1
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A Novel Method to Construct 2-Aminobenzofurans via [4 + 1] Cycloaddition Reaction of In Situ Generated Ortho-Quinone Methides with Isocyanides. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27238538. [PMID: 36500630 PMCID: PMC9737762 DOI: 10.3390/molecules27238538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 11/28/2022] [Accepted: 12/02/2022] [Indexed: 12/09/2022]
Abstract
A new approach for the synthesis of 2-aminobenzofurans has been described via Sc(OTf)3 mediated formal cycloaddition of isocyanides with the in situ generated ortho-quinone methides (o-QMs) from o-hydroxybenzhydryl alcohol. Notably, as a class of readily available and highly active intermediates, o-QMs were first used in the construction of benzofurans. This [4 + 1] cycloaddition reaction provides a straightforward and efficient methodology for the construction of 2-aminobenzofurans scaffold in good yield (up to 93% yield) under mild conditions.
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2
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Ji XS, Zuo HD, Shen YT, Hao WJ, Tu SJ, Jiang B. Electrochemical selective annulative amino-ketalization and amino-oxygenation of 1,6-enynes. Chem Commun (Camb) 2022; 58:10420-10423. [PMID: 36043317 DOI: 10.1039/d2cc03922b] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A new electrochemical selective annulative amino-ketalization and amino-oxygenation of 1,6-enynes with disulfonimides and alcohols is reported, producing a series of functionalized benzofurans under catalyst- and oxidant-free conditions. The annulative aminoketalization proceeds with simple short-chain alcohols such as methanol, ethanol and n-propanol as O-nucleophilic reagents, while the reaction occurs in the annulative aminooxygenation direction in the presence of water and large steric sec-butyl alcohol (SBA).
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Affiliation(s)
- Xiao-Shuang Ji
- School of Chemistry & Materials Science, Jiangsu Normal University, Xuzhou, 221116, P. R. China.
| | - Hang-Dong Zuo
- School of Chemistry & Materials Science, Jiangsu Normal University, Xuzhou, 221116, P. R. China. .,School of Environmental and Safety Engineering, Changzhou University, Changzhou, 213164, Jiangsu, P. R. China
| | - Yi-Ting Shen
- School of Chemistry & Materials Science, Jiangsu Normal University, Xuzhou, 221116, P. R. China.
| | - Wen-Juan Hao
- School of Chemistry & Materials Science, Jiangsu Normal University, Xuzhou, 221116, P. R. China.
| | - Shu-Jiang Tu
- School of Chemistry & Materials Science, Jiangsu Normal University, Xuzhou, 221116, P. R. China.
| | - Bo Jiang
- School of Chemistry & Materials Science, Jiangsu Normal University, Xuzhou, 221116, P. R. China.
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3
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Visible-Light Photocatalytic Reduction of Aryl Halides as a Source of Aryl Radicals. Molecules 2022; 27:molecules27175364. [PMID: 36080129 PMCID: PMC9458128 DOI: 10.3390/molecules27175364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 08/19/2022] [Accepted: 08/20/2022] [Indexed: 11/17/2022] Open
Abstract
Aryl- and heteroaryl units are present in a wide variety of natural products, pharmaceuticals, and functional materials. The method for reduction of aryl halides with ubiquitous distribution is highly sought after for late-stage construction of various aromatic compounds. The visible-light-driven reduction of aryl halides to aryl radicals by electron transfer provides an efficient, simple, and environmentally friendly method for the construction of aromatic compounds. This review summarizes the recent progress in the generation of aryl radicals by visible-light-driven reduction of aryl halides with metal complexes, organic compounds, semiconductors as catalysts, and alkali-assisted reaction system. The ability and mechanism of reduction of aromatic halides in various visible light induced systems are summarized, intending to illustrate a comprehensive introduction of this research topic to the readers.
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4
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Goulart TAC, Recchi AMS, Back DF, Zeni G. Selective 5‐Exo‐Dig versus 6‐Endo‐Dig Cyclization of Benzoimidazole Thiols with Propargyl Alcohols. Adv Synth Catal 2022. [DOI: 10.1002/adsc.202200254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Tales A. C. Goulart
- Laboratório de Síntese Reatividade Avaliação Farmacológica e Toxicológica de Organocalcogênios CCNE, UFSM Santa Maria, Rio Grande do Sul 97105-900 Brazil
| | - Ana M. S. Recchi
- Laboratório de Síntese Reatividade Avaliação Farmacológica e Toxicológica de Organocalcogênios CCNE, UFSM Santa Maria, Rio Grande do Sul 97105-900 Brazil
| | - Davi F. Back
- Laboratório de Materiais Inorgânicos Departamento de Química, UFSM Santa Maria, Rio Grande do Sul 97105-900 Brazil
| | - Gilson Zeni
- Laboratório de Síntese Reatividade Avaliação Farmacológica e Toxicológica de Organocalcogênios CCNE, UFSM Santa Maria, Rio Grande do Sul 97105-900 Brazil
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5
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Zou D, Han G. The Coupling of Carbon and Nitrogen Substituents with Nitroarenes:Vicarious Nucleophilic Substitution of Hydrogen in Nitroarenes. CURR ORG CHEM 2022. [DOI: 10.2174/1385272826666220509142255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Abstract:
In recent years, nitroarenes have been extensively exploited as green, efficient electrophilic arylation reagents used in a variety of organic syntheses. Transition-metal-free cross-coupling reactions and vicarious nucleophilic substitution (VNS) have become practical and reliable synthetic methods to access momentous func-tionalized organic compounds. Thus, the introduction of various substituents into nitroarenes has attracted considerable attention as important synthetic approach-es due to their simplicity and practicality. In this review, we comprehensively summarize the coupling of several carbon and nitrogen substituents with ni-troarenes via nucleophilic substitution under mild conditions, followed by the ap-plication of these transversions in the construction of carbon and heterocyclic rings.
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Affiliation(s)
- Dong Zou
- Department of Pharmacy, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Gang Han
- Department of Pharmacy, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
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6
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Zhang Q, Nie H, Zhang K, Huang H, Song C. A novel base-promoted intramolecular cyclization approach for the synthesis of benzofurans, benzothiophenes and indoles. Tetrahedron 2022. [DOI: 10.1016/j.tet.2022.132815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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7
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Tao Y, Hu R, Xie Z, Lin P, Su W. Cobalt-Catalyzed Regioselective para-Amination of Azobenzenes via Nucleophilic Aromatic Substitution of Hydrogen. J Org Chem 2022; 87:4724-4731. [PMID: 35290054 DOI: 10.1021/acs.joc.2c00026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The metal-catalyzed nucleophilic aromatic substitution of hydrogen (SNArH) via coordination of the substituent on the aromatic ring to the metal catalyst, in terms of reactivity, substrate type, and reaction selectivity, complements the transition metal-catalyzed C-H functionalization that proceeds via C-H metalation but remains an elusive target. Described herein is the development of an unprecedented cobalt-catalyzed para-selective amination of azobenzenes, which is essentially a metal-promoted SNArH process as revealed by Hammett analysis, thus illustrating the concept that coordination of the substituent on the arene ring to the metal catalyst may result in electrophilic activation of the arene ring toward SNArH. This cobalt-catalyzed protocol allows the use of a variety of both aliphatic amines and anilines as aminating reagents, tolerates electronically diverse substituents of azobenzene, and furnishes the corresponding products in good yields with a regiospecific selectivity for para-amination.
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Affiliation(s)
- Yigao Tao
- State Key Laboratory of Structural Chemistry, Center for Excellence in Molecular Synthesis, Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China.,University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China.,School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China.,Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China
| | - Rong Hu
- State Key Laboratory of Structural Chemistry, Center for Excellence in Molecular Synthesis, Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China.,University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China.,School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China.,Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China
| | - Zeyu Xie
- School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Ping Lin
- State Key Laboratory of Structural Chemistry, Center for Excellence in Molecular Synthesis, Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China
| | - Weiping Su
- State Key Laboratory of Structural Chemistry, Center for Excellence in Molecular Synthesis, Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China.,University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
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8
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Xu C, Li X, Bai L. Direct Aerobic α-Hydroxylation of Arylacetates for the Synthesis of Mandelates. J Org Chem 2022; 87:4298-4304. [PMID: 35245055 DOI: 10.1021/acs.joc.1c03149] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Aerobic α-hydroxylation of α-methylene esters has proven challenging due to overoxidation and hydrolysis of the materials. In this article, KOtBu-promoted TBAB-catalyzed α-hydroxylation of α-methylene aryl esters using O2 as the oxygen source has been developed. Both low reaction temperature and catalyst TBAB are keys to success. This reaction provides an environmentally friendly and low-cost approach to mandelates, which are valuable building blocks and widely present in pharmaceuticals.
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Affiliation(s)
- Changming Xu
- School of Chemistry and Chemical Engineering, Lanzhou Jiaotong University, Lanzhou 730070, China
| | - Xiangfan Li
- School of Chemistry and Chemical Engineering, Lanzhou Jiaotong University, Lanzhou 730070, China
| | - Lei Bai
- College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, China
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9
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Ge D, Sun LW, Yu ZL, Luo XL, Xu P, Shen ZL. Regioselective synthesis of 6-nitroindole derivatives from enaminones and nitroaromatic compounds via transition metal-free C-C and C-N bond formation. Org Biomol Chem 2022; 20:1493-1499. [PMID: 35107115 DOI: 10.1039/d1ob02443d] [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
Few methods are known for the synthesis of nitroindole derivatives. A simple and practical Cs2CO3-promoted method for the synthesis of 6-nitroindole derivatives from enaminones and nitroaromatic compounds has been developed. Two new C-C and C-N bonds were formed in a highly regioselective manner under transition metal-free conditions.
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Affiliation(s)
- Danhua Ge
- Chemical Experiment Teaching Center, Institute of Advanced Synthesis, School of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing 211816, China.
| | - Li-Wen Sun
- Chemical Experiment Teaching Center, Institute of Advanced Synthesis, School of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing 211816, China.
| | - Zi-Lun Yu
- Chemical Experiment Teaching Center, Institute of Advanced Synthesis, School of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing 211816, China.
| | - Xin-Long Luo
- Chemical Experiment Teaching Center, Institute of Advanced Synthesis, School of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing 211816, China.
| | - Pei Xu
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, School of Pharmacy, Xuzhou Medical University, Xuzhou 221004, China.
| | - Zhi-Liang Shen
- Chemical Experiment Teaching Center, Institute of Advanced Synthesis, School of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing 211816, China.
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10
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Khan D, Sharma S, Shukla P. Microwave assisted L‐proline catalyzed
One‐Pot Three‐Component
Reaction for the synthesis of
4‐aminoaryl‐2‐phenyl‐2H
‐3‐nitrochromene hybrid via Domino
Michael‐Henry‐Michael
addition reaction. J Heterocycl Chem 2022. [DOI: 10.1002/jhet.4447] [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)
- Danish Khan
- Department of Chemistry Indian Institute of Technology Roorkee Roorkee Uttarakhand India
| | - Saurabh Sharma
- Department of Chemistry Indian Institute of Technology Roorkee Roorkee Uttarakhand India
| | - Prakhar Shukla
- Department of Chemistry Indian Institute of Technology Roorkee Roorkee Uttarakhand India
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11
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li J, Dong Z, Wang B, İşcan A, Jin H, Chen L, Fan Z, Walsh P, Liang G. Arylations with Nitroarenes for One-Pot Syntheses of Triaryl-methanols and Tetraarylmethanes. Org Chem Front 2022. [DOI: 10.1039/d2qo00576j] [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
Triarylmethanols are well-known core structures in natural products and pharmacologically relevant compounds. In general, transition metal-based catalysts or highly reactive organometallics are employed for the synthesis of these compounds. Herein,...
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12
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Li J, Zhang S, Lao J, Zou H. Direct Transition-Metal Free Benzene C-H Functionalization by Intramolecular Non-Nitroarene Nucleophilic Aromatic Substitution of Hydrogen to Diverse AIEgens. CHEMSUSCHEM 2021; 14:3208-3218. [PMID: 34132487 DOI: 10.1002/cssc.202101109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 06/15/2021] [Indexed: 06/12/2023]
Abstract
Direct C(sp2 )-H functionalization through nitroarene-triggered nucleophilic aromatic substitution of hydrogen (SNArH ) has attracted growing attention, owing to its high efficiency and low carbon footprint. In this study, non-nitro-group-assisted SN ArH has been developed for direct benzene functionalization in one pot under mild conditions. The electron-withdrawing carbonyl group and the halide or trifluoromethyl group on the phenyl ring enable the σH adduct formation to fulfill the intramolecular C(sp2 )-C(sp3 ) bond construction. Notably, the cyano group serves as both the electron-withdrawing group to activate the C(sp3 )-H bond and the leaving group to fulfill the β-elimination. Three series of pyrrolo[1,2-b]isoquinolinones, as well as unexpected rearrangement products 3-(1H-pyrrol-2-yl)-1H-inden-1-ones are regioselectively obtained through a simple and efficient base-catalyzed one-pot strategy. Mechanistic studies indicate that the σH adduct from carbanion addition to hydrogen serves as the sole intermediate for all of the aforementioned transformations. These molecules show intense luminescence and the subsequent one-step structural modification results in the aggregation-induced emission (AIE) derivatives with redshifted full-color tunable fluorescence, large Stokes shifts, and good quantum yields. Further living cell imaging investigations suggest their potential application as specific bioprobes for lipid droplet localization and visualization.
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Affiliation(s)
- Jinbiao Li
- College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, P. R. China
| | - Shuaizhong Zhang
- College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, P. R. China
| | - Jiaxin Lao
- College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, P. R. China
| | - Hongbin Zou
- College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, P. R. China
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13
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Sun C, Yu Y, Zhang X, Liu Y, Sun C, Kai G, Shi L, Li H. Transition-metal-free decarbonylative alkylation towards N-aryl α-hydroxy amides via triple C–C bond cleavages and their selective deuteration. Org Chem Front 2021. [DOI: 10.1039/d1qo00530h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
A transition-metal-free decarbonylative alkylation reaction for the synthesis of N-aryl α-hydroxy amides via precise cleavages and reorganizations of three C–C σ bonds has been developed.
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Affiliation(s)
- Chengyu Sun
- State Key Laboratory of Bioreactor Engineering, Shanghai Key Laboratory of New Drug Design, and School of Pharmacy, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
| | - Yang Yu
- State Key Laboratory of Bioreactor Engineering, Shanghai Key Laboratory of New Drug Design, and School of Pharmacy, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
| | - Xiao Zhang
- State Key Laboratory of Bioreactor Engineering, Shanghai Key Laboratory of New Drug Design, and School of Pharmacy, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
| | - Yonghai Liu
- State Key Laboratory of Bioreactor Engineering, Shanghai Key Laboratory of New Drug Design, and School of Pharmacy, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
| | - Chengtao Sun
- Laboratory of Medicinal Plant Biotechnology, College of pharmacy, Zhejiang Chinese Medical University, Hangzhou, Zhejiang, 310053, China
| | - Guoyin Kai
- Laboratory of Medicinal Plant Biotechnology, College of pharmacy, Zhejiang Chinese Medical University, Hangzhou, Zhejiang, 310053, China
| | - Lei Shi
- Huabao Flavours & Fragrances Co., Ltd., 1299 Yecheng Road, Shanghai 201822, China
| | - Hao Li
- State Key Laboratory of Bioreactor Engineering, Shanghai Key Laboratory of New Drug Design, and School of Pharmacy, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
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14
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Mąkosza M. Electrophilic and Nucleophilic Aromatic Substitutions are Mechanistically Similar with Opposite Polarity. Chemistry 2020; 26:15346-15353. [PMID: 33174247 DOI: 10.1002/chem.202003770] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Indexed: 11/07/2022]
Abstract
Confrontation of the recently formulated general mechanism of nucleophilic substitution in electron-deficient arenes with the well-known mechanism of electrophilic substitution revealed that these fundamental processes are mechanistically identical but proceed according to opposite polarity-an Umpolung relation. In this viewpoint this apparently controversial concept is supported by discussion of a variety of experimental results.
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Affiliation(s)
- Mieczysław Mąkosza
- Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224, Warsaw 42, Poland
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15
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Madasu J, Shinde S, Das R, Patel S, Shard A. Potassium tert-butoxide mediated C-C, C-N, C-O and C-S bond forming reactions. Org Biomol Chem 2020; 18:8346-8365. [PMID: 33020791 DOI: 10.1039/d0ob01382j] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Potassium tertiary butoxide (KOtBu) mediated constructions of C-C, C-O, C-N, and C-S bonds are reviewed with special emphasis on their synthetic applications. KOtBu can be used to perform reactions already known to be carried out using transition metals, but it has advantages in terms of environmental congruence and economic cost. KOtBu is widely employed in organic synthesis to mediate the construction of C-C, C-O, C-N, C-S and miscellaneous bonds in good to excellent yields. Synthetic uses of KOtBu in coupling, alkylation, arylation, α-phenylation, cyclization, Heck-type, annulation, photo-arylation, aromatic-substitution, amidation, and silylation reactions are summarized and discussed. The mechanisms through which KOtBu carries out a specific reaction are also discussed. One of the goals of this review is to attract the attention of chemists as to the benefits of using KOtBu as an environmentally benign alternative to transition metals and its applications in the construction of chemical bonds with predominant importance in organic synthesis. This review completely covers the synthetic protocols that have been performed using KOtBu in the last two decades.
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Affiliation(s)
- Jayashree Madasu
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Ahmedabad, Gujarat 380054, India.
| | - Shital Shinde
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Ahmedabad, Gujarat 380054, India.
| | - Rudradip Das
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Ahmedabad, Gujarat 380054, India.
| | - Sagarkumar Patel
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Ahmedabad, Gujarat 380054, India.
| | - Amit Shard
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Ahmedabad, Gujarat 380054, India.
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16
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Loska R, Mąkosza M. Introduction of Carbon Substituents into Nitroarenes via Nucleophilic Substitution of Hydrogen: New Developments. SYNTHESIS-STUTTGART 2020. [DOI: 10.1055/s-0040-1707149] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Nucleophilic substitution of hydrogen in nitroarenes has become a powerful synthetic tool for functionalization of these important organic substrates, complementary to other modern methods. In this review we present new developments in the area of introduction of alkyl and functionalized alkyl substituents into nitroarene rings via nucleophilic substitution of hydrogen, followed by application of these processes in the construction of carbo- and heterocyclic rings. Finally, new developments in the investigation of the mechanism of SNArH are summarized.1 Introduction2 Alkylation and Haloalkylation3 Functionalized Carbon Substituents4 Formation of Carbo- and Heterocyclic Rings5 Mechanistic Aspects of SNArH6 Conclusion
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17
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Yang R, Yue S, Tan W, Xie Y, Cai H. DMSO/ t-BuONa/O 2-Mediated Aerobic Dehydrogenation of Saturated N-Heterocycles. J Org Chem 2020; 85:7501-7509. [PMID: 32368910 DOI: 10.1021/acs.joc.9b03447] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Aromatic N-heterocycles such as quinolines, isoquinolines, and indolines are synthesized via sodium tert-butoxide-promoted oxidative dehydrogenation of the saturated heterocycles in DMSO solution. This reaction proceeds under mild reaction conditions and has a good functional group tolerance. Mechanistic studies suggest a radical pathway involving hydrogen abstraction of dimsyl radicals from the N-H bond or α-C-H of the substrates and subsequent oxidation of the nitrogen or α-aminoalkyl radicals.
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Affiliation(s)
- Ruchun Yang
- College of Chemistry, Nanchang University, Nanchang, Jiangxi 330031, China.,Institute of Organic Chemistry, Jiangxi Science & Technology Normal University, Key Laboratory of Organic Chemistry, Nanchang, Jiangxi 330013, China
| | - Shusheng Yue
- College of Chemistry, Nanchang University, Nanchang, Jiangxi 330031, China
| | - Wei Tan
- Clinic Laboratory, People's Hospital of Yichun City, Yichun, Jiangxi 336000, China
| | - Yongfa Xie
- College of Chemistry, Nanchang University, Nanchang, Jiangxi 330031, China
| | - Hu Cai
- College of Chemistry, Nanchang University, Nanchang, Jiangxi 330031, China
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18
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Trofimov BA, Volkov PA, Telezhkin AA, Khrapova KO, Ivanova NI, Albanov AI, Gusarova NK. Catalyst-Free Double CH-Functionalization of Quinolines with Phosphine Oxides via Two S NHAr Reaction Sequences. J Org Chem 2020; 85:4927-4936. [PMID: 32162918 DOI: 10.1021/acs.joc.0c00084] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Quinolines undergo catalyst-free double CH-functionalization upon treatment with secondary phosphine oxides (70-75 °C, 20-48 h) followed by oxidation of the intermediate 2,4-bisphosphoryltetrahydroquinolines with chloranil. The yields of the target 2,4-bisphosphorylated quinolines are up to 77%. Thus, a double-SNHAr reaction sequence in the same molecule of quinoline has been realized. In the case of 2,4-bisphenylphosphoryltetrahydroquinolines, the aromatization occurs with elimination of one molecule of diphenylphosphine oxide to afford the products of monofunctionalization, 4-diphenylphosphorylquinolines, in 40-45% yields.
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Affiliation(s)
- Boris A Trofimov
- A.E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, 1 Favorsky St., Irkutsk 664033, Russian Federation
| | - Pavel A Volkov
- A.E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, 1 Favorsky St., Irkutsk 664033, Russian Federation
| | - Anton A Telezhkin
- A.E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, 1 Favorsky St., Irkutsk 664033, Russian Federation
| | - Kseniya O Khrapova
- A.E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, 1 Favorsky St., Irkutsk 664033, Russian Federation
| | - Nina I Ivanova
- A.E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, 1 Favorsky St., Irkutsk 664033, Russian Federation
| | - Alexander I Albanov
- A.E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, 1 Favorsky St., Irkutsk 664033, Russian Federation
| | - Nina K Gusarova
- A.E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, 1 Favorsky St., Irkutsk 664033, Russian Federation
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19
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Yuan J, To WP, Zhang ZY, Yue CD, Meng S, Chen J, Liu Y, Yu GA, Che CM. Visible-Light-Promoted Transition-Metal-Free Phosphinylation of Heteroaryl Halides in the Presence of Potassium tert-Butoxide. Org Lett 2018; 20:7816-7820. [DOI: 10.1021/acs.orglett.8b03265] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Jia Yuan
- Key Laboratory of Pesticide & Chemical Biology, Ministry of Education, and Chemical Biology Center, College of Chemistry, Hubei International Scientific and Technological Cooperation Base of Pesticide and Green Synthesis, International Joint Research Center for Intelligent Biosensing Technology and Health, Central China Normal University, Wuhan 430079, P. R. China
| | - Wai-Pong To
- State Key Laboratory of Synthetic Chemistry, and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, China
| | - Zi-Yang Zhang
- Key Laboratory of Pesticide & Chemical Biology, Ministry of Education, and Chemical Biology Center, College of Chemistry, Hubei International Scientific and Technological Cooperation Base of Pesticide and Green Synthesis, International Joint Research Center for Intelligent Biosensing Technology and Health, Central China Normal University, Wuhan 430079, P. R. China
| | - Chang-Duo Yue
- Key Laboratory of Pesticide & Chemical Biology, Ministry of Education, and Chemical Biology Center, College of Chemistry, Hubei International Scientific and Technological Cooperation Base of Pesticide and Green Synthesis, International Joint Research Center for Intelligent Biosensing Technology and Health, Central China Normal University, Wuhan 430079, P. R. China
| | - Sixuan Meng
- Key Laboratory of Pesticide & Chemical Biology, Ministry of Education, and Chemical Biology Center, College of Chemistry, Hubei International Scientific and Technological Cooperation Base of Pesticide and Green Synthesis, International Joint Research Center for Intelligent Biosensing Technology and Health, Central China Normal University, Wuhan 430079, P. R. China
| | - Jian Chen
- Key Laboratory of Pesticide & Chemical Biology, Ministry of Education, and Chemical Biology Center, College of Chemistry, Hubei International Scientific and Technological Cooperation Base of Pesticide and Green Synthesis, International Joint Research Center for Intelligent Biosensing Technology and Health, Central China Normal University, Wuhan 430079, P. R. China
| | - Yungen Liu
- Department of Chemistry, South University of Science and Technology, Shenzhen, Guangdong 518055, P. R. China
| | - Guang-Ao Yu
- Key Laboratory of Pesticide & Chemical Biology, Ministry of Education, and Chemical Biology Center, College of Chemistry, Hubei International Scientific and Technological Cooperation Base of Pesticide and Green Synthesis, International Joint Research Center for Intelligent Biosensing Technology and Health, Central China Normal University, Wuhan 430079, P. R. China
| | - Chi-Ming Che
- State Key Laboratory of Synthetic Chemistry, and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, China
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20
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Lovato K, Guo L, Xu QL, Liu F, Yousufuddin M, Ess DH, Kürti L, Gao H. Transition metal-free direct dehydrogenative arylation of activated C(sp 3)-H bonds: synthetic ambit and DFT reactivity predictions. Chem Sci 2018; 9:7992-7999. [PMID: 30450183 PMCID: PMC6202766 DOI: 10.1039/c8sc02758g] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Accepted: 08/23/2018] [Indexed: 11/21/2022] Open
Abstract
A transition metal-free dehydrogenative method for the direct mono-arylation of a wide range of activated C(sp3)-H bonds has been developed. This operationally simple and environmentally friendly aerobic arylation uses tert-BuOK as the base and nitroarenes as electrophiles to prepare up to gram quantities of structurally diverse sets (>60 examples) of α-arylated esters, amides, nitriles, sulfones and triaryl methanes. DFT calculations provided a predictive model, which states that substrates containing a C(sp3)-H bond with a sufficiently low pK a value should readily undergo arylation. The DFT prediction was confirmed through experimental testing of nearly a dozen substrates containing activated C(sp3)-H bonds. This arylation method was also used in a one-pot protocol to synthesize over twenty compounds containing all-carbon quaternary centers.
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Affiliation(s)
- Kaitlyn Lovato
- Department of Chemistry , Rice University , BioScience Research Collaborative , Houston , Texas 77005 , USA .
| | - Lirong Guo
- Ministry of Education Key Laboratory of Colloid and Interface Chemistry , School of Chemistry and Chemical Engineering , Shandong University , Ji'nan 250100 , China .
| | - Qing-Long Xu
- Jiangsu Key Laboratory of Drug Discovery for Metabolic Disease , State Key Laboratory of Natural Medicines , China Pharmaceutical University , 24 Tongjia Xiang , Nanjing 210009 , China
| | - Fengting Liu
- Ministry of Education Key Laboratory of Colloid and Interface Chemistry , School of Chemistry and Chemical Engineering , Shandong University , Ji'nan 250100 , China .
| | - Muhammed Yousufuddin
- Life and Health Sciences Department , The University of North Texas at Dallas , Dallas , Texas 76016 , USA
| | - Daniel H Ess
- Department of Chemistry and Biochemistry , Brigham Young University , Provo , Utah 84602 , USA .
| | - László Kürti
- Department of Chemistry , Rice University , BioScience Research Collaborative , Houston , Texas 77005 , USA .
| | - Hongyin Gao
- Ministry of Education Key Laboratory of Colloid and Interface Chemistry , School of Chemistry and Chemical Engineering , Shandong University , Ji'nan 250100 , China .
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21
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Agasti S, Dey A, Maiti D. Palladium-catalyzed benzofuran and indole synthesis by multiple C-H functionalizations. Chem Commun (Camb) 2018; 53:6544-6556. [PMID: 28569899 DOI: 10.1039/c7cc02053h] [Citation(s) in RCA: 105] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Heterocyclic compounds are commonly found in the core structures of several pharmaceuticals, natural products, and agrochemicals, thus spurring intensive research for conducting their synthesis in a mild and simpler way. Over the years, a host of different strategies has been introduced in an effort to synthesize these heterocyles. In this context, significant attention has been gained by methodologies that ensure both step as well as atom efficiency. Synthesis of heterocyclic moieties via multiple C-H activations was found to fulfill these expectations besides guaranteeing the use of starting materials that are easily procurable. This review is focused on the current development in the field of benzofuran and indole synthesis using multiple C-H functionalization strategies.
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Affiliation(s)
- Soumitra Agasti
- Department of Chemistry, Indian Institute of Technology Bombay, India.
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22
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Kumar P, Sharma AK, Guntreddi T, Singh R, Singh KN. Transition-Metal-Free Regiospecific Aroylation of Nitroarenes Using Ethyl Arylacetates at Room Temperature. Org Lett 2018; 20:744-747. [PMID: 29345475 DOI: 10.1021/acs.orglett.7b03882] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
A novel regiospecific C(sp3)-C(sp2) coupling between ethyl arylacetates and nitroarenes has been developed to deliver biaryl ketones in excellent yields. The protocol is metal-free, mild, and compatible with a number of functional groups on both of the reacting partners.
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Affiliation(s)
- Promod Kumar
- Department of Chemistry (Centre of Advanced Study), Institute of Science, Banaras Hindu University , Varanasi-221005, India
| | - Anup Kumar Sharma
- Department of Chemistry (Centre of Advanced Study), Institute of Science, Banaras Hindu University , Varanasi-221005, India
| | - Tirumaleswararao Guntreddi
- Department of Chemistry (Centre of Advanced Study), Institute of Science, Banaras Hindu University , Varanasi-221005, India
| | - Rahul Singh
- Department of Chemistry (Centre of Advanced Study), Institute of Science, Banaras Hindu University , Varanasi-221005, India
| | - Krishna Nand Singh
- Department of Chemistry (Centre of Advanced Study), Institute of Science, Banaras Hindu University , Varanasi-221005, India
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23
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Li JS, Yang Q, Yang F, Chen GQ, Li ZW, Kuang YJ, Zhang WJ, Huang PM. Aerobic oxidative acylation of nitroarenes with arylacetic esters under mild conditions: facile access to diarylketones. Org Biomol Chem 2018; 16:140-145. [PMID: 29218339 DOI: 10.1039/c7ob02865b] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
A regioselectivet-BuONa-mediated aerobic oxidative acylation of nitroarenes under mild conditions is developed through a cascade CDC/oxidative decarboxylation process.
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Affiliation(s)
- Jiang-Sheng Li
- Hunan Provincial Key Laboratory of Materials Protection for Electric Power and Transportation
- School of Chemistry and Biological Engineering
- Changsha University of Science & Technology
- Changsha 410114
- P.R. China
| | - Qian Yang
- Hunan Provincial Key Laboratory of Materials Protection for Electric Power and Transportation
- School of Chemistry and Biological Engineering
- Changsha University of Science & Technology
- Changsha 410114
- P.R. China
| | - Fan Yang
- SINOPEC Baling Petrochemical Company
- Yueyang 414014
- P.R. China
- Hunan Provincial Key Laboratory of Materials Protection for Electric Power and Transportation
- School of Chemistry and Biological Engineering
| | - Guo-Qin Chen
- Hunan Provincial Key Laboratory of Materials Protection for Electric Power and Transportation
- School of Chemistry and Biological Engineering
- Changsha University of Science & Technology
- Changsha 410114
- P.R. China
| | - Zhi-Wei Li
- Hunan Provincial Key Laboratory of Materials Protection for Electric Power and Transportation
- School of Chemistry and Biological Engineering
- Changsha University of Science & Technology
- Changsha 410114
- P.R. China
| | - Yin-Jie Kuang
- Hunan Provincial Key Laboratory of Materials Protection for Electric Power and Transportation
- School of Chemistry and Biological Engineering
- Changsha University of Science & Technology
- Changsha 410114
- P.R. China
| | - Wei-Jing Zhang
- Hunan Provincial Key Laboratory of Materials Protection for Electric Power and Transportation
- School of Chemistry and Biological Engineering
- Changsha University of Science & Technology
- Changsha 410114
- P.R. China
| | - Peng-Mian Huang
- Hunan Provincial Key Laboratory of Materials Protection for Electric Power and Transportation
- School of Chemistry and Biological Engineering
- Changsha University of Science & Technology
- Changsha 410114
- P.R. China
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24
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Jana S, Verma A, Kadu R, Kumar S. Visible-light-induced oxidant and metal-free dehydrogenative cascade trifluoromethylation and oxidation of 1,6-enynes with water. Chem Sci 2017; 8:6633-6644. [PMID: 28989690 PMCID: PMC5625288 DOI: 10.1039/c7sc02556d] [Citation(s) in RCA: 98] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 07/08/2017] [Indexed: 12/30/2022] Open
Abstract
Generally, oxy-trifluoromethylation in olefins is achieved using oxidants and transition metal catalysts. However, labile olefins remain unexplored due to their incompatibility with harsh reaction conditions. Here, unprecedented light-induced oxidant and metal-free tandem radical cyclization-trifluoromethylation and dehydrogenative oxygenation of 1,6-enynes have been achieved using a photoredox catalyst, CF3SO2Na, and phenanthrene-9,10-dione (PQ), Langlois' reagent (CF3SO2Na) and water as the oxygen source. This benign protocol allows for access to various CF3-containing C3-aryloyl/acylated benzofurans, benzothiophenes, and indoles. Moreover, the oxidized undesired products, which are inherently formed by the cleavage of the vinylic carbon and heteroatom bond, have been circumvented under oxidant free conditions. The mechanistic investigations by UV-visible and ESR spectroscopy, electrochemical studies, isotope labelling and density functional theory (DFT) suggest that light induced PQ produced a CF3 radical from CF3SO2Na. The generated CF3 radical adds to the alkene, followed by cyclization, to provide a vinylic radical that transfers an electron to PQ and generates a vinylic cation. Alternatively, electron transfer may occur from the CF3-added alkene moiety, forming a carbocation, which would undergo cationic cyclization to generate a vinylic carbocation. The subsequent addition of water to the vinylic cation, followed by the elimination of hydrogen gas, led to the formation of trifluoromethylated C3-aryloyl/acylated heterocycles.
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Affiliation(s)
- Sadhan Jana
- Department of Chemistry , Indian Institute of Science Education and Research (IISER) Bhopal , Bhopal By-pass Road, Bhauri , Bhopal-462066 , India . ; http://home.iiserbhopal.ac.in/∼sangitkumar/
| | - Ajay Verma
- Department of Chemistry , Indian Institute of Science Education and Research (IISER) Bhopal , Bhopal By-pass Road, Bhauri , Bhopal-462066 , India . ; http://home.iiserbhopal.ac.in/∼sangitkumar/
| | - Rahul Kadu
- Department of Chemistry , Indian Institute of Science Education and Research (IISER) Bhopal , Bhopal By-pass Road, Bhauri , Bhopal-462066 , India . ; http://home.iiserbhopal.ac.in/∼sangitkumar/
| | - Sangit Kumar
- Department of Chemistry , Indian Institute of Science Education and Research (IISER) Bhopal , Bhopal By-pass Road, Bhauri , Bhopal-462066 , India . ; http://home.iiserbhopal.ac.in/∼sangitkumar/
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25
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Li SS, Fu S, Wang L, Xu L, Xiao J. t-BuOK-Mediated Oxidative Dehydrogenative C(sp 3)-H Arylation of 2-Alkylazaarenes with Nitroarenes. J Org Chem 2017; 82:8703-8709. [PMID: 28737943 DOI: 10.1021/acs.joc.7b00732] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The first transition-metal free and regioselective C(sp3)-H arylation of 2-alkylazaarenes with nitroarenes has been achieved via t-BuOK-mediated dehydrogenative C(sp3)-C(sp2) coupling. This reaction provides an efficient access to the biologically important and synthetically useful 2-benzyl-substituted azaarenes under mild conditions without the need of prefunctionalization of 2-alkylazaarenes or using the specialized arylating agents.
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Affiliation(s)
- Shuai-Shuai Li
- College of Chemistry and Pharmaceutical Sciences, Qingdao Agricultural University , Qingdao 266109, China
| | - Shiheng Fu
- College of Chemistry and Pharmaceutical Sciences, Qingdao Agricultural University , Qingdao 266109, China
| | - Liang Wang
- College of Chemistry and Pharmaceutical Sciences, Qingdao Agricultural University , Qingdao 266109, China
| | - Lubin Xu
- College of Chemistry and Pharmaceutical Sciences, Qingdao Agricultural University , Qingdao 266109, China
| | - Jian Xiao
- College of Chemistry and Pharmaceutical Sciences, Qingdao Agricultural University , Qingdao 266109, China
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26
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Banerjee S, Yang YF, Jenkins ID, Liang Y, Toutov AA, Liu WB, Schuman DP, Grubbs RH, Stoltz BM, Krenske EH, Houk KN, Zare RN. Ionic and Neutral Mechanisms for C-H Bond Silylation of Aromatic Heterocycles Catalyzed by Potassium tert-Butoxide. J Am Chem Soc 2017; 139:6880-6887. [PMID: 28462580 DOI: 10.1021/jacs.6b13032] [Citation(s) in RCA: 92] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Exploiting C-H bond activation is difficult, although some success has been achieved using precious metal catalysts. Recently, it was reported that C-H bonds in aromatic heterocycles were converted to C-Si bonds by reaction with hydrosilanes under the catalytic action of potassium tert-butoxide alone. The use of Earth-abundant potassium cation as a catalyst for C-H bond functionalization seems to be without precedent, and no mechanism for the process was established. Using ambient ionization mass spectrometry, we are able to identify crucial ionic intermediates present during the C-H silylation reaction. We propose a plausible catalytic cycle, which involves a pentacoordinate silicon intermediate consisting of silane reagent, substrate, and the tert-butoxide catalyst. Heterolysis of the Si-H bond, deprotonation of the heteroarene, addition of the heteroarene carbanion to the silyl ether, and dissociation of tert-butoxide from silicon lead to the silylated heteroarene product. The steps of the silylation mechanism may follow either an ionic route involving K+ and tBuO- ions or a neutral heterolytic route involving the [KOtBu]4 tetramer. Both mechanisms are consistent with the ionic intermediates detected experimentally. We also present reasons why KOtBu is an active catalyst whereas sodium tert-butoxide and lithium tert-butoxide are not, and we explain the relative reactivities of different (hetero)arenes in the silylation reaction. The unique role of KOtBu is traced, in part, to the stabilization of crucial intermediates through cation-π interactions.
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Affiliation(s)
- Shibdas Banerjee
- Department of Chemistry, Stanford University , Stanford, California 94305-5080, United States
| | - Yun-Fang Yang
- Department of Chemistry and Biochemistry, University of California , Los Angeles, California 90095-1569, United States
| | - Ian D Jenkins
- Eskitis Institute, Griffith University , Nathan, QLD 4111, Australia
| | - Yong Liang
- Department of Chemistry and Biochemistry, University of California , Los Angeles, California 90095-1569, United States
| | - Anton A Toutov
- Division of Chemistry and Chemical Engineering, California Institute of Technology , Pasadena, California 91125, United States
| | - Wen-Bo Liu
- Division of Chemistry and Chemical Engineering, California Institute of Technology , Pasadena, California 91125, United States
| | - David P Schuman
- Division of Chemistry and Chemical Engineering, California Institute of Technology , Pasadena, California 91125, United States
| | - Robert H Grubbs
- Division of Chemistry and Chemical Engineering, California Institute of Technology , Pasadena, California 91125, United States
| | - Brian M Stoltz
- Division of Chemistry and Chemical Engineering, California Institute of Technology , Pasadena, California 91125, United States
| | - Elizabeth H Krenske
- School of Chemistry and Molecular Biosciences, The University of Queensland , Brisbane, QLD 4072, Australia
| | - Kendall N Houk
- Department of Chemistry and Biochemistry, University of California , Los Angeles, California 90095-1569, United States
| | - Richard N Zare
- Department of Chemistry, Stanford University , Stanford, California 94305-5080, United States
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27
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Kaiser D, de la Torre A, Shaaban S, Maulide N. Metal-Free Formal Oxidative C-C Coupling by In Situ Generation of an Enolonium Species. Angew Chem Int Ed Engl 2017; 56:5921-5925. [PMID: 28429392 DOI: 10.1002/anie.201701538] [Citation(s) in RCA: 92] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2017] [Revised: 03/11/2017] [Indexed: 01/27/2023]
Abstract
Much contemporary organic synthesis relies on transformations that are driven by the intrinsic, so-called "natural", polarity of chemical bonds and reactive centers. The design of unconventionally polarized synthons is a highly desirable strategy, as it generally enables unprecedented retrosynthetic disconnections for the synthesis of complex substances. Whereas the umpolung of carbonyl centers is a well-known strategy, polarity reversal at the α-position of a carbonyl group is much rarer. Herein, we report the design of a novel electrophilic enolonium species and its application in efficient and chemoselective, metal-free oxidative C-C coupling.
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Affiliation(s)
- Daniel Kaiser
- Institute of Organic Chemistry, University of Vienna, Währinger Strasse 38, 1090, Wien, Austria
| | - Aurélien de la Torre
- Institute of Organic Chemistry, University of Vienna, Währinger Strasse 38, 1090, Wien, Austria
| | - Saad Shaaban
- Institute of Organic Chemistry, University of Vienna, Währinger Strasse 38, 1090, Wien, Austria
| | - Nuno Maulide
- Institute of Organic Chemistry, University of Vienna, Währinger Strasse 38, 1090, Wien, Austria
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28
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Kaiser D, de la Torre A, Shaaban S, Maulide N. Metallfreie formale oxidative C-C-Kupplung durch In-situ-Erzeugung einer elektrophilen Enoloniumspezies. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201701538] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Daniel Kaiser
- Institut für Organische Chemie; Universität Wien; Währinger Straße 38 1090 Wien Österreich
| | - Aurélien de la Torre
- Institut für Organische Chemie; Universität Wien; Währinger Straße 38 1090 Wien Österreich
| | - Saad Shaaban
- Institut für Organische Chemie; Universität Wien; Währinger Straße 38 1090 Wien Österreich
| | - Nuno Maulide
- Institut für Organische Chemie; Universität Wien; Währinger Straße 38 1090 Wien Österreich
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29
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Sattar M, Rathore V, Prasad CD, Kumar S. Transition-metal-free Chemoselective Oxidative C-C Coupling of the sp 3 C-H Bond of Oxindoles with Arenes and Addition to Alkene: Synthesis of 3-Aryl Oxindoles, and Benzofuro- and Indoloindoles. Chem Asian J 2017; 12:734-743. [PMID: 28169505 DOI: 10.1002/asia.201601647] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2016] [Revised: 02/03/2017] [Indexed: 01/11/2023]
Abstract
A transition-metal (TM)-free and halogen-free NaOtBu-mediated oxidative cross-coupling between the sp3 C-H bond of oxindoles and sp2 C-H bond of nitroarenes has been developed to access 3-aryl substituted and 3,3-aryldisubstituted oxindoles in DMSO at room temperature in a short time. Interestingly, the sp3 C-H bond of oxindoles could also react with styrene under TM-free conditions for the practical synthesis of quaternary 3,3-disubstituted oxindoles. The synthesized 3-oxindoles have also been further transformed into advanced heterocycles, that is, benzofuroindoles, indoloindoles, and substituted indoles. Mechanistic experiments of the reaction suggests the formation of an anion intermediate from the sp3 C-H bond of oxindole by tert-butoxide base in DMSO. The addition of nitrobenzene to the in-situ generated carbanion leads to the 3-(nitrophenyl)oxindolyl carbanion in DMSO which is subsequently oxidized to 3-(nitro-aryl) oxindole by DMSO.
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Affiliation(s)
- Moh Sattar
- Department of Chemistry, Indian Institute of Science Education and Research, Bhopal, Bhopal Bypass Road, Bhauri Bhopal, Madhya Pradesh, 462066, India
| | - Vandana Rathore
- Department of Chemistry, Indian Institute of Science Education and Research, Bhopal, Bhopal Bypass Road, Bhauri Bhopal, Madhya Pradesh, 462066, India
| | - Ch Durga Prasad
- Department of Chemistry, Indian Institute of Science Education and Research, Bhopal, Bhopal Bypass Road, Bhauri Bhopal, Madhya Pradesh, 462066, India
| | - Sangit Kumar
- Department of Chemistry, Indian Institute of Science Education and Research, Bhopal, Bhopal Bypass Road, Bhauri Bhopal, Madhya Pradesh, 462066, India
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30
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Prasad CD, Sattar M, Kumar S. Transition-Metal-Free Selective Oxidative C(sp3)–S/Se Coupling of Oxindoles, Tetralone, and Arylacetamides: Synthesis of Unsymmetrical Organochalcogenides. Org Lett 2017; 19:774-777. [DOI: 10.1021/acs.orglett.6b03735] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Ch. Durga Prasad
- Department of Chemistry, Indian Institute of Science Education and Research (IISER), Bhopal, MP 462 066, India
| | - Moh. Sattar
- Department of Chemistry, Indian Institute of Science Education and Research (IISER), Bhopal, MP 462 066, India
| | - Sangit Kumar
- Department of Chemistry, Indian Institute of Science Education and Research (IISER), Bhopal, MP 462 066, India
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