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Zheng Y, Chen C, Lu Y, Huang S. Recent advances in electrochemically enabled construction of indoles from non-indole-based substrates. Chem Commun (Camb) 2024; 60:8516-8525. [PMID: 39036971 DOI: 10.1039/d4cc03040k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/23/2024]
Abstract
Indole motifs are important heterocycles found in natural products, pharmaceuticals, agricultural chemicals, and materials. Although there are well-established classical name reactions for indole synthesis, these transformations often require harsh reaction conditions, have a limited substrate scope, and exhibit poor regioselectivity. As a result, organic synthesis chemists have been exploring efficient and practical methods, leading to numerous strategies for synthesizing a variety of functionalized indoles. In recent years, electrochemistry has emerged as an environmentally friendly and sustainable synthetic tool, with widespread applications in organic synthesis. This technology allows for elegant synthetic routes to be developed for the construction of indoles under external oxidant-free conditions. This feature article specifically focuses on recent advancements in indole synthesis from non-indole-based substrates, as well as the mechanisms underlying these transformations.
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Affiliation(s)
- Yu Zheng
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, International Innovation Center for Forest Chemicals and Materials, Nanjing Forestry University, Nanjing 210037, China.
| | - Chunxi Chen
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, International Innovation Center for Forest Chemicals and Materials, Nanjing Forestry University, Nanjing 210037, China.
| | - Yanju Lu
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, International Innovation Center for Forest Chemicals and Materials, Nanjing Forestry University, Nanjing 210037, China.
| | - Shenlin Huang
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, International Innovation Center for Forest Chemicals and Materials, Nanjing Forestry University, Nanjing 210037, China.
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Chang X, Chen X, Lu S, Zhao Y, Ma Y, Zhang D, Yang L, Sun P. Electrochemical [3+2] Cycloaddition of Anilines and 1,3‐Dicarbonyl Compounds: Construction of Multisubstituted Indoles. Adv Synth Catal 2022. [DOI: 10.1002/adsc.202200488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Xiaoqiang Chang
- China Academy of Chinese Medical Sciences Institute of Chinese Materia Medica CHINA
| | - Xingyu Chen
- Institute of Chinese Materia Medica and Artemisinin Research Center, China Academy of Chinese Medical Sciences, Beijing 100700, P. R. China CHINA
| | - Sixian Lu
- China Academy of Chinese Medical Sciences Institute of Chinese Materia Medica CHINA
| | - Yifan Zhao
- Institute of Chinese Materia Medica and Artemisinin Research Center, China Academy of Chinese Medical Sciences, Beijing 100700, P. R. China CHINA
| | | | | | - Lan Yang
- China Academy of Chinese Medical Sciences Institute of Chinese Materia Medica CHINA
| | - Peng Sun
- China Academy of Chinese Medical Sciences Institute of Chinese Materia Medica CHINA
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Willand-Charnley R, Paris TJ. Modern Synthesis and Chemistry of Stabilized Ketene N,O-Acetals. SYNTHESIS-STUTTGART 2022. [DOI: 10.1055/a-1713-8481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
AbstractKetene N,O-acetals are robust and versatile synthons. Herein, we outline the synthesis of stable ketene N,O-acetals in the twenty-first century. In addition, we review recent developments in the chemistry of ketene N,O-acetals, as it applies to the vinylogous Mukaiyama aldol reaction, electrolysis, and pericyclic transformations. While dated reports rely on in situ use, modern methods of ketene N,O-acetal synthesis are heavily oriented towards producing products with high ‘bench’ stability; moreover, in the present century, chemists typically enhance the stability of ketene N,O-acetals by positioning an electron-withdrawing group at the β-terminus or at the N-position. As propitious substrates in the vinylogous Mukaiyama aldol reaction, ketene N,O-acetals readily provide polyketide adducts with high regioselectivity. When exposed to electrolysis conditions, the title functional group forms a reactive radical cation and cleanly couples with a variety of activated olefins. Given their electron-rich nature, ketene N,O-acetals act as facile substrates in several rearrangement reactions; further, ketene N,O-acetals reserve the ability to act as either dienophiles or dienes in Diels–Alder reactions. Lastly, ketene N,O-acetals are seemingly more stable than their O,O-counterparts and more reactive than analogous N,N- or S,S-acetals; these factors, in combination, make ketene N,O-acetals advantageous substitutes for other ketene acetal homologues.1 Introduction2 Select Methods of Stabilization-Oriented Ketene N,O-Acetal Synthesis3 Ketene N,O-Acetals in the Vinylogous Mukaiyama Aldol Reaction4 Ketene N,O-Acetals in Anodic Coupling and Electrochemical Oxidation Reactions5 Rearrangement and Diels–Alder Reactions of Ketene N,O-Acetals6 Conclusions, Perspectives, and Directions
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Affiliation(s)
| | - Timothy J. Paris
- Medicinal Chemistry Knowledge Center, Stanford ChEM-H, Stanford University
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Chen X, Huang Z, Xu J. Catalyst‐Free Electrophilic Ring Expansion of
N
‐Unprotected Aziridines with
α
‐Oxoketenes to Efficient Access 2‐Alkylidene‐1,3‐Oxazolidines. Adv Synth Catal 2021. [DOI: 10.1002/adsc.202100320] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Xingpeng Chen
- State Key Laboratory of Chemical Resource Engineering, Department of Organic Chemistry, College of Chemistry Beijing University of Chemical Technology Beijing 100029 People's Republic of China
| | - Zhengshuo Huang
- State Key Laboratory of Chemical Resource Engineering, Department of Organic Chemistry, College of Chemistry Beijing University of Chemical Technology Beijing 100029 People's Republic of China
| | - Jiaxi Xu
- State Key Laboratory of Chemical Resource Engineering, Department of Organic Chemistry, College of Chemistry Beijing University of Chemical Technology Beijing 100029 People's Republic of China
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Yu Y, Zhong J, Xu K, Yuan Y, Ye K. Recent Advances in the Electrochemical Synthesis and Functionalization of Indole Derivatives. Adv Synth Catal 2020. [DOI: 10.1002/adsc.201901520] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Yi Yu
- Key Laboratory for Molecule Synthesis and Function Discovery (Fujian Province University), College of ChemistryFuzhou University Fuzhou 350116 People's Republic of China
| | - Jun‐Song Zhong
- Key Laboratory for Molecule Synthesis and Function Discovery (Fujian Province University), College of ChemistryFuzhou University Fuzhou 350116 People's Republic of China
| | - Kai Xu
- Key Laboratory for Molecule Synthesis and Function Discovery (Fujian Province University), College of ChemistryFuzhou University Fuzhou 350116 People's Republic of China
| | - Yaofeng Yuan
- Key Laboratory for Molecule Synthesis and Function Discovery (Fujian Province University), College of ChemistryFuzhou University Fuzhou 350116 People's Republic of China
| | - Ke‐Yin Ye
- Key Laboratory for Molecule Synthesis and Function Discovery (Fujian Province University), College of ChemistryFuzhou University Fuzhou 350116 People's Republic of China
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Yadav D, Shukla G, Ansari MA, Srivastava A, Singh MS. Chemoselective one-pot access to benzo[e]indole-4,5-diones and naphtho[2,1-b]thiophene-4,5-diones via copper-catalyzed oxidative [3 + 2] annulation of α-oxoketene N,S-acetals/β-ketothioamides with α-/β-naphthols. Tetrahedron 2018. [DOI: 10.1016/j.tet.2018.08.026] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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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.
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Affiliation(s)
- Markus D Kärkäs
- Department of Chemistry, Organic Chemistry, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden.
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Gao X, Wang P, Zeng L, Tang S, Lei A. Cobalt(II)-Catalyzed Electrooxidative C–H Amination of Arenes with Alkylamines. J Am Chem Soc 2018. [DOI: 10.1021/jacs.7b13049] [Citation(s) in RCA: 231] [Impact Index Per Article: 38.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Xinlong Gao
- The Institute for Advanced Studies (IAS), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, People’s Republic of China
| | - Pan Wang
- The Institute for Advanced Studies (IAS), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, People’s Republic of China
| | - Li Zeng
- The Institute for Advanced Studies (IAS), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, People’s Republic of China
| | - Shan Tang
- The Institute for Advanced Studies (IAS), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, People’s Republic of China
| | - Aiwen Lei
- The Institute for Advanced Studies (IAS), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, People’s Republic of China
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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.
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Affiliation(s)
| | | | - Phil S. Baran
- Department of Chemistry, The Scripps Research Institute, La Jolla, California 92037, United States
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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
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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.
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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
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Dar'in DV, Lobanov PS. Push-pull enamines in the synthesis of fused azaheterocycles. RUSSIAN CHEMICAL REVIEWS 2015. [DOI: 10.1070/rcr4528] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Francke R. Recent advances in the electrochemical construction of heterocycles. Beilstein J Org Chem 2014; 10:2858-73. [PMID: 25550752 PMCID: PMC4273298 DOI: 10.3762/bjoc.10.303] [Citation(s) in RCA: 94] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2014] [Accepted: 11/18/2014] [Indexed: 01/09/2023] Open
Abstract
Due to the fact that the major portion of pharmaceuticals and agrochemicals contains heterocyclic units and since the overall number of commercially used heterocyclic compounds is steadily growing, heterocyclic chemistry remains in the focus of the synthetic community. Enormous efforts have been made in the last decades in order to render the production of such compounds more selective and efficient. However, most of the conventional methods for the construction of heterocyclic cores still involve the use of strong acids or bases, the operation at elevated temperatures and/or the use of expensive catalysts and reagents. In this regard, electrosynthesis can provide a milder and more environmentally benign alternative. In fact, numerous examples for the electrochemical construction of heterocycles have been reported in recent years. These cases demonstrate that ring formation can be achieved efficiently under ambient conditions without the use of additional reagents. In order to account for the recent developments in this field, a selection of representative reactions is presented and discussed in this review.
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Affiliation(s)
- Robert Francke
- Department of Chemistry, University of Rostock, Albert-Einstein-Str. 3a, 18059 Rostock, Germany
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Shchepochkin AV, Chupakhin ON, Charushin VN, Petrosyan VA. Direct nucleophilic functionalization of C(sp2)–H-bonds in arenes and hetarenes by electrochemical methods. RUSSIAN CHEMICAL REVIEWS 2013. [DOI: 10.1070/rc2013v082n08abeh004386] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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