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Abstract
Nitroxides, also known as nitroxyl radicals, are long-lived or stable radicals with the general structure R1R2N-O•. The spin distribution over the nitroxide N and O atoms contributes to the thermodynamic stability of these radicals. The presence of bulky N-substituents R1 and R2 prevents nitroxide radical dimerization, ensuring their kinetic stability. Despite their reactivity toward various transient C radicals, some nitroxides can be easily stored under air at room temperature. Furthermore, nitroxides can be oxidized to oxoammonium salts (R1R2N═O+) or reduced to anions (R1R2N-O-), enabling them to act as valuable oxidants or reductants depending on their oxidation state. Therefore, they exhibit interesting reactivity across all three oxidation states. Due to these fascinating properties, nitroxides find extensive applications in diverse fields such as biochemistry, medicinal chemistry, materials science, and organic synthesis. This review focuses on the versatile applications of nitroxides in organic synthesis. For their use in other important fields, we will refer to several review articles. The introductory part provides a brief overview of the history of nitroxide chemistry. Subsequently, the key methods for preparing nitroxides are discussed, followed by an examination of their structural diversity and physical properties. The main portion of this review is dedicated to oxidation reactions, wherein parent nitroxides or their corresponding oxoammonium salts serve as active species. It will be demonstrated that various functional groups (such as alcohols, amines, enolates, and alkanes among others) can be efficiently oxidized. These oxidations can be carried out using nitroxides as catalysts in combination with various stoichiometric terminal oxidants. By reducing nitroxides to their corresponding anions, they become effective reducing reagents with intriguing applications in organic synthesis. Nitroxides possess the ability to selectively react with transient radicals, making them useful for terminating radical cascade reactions by forming alkoxyamines. Depending on their structure, alkoxyamines exhibit weak C-O bonds, allowing for the thermal generation of C radicals through reversible C-O bond cleavage. Such thermally generated C radicals can participate in various radical transformations, as discussed toward the end of this review. Furthermore, the application of this strategy in natural product synthesis will be presented.
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Affiliation(s)
- Dirk Leifert
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität, Corrensstrasse 40, 48149 Münster, Germany
| | - Armido Studer
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität, Corrensstrasse 40, 48149 Münster, Germany
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Wan YB, Hu XP. Highly Enantioselective Iridium-Catalyzed Hydrogenation of o-Amidophenyl Ketones Enabled by 1,2-Diphenylethylenediamine-Derived P,N,N-Ligands with Tertiary Amine Terminus. Org Lett 2022; 24:5797-5801. [PMID: 35912453 DOI: 10.1021/acs.orglett.2c02316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A readily available and highly modular class of chiral P,N,N-ligands based on a structurally flexible nonchiral phosphine-amine framework with an optically active 1,2-diphenylethylenediamine unit bearing a tertiary amine terminus as the chiral source have been developed and successfully applied in the Ir-catalyzed asymmetric hydrogenation of o-amidophenyl ketones. These tridentate P,N,N-ligands exhibited excellent activity, enantioselectivity, and substrate tolerance, thus furnishing various optically active o-amidobenzhydrols in up to 99% yields and with >99% ee. The utility of this protocol has been proven by synthetically diverse product transformation and highly enantioselective production of a rice plant growth regulator, (S)-inabenfide.
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Affiliation(s)
- Yin-Bo Wan
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiang-Ping Hu
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China
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Li SJ, Fang W, Richardson JO, Fang DC. Tunnelling assisted hydrogen elimination mechanisms of FeCl 3/TEMPO. Chem Commun (Camb) 2021; 58:565-568. [PMID: 34909806 DOI: 10.1039/d1cc06035j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Metal-TEMPO hybrids are a family of novel and promising catalysts for aerobic oxidation of alcohols, yet the underlying mechanisms have not been understood theoretically. Using density functional theory, we probe the hydrogen abstraction mechanisms of FeCl3/TEMPO on two characteristic substrates, 9,10-dihydroanthracene and benzyl alcohol. We found that the low spin state of FeCl3/TEMPO is more favourable, and that the N atom is the preferred hydrogen acceptor. Moreover, dispersion interactions assist the reaction, as well as nuclear tunnelling, which even at room temperature can speed up the process by almost two orders of magnitude. We also predict that pronounced kinetic isotope effects (KIE) could be observed due to tunnelling. Our findings provide insights into improving the substrate scope and the development of new transformations for the FeCl3/TEMPO system.
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Affiliation(s)
- Shi-Jun Li
- College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China. .,Green Catalysis Center, and College of Chemistry, Zhengzhou University, 100 Science Avenue, Zhengzhou, Henan, 450001, P. R. China
| | - Wei Fang
- Laboratory for Physical Chemistry, ETH Zurich, Zurich 8093, Switzerland. .,State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical Computational Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, P. R. China
| | | | - De-Cai Fang
- College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China.
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Beejapur HA, Zhang Q, Hu K, Zhu L, Wang J, Ye Z. TEMPO in Chemical Transformations: From Homogeneous to Heterogeneous. ACS Catal 2019. [DOI: 10.1021/acscatal.8b05001] [Citation(s) in RCA: 88] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Hazi Ahmad Beejapur
- State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, Zhejiang Province Key Laboratory of Biofuel, Biodiesel Laboratory of China Petroleum and Chemical Industry Federation, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, P. R. China
| | - Qi Zhang
- State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, Zhejiang Province Key Laboratory of Biofuel, Biodiesel Laboratory of China Petroleum and Chemical Industry Federation, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, P. R. China
| | - Kecheng Hu
- State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, Zhejiang Province Key Laboratory of Biofuel, Biodiesel Laboratory of China Petroleum and Chemical Industry Federation, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, P. R. China
| | - Li Zhu
- State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, Zhejiang Province Key Laboratory of Biofuel, Biodiesel Laboratory of China Petroleum and Chemical Industry Federation, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, P. R. China
| | - Jianli Wang
- State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, Zhejiang Province Key Laboratory of Biofuel, Biodiesel Laboratory of China Petroleum and Chemical Industry Federation, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, P. R. China
| | - Zhibin Ye
- Department of Chemical and Materials Engineering, Concordia University, Montreal, Quebec H3G 1M8, Canada
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Recent developments in non-enzymatic catalytic oxidative kinetic resolution of secondary alcohols. Tetrahedron 2018. [DOI: 10.1016/j.tet.2018.05.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Efficient aerobic oxidation of alcohols to aldehydes and ketones using a ruthenium carbonyl complex of a tert-butyl-substituted tetramethylcyclopentadienyl ligand as catalyst. TRANSIT METAL CHEM 2018. [DOI: 10.1007/s11243-018-0251-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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Mamillapalli NC, Sekar G. Enantioselective Synthesis of α-Hydroxy Amides and β-Amino Alcohols from α-Keto Amides. Chemistry 2015; 21:18584-8. [DOI: 10.1002/chem.201503569] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Indexed: 11/11/2022]
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Murakami K, Sasano Y, Tomizawa M, Shibuya M, Kwon E, Iwabuchi Y. Highly Enantioselective Organocatalytic Oxidative Kinetic Resolution of Secondary Alcohols Using Chiral Alkoxyamines as Precatalysts: Catalyst Structure, Active Species, and Substrate Scope. J Am Chem Soc 2014; 136:17591-600. [DOI: 10.1021/ja509766f] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Keiichi Murakami
- Department of Organic Chemistry,
Graduate School of Pharmaceutical
Sciences and ‡Research and Analytical Center for Giant Molecules, Graduate School
of Science, Tohoku University, 6-3 Aoba, Aramaki, Aoba-ku, Sendai 980-8578, Japan
| | - Yusuke Sasano
- Department of Organic Chemistry,
Graduate School of Pharmaceutical
Sciences and ‡Research and Analytical Center for Giant Molecules, Graduate School
of Science, Tohoku University, 6-3 Aoba, Aramaki, Aoba-ku, Sendai 980-8578, Japan
| | - Masaki Tomizawa
- Department of Organic Chemistry,
Graduate School of Pharmaceutical
Sciences and ‡Research and Analytical Center for Giant Molecules, Graduate School
of Science, Tohoku University, 6-3 Aoba, Aramaki, Aoba-ku, Sendai 980-8578, Japan
| | - Masatoshi Shibuya
- Department of Organic Chemistry,
Graduate School of Pharmaceutical
Sciences and ‡Research and Analytical Center for Giant Molecules, Graduate School
of Science, Tohoku University, 6-3 Aoba, Aramaki, Aoba-ku, Sendai 980-8578, Japan
| | - Eunsang Kwon
- Department of Organic Chemistry,
Graduate School of Pharmaceutical
Sciences and ‡Research and Analytical Center for Giant Molecules, Graduate School
of Science, Tohoku University, 6-3 Aoba, Aramaki, Aoba-ku, Sendai 980-8578, Japan
| | - Yoshiharu Iwabuchi
- Department of Organic Chemistry,
Graduate School of Pharmaceutical
Sciences and ‡Research and Analytical Center for Giant Molecules, Graduate School
of Science, Tohoku University, 6-3 Aoba, Aramaki, Aoba-ku, Sendai 980-8578, Japan
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Das OINDRILA, Paine TAPANKANTI. Copper Catalysts for Aerobic Oxidation of Alcohols. TRANSITION METAL CATALYSIS IN AEROBIC ALCOHOL OXIDATION 2014. [DOI: 10.1039/9781782621652-00040] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Inspired by reactions catalyzed by galactose oxidase, a copper-containing enzyme, extensive studies were carried out on copper-based catalysts for alcohol oxidation using O2 as the terminal oxidant. Significant advances have been made towards the development of homogeneous and heterogeneous copper catalysts. These advances over the past decades are reviewed.
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Affiliation(s)
- OINDRILA Das
- Department of Inorganic Chemistry, Indian Association for the Cultivation of Science 2A&2B Raja S. C. Mullick Road, Jadavpur Kolkata 700032 India
| | - TAPAN KANTI Paine
- Department of Inorganic Chemistry, Indian Association for the Cultivation of Science 2A&2B Raja S. C. Mullick Road, Jadavpur Kolkata 700032 India
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Ahlburg A, Lindhardt AT, Taaning RH, Modvig AE, Skrydstrup T. An Air-Tolerant Approach to the Carbonylative Suzuki–Miyaura Coupling: Applications in Isotope Labeling. J Org Chem 2013; 78:10310-8. [DOI: 10.1021/jo401696c] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Andreas Ahlburg
- Center for Insoluble
Protein Structures (inSPIN), Department of Chemistry and
the Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Gustav
Wieds Vej 14, 8000 Aarhus C, Central Denmark Region, Denmark
| | - Anders T. Lindhardt
- Interdisciplinary Nanoscience Center (iNANO), Biological & Chemical Engineering, Department of Engineering, Aarhus University, Findlandsgade 22, 8200 Aarhus N, Denmark
| | - Rolf. H. Taaning
- Center for Insoluble
Protein Structures (inSPIN), Department of Chemistry and
the Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Gustav
Wieds Vej 14, 8000 Aarhus C, Central Denmark Region, Denmark
| | - Amalie E. Modvig
- Center for Insoluble
Protein Structures (inSPIN), Department of Chemistry and
the Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Gustav
Wieds Vej 14, 8000 Aarhus C, Central Denmark Region, Denmark
| | - Troels Skrydstrup
- Center for Insoluble
Protein Structures (inSPIN), Department of Chemistry and
the Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Gustav
Wieds Vej 14, 8000 Aarhus C, Central Denmark Region, Denmark
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Allen SE, Walvoord RR, Padilla-Salinas R, Kozlowski MC. Aerobic copper-catalyzed organic reactions. Chem Rev 2013; 113:6234-458. [PMID: 23786461 PMCID: PMC3818381 DOI: 10.1021/cr300527g] [Citation(s) in RCA: 1228] [Impact Index Per Article: 111.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Scott E. Allen
- Department of Chemistry, Roy and Diana Vagelos Laboratories, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Ryan R. Walvoord
- Department of Chemistry, Roy and Diana Vagelos Laboratories, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Rosaura Padilla-Salinas
- Department of Chemistry, Roy and Diana Vagelos Laboratories, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Marisa C. Kozlowski
- Department of Chemistry, Roy and Diana Vagelos Laboratories, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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Yamasaki R, Ikeda H, Masu H, Azumaya I, Saito S. Synthesis and properties of phenylogous amides. Tetrahedron 2012. [DOI: 10.1016/j.tet.2012.07.084] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Tebben L, Studer A. Nitroxides: applications in synthesis and in polymer chemistry. Angew Chem Int Ed Engl 2011; 50:5034-68. [PMID: 21538729 DOI: 10.1002/anie.201002547] [Citation(s) in RCA: 505] [Impact Index Per Article: 38.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2010] [Indexed: 01/23/2023]
Abstract
This Review describes the application of nitroxides to synthesis and polymer chemistry. The synthesis and physical properties of nitroxides are discussed first. The largest section focuses on their application as stoichiometric and catalytic oxidants in organic synthesis. The oxidation of alcohols and carbanions, as well as oxidative C-C bond-forming reactions are presented along with other typical oxidative transformations. A section is also dedicated to the extensive use of nitroxides as trapping reagents for C-centered radicals in radical chemistry. Alkoxyamines derived from nitroxides are shown to be highly useful precursors of C-centered radicals in synthesis and also in polymer chemistry. The last section discusses the basics of nitroxide-mediated radical polymerization (NMP) and also highlights new developments in the synthesis of complex polymer architectures.
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Affiliation(s)
- Ludger Tebben
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität, Corrensstrasse 40, 48149 Münster, Germany
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Gartshore CJ, Lupton DW. Readily Accessible Oxazolidine Nitroxyl Radicals: Bifunctional Cocatalysts for Simplified Copper Based Aerobic Oxidation. Adv Synth Catal 2010. [DOI: 10.1002/adsc.201000627] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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17
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Yin L, Jia X, Li XS, Chan AS. Simply air: Vanadium-catalyzed oxidative kinetic resolution of methyl o-chloromandelate by ambient air. CHINESE CHEM LETT 2010. [DOI: 10.1016/j.cclet.2010.03.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Wang CJ, Xu ZP, Wang X, Teng HL. Axial [6,6′-(2,4-pentadioxy)]-1,1′-biphenyl-2,2′-diamine (PD-BIPHAM): practical synthesis and applications in asymmetric hydrogenation. Tetrahedron 2010. [DOI: 10.1016/j.tet.2010.03.073] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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