, Soochow University, Suzhou, 215123, P.R. China
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38
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Das A, Jobelius H, Schleinitz J, Gamboa-Ramirez S, Creste G, Kervern G, Raya J, Le Breton N, Guénet A, Boubegtiten-Fezoua Z, Grimaud L, Orio M, Rogez G, Hellwig P, Choua S, Ferlay S, Desage-El Murr M. A hybrid bioinspired catechol-alloxazine triangular nickel complex stabilizing protons and electrons. Inorg Chem Front 2021. [DOI: 10.1039/d1qi01131f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
A new class of redox-active ligands merging catechol and alloxazine structures is reported. A trimetallic triangular complex is formed upon complexation to nickel.
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Affiliation(s)
- Agnideep Das
- Université de Strasbourg, Institut de Chimie, CNRS UMR7177, 67000 Strasbourg, France
| | - Hannah Jobelius
- Université de Strasbourg, Institut de Chimie, CNRS UMR7177, 67000 Strasbourg, France
- Université de Strasbourg, Chimie de la Matière Complexe, CNRS UMR7140, 67000 Strasbourg, France
| | - Jules Schleinitz
- Laboratoire des biomolécules, LBM, Département de chimie, École normale supérieure, PSL University, Sorbonne Université, CNRS, 75005 Paris, France
| | | | - Geordie Creste
- Université de Strasbourg, Institut de Chimie, CNRS UMR7177, 67000 Strasbourg, France
| | - Gwendal Kervern
- Université de Lorraine, Faculté des Sciences, boulevard des Aiguillettes, CNRS UMR7036, BP 70239, 54506 Vandoeuvre-les-Nancy Cedex, France
| | - Jesus Raya
- Université de Strasbourg, Institut de Chimie, CNRS UMR7177, 67000 Strasbourg, France
| | - Nolwenn Le Breton
- Université de Strasbourg, Institut de Chimie, CNRS UMR7177, 67000 Strasbourg, France
| | - Aurélie Guénet
- Université de Strasbourg, Institut de Chimie, CNRS UMR7177, 67000 Strasbourg, France
| | | | - Laurence Grimaud
- Laboratoire des biomolécules, LBM, Département de chimie, École normale supérieure, PSL University, Sorbonne Université, CNRS, 75005 Paris, France
| | - Maylis Orio
- Aix Marseille Univ, CNRS, Centrale Marseille, iSm2, Marseille, France
| | - Guillaume Rogez
- Institut de Physique et Chimie des Matériaux de Strasbourg, Université de Strasbourg, CNRS, UMR 7504, F-67000 Strasbourg, France
| | - Petra Hellwig
- Université de Strasbourg, Chimie de la Matière Complexe, CNRS UMR7140, 67000 Strasbourg, France
| | - Sylvie Choua
- Université de Strasbourg, Institut de Chimie, CNRS UMR7177, 67000 Strasbourg, France
| | - Sylvie Ferlay
- Université de Strasbourg, Chimie de la Matière Complexe, CNRS UMR7140, 67000 Strasbourg, France
| | - Marine Desage-El Murr
- Université de Strasbourg, Institut de Chimie, CNRS UMR7177, 67000 Strasbourg, France
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