1
|
Devi S, Jyoti, Kiran, Wadhwa D, Sindhu J. Electro-organic synthesis: an environmentally benign alternative for heterocycle synthesis. Org Biomol Chem 2022; 20:5163-5229. [PMID: 35730661 DOI: 10.1039/d2ob00572g] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Heterocyclic compounds are considered to be one of the most established structural classes due to their extensive application in agrochemicals, pharmaceuticals and organic materials. Over the past few years, the development of heterocyclic compounds has gone through a considerable renaissance from conventional traditional methodologies to non-conventional electro-organic synthesis. Replacing metal catalysts, strong oxidants and multi-step methodologies with metal and strong oxidant-free single-step protocols has revolutionized the field of sustainable organic synthesis. Electro-organic synthesis has evolved as a scalable and sustainable approach in different synthetic protocols in an environment-benign manner. The current review outlines the recent developments in C-C, C-N, C-S and C-O/Se bond formation for heterocycle synthesis using electrochemical methods. Different synthetic strategies and their detailed mechanistic description are presented to enlighten the future applications of electrochemistry in heterocycle synthesis.
Collapse
Affiliation(s)
- Suman Devi
- Department of Chemistry, Chaudhary Bansi Lal university, Bhiwani-127021, India.
| | - Jyoti
- Department of Chemistry, Chaudhary Bansi Lal university, Bhiwani-127021, India.
| | - Kiran
- Department of Chemistry, COBS&H, CCSHAU, Hisar-125004, India.
| | - Deepak Wadhwa
- Department of Chemistry, Chaudhary Bansi Lal university, Bhiwani-127021, India.
| | - Jayant Sindhu
- Department of Chemistry, COBS&H, CCSHAU, Hisar-125004, India.
| |
Collapse
|
2
|
Yu C, Liang M, Dai SY, Cheng HJ, Ma L, Lai F, Liu XM, Li WG. Thermal stability and pathways for the oxidation of four 3-phenyl-2-propene compounds. RSC Adv 2021; 11:32654-32670. [PMID: 35493582 PMCID: PMC9042203 DOI: 10.1039/d1ra04836h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 09/03/2021] [Indexed: 11/21/2022] Open
Abstract
Cinnamaldehyde, cinnamyl alcohol, β-methylstyrene and cinnamic acid are four important biomass 3-phenyl-2-propene compounds. In the field of perfume and organic synthesis, their thermal stability and oxidation pathways deserve attention. This paper reports a new attempt to investigate the thermal stability and reactivity by a custom-designed mini closed pressure vessel test (MCPVT). The pressure and temperature behaviors were measured by MCPVT under nitrogen and oxygen atmosphere. The temperature of initial oxygen absorption (T a) and rapid oxidation (T R) were calculated. The results showed that four 3-phenyl-2-propene compounds were stable under nitrogen atmosphere. The T a of cinnamaldehyde, cinnamyl alcohol, β-methylstyrene, and cinnamic acid was 271.25 K, 292.375 K, 323.125 K, and 363.875 K, and their T R was 301.125 K, 332.75 K, 357.91 K, and 385.375 K, respectively. The oxidation reactivity order was derived to be cinnamaldehyde > cinnamyl alcohol > β-methylstyrene > cinnamic acid. The oxidation kinetics were determined using n versus time (n-t) plots, which showed a second-order reaction. Peroxide was determined by iodimetry, and the oxidation products were analyzed by gas chromatography-mass spectrometry (GC-MS). The results showed that the peroxide value of cinnamaldehyde, cinnamyl alcohol, β-methylstyrene, and cinnamic acid reached 18.88, 15.07, 9.62, and 4.24 mmol kg-1 at 373 K for 6 h, respectively. The common oxidation products of four 3-phenyl-2-propene compounds were benzaldehyde, benzoic acid, and epoxide, which resulted from the carbon-carbon double bond oxidation. The substituents' oxidation products were obtained from the oxidation of cinnamaldehyde, cinnamyl alcohol, and β-methylstyrene. In particular, the difference is that no oxidation products of the carboxyl group of cinnamic acid were detected. The common oxidation products of the four 3-phenyl-2-propene compounds were benzaldehyde, benzoic acid, and epoxide, which resulted from the carbon-carbon double bond oxidation. The substituents' oxidation products were caught in the oxidation of cinnamaldehyde, cinnamyl alcohol, and β-methylstyrene. In particular, the difference is that no oxidation products of the carboxyl group of cinnamic acid were detected. According to the complex oxidation products, important insights into the oxidation pathways were provided.
Collapse
Affiliation(s)
- Chang Yu
- College of Chemistry and Chemical Engineering, Guangxi University Nanning 530004 Guangxi China
| | - Min Liang
- College of Chemistry and Chemical Engineering, Guangxi University Nanning 530004 Guangxi China
| | - Su-Yi Dai
- College of Chemistry and Chemical Engineering, Guangxi University Nanning 530004 Guangxi China
| | - Hai-Jun Cheng
- College of Chemistry and Chemical Engineering, Guangxi University Nanning 530004 Guangxi China
| | - Li Ma
- College of Chemistry and Chemical Engineering, Guangxi University Nanning 530004 Guangxi China
| | - Fang Lai
- College of Chemistry and Chemical Engineering, Guangxi University Nanning 530004 Guangxi China
| | - Xiong-Min Liu
- College of Chemistry and Chemical Engineering, Guangxi University Nanning 530004 Guangxi China
| | - Wei-Guang Li
- College of Chemistry and Chemical Engineering, Guangxi University Nanning 530004 Guangxi China
| |
Collapse
|
3
|
Medcalf Z, Moeller KD. Anodic Olefin Coupling Reactions: Elucidating Radical Cation Mechanisms and the Interplay between Cyclization and Second Oxidation Steps. CHEM REC 2021; 21:2442-2452. [PMID: 34117713 DOI: 10.1002/tcr.202100118] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 05/18/2021] [Indexed: 12/13/2022]
Abstract
Anodic olefin coupling reactions generate new bonds and ring skeletons through a net two electron process that reverses the polarity of a known, electron-rich functional group. While much of the early work on the mechanism of these reactions focused on the initial oxidation and cyclization steps of the process, the second oxidation step also plays a central role in determining the success of the reaction. Evidence supporting this observation is presented, along with evidence that optimization of this second oxidation step is not enough to pull a poor cyclization to the desired product. Successful cyclization reactions require optimization of both processes.
Collapse
Affiliation(s)
- Zach Medcalf
- Department of Chemistry, Washington University in Saint Louis, One Brookings Drive, 63130-4899, St Louis, MO, USA
| | - Kevin D Moeller
- Department of Chemistry, Washington University in Saint Louis, One Brookings Drive, 63130-4899, St Louis, MO, USA
| |
Collapse
|
4
|
|
5
|
Dwivedi V, Kalsi D, Sundararaju B. Electrochemical‐/Photoredox Aspects of Transition Metal‐Catalyzed Directed C−H Bond Activation. ChemCatChem 2019. [DOI: 10.1002/cctc.201900680] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Vikas Dwivedi
- Department of ChemistryIndian Institute of Technology Kanpur Kanpur Uttar Pradesh 208 016 India
| | - Deepti Kalsi
- Department of ChemistryIndian Institute of Technology Kanpur Kanpur Uttar Pradesh 208 016 India
| | - Basker Sundararaju
- Department of ChemistryIndian Institute of Technology Kanpur Kanpur Uttar Pradesh 208 016 India
| |
Collapse
|
6
|
Kärkäs MD. Electrochemical strategies for C-H functionalization and C-N bond formation. Chem Soc Rev 2018; 47:5786-5865. [PMID: 29911724 DOI: 10.1039/c7cs00619e] [Citation(s) in RCA: 588] [Impact Index Per Article: 98.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Conventional methods for carrying out carbon-hydrogen functionalization and carbon-nitrogen bond formation are typically conducted at elevated temperatures, and rely on expensive catalysts as well as the use of stoichiometric, and perhaps toxic, oxidants. In this regard, electrochemical synthesis has recently been recognized as a sustainable and scalable strategy for the construction of challenging carbon-carbon and carbon-heteroatom bonds. Here, electrosynthesis has proven to be an environmentally benign, highly effective and versatile platform for achieving a wide range of nonclassical bond disconnections via generation of radical intermediates under mild reaction conditions. This review provides an overview on the use of anodic electrochemical methods for expediting the development of carbon-hydrogen functionalization and carbon-nitrogen bond formation strategies. Emphasis is placed on methodology development and mechanistic insight and aims to provide inspiration for future synthetic applications in the field of electrosynthesis.
Collapse
Affiliation(s)
- Markus D Kärkäs
- Department of Chemistry, Organic Chemistry, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden.
| |
Collapse
|
7
|
Zhang L, Zhang Z, Hong J, Yu J, Zhang J, Mo F. Oxidant-Free C(sp 2)-H Functionalization/C-O Bond Formation: A Kolbe Oxidative Cyclization Process. J Org Chem 2018; 83:3200-3207. [PMID: 29471627 DOI: 10.1021/acs.joc.8b00089] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
An anodic oxidation/cyclization of 2-arylbenzoic acids for the synthesis of dibenzopyranones has been developed. The reaction proceeds at room temperature with no oxidant or electrolyte required and exhibits a high atom economy with H2 being the only byproduct. A series of dibenzopyranones was obtained in good to excellent yields. Urolithins A, B, and C are formally synthesized by adopting this method as a key step to demonstrate its synthetic utility.
Collapse
Affiliation(s)
- Lei Zhang
- Department of Energy and Resources Engineering, College of Engineering , Peking University , Beijing 100871 , China
| | - Zhenxing Zhang
- Department of Energy and Resources Engineering, College of Engineering , Peking University , Beijing 100871 , China
| | - Junting Hong
- Department of Energy and Resources Engineering, College of Engineering , Peking University , Beijing 100871 , China
| | - Jian Yu
- Department of Energy and Resources Engineering, College of Engineering , Peking University , Beijing 100871 , China
| | - Jianning Zhang
- Department of Energy and Resources Engineering, College of Engineering , Peking University , Beijing 100871 , China
| | - Fanyang Mo
- Department of Energy and Resources Engineering, College of Engineering , Peking University , Beijing 100871 , China
| |
Collapse
|
8
|
Okada Y, Chiba K. Redox-Tag Processes: Intramolecular Electron Transfer and Its Broad Relationship to Redox Reactions in General. Chem Rev 2017; 118:4592-4630. [PMID: 29218989 DOI: 10.1021/acs.chemrev.7b00400] [Citation(s) in RCA: 114] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Explosive growth in the use of open shell reactivity, including neutral radicals and radical ions, in the field of synthetic organic chemistry has been observed in the past decade, particularly since the advent of ruthenium complexes in 2008. These complexes generally induce single-electron transfer (SET) processes via visible-light absorption. Additionally, recent significant advancements in organic electrochemistry involving SET processes to provide open shell reactivity offer a complementary method to traditional polarity-driven reactions described by two-electron transfer processes. In this Review, we highlight the importance of intramolecular SET processes in the field of synthetic organic chemistry, which seem to be more elusive than the intermolecular versions, since they are net redox-neutral and thus cannot simply be regarded as oxidations or reductions. Such intramolecular SET processes can rationally be understood in combination with concomitant bond formations and/or cleavages, and are regulated by a structural motif that we call a "redox tag." In order to describe modern radical-driven reactions involving SET processes, we focus on a classical formalism in which electrons are treated as particles rather than waves, which offers a practical yet powerful approach to explain and/or predict synthetic outcomes.
Collapse
Affiliation(s)
- Yohei Okada
- Department of Chemical Engineering , Tokyo University of Agriculture and Technology , 2-24-16 Naka-cho , Koganei, Tokyo 184-8588 , Japan
| | - Kazuhiro Chiba
- Department of Applied Biological Science , Tokyo University of Agriculture and Technology , 3-5-8 Saiwai-cho , Fuchu, Tokyo 183-8509 , Japan
| |
Collapse
|
9
|
Yan M, Kawamata Y, Baran PS. Synthetic Organic Electrochemical Methods Since 2000: On the Verge of a Renaissance. Chem Rev 2017; 117:13230-13319. [PMID: 28991454 PMCID: PMC5786875 DOI: 10.1021/acs.chemrev.7b00397] [Citation(s) in RCA: 1892] [Impact Index Per Article: 270.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Electrochemistry represents one of the most intimate ways of interacting with molecules. This review discusses advances in synthetic organic electrochemistry since 2000. Enabling methods and synthetic applications are analyzed alongside innate advantages as well as future challenges of electroorganic chemistry.
Collapse
Affiliation(s)
| | | | - Phil S. Baran
- Department of Chemistry, The Scripps Research Institute, La Jolla, California 92037, United States
| |
Collapse
|
10
|
Affiliation(s)
- Yangye Jiang
- Beijing Key Laboratory of Environmental and Viral Oncology, College of Life Science & Bioengineering, Beijing University of Technology, Beijing 100124, China
| | - Kun Xu
- Beijing Key Laboratory of Environmental and Viral Oncology, College of Life Science & Bioengineering, Beijing University of Technology, Beijing 100124, China
- College of Chemistry and Pharmaceutical Engineering, Nanyang Normal University, Nanyang, Henan 473061, China
| | - Chengchu Zeng
- Beijing Key Laboratory of Environmental and Viral Oncology, College of Life Science & Bioengineering, Beijing University of Technology, Beijing 100124, China
| |
Collapse
|
11
|
Abstract
The preparation and transformation of heterocyclic structures have always been of great interest in organic chemistry. Electrochemical technique provides a versatile and powerful approach to the assembly of various heterocyclic structures. In this review, we examine the advance in relation to the electrochemical construction of heterocyclic compounds published since 2000 via intra- and intermolecular cyclization reactions.
Collapse
Affiliation(s)
- Yangye Jiang
- Beijing Key Laboratory of Environmental and Viral Oncology, College of Life Science & Bioengineering , Beijing University of Technology , Beijing 100124 , China
| | - Kun Xu
- Beijing Key Laboratory of Environmental and Viral Oncology, College of Life Science & Bioengineering , Beijing University of Technology , Beijing 100124 , China.,College of Chemistry and Pharmaceutical Engineering , Nanyang Normal University , Nanyang , Henan 473061 , China
| | - Chengchu Zeng
- Beijing Key Laboratory of Environmental and Viral Oncology, College of Life Science & Bioengineering , Beijing University of Technology , Beijing 100124 , China
| |
Collapse
|
12
|
Feng R, Smith JA, Moeller KD. Anodic Cyclization Reactions and the Mechanistic Strategies That Enable Optimization. Acc Chem Res 2017; 50:2346-2352. [PMID: 28858480 DOI: 10.1021/acs.accounts.7b00287] [Citation(s) in RCA: 145] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Oxidation reactions are powerful tools for synthesis because they allow us to reverse the polarity of electron-rich functional groups, generate highly reactive intermediates, and increase the functionality of molecules. For this reason, oxidation reactions have been and continue to be the subject of intense study. Central to these efforts is the development of mechanism-based strategies that allow us to think about the reactive intermediates that are frequently central to the success of the reactions and the mechanistic pathways that those intermediates trigger. For example, consider oxidative cyclization reactions that are triggered by the removal of an electron from an electron-rich olefin and lead to cyclic products that are functionalized for further elaboration. For these reactions to be successful, the radical cation intermediate must first be generated using conditions that limit its polymerization and then channeled down a productive desired pathway. Following the cyclization, a second oxidation step is necessary for product formation, after which the resulting cation must be quenched in a controlled fashion to avoid undesired elimination reactions. Problems can arise at any one or all of these steps, a fact that frequently complicates reaction optimization and can discourage the development of new transformations. Fortunately, anodic electrochemistry offers an outstanding opportunity to systematically probe the mechanism of oxidative cyclization reactions. The use of electrochemical methods allows for the generation of radical cations under neutral conditions in an environment that helps prevent polymerization of the intermediate. Once the intermediates have been generated, a series of "telltale indicators" can be used to diagnose which step in an oxidative cyclization is problematic for less successful transformation. A set of potential solutions to address each type of problem encountered has been developed. For example, problems with the initial cyclization reaction leading to either polymerization of the radical cation, elimination of a proton from or solvent trapping of that intermediate, or solvent trapping of the radical cation can be identified in the proton NMR spectrum of the crude reaction material. Such an NMR spectrum shows retention of the trapping group. The problems can be addressed by tuning the radical cation, altering the trapping group, or channeling the reactive intermediate down a radical pathway. Specific examples each are shown in this Account. Problems with the second oxidation step can be identified by poor current efficiency or general decomposition in spite of cyclic voltammetry evidence for a rapid cyclization. Solutions involve improving the oxidation conditions for the radical after cyclization by either the addition of a properly placed electron-donating group in the substrate or an increase in the concentration of electrolyte in the reaction (a change that stabilizes the cation generated from the second oxidation step). Problems with the final cation typically lead to overoxidation. Solutions to this problem require an approach that either slows down elimination side reactions or changes the reaction conditions so that the cation can be quickly trapped in an irreversible fashion. Again, this Account highlights these strategies along with the specific experimental protocols utilized.
Collapse
Affiliation(s)
- Ruozhu Feng
- Department of Chemistry, Washington University, St. Louis, Missouri 63130, United States
| | - Jake A. Smith
- Department of Chemistry, Washington University, St. Louis, Missouri 63130, United States
| | - Kevin D. Moeller
- Department of Chemistry, Washington University, St. Louis, Missouri 63130, United States
| |
Collapse
|