1
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Zhou N, Zhao J, Sun C, Lai Y, Ruan Z, Feng P. Electro-Oxidative C-N Bond Formation through Azolation of Indole Derivatives: An Access to 3-Substituent-2-(Azol-1-yl)indoles. J Org Chem 2021; 86:16059-16067. [PMID: 34520191 DOI: 10.1021/acs.joc.1c01271] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A practical protocol to synthesize 3-substituent-2-(azol-1-yl)indole derivatives has been developed via an electrochemical oxidative cross coupling process under mild conditions. This electro-oxidative C-N bond formation strategy tolerates a range of functional groups and is amenable to gram scale synthesis. Moreover, this method was applied to the late-stage functionalization of bioactive molecules.
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Affiliation(s)
- Naifu Zhou
- Department of Chemistry and Guangdong Provincial Key Laboratory of Functional Supramolecular Coordination Materials and Applications, Jinan University, Guangzhou 510632, China
| | - Junhao Zhao
- Department of Chemistry and Guangdong Provincial Key Laboratory of Functional Supramolecular Coordination Materials and Applications, Jinan University, Guangzhou 510632, China
| | - Chengbo Sun
- Department of Chemistry and Guangdong Provincial Key Laboratory of Functional Supramolecular Coordination Materials and Applications, Jinan University, Guangzhou 510632, China
| | - Yuqin Lai
- Department of Chemistry and Guangdong Provincial Key Laboratory of Functional Supramolecular Coordination Materials and Applications, Jinan University, Guangzhou 510632, China
| | - Zhixiong Ruan
- Key Laboratory of Molecular Target & Clinical Pharmacology and the State Key Laboratory of Respiratory Disease, School of Pharmaceutical Science, and the Fifth Affiliated Hospital, Guangzhou Medical University, Guangzhou 511436, China
| | - Pengju Feng
- Department of Chemistry and Guangdong Provincial Key Laboratory of Functional Supramolecular Coordination Materials and Applications, Jinan University, Guangzhou 510632, China
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2
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Li ZC, Zhang Y, Yan BX, Wang XN, Zhai DH, Li Q, Zheng HX, Zhao CQ. The conversion of ether bonds to hydroxyl via a base-promoted rearrangement of cyclic phosphine oxides. Org Chem Front 2021. [DOI: 10.1039/d1qo00925g] [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
Biphenyl derived secondary phosphine oxides having 2′-hydroxyl were prepared.
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Affiliation(s)
- Zhan-Cai Li
- College of Chemistry and Chemical Engineering, Liaocheng University, No. 1, Hunan Road, Liaocheng, Shandong, 252059, China
| | - Yu Zhang
- College of Chemistry and Chemical Engineering, Liaocheng University, No. 1, Hunan Road, Liaocheng, Shandong, 252059, China
| | - Bing-Xia Yan
- College of Chemistry and Chemical Engineering, Liaocheng University, No. 1, Hunan Road, Liaocheng, Shandong, 252059, China
| | - Xiao-Ning Wang
- College of Chemistry and Chemical Engineering, Liaocheng University, No. 1, Hunan Road, Liaocheng, Shandong, 252059, China
| | - De-Hua Zhai
- College of Chemistry and Chemical Engineering, Liaocheng University, No. 1, Hunan Road, Liaocheng, Shandong, 252059, China
| | - Qiang Li
- College of Chemistry and Chemical Engineering, Liaocheng University, No. 1, Hunan Road, Liaocheng, Shandong, 252059, China
| | - Hong-Xing Zheng
- College of Chemistry and Chemical Engineering, Liaocheng University, No. 1, Hunan Road, Liaocheng, Shandong, 252059, China
| | - Chang-Qiu Zhao
- College of Chemistry and Chemical Engineering, Liaocheng University, No. 1, Hunan Road, Liaocheng, Shandong, 252059, China
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3
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Devi R, Mukhopadhyay S, Jyoti Das A, Kumar Das S. Base-mediated synthesis of benzimidazole-fused 1,4-benzoxazepines via sequential intermolecular epoxide ring-opening/intramolecular SNAr reactions. Tetrahedron Lett 2020. [DOI: 10.1016/j.tetlet.2020.152491] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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4
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Yan BX, Zhang Y, Zheng HX, Ye JJ, Wang XN, Li Q, Zhao CQ. Cleavage of Aromatic C-O Bonds via Intramolecular S NAr Reaction and Preparation of P, C, Axial-Stereogenic Menthyl Phosphine Derivatives. Org Lett 2020; 22:7947-7951. [PMID: 32996768 DOI: 10.1021/acs.orglett.0c02861] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Phosphine ligands with up to six chiral sites were prepared, starting from 2-phenylphenol, via O- and P-alkylation, cyclization, and coupling. The chirality was transferred from (L)-menthyl to phosphorus, α-carbon, and axis, to achieve excellent diastereoselectivities. During an intramolecular SNAr reaction with alkoxyl as the leaving groups, the C-O bond was converted to a C-C bond. Both phosphine boranes and oxides could be used for the conversions, affording a series of cyclic phosphines.
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Affiliation(s)
- Bing-Xia Yan
- College of Chemistry and Chemical Engineering, Liaocheng University, No. 1, Hunan Road, Liaocheng, Shandong 252059, China
| | - Yu Zhang
- College of Chemistry and Chemical Engineering, Liaocheng University, No. 1, Hunan Road, Liaocheng, Shandong 252059, China
| | - Hong-Xing Zheng
- College of Chemistry and Chemical Engineering, Liaocheng University, No. 1, Hunan Road, Liaocheng, Shandong 252059, China
| | - Jing-Jing Ye
- College of Chemistry and Chemical Engineering, Liaocheng University, No. 1, Hunan Road, Liaocheng, Shandong 252059, China
| | - Xiao-Ning Wang
- College of Chemistry and Chemical Engineering, Liaocheng University, No. 1, Hunan Road, Liaocheng, Shandong 252059, China
| | - Qiang Li
- College of Chemistry and Chemical Engineering, Liaocheng University, No. 1, Hunan Road, Liaocheng, Shandong 252059, China
| | - Chang-Qiu Zhao
- College of Chemistry and Chemical Engineering, Liaocheng University, No. 1, Hunan Road, Liaocheng, Shandong 252059, China
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5
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Chou TC, Cheng JF, Gholap AR, Huang JJK, Chen JC, Huang JK, Tseng JC. Aromatization-driven Grob-fragmentation approach toward polyazaacenes. Synthesis and amination of multi-functionalized diazapentacenes. Tetrahedron 2019. [DOI: 10.1016/j.tet.2019.130689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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6
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Shigeno M, Hayashi K, Nozawa-Kumada K, Kondo Y. Organic Superbase t-Bu-P4 Catalyzes Amination of Methoxy(hetero)arenes. Org Lett 2019; 21:5505-5508. [PMID: 31264886 DOI: 10.1021/acs.orglett.9b01805] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We report that the organic superbase t-Bu-P4 efficiently catalyzes the amination of methoxy(hetero)arenes with amine nucleophiles such as aniline, indoline, and aminopyridine derivatives. This catalytic reaction is effective for the transformation of electron-deficient methoxyarenes possessing diverse functionalities (carbonyl, cyano, nitro, and halogen) as well as methoxyheteroarenes, including pyrazine, quinoline, isoquinoline, and pyridine derivatives. Intramolecular reactions provide six- and seven-membered ring cyclic amine products.
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Affiliation(s)
- Masanori Shigeno
- Department of Biophysical Chemistry, Graduate School of Pharmaceutical Sciences , Tohoku University , Aoba, Sendai 980-8578 , Japan
| | - Kazutoshi Hayashi
- Department of Biophysical Chemistry, Graduate School of Pharmaceutical Sciences , Tohoku University , Aoba, Sendai 980-8578 , Japan
| | - Kanako Nozawa-Kumada
- Department of Biophysical Chemistry, Graduate School of Pharmaceutical Sciences , Tohoku University , Aoba, Sendai 980-8578 , Japan
| | - Yoshinori Kondo
- Department of Biophysical Chemistry, Graduate School of Pharmaceutical Sciences , Tohoku University , Aoba, Sendai 980-8578 , Japan
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7
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Charushin VN, Chupakhin ON. Nucleophilic C—H functionalization of arenes: a contribution to green chemistry. Russ Chem Bull 2019. [DOI: 10.1007/s11172-019-2441-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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8
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Shigeno M, Hayashi K, Nozawa-Kumada K, Kondo Y. Phosphazene Base tBu-P4 Catalyzed Methoxy-Alkoxy Exchange Reaction on (Hetero)Arenes. Chemistry 2019; 25:6077-6081. [PMID: 30807672 DOI: 10.1002/chem.201900498] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 02/22/2019] [Indexed: 12/14/2022]
Abstract
The organic superbase tBu-P4 catalyzes methoxy-alkoxy exchange reactions on (hetero)arenes with alcohols. The catalytic reaction proceeded efficiently with electron-deficient methoxy(hetero)arenes as well as with a variety of alcohols, including 3-amino-1-propanol, β-citronellol, menthol, and cholesterol. An intramolecular version of this reaction furnished six- and seven-membered ring compounds.
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Affiliation(s)
- Masanori Shigeno
- Department of Biophysical Chemistry, Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba, Sendai, 980-8578, Japan
| | - Kazutoshi Hayashi
- Department of Biophysical Chemistry, Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba, Sendai, 980-8578, Japan
| | - Kanako Nozawa-Kumada
- Department of Biophysical Chemistry, Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba, Sendai, 980-8578, Japan
| | - Yoshinori Kondo
- Department of Biophysical Chemistry, Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba, Sendai, 980-8578, Japan
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9
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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: 582] [Impact Index Per Article: 97.0] [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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10
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Wang X, Li C, Wang X, Wang Q, Dong XQ, Duan A, Zhao W. Metal-Free Etherification of Aryl Methyl Ether Derivatives by C–OMe Bond Cleavage. Org Lett 2018; 20:4267-4272. [DOI: 10.1021/acs.orglett.8b01696] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Xueqiang Wang
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, China
| | - Chenchen Li
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, China
| | - Xia Wang
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, China
| | - Qingli Wang
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, China
| | - Xiu-Qin Dong
- Key Laboratory of Biomedical Polymers, Ministry of Education, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, Hubei 430072, China
| | - Abing Duan
- College of Environmental Science and Engineering, Hunan University, Changsha, Hunan 410082, China
| | - Wanxiang Zhao
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, China
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11
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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: 1865] [Impact Index Per Article: 266.4] [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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12
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Chupakhin ON, Charushin VN. Nucleophilic C–H functionalization of arenes: a new logic of organic synthesis. PURE APPL CHEM 2017. [DOI: 10.1515/pac-2017-0108] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AbstractDirect metal-free C–H functionalization of arenes with nucleophiles is a new chapter in the chemistry of aromatics. Comprehensive studies on nucleophilic substitution of hydrogen in arenes (the SNH reactions), including mechanisms, intermediates, mathematic and electrochemical modeling, kinetics, electron-transfer, etc. have shown that this is not the hydride ion, but C–H proton is departed, and this process is facilitated by the presence of an appropriate oxidant or an auxiliary group. The SNH reactions, as a part of the general C–H functionalization concept, change the logic of organic synthesis. They open new opportunities, avoiding incorporation of good leaving groups or other auxiliaries in an aromatic ring, as a prefunctionalization step, thus providing a better correspondence to the principles of green chemistry.
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Affiliation(s)
- Oleg N. Chupakhin
- Ural Federal Univeristy named after the First President of Russia B.N. Eltsin, Postovsky Institute of Organic Synthesis, Ural Branch of the Russian Academy of Sciences, S.Kovalevskaya/Academicheskaya st. 22/20, 620099 Ekaterinburg, Russia
| | - Valery N. Charushin
- Ural Federal Univeristy named after the First President of Russia B.N. Eltsin, Postovsky Institute of Organic Synthesis, Ural Branch of the Russian Academy of Sciences, S.Kovalevskaya/Academicheskaya st. 22/20, 620099 Ekaterinburg, Russia
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13
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Khutorianskyi VV, Sonawane M, Pošta M, Klepetářová B, Beier P. Oxidative nucleophilic aromatic amination of nitrobenzenes. Chem Commun (Camb) 2016; 52:7237-40. [PMID: 27152372 DOI: 10.1039/c6cc02235a] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Nitrobenzenes substituted with electron-acceptor groups such as halogen, nitro, trifluoromethyl, pentafluorosulfanyl, or cyano underwent oxidative nucleophilic substitution with lithium salts of arylamines to afford N-aryl-2-nitroanilines.
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Affiliation(s)
- V V Khutorianskyi
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nám. 2, 166 10 Prague, Czech Republic.
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14
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Rostamizadeh S, Nojavan M, Aryan R. Synthesis of N2-arylaminopyrimidine-5-carbonitrile derivatives via SNAr amination reaction. CHINESE CHEM LETT 2015. [DOI: 10.1016/j.cclet.2014.10.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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15
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Abstract
New polynitrostilbenes were directly synthesised by the Knoevenagel condensation of aromatic aldehydes with nitrotoluenes. The differential scanning calorimetry results demonstrated that the introduction of an amino group and C=C double bonds could improve the thermal stability.
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16
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Glaser R, Ulmer L, Coyle S. Mechanistic models for LAH reductions of acetonitrile and malononitrile. Aggregation effects of Li+ and AlH3 on imide-enamide equilibria. J Org Chem 2013; 78:1113-26. [PMID: 23327108 DOI: 10.1021/jo302527k] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The results are reported of an ab initio study of the addition of LiAlH(4) to acetonitrile and malononitrile at the MP2(full)/6-311+G* level considering the effects of electron correlation at higher levels up to QCISD(T)/6-311++G(2df,2pd) and including ether solvation. All imide (RCH(2)CH═N(-)) and enamide (RCH(-)CH═NH ↔ RCH═CHN(-)H) adducts feature strong interactions between the organic anion and both Li(+) and AlH(3). The relative stabilities of the tautomeric LAH adducts are compared to the tautomer preference energies of the LiH adducts and of the hydride adducts of the nitriles. Alane affinities were determined for the lithium ion pairs formed by LiH addition to the nitriles. The results show that alane binding greatly affects the imide-enamide equilibria and that alane complexation might even provide a thermodynamic preference for the imide intermediate. While lithium enamides of malononitrile are much more stable than lithium imides, alane binding dramatically reduces the enamide preference so that both tautomers are present at equilibrium. Implications are discussed regarding to the propensity for multiple hydride reductions and with regard to the mechanism of reductive nitrile dimerization. A detailed mechanism is proposed for the formation of 2-aminonicotinonitrile (2ANN) in the LAH reduction of malononitrile.
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Affiliation(s)
- Rainer Glaser
- Department of Chemistry, University of Missouri, Columbia, Missouri 65211, USA.
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17
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Cruz H, Gallardo I, Guirado G. Electrochemical Synthesis of Organophosphorus Compounds through Nucleophilic Aromatic Substitution: Mechanistic Investigations and Synthetic Scope. European J Org Chem 2011. [DOI: 10.1002/ejoc.201101357] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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18
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19
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Clark GR, Ferguson LA, McIntosh AE, Söhnel T, Wright LJ. Functionalization of metallabenzenes through nucleophilic aromatic substitution of hydrogen. J Am Chem Soc 2010; 132:13443-52. [PMID: 20822136 DOI: 10.1021/ja105239t] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The cationic metallabenzenes [Ir(C(5)H(4){SMe-1})(κ(2)-S(2)CNEt(2))(PPh(3))(2)]PF(6) (1) and [Os(C(5)H(4){SMe-1})(CO)(2)(PPh(3))(2)][CF(3)SO(3)] (2) undergo regioselective nucleophilic aromatic substitution of hydrogen at the metallabenzene ring position γ to the metal in a two-step process that first involves treatment with appropriate nucleophiles and then oxidation. Thus, reaction between compound 1 and NaBH(4), MeLi, or NaOEt gives the corresponding neutral iridacyclohexa-1,4-diene complexes Ir(C(5)H(3){SMe-1}{H-3}{Nu-3})(κ(2)-S(2)CNEt(2))(PPh(3))(2) (Nu = H (3), Me (4), OEt (5)). Similarly, reaction between 2 and NaBH(4) or MeLi gives the corresponding osmacyclohexa-1,4-diene complexes Os(C(5)H(3){SMe-1}{H-3}{Nu-3})(CO)(2)(PPh(3))(2) (Nu = H (8), Me (9)). The metallacyclohexa-1,4-diene rings in all these compounds are rearomatized on treatment with the oxidizing agent O(2), CuCl(2), or 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ). Accordingly, the cationic metallabenzene 1 or 2 is returned after reaction between 3 and DDQ/NEt(4)PF(6) or between 8 and DDQ/NaO(3)SCF(3), respectively. The substituted cationic iridabenzene [Ir(C(5)H(3){SMe-1}{Me-3})(κ(2)-S(2)CNEt(2))(PPh(3))(2)]PF(6) (6) or [Ir(C(5)H(4){SMe-1}{OEt-3})(κ(2)-S(2)CNEt(2))(PPh(3))(2)]PF(6) (7) is produced in a similar manner through reaction between 4 or 5, respectively, and DDQ/NEt(4)PF(6), and the substituted cationic osmabenzene [Os(C(5)H(3){SMe-1}{Me-3})(CO)(2)(PPh(3))(2)]Cl (10) is formed in good yield on treatment of 9 with CuCl(2). The starting cationic iridabenzene 1 is conveniently prepared by treatment of the neutral iridabenzene Ir(C(5)H(4){SMe-1})Cl(2)(PPh(3))(2) with NaS(2)CNEt(2) and NEt(4)PF(6), and the related starting cationic osmabenzene 2 is obtained by treatment of Os(C(5)H(4){S-1})(CO)(PPh(3))(2) with CF(3)SO(3)CH(3) and CO. The stepwise transformations of 1 into 6 or 7 as well as 2 into 10 provide the first examples in metallabenzene chemistry of regioselective nucleophilic aromatic substitutions of hydrogen by external nucleophiles. DFT calculations have been used to rationalize the preferred sites for nucleophilic attack at the metallabenzene rings of 1 and 2. The crystal structures of 1, 3, 6, and 7 have been obtained.
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Affiliation(s)
- George R Clark
- Department of Chemistry, The University of Auckland, Private Bag 92019, Auckland, New Zealand
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Holovko-Kamoshenkova OM, Kirij NV, Boiko VN, Rozhenko AB, Yagupolskii YL. Stable gem-trifluoromethyl anionic σ-complexes based on 1,3,5-tris(sulfonyl)benzene derivatives and their transformations. J Fluor Chem 2010. [DOI: 10.1016/j.jfluchem.2010.09.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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21
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Sulikowski D, Mąkosza M. Oxidative Nucleophilic Substitution of Hydrogen in Nitroarenes with Carbanions of Protected Serine and Threonine Esters. European J Org Chem 2010. [DOI: 10.1002/ejoc.201000498] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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22
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Yang XF, Su Z, Liu C, Qi H, Zhao M. A thiol-selective fluorogenic probe based on the cleavage of 4-methylumbelliferyl-2’,4’,6’-trinitropheyl ether. Anal Bioanal Chem 2010; 396:2667-74. [DOI: 10.1007/s00216-010-3475-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2009] [Revised: 01/13/2010] [Accepted: 01/14/2010] [Indexed: 11/24/2022]
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23
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Álvarez-Griera L, Gallardo I, Guirado G. Estimation of nitrobenzyl radicals reduction potential using spectro-electrochemical techniques. Electrochim Acta 2009. [DOI: 10.1016/j.electacta.2009.02.037] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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24
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Ma̧kosza M, Sulikowski D. Synthesis of α-(Nitroaryl)benzylphosphonates via Oxidative Nucleophilic Substitution of Hydrogen in Nitroarenes. J Org Chem 2009; 74:3827-32. [DOI: 10.1021/jo900204e] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Mieczysław Ma̧kosza
- Institute of Organic Chemistry PAS, Kasprzaka 44/52, 00-224 Warszawa, Poland
| | - Daniel Sulikowski
- Institute of Organic Chemistry PAS, Kasprzaka 44/52, 00-224 Warszawa, Poland
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25
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Gulevskaya AV, Verbeeck S, Burov ON, Meyers C, Korbukova IN, Herrebout W, Maes BUW. Synthesis of (Alkylamino)nitroarenes by Oxidative Alkylamination of Nitroarenes. European J Org Chem 2009. [DOI: 10.1002/ejoc.200800740] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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26
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Gallardo I, Guirado G. Oxygen carriers based on electrochemically reduced trinitroarenes. Phys Chem Chem Phys 2008; 10:4456-62. [PMID: 18654686 DOI: 10.1039/b801419a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
1,3,5-Trinitrobenzene, 2,4,6-trinitrotoluene and 1-methoxy-2,4,6-trinitrobenzene undergoes reversible dimerization, after electrochemical reduction of two units of corresponding anion radical. The pi-dimer formed captures molecular oxygen (O(2)) leading to a sigma(o-o)(H)-adduct, in an atmosphere of oxygen or even air. The sigma(o-o)(H)-adduct is able to reversibly bind and remove dioxygen after an external redox stimulus.
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Affiliation(s)
- Iluminada Gallardo
- Departament de Química, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.
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Gallardo I, Guirado G. Thermodynamic Study of σH Complexes in Nucleophilic Aromatic Substitution Reactions: Relative Stabilities of Electrochemically Generated Radicals. European J Org Chem 2008. [DOI: 10.1002/ejoc.200701098] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Gallardo I, Guirado G, Marquet J, Vilà N. Evidence for a π Dimer in the Electrochemical Reduction of 1,3,5-Trinitrobenzene: A Reversible N2-Fixation System. Angew Chem Int Ed Engl 2007; 46:1321-5. [PMID: 17195265 DOI: 10.1002/anie.200602690] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Iluminada Gallardo
- Departament de Química, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.
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Gallardo I, Guirado G, Marquet J, Vilà N. Evidence for a π Dimer in the Electrochemical Reduction of 1,3,5-Trinitrobenzene: A Reversible N2-Fixation System. Angew Chem Int Ed Engl 2007. [DOI: 10.1002/ange.200602690] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Gallardo I, Guirado G. Electrochemical mechanism of spiro and zwitterionic Meisenheimer compounds: A potential fluorescence molecular switching system. Electrochem commun 2007. [DOI: 10.1016/j.elecom.2006.08.054] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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Terrier F, Lakhdar S, Boubaker T, Goumont R. Ranking the Reactivity of Superelectrophilic Heteroaromatics on the Electrophilicity Scale. J Org Chem 2005; 70:6242-53. [PMID: 16050683 DOI: 10.1021/jo0505526] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The kinetics of the reactions of a series of reference carbon nucleophiles, consisting of N-methylpyrrole A, indole B, N-methylindole C, and enamines D-G, with 10 electron-deficient aromatic and heteroaromatic substrates (1-10), resulting in the formation of stable anionic sigma-adducts, have been investigated in acetonitrile at 20 degrees C. It is shown that the second-order rate constants k(1) pertaining to the carbon-carbon coupling step of these processes fit nicely the three-parameter equation log k (20 degrees C) = s(N + E), allowing the determination of the electrophilicity parameters E of 1-10 and therefore the ranking of these neutral electron-deficient compounds on the comprehensive electrophilicity scale defined for cationic electrophiles by Mayr et al. (Mayr, H.; Kempf, B,; Ofial, A. R. Acc. Chem. Res. 2003, 36, 66). The E values of 1-10 are found to cover a range from -13 to -5, going from 1,3,5-trinitrobenzene 1, the least reactive molecule, to 4,6-dinitrotetrazolo[1,5-a]pyridine 8, 4-nitro-6-trifluoromethanesulfonylbenzofuroxan 3, and 4,6-dinitrobenzofuroxan 2, the three most reactive heterocycles. Of major interest is that the E value of 2 is essentially the same as that for 4-nitrobenzenediazonium cation (E = -5.1), approaching that of the tropylium cation family (E approximately -3 to -6) as well as a number of metal-coordinated carbenium ions. Such a ranking holds promise for expanding the range of coupling reactions which can be envisioned with such strongly electron-deficient neutral heteroaromatics as nitrobenzofuroxans and related compounds. Arguments are also given which exclude the possibility for the reactions studied to proceed via an electron-transfer mechanism.
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Affiliation(s)
- François Terrier
- Laboratoire SIRCOB, UMR 8086, Institut Lavoisier-Franklin, Université de Versailles, 45, Avenue des Etats-Unis, 78035 Versailles Cedex, France.
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Tejero I, Huertas I, González-Lafont A, Lluch JM, Marquet J. A Fast Radical Chain Mechanism in the Polyfluoroalkoxylation of Aromatics through NO2 Group Displacement. Mechanistic and Theoretical Studies. J Org Chem 2005; 70:1718-27. [PMID: 15730293 DOI: 10.1021/jo048354m] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Introduction of polyfluoroalkoxy and polyfluoroalkylthio substituents in aromatic rings can be achieved with mild conditions and short times thorough reaction of concentrated solutions of dinitrobenzenes in DMF with polyfluoro alcohols and polyfluoro thiols in moderate excess, in the presence of excess tetrabutylammonium fluoride as a base. Mechanistic studies suggest that under these conditions a fast radical chain mechanism operates. This mechanism is elicited by oxidation of a Meisenheimer complex and proceeds through a radical aromatic substitution with the polyfluoroalkoxy or the polyfluoroalkylthio radicals as key intermediates. At low concentrations, entrainment can be achieved with superoxide anion. A rationale for this effect is discussed. Answers to particular questions about the proposed mechanism are achieved through a theoretical study at the B3LYP/6-31+G(d,p) level. Specifically, the competition between the radical mechanism and the corresponding polar one (classical S(N)Ar reaction) is studied in that way, with the conclusion that the key steps of the radical mechanism in our reaction conditions (polar aprotic solvent) are at least as efficient as the ones of the polar one, thus justifying the observed kinetic advantage for the chain reaction in the conditions where an efficient initiation occurs.
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Affiliation(s)
- Ismael Tejero
- Departament de Química, Universitat Autonoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
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Zhou H, Tai Y, Sun C, Pan Y. Separation and characterization of synthetic impurities of triclabendazole by reversed-phase high-performance liquid chromatography/electrospray ionization mass spectrometry. J Pharm Biomed Anal 2005; 37:97-107. [PMID: 15664748 DOI: 10.1016/j.jpba.2004.09.049] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2004] [Revised: 09/28/2004] [Accepted: 09/29/2004] [Indexed: 10/26/2022]
Abstract
A simple high-performance liquid chromatography/electrospray ionization mass spectrometry (HPLC/ESI-MS) method for the separation and characterization of impurities in the synthesis of triclabendazole has been developed. The analytical separation was achieved on a reversed-phase C18 column using acetonitrile and water (60:40, v/v) as mobile solvent at a flow-rate of 1.0 ml/min at 25 degrees C, and an UV detection at 230 nm. The on-line HPLC/ESI-MSn examinations were performed using ion trap analyzer with extraction ion chromatography (EIC) technique in positive or negative ion modes. The semi-preparative separation was performed with a reversed-phase column using methanol and water (75:25, v/v) as mobile solvent at a flow-rate of 4 ml/min at 25 degrees C, and an UV detection at 230 nm. Thus, two impurities were detected and identified as 5-chloro-6-(2,3,4-trichlorophenoxy)-2-methylsulfanyl-1H-benzoimidazole and 5-chloro-6-(2,3-dichlorophenoxy)-1-methyl-2-methylsulfanyl-1H-benzoimidazole. Meanwhile, some intermediates of impurity-1 in multi-step synthetic reactions, were tracked. Structural elucidation by 1D and 2D NMR and ESI-MSn was discussed.
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Affiliation(s)
- Hui Zhou
- Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang Province 310027, China
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Maruoka H, Tomioka Y. Reactions of nitroarenes with secondary and tertiary carbanions bearing both a leaving group and electron-withdrawing group: An approach to dihydronaphth[2,1-c]isoxazoleN-oxides and dihydroisoxazolo[4,3-f]quinolineN-oxides. J Heterocycl Chem 2003. [DOI: 10.1002/jhet.5570400613] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Gallardo I, Guirado G, Marquet J. Alkylation of nitroaromatics with tetraalkylborate ion via electrochemical oxidation. J Org Chem 2003; 68:7334-41. [PMID: 12968884 DOI: 10.1021/jo030158c] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Aromatic nucleophilic substitution reaction (S(N)Ar) is one of the most thoroughly studied reactions. Alkylation of nitroaromatics with Grignard reagents via chemical oxidation of the sigma(H)-complexes is the most general method to introduce an alkyl group into a nitroaromatic compound. This approach has considerable drawbacks, especially when more than one nitro group are present in the aromatic ring. In this article, we present an electrochemical approach, which offers a new very selective methodology for obtaining alkyl polynitroaromatic compounds. Different strategies based on the use of tetralkylborate anion as nucleophiles are used so as to increase efficiency and to reduce the drawbacks associated with this reaction. A wide list of dinitro- and trinitro-aromatic compounds are studied, the range of yields obtained being from fair (40%) to excellent (85%). The key to improvement in the process is the use of electrochemical techniques for the oxidation of the mixture sigma(H)-complexes/tetrabutylborate ion. The electroactive character of the nucleophile, which can be oxidized to an alkyl radical, means that the S(N)Ar of the hydrogen polar mechanism is not the only mechanism operating during the electroxidation process, since the hydrogen radical S(N)Ar mechanism is running at the same time. Electrochemical mechanistic studies allow the participation of each mechanism in the global product yield obtained to be quantified.
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Affiliation(s)
- Iluminada Gallardo
- Departament de Química, Universitat Autónoma de Barcelona, E-08193 Bellaterra, Barcelona, Spain.
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Terrier F, Mokhtari M, Goumont R, Hallé JC, Buncel E. High Brønsted beta nuc values in SNAr displacement. An indicator of the SET pathway? Org Biomol Chem 2003; 1:1757-63. [PMID: 12926366 DOI: 10.1039/b301031g] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Nucleophilic substitutions of 4-chloro-7-nitrobenzofurazan (NBD-Cl) and 3-methyl-1-(4-nitrobenzofurazanyl)-imidazolium ions (NBD-Im+) with a series of 4-X-substituted anilines have been kinetically investigated in 70-30 (v/v) and 20-80 (v/v) H2O-Me2SO mixtures. The rate-limiting step in these reactions is nucleophilic addition with formation of Meisenheimer-type sigma-adducts followed by fast expulsion of the leaving group (Cl- or Im). The reactions are characterized by a notable sensitivity to basicity of the aniline nucleophiles, with Hammett rho values of -2.68 and -3.82 in 30% and 80% Me2SO, respectively, for NBD-Cl and even more negative values, -3.43 and -5.27, respectively, for NBD-Im+. This is consistent with significant development of positive charge at the nitrogen atom of the zwitterionic sigma-adduct. Unexpectedly, the Brønsted-type plots reveal abnormally high beta nuc values, ca. 1.0 and 1.3-1.4, respectively. Satisfactory correlations between the rates of the reactions and the oxidation potentials of the respective anilines support a SET mechanism for this process, i.e. initial (fast) electron-transfer from the aniline donor to the nitrobenzofurazan acceptor moiety and subsequent (slow) coupling of the resulting cation and anion radicals within the solvent cage with formation of the sigma-adduct. An alternative possible explanation of the high beta nuc values being related to the strong--I effect exerted by the negatively charged 4-nitrobenzofurazanyl structure, which would induce a greater positive charge at the developing anilinium nitrogen atom in the sigma-adduct-like transition state as compared with the situation in the reference protonation equilibria of anilines, is considered less probable. It is thus proposed that obtention of abnormal beta nuc values may be an indicator of electron-transfer in nucleophilic aromatic substitution and highlights the transition from the polar (SNAr) to the single electron-transfer (SET) mechanism.
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Affiliation(s)
- François Terrier
- Laboratoire SIRCOB, Institut Lavoisier-Franklin, ESA CNRS 8086, Université de Versailles, 45 Avenue des Etats-Unis, 78035-Versailles, France.
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Gallardo I, Guirado G, Marquet J. Electrochemical synthesis of alkyl nitroaromatic compounds. J Org Chem 2003; 68:631-3. [PMID: 12530899 DOI: 10.1021/jo025898k] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Alkyl nitroaromatic compounds were readily prepared via nucleophilic aromatic substitution for hydrogen or a heteroatom by electrochemical oxidation of the sigma-complex. Butyllithium and butylmagnesium chloride were used as nucleophiles, and several nitrocompounds were tested to explore the possibilities of the NASH and NASX reactions promoted electrochemically.
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Affiliation(s)
- Iluminada Gallardo
- Departament de Química, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Spain.
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