1
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Roy M, Sardar B, Mallick I, Srimani D. Generation of alkyl and acyl radicals by visible-light photoredox catalysis: direct activation of C-O bonds in organic transformations. Beilstein J Org Chem 2024; 20:1348-1375. [PMID: 38887583 PMCID: PMC11181251 DOI: 10.3762/bjoc.20.119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Accepted: 05/27/2024] [Indexed: 06/20/2024] Open
Abstract
Alkyl and acyl radicals play a critical role in the advancement of chemical synthesis. The generation of acyl and alkyl radicals by activation of C-O bonds using visible-light photoredox catalysis offers a mild and environmentally benign approach to useful chemical transformations. Alcohols, carboxylic acids, anhydrides, xanthates, oxalates, N-phthalimides, and thiocarbonates are some examples of alkyl and acyl precursors that can produce reactive radicals by homolysis of the C-O bond. These radicals can then go through a variety of transformations that are beneficial for the construction of synthetic materials that are otherwise difficult to access. This study summarizes current developments in the use of organic photocatalysts, transition-metal photoredox catalysts, and metallaphotocatalysts to produce acyl and alkyl radicals driven by visible light.
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Affiliation(s)
- Mithu Roy
- Department of Chemistry, Indian Institute of Technology-Guwahati, Kamrup, Assam 781039, India
| | - Bitan Sardar
- Department of Chemistry, Indian Institute of Technology-Guwahati, Kamrup, Assam 781039, India
| | - Itu Mallick
- Department of Chemistry, Indian Institute of Technology-Guwahati, Kamrup, Assam 781039, India
| | - Dipankar Srimani
- Department of Chemistry, Indian Institute of Technology-Guwahati, Kamrup, Assam 781039, India
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2
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Krüger-Braunert T, Linker T. One-Pot Synthesis of 1,3-Cyclohexadienes by Birch Reduction in the Presence of Carbonyl Compounds. Angew Chem Int Ed Engl 2024:e202407568. [PMID: 38740549 DOI: 10.1002/anie.202407568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2024] [Revised: 04/28/2024] [Accepted: 04/29/2024] [Indexed: 05/16/2024]
Abstract
Birch reductions are well-known transformations of arenes, applied for large scale synthesis of 1,4-cyclohexadienes. Herein, we describe first reactions of benzoic acids in the presence of carbonyl compounds, affording aldol products in moderate to high yields. Alkyl aldehydes give the expected nonconjugated dienes by reaction at the α-position. Interestingly, the intermediately formed enolate attacks aryl aldehydes and ketones from its γ-position, which can be explained by steric hindrance. This opens the door for the one-pot synthesis of 1,3-cyclohexadienes, which are not accessible by classical Birch reductions. Our method is applicable to benzoic, m- and p-toluic acid and various carbonyl compounds, and more than 25 new products were isolated in up to 93 % yield. Prochiral aryl aldehydes afford diastereomeric mixtures in ratios of about 4 : 1, but in the cyclohexadiene ring only trans isomers are formed with high selectivity. Finally, the 1,3-cyclohexadienes are suitable precursors for further transformations, which we have demonstrated in first examples. Thus, aromatization affords products of a formal meta selective Friedel-Crafts alkylation, and four new stereocenters were generated by cycloaddition of singlet oxygen with excellent selectivity.
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Affiliation(s)
- Tobias Krüger-Braunert
- Department of Chemistry, University of Potsdam, Karl-Liebknecht-Str. 24-25, D-14476, Potsdam/Golm, Germany
| | - Torsten Linker
- Department of Chemistry, University of Potsdam, Karl-Liebknecht-Str. 24-25, D-14476, Potsdam/Golm, Germany
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3
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Ratnam S, Unone S, Janssen-Müller D. 2,2'-Biquinoline-Based Recyclable Electroauxiliaries for the Generation of Alkyl Radicals via C-C Bond Cleavage. Chemistry 2023; 29:e202301685. [PMID: 37265104 DOI: 10.1002/chem.202301685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 06/01/2023] [Accepted: 06/02/2023] [Indexed: 06/03/2023]
Abstract
Alkyl radical precursors are essential for a wide variety of photocatalytic and 3d-metal-catalyzed C-C bond forming reactions. Neutral organic heterocycles as electroauxiliaries such as 4-alkyl Hantzsch esters have become reliable tools for alkyl radical formation. Here we show that 2,2'-biquinoline-derived alkyl-substituted dihydroquinolines act as competent radical precursors with the ability to form primary, secondary and tertiary alkyl radicals. Hydroalkylation of benzalmalononitriles and N-Boc protected diazenes has been achieved through copper catalysis under mild conditions of 50 °C with good to very good yields of up to 85 %. Furthermore, the dihydroquinolines' reactivity towards a denitrative alkylation of nitroolefins such as β-nitrostyrene was discovered. Most importantly, the released biquinoline can be recycled, which greatly improves the overall atom-economy of these alkyl radical precursors in comparison to previous N-heterocyclic electroauxiliaries.
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Affiliation(s)
- Shahilan Ratnam
- Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammannstr. 2, 37077, Göttingen, Germany
| | - Shreya Unone
- Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammannstr. 2, 37077, Göttingen, Germany
| | - Daniel Janssen-Müller
- Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammannstr. 2, 37077, Göttingen, Germany
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4
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Xu L, Shi H. Ruthenium-Catalyzed Activation of Nonpolar C-C Bonds via π-Coordination-Enabled Aromatization. Angew Chem Int Ed Engl 2023; 62:e202307285. [PMID: 37379224 DOI: 10.1002/anie.202307285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 06/26/2023] [Accepted: 06/27/2023] [Indexed: 06/30/2023]
Abstract
Activation of C-C bonds allows editing of molecular skeletons, but methods for selective activation of nonpolar C-C bonds in the absence of a chelation effect or a driving force derived from opening of a strained ring are scarce. Herein, we report a method for ruthenium-catalyzed activation of nonpolar C-C bonds of pro-aromatic compounds by means of π-coordination-enabled aromatization. This method was effective for cleavage of C-C(alkyl) and C-C(aryl) bonds and for ring-opening of spirocyclic compounds, providing an array of benzene-ring-containing products. The isolation of a methyl ruthenium complex intermediate supports a mechanism involving ruthenium-mediated C-C bond cleavage.
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Affiliation(s)
- Lun Xu
- Key Laboratory of Precise Synthesis of Functional Molecules of Zhejiang Province, Department of Chemistry, School of Science and Research Center for Industries of the Future, Westlake University, 600 Dunyu Road, Hangzhou, 310030, Zhejiang Province, China
| | - Hang Shi
- Key Laboratory of Precise Synthesis of Functional Molecules of Zhejiang Province, Department of Chemistry, School of Science and Research Center for Industries of the Future, Westlake University, 600 Dunyu Road, Hangzhou, 310030, Zhejiang Province, China
- Institute of Natural Sciences, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou, 310024, Zhejiang Province, China
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5
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Constantin T, Górski B, Tilby MJ, Chelli S, Juliá F, Llaveria J, Gillen KJ, Zipse H, Lakhdar S, Leonori D. Halogen-atom and group transfer reactivity enabled by hydrogen tunneling. Science 2022; 377:1323-1328. [DOI: 10.1126/science.abq8663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The generation of carbon radicals by halogen-atom and group transfer reactions is generally achieved using tin and silicon reagents that maximize the interplay of enthalpic (thermodynamic) and polar (kinetic) effects. In this work, we demonstrate a distinct reactivity mode enabled by quantum mechanical tunneling that uses the cyclohexadiene derivative γ-terpinene as the abstractor under mild photochemical conditions. This protocol activates alkyl and aryl halides as well as several alcohol and thiol derivatives. Experimental and computational studies unveiled a noncanonical pathway whereby a cyclohexadienyl radical undergoes concerted aromatization and halogen-atom or group abstraction through the reactivity of an effective H atom. This activation mechanism is seemingly thermodynamically and kinetically unfavorable but is rendered feasible through quantum tunneling.
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Affiliation(s)
| | - Bartosz Górski
- Department of Chemistry, University of Manchester, Manchester M13 9PL, UK
| | - Michael J. Tilby
- Department of Chemistry, University of Manchester, Manchester M13 9PL, UK
| | - Saloua Chelli
- CNRS/Université Toulouse III—Paul Sabatier, Laboratoire Hétérochimie Fondamentale et Appliquée, LHFA UMR 5069, 31062 Toulouse Cedex 09, France
| | - Fabio Juliá
- Department of Chemistry, University of Manchester, Manchester M13 9PL, UK
| | - Josep Llaveria
- Global Discovery Chemistry, Therapeutics Discovery, Janssen Research & Development, Janssen-Cilag S.A., 45007 Toledo, Spain
| | - Kevin J. Gillen
- LifeArc, Accelerator Building, Open Innovation Campus, Stevenage SG1 2FX, UK
| | - Hendrik Zipse
- Department Chemie, LMU München, D-81377 München, Germany
| | - Sami Lakhdar
- CNRS/Université Toulouse III—Paul Sabatier, Laboratoire Hétérochimie Fondamentale et Appliquée, LHFA UMR 5069, 31062 Toulouse Cedex 09, France
| | - Daniele Leonori
- Institute of Organic Chemistry, RWTH Aachen University, 52056 Aachen, Germany
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6
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Lee SC, Li LY, Tsai ZN, Lee YH, Tsao YT, Huang PG, Cheng CK, Lin HB, Chen TW, Yang CH, Chiu CC, Liao HH. Aromatization as an Impetus to Harness Ketones for Metallaphotoredox-Catalyzed Benzoylation/Benzylation of (Hetero)arenes. Org Lett 2021; 24:85-89. [PMID: 34913706 DOI: 10.1021/acs.orglett.1c03672] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Herein we report ketones as feedstock materials in radical cross-coupling reactions under Ni/photoredox dual catalysis. In this approach, simple condensation first converts ketones into prearomatic intermediates that then act as activated radical sources for cross-coupling with aryl halides. Our strategy enables the direct benzylation/benzoylation of (hetero)arenes under mild reaction conditions with high functional group tolerance.
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Affiliation(s)
- Shao-Chi Lee
- Department of Chemistry, National Sun Yat-sen University, Kaohsiung 80424, Taiwan, R.O.C
| | - Li-Yun Li
- Department of Chemistry, National Sun Yat-sen University, Kaohsiung 80424, Taiwan, R.O.C
| | - Zong-Nan Tsai
- Department of Chemistry, National Sun Yat-sen University, Kaohsiung 80424, Taiwan, R.O.C
| | - Yi-Hsin Lee
- Department of Chemistry, National Sun Yat-sen University, Kaohsiung 80424, Taiwan, R.O.C
| | - Yong-Ting Tsao
- Department of Chemistry, National Sun Yat-sen University, Kaohsiung 80424, Taiwan, R.O.C
| | - Pin-Gong Huang
- Department of Chemistry, National Sun Yat-sen University, Kaohsiung 80424, Taiwan, R.O.C
| | - Cheng-Ku Cheng
- Department of Chemistry, National Sun Yat-sen University, Kaohsiung 80424, Taiwan, R.O.C
| | - Heng-Bo Lin
- Department of Chemistry, National Sun Yat-sen University, Kaohsiung 80424, Taiwan, R.O.C
| | - Ting-Wei Chen
- Department of Chemistry, National Sun Yat-sen University, Kaohsiung 80424, Taiwan, R.O.C
| | - Chung-Hsin Yang
- Department of Chemistry, National Sun Yat-sen University, Kaohsiung 80424, Taiwan, R.O.C
| | - Cheng-Chau Chiu
- Department of Chemistry, National Sun Yat-sen University, Kaohsiung 80424, Taiwan, R.O.C
| | - Hsuan-Hung Liao
- Department of Chemistry, National Sun Yat-sen University, Kaohsiung 80424, Taiwan, R.O.C
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7
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Lin L, Zhu J. Antiaromaticity-Promoted Radical Stability in α-Methyl Heterocyclics. J Org Chem 2021; 86:15558-15567. [PMID: 34632764 DOI: 10.1021/acs.joc.1c02050] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Aromaticity is a fundamental and important concept in chemistry, and usually, the enhancement of aromaticity brings additional thermodynamic stability to a compound. Moreover, since radicals can act as intermediates in chemical reactions, they have attracted considerable attention from both experimental and theoretical chemists for a long time. However, it remains unclear whether there is a relationship between the thermodynamic stability of cyclic planar radicals and their aromaticity. In this work, using various aromaticity indices including anisotropy of the induced current density analysis and nucleus-independent chemical shifts against the radical stabilization energy, we systematically investigated the relationship between aromaticity and the thermodynamic stability of α-methyl heterocyclics. Density functional theory calculations suggest that the stronger the antiaromaticity of the original form heterocyclics, the higher the thermodynamic stability of the corresponding radicals, which is in sharp contrast to the general knowledge that aromaticity brings compounds' thermodynamic stabilities. The principal interacting spin orbital analysis shows that the stronger the π-bond formed between the heterocyclics and the α-methyl carbon, the more spin density the radicals tend to be distributed on the heterocyclics. Thus, the strong π-bonding is one of the factors for improving the thermodynamic stability of radicals.
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Affiliation(s)
- Lu Lin
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People's Republic of China
| | - Jun Zhu
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People's Republic of China
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8
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9
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Wu B, Wang J, Liu X, Zhu R. Bicyclo[2.2.0]hexene derivatives as a proaromatic platform for group transfer and chemical sensing. Nat Commun 2021; 12:3680. [PMID: 34140512 PMCID: PMC8211693 DOI: 10.1038/s41467-021-24054-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 05/26/2021] [Indexed: 12/22/2022] Open
Abstract
Here we report the design, preparation, synthetic utility, and sensing application of a class of proaromatic structures, namely bicyclo[2.2.0]hexene (BCH) derivatives. Building on a valence isomerism concept, they feature modular and easy synthesis as well as high thermal stability, and can be oxidatively activated under mild conditions. New alkyl transfer reactions using BCHs as a radical donor have been developed to showcase the utility of their proaromaticity. Moreover, the redox-triggered valence isomerization of a quinoline-derived BCH led to colorimetric and fluorescent responses toward vapors of electrophilic reagents in solution and solid phase, respectively. This optical response was shown to involve a 1,3-cyclohexadiene structure that possesses an intramolecular charge transfer excited state with interesting aggregation induced emission (AIE) character. Thus, the potential of BCHs has been demonstrated as a versatile platform for the development of new reagents and functional materials. Cyclohexadienes have been widely explored as proaromatic surrogates for group transfer reactions but limited storage stability and difficult accessibility of these compounds limits the application range. Here, the authors present a class of proaromatic bicyclo[2.2.0]hexene derivatives and demonstrate their application in alkyl transfer reactions and sensing applications.
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Affiliation(s)
- Bin Wu
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
| | - Jianing Wang
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
| | - Xingchen Liu
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
| | - Rong Zhu
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing, China.
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10
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Pirouz M, Saeed Abaee M, Harris P, Mojtahedi MM. One-pot synthesis of benzofurans via heteroannulation of benzoquinones. HETEROCYCL COMMUN 2021. [DOI: 10.1515/hc-2020-0120] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Abstract
Three different reactions were explored leading to the synthesis of various benzofurans. All reactions took place under AcOH catalysis in a one-pot manner. As a result, benzoquinone derivatives underwent heteroannulation with either itself or cyclohexanones to produce furanylidene-benzofuran or benzofuran structures, respectively.
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Affiliation(s)
- Maryam Pirouz
- Organic Chemistry Department , Chemistry and Chemical Engineering Research Center of Iran , P.O. Box 14335-186 , Tehran , Iran
| | - M. Saeed Abaee
- Organic Chemistry Department , Chemistry and Chemical Engineering Research Center of Iran , P.O. Box 14335-186 , Tehran , Iran
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11
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Chen D, Berhane IA, Chemler SR. Copper-Catalyzed Enantioselective Hydroalkoxylation of Alkenols for the Synthesis of Cyclic Ethers. Org Lett 2020; 22:7409-7414. [PMID: 32496794 PMCID: PMC7541751 DOI: 10.1021/acs.orglett.0c01691] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The copper-catalyzed enantioselective intramolecular hydroalkoxylation of unactivated alkenes for the synthesis of tetrahydrofurans, phthalans, isochromans, and morpholines from 4- and 5-alkenols is reported. The substrate scope is complementary to existing enantioselective alkene hydroalkoxylations and is broad with respect to substrate backbone and alkene substitution. The asymmetric induction and isotopic labeling studies support a polar/radical mechanism involving enantioselective oxycupration followed by C-[Cu] homolysis and hydrogen atom transfer. Synthesis of the antifungal insecticide furametpyr was accomplished.
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Affiliation(s)
- Dake Chen
- Chemistry Department, State University of New York at Buffalo, Buffalo, New York 14260, United States
| | - Ilyas A Berhane
- Chemistry Department, State University of New York at Buffalo, Buffalo, New York 14260, United States
| | - Sherry R Chemler
- Chemistry Department, State University of New York at Buffalo, Buffalo, New York 14260, United States
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12
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Crespi S, Fagnoni M. Generation of Alkyl Radicals: From the Tyranny of Tin to the Photon Democracy. Chem Rev 2020; 120:9790-9833. [PMID: 32786419 PMCID: PMC8009483 DOI: 10.1021/acs.chemrev.0c00278] [Citation(s) in RCA: 189] [Impact Index Per Article: 47.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Indexed: 01/09/2023]
Abstract
Alkyl radicals are key intermediates in organic synthesis. Their classic generation from alkyl halides has a severe drawback due to the employment of toxic tin hydrides to the point that "flight from the tyranny of tin" in radical processes was considered for a long time an unavoidable issue. This review summarizes the main alternative approaches for the generation of unstabilized alkyl radicals, using photons as traceless promoters. The recent development in photochemical and photocatalyzed processes enabled the discovery of a plethora of new alkyl radical precursors, opening the world of radical chemistry to a broader community, thus allowing a new era of photon democracy.
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Affiliation(s)
- Stefano Crespi
- Stratingh
Institute for Chemistry, Center for Systems
Chemistry University of Groningen, Nijenborgh 4, 9747
AG Groningen, The Netherlands
| | - Maurizio Fagnoni
- PhotoGreen
Lab, Department of Chemistry, V. Le Taramelli 10, 27100 Pavia, Italy
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13
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Wang YC, Huang YH, Tsai HC, Basha RS, Chou CM. Palladium-Catalyzed Proaromatic C(Alkenyl)–H Olefination: Synthesis of Densely Functionalized 1,3-Dienes. Org Lett 2020; 22:6765-6770. [DOI: 10.1021/acs.orglett.0c02241] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Yu-Chun Wang
- Department of Applied Chemistry, National University of Kaohsiung, 700 Kaohsiung University Road,
Nanzih District, Kaohsiung 81148, Taiwan
| | - Yen-Hsiang Huang
- Department of Applied Chemistry, National University of Kaohsiung, 700 Kaohsiung University Road,
Nanzih District, Kaohsiung 81148, Taiwan
| | - Hung-Chang Tsai
- Department of Applied Chemistry, National University of Kaohsiung, 700 Kaohsiung University Road,
Nanzih District, Kaohsiung 81148, Taiwan
| | - R. Sidick Basha
- Department of Applied Chemistry, National University of Kaohsiung, 700 Kaohsiung University Road,
Nanzih District, Kaohsiung 81148, Taiwan
| | - Chih-Ming Chou
- Department of Applied Chemistry, National University of Kaohsiung, 700 Kaohsiung University Road,
Nanzih District, Kaohsiung 81148, Taiwan
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14
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Deriabin KV, Dobrynin MV, Islamova RM. A metal-free radical technique for cross-linking of polymethylhydrosiloxane or polymethylvinylsiloxane using AIBN. Dalton Trans 2020; 49:8855-8858. [PMID: 32589173 DOI: 10.1039/d0dt01061h] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A new method was developed for the metal-free cross-linking of silicone rubbers. This process uses azobisisobutyronitrile (AIBN) to selectively react with Si-H and vinyl groups as a free-radical initiator for the thermal curing of polymethylhydrosiloxane (PMHS) and polymethylvinylsiloxane (PMVS). The AIBN-initiated curing reaction between the Si-H groups of PMHS generated Si-O-Si and Si-Si cross-links. In contrast, PMVS was cured via the formation of C-C bonds through "methyl-vinyl" and "vinyl-vinyl" mechanisms. Curing reactions were performed at 80-120 °C in air and confirmed by 13C and 29Si solid state NMR analyses and swelling trials.
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Affiliation(s)
- Konstantin V Deriabin
- Saint Petersburg State University, 7/9, Universitetskaya nab., Saint Petersburg, 199034, Russia.
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15
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Halder A, Ha M, Zhai H, Yang B, Pellin MJ, Seifert S, Alexandrova AN, Vajda S. Oxidative Dehydrogenation of Cyclohexane by Cu
vs
Pd Clusters: Selectivity Control by Specific Cluster Dynamics. ChemCatChem 2020. [DOI: 10.1002/cctc.201901795] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Avik Halder
- Materials Science Division Argonne National Laboratory Lemont IL-60439 USA
| | - Mai‐Anh Ha
- Department of Chemistry and Biochemistry University of California Los Angeles CA-90095 USA
| | - Huanchen Zhai
- Department of Chemistry and Biochemistry University of California Los Angeles CA-90095 USA
| | - Bing Yang
- Materials Science Division Argonne National Laboratory Lemont IL-60439 USA
| | - Michael J. Pellin
- Materials Science Division Argonne National Laboratory Lemont IL-60439 USA
| | - Sönke Seifert
- X-ray Science Division Argonne National Laboratory Lemont IL-60439 USA
| | - Anastassia N. Alexandrova
- Department of Chemistry and Biochemistry University of California Los Angeles CA-90095 USA
- California NanoSystems Institute Los Angeles CA-90095 USA
| | - Stefan Vajda
- Materials Science Division Argonne National Laboratory Lemont IL-60439 USA
- Institute for Molecular Engineering The University of Chicago Chicago IL-60637 USA
- Department of Nanocatalysis J. Heyrovský Institute of Physical Chemistry Czech Academy of Sciences Prague 8 18223 Czech Republic
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16
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Bhawal BN, Morandi B. Catalytic Isofunctional Reactions—Expanding the Repertoire of Shuttle and Metathesis Reactions. Angew Chem Int Ed Engl 2019; 58:10074-10103. [DOI: 10.1002/anie.201803797] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Indexed: 12/16/2022]
Affiliation(s)
- Benjamin N. Bhawal
- Max-Planck-Institut für Kohlenforschung 45470 Mülheim an der Ruhr Germany
- Laboratorium für Organische ChemieETH Zürich 8093 Zürich Switzerland
| | - Bill Morandi
- Max-Planck-Institut für Kohlenforschung 45470 Mülheim an der Ruhr Germany
- Laboratorium für Organische ChemieETH Zürich 8093 Zürich Switzerland
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17
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Bhawal BN, Morandi B. Katalytische, isofunktionelle Reaktionen – Erweiterung des Repertoires an Shuttle‐ und Metathesereaktionen. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201803797] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Benjamin N. Bhawal
- Max-Planck-Institut für Kohlenforschung 45470 Mülheim an der Ruhr Deutschland
- Laboratorium für Organische ChemieETH Zürich 8093 Zürich Schweiz
| | - Bill Morandi
- Max-Planck-Institut für Kohlenforschung 45470 Mülheim an der Ruhr Deutschland
- Laboratorium für Organische ChemieETH Zürich 8093 Zürich Schweiz
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18
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Zhang Y, Zhang S, Xu G, Li M, Tang C, Fan W. Cu-Catalyzed carbamoylation versus amination of quinoline N-oxide with formamides. Org Biomol Chem 2019; 17:309-314. [DOI: 10.1039/c8ob02844c] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Carbamoylation and amination of quinoline with formamides was developed via copper-catalyzed C–C and C–N bond formations.
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Affiliation(s)
- Yan Zhang
- School of Pharmaceutical Science
- Jiangnan University
- Wuxi 214122
- P. R. China
| | - Shiwei Zhang
- School of Pharmaceutical Science
- Jiangnan University
- Wuxi 214122
- P. R. China
| | - Guangxing Xu
- School of Pharmaceutical Science
- Jiangnan University
- Wuxi 214122
- P. R. China
| | - Min Li
- School of Pharmaceutical Science
- Jiangnan University
- Wuxi 214122
- P. R. China
| | - Chunlei Tang
- School of Pharmaceutical Science
- Jiangnan University
- Wuxi 214122
- P. R. China
| | - Weizheng Fan
- School of Pharmaceutical Science
- Jiangnan University
- Wuxi 214122
- P. R. China
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19
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Zhou ZZ, Zhao JH, Gou XY, Chen XM, Liang YM. Visible-light-mediated hydrodehalogenation and Br/D exchange of inactivated aryl and alkyl halides with a palladium complex. Org Chem Front 2019. [DOI: 10.1039/c9qo00240e] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Photo-induced radical reductive dehalogenation of inactivated aryl/alkyl bromides and chlorides with a palladium complex is described. Reductive cyclization, dehalogenative deuteration, and radical addition process can be achieved smoothly.
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Affiliation(s)
- Zhao-Zhao Zhou
- School of Nuclear Science and Technology, Lanzhou University
- Lanzhou, 730000
- P.R. China
- State Key Laboratory of Applied Organic Chemistry
- Lanzhou University
| | - Jia-Hui Zhao
- State Key Laboratory of Applied Organic Chemistry
- Lanzhou University
- Lanzhou, 730000
- P.R. China
| | - Xue-Ya Gou
- State Key Laboratory of Applied Organic Chemistry
- Lanzhou University
- Lanzhou, 730000
- P.R. China
| | - Xi-Meng Chen
- School of Nuclear Science and Technology, Lanzhou University
- Lanzhou, 730000
- P.R. China
| | - Yong-Min Liang
- State Key Laboratory of Applied Organic Chemistry
- Lanzhou University
- Lanzhou, 730000
- P.R. China
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20
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Bhunia A, Bergander K, Studer A. Cooperative Palladium/Lewis Acid-Catalyzed Transfer Hydrocyanation of Alkenes and Alkynes Using 1-Methylcyclohexa-2,5-diene-1-carbonitrile. J Am Chem Soc 2018; 140:16353-16359. [PMID: 30392374 DOI: 10.1021/jacs.8b10651] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Catalytic transfer hydrocyanation represents a clean and safe alternative to hydrocyanation processes using toxic HCN gas. Such reactions provide access to pharmaceutically important nitrile derivatives starting with alkenes and alkynes. Herein, an efficient and practical cooperative palladium/Lewis acid-catalyzed transfer hydrocyanation of alkenes and alkynes is presented using 1-methylcyclohexa-2,5-diene-1-carbonitrile as a benign and readily available HCN source. A large set of nitrile derivatives (>50 examples) are prepared from both aliphatic and aromatic alkenes with good to excellent anti-Markovnikov selectivity. A range of aliphatic alkenes engage in selective hydrocyanation to provide the corresponding nitriles. The introduced method is useful for chain walking hydrocyanation of internal alkenes to afford terminal nitriles in good regioselectivities. This protocol is also applicable to late-stage modification of bioactive molecules.
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Affiliation(s)
- Anup Bhunia
- Organisch-Chemisches Institut , Westfalische Wilhelms-Universität , Corrensstraβe 40 , 48149 Münster , Germany
| | - Klaus Bergander
- Organisch-Chemisches Institut , Westfalische Wilhelms-Universität , Corrensstraβe 40 , 48149 Münster , Germany
| | - Armido Studer
- Organisch-Chemisches Institut , Westfalische Wilhelms-Universität , Corrensstraβe 40 , 48149 Münster , Germany
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21
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Jiang H, Studer A. Amidyl Radicals by Oxidation of α‐Amido‐oxy Acids: Transition‐Metal‐Free Amidofluorination of Unactivated Alkenes. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201804966] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Heng Jiang
- Organisch-Chemisches InstitutWestfälische Wilhelms-Universität Corrensstraße 40 48149 Münster Germany
| | - Armido Studer
- Organisch-Chemisches InstitutWestfälische Wilhelms-Universität Corrensstraße 40 48149 Münster Germany
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22
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Jiang H, Studer A. Amidyl Radicals by Oxidation of α-Amido-oxy Acids: Transition-Metal-Free Amidofluorination of Unactivated Alkenes. Angew Chem Int Ed Engl 2018; 57:10707-10711. [PMID: 29855130 DOI: 10.1002/anie.201804966] [Citation(s) in RCA: 79] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2018] [Revised: 05/28/2018] [Indexed: 01/23/2023]
Abstract
A three-component transition-metal-free amidofluorination of unactivated alkenes and styrenes is presented. α-Amido-oxy acids are introduced as efficient and easily accessible amidyl radical precursors that are oxidized by a photoexcited organic sensitizer (Mes-Acr-Me) to the corresponding carboxyl radical. Sequential CO2 and aldehyde/ketone fragmentation leads to an N-centered radical that adds to an alkene. Commercial Selectfluor is used to trap the adduct radical through fluorine-atom transfer. The transformation features by high functional-group tolerance, broad substrate scope, and practical mild conditions. Mechanistic studies support the radical nature of the cascade.
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Affiliation(s)
- Heng Jiang
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität, Corrensstraße 40, 48149, Münster, Germany
| | - Armido Studer
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität, Corrensstraße 40, 48149, Münster, Germany
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23
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Chen JQ, Chang R, Lin JB, Luo YC, Xu PF. Photoredox-Induced Intramolecular 1,5-H Transfer Reaction of Aryl Iodides for the Synthesis of Spirocyclic γ-Lactams. Org Lett 2018; 20:2395-2398. [PMID: 29613807 DOI: 10.1021/acs.orglett.8b00731] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
This work develops a photocatalysis method for the synthesis of γ-spirolactams through a tandem intramolecular 1,5-HAT reaction-cyclization process. A variety of novel γ-spirolactams are prepared in good to excellent yields with this method. This transformation features mild reaction conditions and exceptional functional group tolerance. Additionally, γ-terpinene is applied to this transformation as a hydrogen atom donor for the first time.
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Affiliation(s)
- Jian-Qiang Chen
- State Key Laboratory of Applied Organic Chemistry , Lanzhou University , Lanzhou 730000 , PR China
| | - Rui Chang
- State Key Laboratory of Applied Organic Chemistry , Lanzhou University , Lanzhou 730000 , PR China
| | - Jun-Bing Lin
- State Key Laboratory of Applied Organic Chemistry , Lanzhou University , Lanzhou 730000 , PR China
| | - Yong-Chun Luo
- State Key Laboratory of Applied Organic Chemistry , Lanzhou University , Lanzhou 730000 , PR China
| | - Peng-Fei Xu
- State Key Laboratory of Applied Organic Chemistry , Lanzhou University , Lanzhou 730000 , PR China
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24
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Barth F, Achrainer F, Pütz AM, Zipse H. Aminopyridine-Borane Complexes as Hydrogen Atom Donor Reagents: Reaction Mechanism and Substrate Selectivity. Chemistry 2017; 23:13455-13464. [PMID: 28699670 DOI: 10.1002/chem.201702469] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Indexed: 11/12/2022]
Abstract
Lewis base-borane complexes are shown to be potent hydrogen atom donors in radical chain reduction reactions. Results obtained in 1 H, 11 B, and 13 C NMR measurements and kinetic experiments support a complex reaction mechanism involving the parent borane as well as its initial reaction products as active hydrogen atom donors. Efficient reduction reactions of iodides, bromides, and xanthates in apolar solvents rely on initiator systems generating oxygen-centered radicals under thermal conditions and pyridine-borane complexes carrying solubilizing substituents. In contrast to tin hydride reagents, the pyridine-boranes reduce xanthates faster than the corresponding iodides.
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Affiliation(s)
- Florian Barth
- Ludwig-Maximilians-Universität München, Department of Chemistry, Butenandtstr. 5-13, 81377, München, Germany
| | - Florian Achrainer
- Ludwig-Maximilians-Universität München, Department of Chemistry, Butenandtstr. 5-13, 81377, München, Germany
| | - Alexander M Pütz
- Ludwig-Maximilians-Universität München, Department of Chemistry, Butenandtstr. 5-13, 81377, München, Germany
| | - Hendrik Zipse
- Ludwig-Maximilians-Universität München, Department of Chemistry, Butenandtstr. 5-13, 81377, München, Germany
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25
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Xuan J, Studer A. Radical cascade cyclization of 1,n-enynes and diynes for the synthesis of carbocycles and heterocycles. Chem Soc Rev 2017; 46:4329-4346. [DOI: 10.1039/c6cs00912c] [Citation(s) in RCA: 261] [Impact Index Per Article: 37.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
This review highlights recent advances in radical cascade cyclization of 1,n-enynes and diynes for the construction of carbo- and heterocycles.
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Affiliation(s)
- Jun Xuan
- Department of Chemistry
- Anhui University
- Hefei
- People's Republic of China
| | - Armido Studer
- Institute of Organic Chemistry
- Westfälische Wilhems-University
- 48149 Münster
- Germany
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26
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Affiliation(s)
- Benjamin N. Bhawal
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz
1, 45470 Mülheim
an der Ruhr, Germany
| | - Bill Morandi
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz
1, 45470 Mülheim
an der Ruhr, Germany
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27
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Yan M, Lo JC, Edwards JT, Baran PS. Radicals: Reactive Intermediates with Translational Potential. J Am Chem Soc 2016; 138:12692-12714. [PMID: 27631602 PMCID: PMC5054485 DOI: 10.1021/jacs.6b08856] [Citation(s) in RCA: 678] [Impact Index Per Article: 84.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Indexed: 02/08/2023]
Abstract
This Perspective illustrates the defining characteristics of free radical chemistry, beginning with its rich and storied history. Studies from our laboratory are discussed along with recent developments emanating from others in this burgeoning area. The practicality and chemoselectivity of radical reactions enable rapid access to molecules of relevance to drug discovery, agrochemistry, material science, and other disciplines. Thus, these reactive intermediates possess inherent translational potential, as they can be widely used to expedite scientific endeavors for the betterment of humankind.
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Affiliation(s)
- Ming Yan
- Department
of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Julian C. Lo
- Department
of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Jacob T. Edwards
- Department
of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Phil S. Baran
- Department
of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
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28
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Povie G, Ford L, Pozzi D, Soulard V, Villa G, Renaud P. Catechols as Sources of Hydrogen Atoms in Radical Deiodination and Related Reactions. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201604950] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Guillaume Povie
- Department of Chemistry and Biochemistry; University of Bern; Freiestrasse 3 3012 Bern Switzerland
| | - Leigh Ford
- Department of Chemistry and Biochemistry; University of Bern; Freiestrasse 3 3012 Bern Switzerland
| | - Davide Pozzi
- Department of Chemistry and Biochemistry; University of Bern; Freiestrasse 3 3012 Bern Switzerland
| | - Valentin Soulard
- Department of Chemistry and Biochemistry; University of Bern; Freiestrasse 3 3012 Bern Switzerland
| | - Giorgio Villa
- Department of Chemistry and Biochemistry; University of Bern; Freiestrasse 3 3012 Bern Switzerland
| | - Philippe Renaud
- Department of Chemistry and Biochemistry; University of Bern; Freiestrasse 3 3012 Bern Switzerland
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29
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Povie G, Ford L, Pozzi D, Soulard V, Villa G, Renaud P. Catechols as Sources of Hydrogen Atoms in Radical Deiodination and Related Reactions. Angew Chem Int Ed Engl 2016; 55:11221-5. [DOI: 10.1002/anie.201604950] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Indexed: 12/31/2022]
Affiliation(s)
- Guillaume Povie
- Department of Chemistry and Biochemistry; University of Bern; Freiestrasse 3 3012 Bern Switzerland
| | - Leigh Ford
- Department of Chemistry and Biochemistry; University of Bern; Freiestrasse 3 3012 Bern Switzerland
| | - Davide Pozzi
- Department of Chemistry and Biochemistry; University of Bern; Freiestrasse 3 3012 Bern Switzerland
| | - Valentin Soulard
- Department of Chemistry and Biochemistry; University of Bern; Freiestrasse 3 3012 Bern Switzerland
| | - Giorgio Villa
- Department of Chemistry and Biochemistry; University of Bern; Freiestrasse 3 3012 Bern Switzerland
| | - Philippe Renaud
- Department of Chemistry and Biochemistry; University of Bern; Freiestrasse 3 3012 Bern Switzerland
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30
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Davies J, Svejstrup TD, Fernandez Reina D, Sheikh NS, Leonori D. Visible-Light-Mediated Synthesis of Amidyl Radicals: Transition-Metal-Free Hydroamination and N-Arylation Reactions. J Am Chem Soc 2016; 138:8092-5. [DOI: 10.1021/jacs.6b04920] [Citation(s) in RCA: 225] [Impact Index Per Article: 28.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Jacob Davies
- School
of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Thomas D. Svejstrup
- School
of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | | | - Nadeem S. Sheikh
- Department
of Chemistry, Faculty of Science, King Faisal University, Al-Ahsa 31982, Saudi Arabia
| | - Daniele Leonori
- School
of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, U.K
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31
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Methoxycarbonyl migration in 3-methylene-1,4-cyclohexadienes. An extension of the von Auwers rearrangement. Tetrahedron 2016. [DOI: 10.1016/j.tet.2016.03.032] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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32
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Walton JC. Synthetic Strategies for 5- and 6-Membered Ring Azaheterocycles Facilitated by Iminyl Radicals. Molecules 2016; 21:molecules21050660. [PMID: 27213311 PMCID: PMC6273063 DOI: 10.3390/molecules21050660] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Revised: 05/11/2016] [Accepted: 05/16/2016] [Indexed: 01/09/2023] Open
Abstract
The totality of chemical space is so immense that only a small fraction can ever be explored. Computational searching has indicated that bioactivity is associated with a comparatively small number of ring-containing structures. Pyrrole, indole, pyridine, quinoline, quinazoline and related 6-membered ring-containing aza-arenes figure prominently. This review focuses on the search for fast, efficient and environmentally friendly preparative methods for these rings with specific emphasis on iminyl radical-mediated procedures. Oxime derivatives, particularly oxime esters and oxime ethers, are attractive precursors for these radicals. Their use is described in conventional thermolytic, microwave-assisted and UV-vis based preparative procedures. Photoredox-catalyzed protocols involving designer oxime ethers are also covered. Choice can be made amongst these synthetic strategies for a wide variety of 5- and 6-membered ring heterocycles including phenanthridine and related aza-arenes. Applications to selected natural products and bioactive molecules, including trispheridine, vasconine, luotonin A and rutaecarpine, are included.
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Affiliation(s)
- John C Walton
- University of St. Andrews, EaStCHEM School of Chemistry, St. Andrews, Fife KY16 9ST, UK.
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33
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Affiliation(s)
- Han Wang
- Institute
of Organic Chemistry, RWTH Aachen University, Landoltweg 1, D-52074 Aachen, Germany
| | - Marcus Frings
- Institute
of Organic Chemistry, RWTH Aachen University, Landoltweg 1, D-52074 Aachen, Germany
| | - Carsten Bolm
- Institute
of Organic Chemistry, RWTH Aachen University, Landoltweg 1, D-52074 Aachen, Germany
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34
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35
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36
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Qrareya H, Dondi D, Ravelli D, Fagnoni M. Decatungstate-Photocatalyzed Si−H/C−H Activation in Silyl Hydrides: Hydrosilylation of Electron-Poor Alkenes. ChemCatChem 2015. [DOI: 10.1002/cctc.201500562] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Hisham Qrareya
- PhotoGreen Lab; Department of Chemistry; University of Pavia; Viale Taramelli 12 27100 Pavia Italy
| | - Daniele Dondi
- Department of Chemistry; University of Pavia; Viale Taramelli 12 27100 Pavia Italy
| | - Davide Ravelli
- PhotoGreen Lab; Department of Chemistry; University of Pavia; Viale Taramelli 12 27100 Pavia Italy
| | - Maurizio Fagnoni
- PhotoGreen Lab; Department of Chemistry; University of Pavia; Viale Taramelli 12 27100 Pavia Italy
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37
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Greulich TW, Daniliuc CG, Studer A. N-aminopyridinium salts as precursors for N-centered radicals--direct amidation of arenes and heteroarenes. Org Lett 2014; 17:254-7. [PMID: 25541887 DOI: 10.1021/ol503338b] [Citation(s) in RCA: 183] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Readily prepared N-aminopyridinium salts are valuable precursors for the generation of N-centered radicals. Reduction of these salts by single electron transfer allows for clean generation of amidyl radicals. It is shown that direct radical C-H amination of heteroarenes and arenes can be achieved with N-aminopyridinium salts under mild conditions by using photoredox catalysis.
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Affiliation(s)
- Tobias W Greulich
- Fachbereich Chemie, Organisch-Chemisches Institut, Westfälische Wilhelms-Universität , Corrensstraße 40, 48149 Münster, Germany
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38
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Lv L, Lu S, Guo Q, Shen B, Li Z. Iron-Catalyzed Acylation-Oxygenation of Terminal Alkenes for the Synthesis of Dihydrofurans Bearing a Quaternary Carbon. J Org Chem 2014; 80:698-704. [DOI: 10.1021/jo502535k] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Leiyang Lv
- Department
of Chemistry, Renmin University of China, Beijing 100872, China
| | - Shenglin Lu
- Department
of Chemistry, Renmin University of China, Beijing 100872, China
| | - Qiaoxia Guo
- State
Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing 102249, China
| | - Baojian Shen
- State
Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing 102249, China
| | - Zhiping Li
- Department
of Chemistry, Renmin University of China, Beijing 100872, China
- State
Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing 102249, China
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39
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Gao L, Tang H, Wang Z. Oxidative coupling of methylamine with an aminyl radical: direct amidation catalyzed by I2/TBHP with HCl. Chem Commun (Camb) 2014; 50:4085-8. [PMID: 24618846 DOI: 10.1039/c4cc00621f] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Oxidative coupling of methylamines with an aminyl radical to construct amides was developed in the presence of an I2/TBHP catalyst under acidic conditions via the two cleavages of the sp(3) C-N bond of aryl-methylamines and the sp(2) C-N bond of N-substituted formamides respectively. This transition-metal-free protocol provides a novel synthetic tool for the construction of N-substituted amides and a series of arylamides can be easily obtained with good yields.
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Affiliation(s)
- Lingfeng Gao
- Hefei National Laboratory for Physical Sciences at Microscale, CAS Key Laboratory of Soft Matter Chemistry & Collaborative Innovation Center of Suzhou Nano Science and Technology, University of Science and Technology of China, Hefei, 230026, P. R. China.
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40
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Yi H, Zhang X, Qin C, Liao Z, Liu J, Lei A. Visible Light-Induced γ-Alkoxynitrile SynthesisviaThree- Component Alkoxycyanomethylation of Alkenes. Adv Synth Catal 2014. [DOI: 10.1002/adsc.201400548] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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41
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Ye JQ, Zhang ZL, Zha ZG, Wang ZY. A green and efficient access to aryl nitriles via an electrochemical anodic oxidation. CHINESE CHEM LETT 2014. [DOI: 10.1016/j.cclet.2014.04.024] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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42
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A radical revolution in synthesis. Nat Chem 2014; 6:659-61. [DOI: 10.1038/nchem.2012] [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]
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43
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Dumeunier R, Huber A. Toluene as a novel carrier of xanthates—preparation, use and surrogate of S-tri- and di-chloromethyl xanthates. Tetrahedron Lett 2014. [DOI: 10.1016/j.tetlet.2014.06.030] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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44
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Chaudhari DA, Kattanguru P, Fernandes RA. A practical and improved process for the synthesis of Hagen’s gland lactones by catalytic hydro-deiodination. ACTA ACUST UNITED AC 2014. [DOI: 10.1016/j.tetasy.2014.05.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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45
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Manley DW, Mills A, O'Rourke C, Slawin AMZ, Walton JC. Catalyst-free photoredox addition-cyclisations: exploitation of natural synergy between aryl acetic acids and maleimide. Chemistry 2014; 20:5492-500. [PMID: 24652772 PMCID: PMC4506563 DOI: 10.1002/chem.201304929] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Indexed: 11/23/2022]
Abstract
Suitably functionalised carboxylic acids undergo a previously unknown photoredox reaction when irradiated with UVA in the presence of maleimide. Maleimide was found to synergistically act as a radical generating photoxidant and as a radical acceptor, negating the need for an extrinsic photoredox catalyst. Modest to excellent yields of the product chromenopyrroledione, thiochromenopyrroledione and pyrroloquinolinedione derivatives were obtained in thirteen preparative photolyses. In situ NMR spectroscopy was used to study each reaction. Reactant decay and product build-up were monitored, enabling reaction profiles to be plotted. A plausible mechanism, whereby photo-excited maleimide acts as an oxidant to generate a radical ion pair, has been postulated and is supported by UV/Vis. spectroscopy and DFT computations. The radical-cation reactive intermediates were also characterised in solution by EPR spectroscopy.
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Affiliation(s)
- David W Manley
- EaStCHEM School of Chemistry, University of St. AndrewsPurdie Building, North Haugh, St Andrews, Fife, KY16 9ST (UK) E-mail:
| | - Andrew Mills
- School of Chemistry and Chemical Engineering, Queen's University BelfastStranmillis Road, Belfast BT9 5AG (UK)
| | - Christopher O'Rourke
- School of Chemistry and Chemical Engineering, Queen's University BelfastStranmillis Road, Belfast BT9 5AG (UK)
| | - Alexandra M Z Slawin
- EaStCHEM School of Chemistry, University of St. AndrewsPurdie Building, North Haugh, St Andrews, Fife, KY16 9ST (UK) E-mail:
| | - John C Walton
- EaStCHEM School of Chemistry, University of St. AndrewsPurdie Building, North Haugh, St Andrews, Fife, KY16 9ST (UK) E-mail:
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46
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Affiliation(s)
- Fabrice Dénès
- Laboratoire CEISAM UMR CNRS 6230 - UFR des Sciences et Techniques, Université de Nantes , 2 rue de la Houssinière, BP 92208 - 44322 Nantes Cedex 3, France
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47
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Li G, Wu L, Lv G, Liu H, Fu Q, Zhang X, Tang Z. Alkyl transfer from C–C cleavage: replacing the nitro group of nitro-olefins. Chem Commun (Camb) 2014; 50:6246-8. [DOI: 10.1039/c4cc01119h] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Hydrogenation is only the beginning: alkyl groups are mildly transferred from alkyl substituted Hantzsch esters to replace the nitro groups of nitro olefins to providetrans-olefins in moderate to excellent yields.
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Affiliation(s)
- Guangxun Li
- Natural Products Research Center
- Chengdu Institution of Biology
- Chinese Academy of Science
- Chengdu, China
| | - Lei Wu
- Natural Products Research Center
- Chengdu Institution of Biology
- Chinese Academy of Science
- Chengdu, China
| | - Gang Lv
- Natural Products Research Center
- Chengdu Institution of Biology
- Chinese Academy of Science
- Chengdu, China
| | - Hongxin Liu
- Natural Products Research Center
- Chengdu Institution of Biology
- Chinese Academy of Science
- Chengdu, China
| | - Qingquan Fu
- Natural Products Research Center
- Chengdu Institution of Biology
- Chinese Academy of Science
- Chengdu, China
| | - Xiaomei Zhang
- Chengdu Institute of Organic Chemistry
- Chinese Academy of Sciences
- Chengdu, China
| | - Zhuo Tang
- Natural Products Research Center
- Chengdu Institution of Biology
- Chinese Academy of Science
- Chengdu, China
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48
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Pan X, Lalevée J, Lacôte E, Curran DP. Disulfides and Boryl Sulfides Serve as both Initiators and Precatalysts in Radical Reductions of Halides by an N‐Heterocyclic Carbene⋅Borane. Adv Synth Catal 2013. [DOI: 10.1002/adsc.201300752] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Xiangcheng Pan
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Jacques Lalevée
- Institut de Science des Matériaux de Mulhouse IS2 M – LRC CNRS 7228 – ENSCMu‐UHA, 15 rue Jean Starcky, 68057 Mulhouse Cedex, France
| | - Emmanuel Lacôte
- ICSN CNRS, Avenue de la Terrasse, 91198 Gif‐sur‐Yvette Cedex, France
- Université de Lyon, Institut de chimie de Lyon, UMR 5265 CNRS – Université Lyon I – ESCPE Lyon, 43 Bd du 11 novembre 1918, 69616 Villeurbanne, France
| | - Dennis P. Curran
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260, USA
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Xu K, Hu Y, Zhang S, Zha Z, Wang Z. Direct Amidation of Alcohols with N-Substituted Formamides under Transition-Metal-Free Conditions. Chemistry 2012; 18:9793-7. [DOI: 10.1002/chem.201201203] [Citation(s) in RCA: 125] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2012] [Revised: 05/17/2012] [Indexed: 12/20/2022]
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50
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Liu Z, Zhang J, Chen S, Shi E, Xu Y, Wan X. Cross Coupling of Acyl and Aminyl Radicals: Direct Synthesis of Amides Catalyzed by Bu4NI with TBHP as an Oxidant. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201108763] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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