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Sun W, Wilding-Steele L, Brown RCD, Harrowven DC. Aryl-aryl cross-coupling reactions without reagents or catalysts: photocyclization of ortho-iodoaryl ethers and related compounds via triplet aryl cation intermediates. Chem Commun (Camb) 2023; 59:10797-10800. [PMID: 37594190 DOI: 10.1039/d3cc03271j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/19/2023]
Abstract
Cyclisations of benzyl ortho-iodoaryl ethers to benzo[c]chromenes can be effected without reagents or catalysts by irradiation with UVC under flow. Reactions proceed via triplet aryl cation generation, 5-exo and 3-exo-cyclisations, and rearomatisation. They have wide scope, are easy to effect and extend to a myriad of related ring systems.
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Affiliation(s)
- Wei Sun
- Department of Chemistry, University of Southampton, Highfield, Southampton, SO17 1BJ, UK.
| | - Luke Wilding-Steele
- Department of Chemistry, University of Southampton, Highfield, Southampton, SO17 1BJ, UK.
| | - Richard C D Brown
- Department of Chemistry, University of Southampton, Highfield, Southampton, SO17 1BJ, UK.
| | - David C Harrowven
- Department of Chemistry, University of Southampton, Highfield, Southampton, SO17 1BJ, UK.
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Luo CH, Wang PL, Chang CC. Cascade Vinyl Radical Ipso-Cyclization Reactions and the Formation of α,β-Unsaturated-β-aryl-γ-lactams from N-Propargyl Benzamides. J Org Chem 2021; 86:15033-15044. [PMID: 34591475 DOI: 10.1021/acs.joc.1c01717] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Various N-(2-bromo-allyl) benzamides were used as the starting materials to study vinyl radical cyclization reactions. The vinyl radicals underwent ipso-cyclization, fragmentation, and cyclization reactions to produce β-aryl-γ-lactams with the carbonyl group remaining intact. To further study this cascade radical reaction, vinyl radicals were generated by the addition of a tributyltin radical to alkyne moieties, followed by radical ipso-cyclization, fragmentation, cyclization, and β-scission reactions with the production of a series of α,β-unsaturated-β-aryl-γ-lactam derivatives. This new type of radical reaction was examined from the substituent effects on both the amino groups and the aryl groups. A bulky tert-butyl substituent on the amino group enhanced the formation of a Z-conformation of the benzamides and facilitated vinyl radical ipso-cyclization reactions. A synthetic method for preparing α,β-unsaturated-β-aryl-γ-lactams from N-propargyl benzamides was developed.
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Affiliation(s)
- Chih-Hao Luo
- Department of Chemistry, Fu Jen Catholic University, 510 Zhongzheng Road, Xinzhuang District, New Taipei City, 24205 Taiwan
| | - Pei-Ling Wang
- Department of Chemistry, Fu Jen Catholic University, 510 Zhongzheng Road, Xinzhuang District, New Taipei City, 24205 Taiwan
| | - Che-Chien Chang
- Department of Chemistry, Fu Jen Catholic University, 510 Zhongzheng Road, Xinzhuang District, New Taipei City, 24205 Taiwan
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Zhou Q, Xiong FT, Chen P, Xiong BQ, Tang KW, Liu Y. The visible-light-induced acylation/cyclization of alkynoates with acyl oximes for the construction of 3-acylcoumarins. Org Biomol Chem 2021; 19:9012-9020. [PMID: 34610069 DOI: 10.1039/d1ob01568k] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A nitrogen-centered radical-mediated carbon-carbon bond cleavage strategy is described to synthesize functionalized 3-acylcoumarins. The strategy is enabled by the visible-light-induced acylation/cyclization of alkynoates with various acyl oxime compounds in acetonitrile. The difunctionalization of carbon-carbon triple bonds precedes the generation of iminyl radicals, which is followed by the formation of acyl radicals. The acyl radicals then attack the carbon-carbon triple bonds, followed by 5-exo-trig cyclization and 1,2-ester migration. This strategy has wide substrate adaptability and good substituent tolerance.
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Affiliation(s)
- Quan Zhou
- Department of Chemistry and Chemical Engineering, Hunan Institute of Science and Technology, Yueyang 414006, China.
| | - Fang-Ting Xiong
- Department of Chemistry and Chemical Engineering, Hunan Institute of Science and Technology, Yueyang 414006, China.
| | - Pu Chen
- Department of Chemistry and Chemical Engineering, Hunan Institute of Science and Technology, Yueyang 414006, China.
| | - Bi-Quan Xiong
- Department of Chemistry and Chemical Engineering, Hunan Institute of Science and Technology, Yueyang 414006, China.
| | - Ke-Wen Tang
- Department of Chemistry and Chemical Engineering, Hunan Institute of Science and Technology, Yueyang 414006, China.
| | - Yu Liu
- Department of Chemistry and Chemical Engineering, Hunan Institute of Science and Technology, Yueyang 414006, China.
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Boz E, Özcan H, Zaim Ö, Tüzün NŞ. Regioselectivity Patterns in Radical Cyclization of Diosphenol Derivatives with Different Ring Size: A Combined Experimental and DFT Study. ChemistrySelect 2021. [DOI: 10.1002/slct.202004601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Esra Boz
- Department of Chemistry Istanbul Technical University 34469 Istanbul Turkey
| | - Hafize Özcan
- Department of Chemistry Trakya University 22030 Edirne Turkey
| | - Ömer Zaim
- Department of Chemistry Trakya University 22030 Edirne Turkey
| | - Nurcan Ş. Tüzün
- Department of Chemistry Istanbul Technical University 34469 Istanbul Turkey
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The role of organic electron donors in the initiation of BHAS base-induced coupling reactions between haloarenes and arenes. Sci China Chem 2019. [DOI: 10.1007/s11426-019-9611-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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6
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dos Passos Gomes G, Wimmer A, Smith JM, König B, Alabugin IV. CO2 or SO2: Should It Stay, or Should It Go? J Org Chem 2019; 84:6232-6243. [DOI: 10.1021/acs.joc.9b00503] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Gabriel dos Passos Gomes
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32309, United States
| | - Alexander Wimmer
- Institut für Organische Chemie, Universität Regensburg, Universitätsstraße 31, Regensburg 93040, Germany
| | - Joel M. Smith
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32309, United States
| | - Burkhard König
- Institut für Organische Chemie, Universität Regensburg, Universitätsstraße 31, Regensburg 93040, Germany
| | - Igor V. Alabugin
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32309, United States
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Syroeshkin MA, Kuriakose F, Saverina EA, Timofeeva VA, Egorov MP, Alabugin IV. Hochkonversion von Reduktionsmitteln. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201807247] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Mikhail A. Syroeshkin
- N. D. Zelinsky Institute of Organic Chemistry Leninskyprosp. 47 119991 Moskau Russland
| | - Febin Kuriakose
- Department of Chemistry and Biochemistry Florida State University Tallahassee FL USA
| | - Evgeniya A. Saverina
- N. D. Zelinsky Institute of Organic Chemistry Leninskyprosp. 47 119991 Moskau Russland
- UMR CNRS 6226 ISCR University of Rennes 1 Rennes Frankreich
| | | | - Mikhail P. Egorov
- N. D. Zelinsky Institute of Organic Chemistry Leninskyprosp. 47 119991 Moskau Russland
| | - Igor V. Alabugin
- Department of Chemistry and Biochemistry Florida State University Tallahassee FL USA
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Syroeshkin MA, Kuriakose F, Saverina EA, Timofeeva VA, Egorov MP, Alabugin IV. Upconversion of Reductants. Angew Chem Int Ed Engl 2019; 58:5532-5550. [DOI: 10.1002/anie.201807247] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2018] [Indexed: 11/08/2022]
Affiliation(s)
- Mikhail A. Syroeshkin
- N. D. Zelinsky Institute of Organic Chemistry Leninsky prosp. 47 119991 Moscow Russia
| | - Febin Kuriakose
- Department of Chemistry and Biochemistry Florida State University Tallahassee FL USA
| | - Evgeniya A. Saverina
- N. D. Zelinsky Institute of Organic Chemistry Leninsky prosp. 47 119991 Moscow Russia
- UMR CNRS 6226 ISCR University of Rennes 1 Rennes France
| | | | - Mikhail P. Egorov
- N. D. Zelinsky Institute of Organic Chemistry Leninsky prosp. 47 119991 Moscow Russia
| | - Igor V. Alabugin
- Department of Chemistry and Biochemistry Florida State University Tallahassee FL USA
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Nocera G, Young A, Palumbo F, Emery KJ, Coulthard G, McGuire T, Tuttle T, Murphy JA. Electron Transfer Reactions: KO tBu (but not NaO tBu) Photoreduces Benzophenone under Activation by Visible Light. J Am Chem Soc 2018; 140:9751-9757. [PMID: 29996048 DOI: 10.1021/jacs.8b06089] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Long-standing controversial reports of electron transfer from KO tBu to benzophenone have been investigated and resolved. The mismatch in the oxidation potential of KO tBu (+0.10 V vs SCE in DMF) and the first reduction potential of benzophenone (of many values cited in the literature, the least negative value is -1.31 V vs SCE in DMF), preclude direct electron transfer. Experimental and computational results now establish that a complex is formed between the two reagents, with the potassium ion providing the linkage, which markedly shifts the absorption spectrum to provide a tail in the visible light region. Photoactivation at room temperature by irradiation at defined wavelength (365 or 400 nm), or even by winter daylight, leads to the development of the blue color of the potassium salt of benzophenone ketyl, whereas no reaction is observed when the reaction mixture is maintained in darkness. So, no electron transfer occurs in the ground state. However, when photoexcited, electron transfer occurs within a complex formed from benzophenone and KO tBu. TDDFT studies match experimental findings and also define the electronic transition within the complex as n → π*, originating on the butoxide oxygen. Computation and experiment also align in showing that this reaction is selective for KO tBu; no such effect occurs with NaO tBu, providing the first case where such alkali metal ion selectivity is rationalized in detail. Chemical evidence is provided for the photoactivated electron transfer from KO tBu to benzophenone: tert-butoxyl radicals are formed and undergo fragmentation to form (acetone and) methyl radicals, some of which are trapped by benzophenone. Likewise, when KOC(Et)3 is used in place of KO tBu, then ethylation of benzophenone is seen. Further evidence of electron transfer was seen when the reaction was conducted in benzene, in the presence of p-iodotoluene; this triggered BHAS coupling to form 4-methylbiphenyl in 74% yield.
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Affiliation(s)
- Giuseppe Nocera
- Department of Pure and Applied Chemistry , University of Strathclyde , 295 Cathedral Street , Glasgow , G1 1XL , U.K
| | - Allan Young
- Department of Pure and Applied Chemistry , University of Strathclyde , 295 Cathedral Street , Glasgow , G1 1XL , U.K
| | - Fabrizio Palumbo
- Department of Pure and Applied Chemistry , University of Strathclyde , 295 Cathedral Street , Glasgow , G1 1XL , U.K
| | - Katie J Emery
- Department of Pure and Applied Chemistry , University of Strathclyde , 295 Cathedral Street , Glasgow , G1 1XL , U.K
| | - Graeme Coulthard
- Department of Pure and Applied Chemistry , University of Strathclyde , 295 Cathedral Street , Glasgow , G1 1XL , U.K
| | - Thomas McGuire
- Medicinal Chemistry, Oncology, IMED Biotech Unit , AstraZeneca , 319 Milton Road , Cambridge CB4 0WG , U.K
| | - Tell Tuttle
- Department of Pure and Applied Chemistry , University of Strathclyde , 295 Cathedral Street , Glasgow , G1 1XL , U.K
| | - John A Murphy
- Department of Pure and Applied Chemistry , University of Strathclyde , 295 Cathedral Street , Glasgow , G1 1XL , U.K
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