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Abstract
Nitroxides, also known as nitroxyl radicals, are long-lived or stable radicals with the general structure R1R2N-O•. The spin distribution over the nitroxide N and O atoms contributes to the thermodynamic stability of these radicals. The presence of bulky N-substituents R1 and R2 prevents nitroxide radical dimerization, ensuring their kinetic stability. Despite their reactivity toward various transient C radicals, some nitroxides can be easily stored under air at room temperature. Furthermore, nitroxides can be oxidized to oxoammonium salts (R1R2N═O+) or reduced to anions (R1R2N-O-), enabling them to act as valuable oxidants or reductants depending on their oxidation state. Therefore, they exhibit interesting reactivity across all three oxidation states. Due to these fascinating properties, nitroxides find extensive applications in diverse fields such as biochemistry, medicinal chemistry, materials science, and organic synthesis. This review focuses on the versatile applications of nitroxides in organic synthesis. For their use in other important fields, we will refer to several review articles. The introductory part provides a brief overview of the history of nitroxide chemistry. Subsequently, the key methods for preparing nitroxides are discussed, followed by an examination of their structural diversity and physical properties. The main portion of this review is dedicated to oxidation reactions, wherein parent nitroxides or their corresponding oxoammonium salts serve as active species. It will be demonstrated that various functional groups (such as alcohols, amines, enolates, and alkanes among others) can be efficiently oxidized. These oxidations can be carried out using nitroxides as catalysts in combination with various stoichiometric terminal oxidants. By reducing nitroxides to their corresponding anions, they become effective reducing reagents with intriguing applications in organic synthesis. Nitroxides possess the ability to selectively react with transient radicals, making them useful for terminating radical cascade reactions by forming alkoxyamines. Depending on their structure, alkoxyamines exhibit weak C-O bonds, allowing for the thermal generation of C radicals through reversible C-O bond cleavage. Such thermally generated C radicals can participate in various radical transformations, as discussed toward the end of this review. Furthermore, the application of this strategy in natural product synthesis will be presented.
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Affiliation(s)
- Dirk Leifert
- 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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2
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Huang G, Ye J, Bashir MA, Chen Y, Chen W, Lu X. Hypervalent Iodine Mediated Synthesis of Sulfinamidines from Sulfenamides. J Org Chem 2023; 88:11728-11734. [PMID: 37506052 DOI: 10.1021/acs.joc.3c00999] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/30/2023]
Abstract
In this study, we present a novel, efficient method for the oxidative amination of sulfenamides using diacetoxyiodobenzene (PhI(OAc)2) and amines under basic conditions. This innovative technique streamlines the synthesis of sulfinamidines under mild, metal-free conditions, achieving outstanding yields of up to 99%. Furthermore, we propose possible pathways that elucidate the observed molecular sequence of events in this reaction. This cutting-edge approach not only advances the synthesis of valuable sulfinamidine compounds but also expands the synthetic toolbox available to chemists, paving the way for future discoveries in organic synthesis and potential applications in medicinal chemistry.
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Affiliation(s)
- Guoling Huang
- Laboratory of Marine Green Fine Chemicals, School of Chemistry and Chemical Engineering, Lingnan Normal University, Zhanjiang, 524048, P. R. China
| | - Jianlin Ye
- Laboratory of Marine Green Fine Chemicals, School of Chemistry and Chemical Engineering, Lingnan Normal University, Zhanjiang, 524048, P. R. China
| | | | - Yuetong Chen
- Laboratory of Marine Green Fine Chemicals, School of Chemistry and Chemical Engineering, Lingnan Normal University, Zhanjiang, 524048, P. R. China
| | - Wenjing Chen
- Laboratory of Marine Green Fine Chemicals, School of Chemistry and Chemical Engineering, Lingnan Normal University, Zhanjiang, 524048, P. R. China
| | - Xunbo Lu
- Laboratory of Marine Green Fine Chemicals, School of Chemistry and Chemical Engineering, Lingnan Normal University, Zhanjiang, 524048, P. R. China
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3
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Metal-free oxidative radical arylation of styrene with anilines to access 2-arylacetophenones and selective oxidation of amine. J Mol Struct 2023. [DOI: 10.1016/j.molstruc.2023.134995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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4
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Malik AA, Ara T. Primary amines as new carbonyl surrogate in Kabachnik‐fields reaction: A new metal free one pot approach to synthesize α‐Aminophosphonates in water. ChemistrySelect 2022. [DOI: 10.1002/slct.202202900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Asif A Malik
- Department of Chemistry Organic Chemistry Division National Institute of Technology (NIT) Srinagar 190006 India
| | - Tabassum Ara
- Department of Chemistry Organic Chemistry Division National Institute of Technology (NIT) Srinagar 190006 India
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5
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Sihag M, Soni R, Rani N, Kinger M, Kumar Aneja D. Recent Synthetic Applications of Hypervalent Iodine Reagents. A Review in Three Installments: Installment III. ORG PREP PROCED INT 2022. [DOI: 10.1080/00304948.2022.2114239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/10/2022]
Affiliation(s)
- Monika Sihag
- Department of Chemistry, Chaudhary Bansi Lal University, Bhiwani, Haryana, India
| | - Rinku Soni
- Department of Chemistry, Chaudhary Bansi Lal University, Bhiwani, Haryana, India
| | - Neha Rani
- Department of Chemistry, Chaudhary Bansi Lal University, Bhiwani, Haryana, India
| | - Mayank Kinger
- Department of Chemistry, Chaudhary Bansi Lal University, Bhiwani, Haryana, India
| | - Deepak Kumar Aneja
- Department of Chemistry, Chaudhary Bansi Lal University, Bhiwani, Haryana, India
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6
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Suryavanshi GM, Rupanawar BD, Mane KD. Hypervalent Iodine Mediated Oxidation Followed by Acetoxylation / Tosylation of α-Substituted Benzylamines Accessing to α-Acyloxy / Tosyloxy Ketones. NEW J CHEM 2022. [DOI: 10.1039/d2nj02271k] [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
An efficient and metal-free method has been developed for sequential oxidation followed by acetoxylation, tosylation of α-alkylbenzylamines for the synthesis of α-acyloxy / tosyloxy ketones by using hypervalent iodine (III)...
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7
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Iwabuchi Y, Nagasawa S. The Utility of Oxoammonium Species in Organic Synthesis: Beyond Alcohol Oxidation. HETEROCYCLES 2022. [DOI: 10.3987/rev-21-sr(r)2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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8
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Prakash N, Rajeev R, John A, Vijayan A, George L, Varghese A. 2,2,6,6‐Tetramethylpiperidinyloxyl (TEMPO) Radical Mediated Electro‐Oxidation Reactions: A Review. ChemistrySelect 2021. [DOI: 10.1002/slct.202102346] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Nishitha Prakash
- Department of Chemistry CHRIST (Deemed to be University) Hosur Road Bengaluru 560029 India
| | - Rijo Rajeev
- Department of Chemistry CHRIST (Deemed to be University) Hosur Road Bengaluru 560029 India
| | - Anjali John
- Department of Chemistry CHRIST (Deemed to be University) Hosur Road Bengaluru 560029 India
| | - Ajesh Vijayan
- Department of Chemistry CHRIST (Deemed to be University) Hosur Road Bengaluru 560029 India
| | - Louis George
- Department of Chemistry CHRIST (Deemed to be University) Hosur Road Bengaluru 560029 India
| | - Anitha Varghese
- Department of Chemistry CHRIST (Deemed to be University) Hosur Road Bengaluru 560029 India
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Panigrahi A, Muniraj N, Prabhu KR. N-Triflination of pyrazolones: a new method for N-S bond formation. Org Biomol Chem 2021; 19:5534-5538. [PMID: 34105585 DOI: 10.1039/d1ob00862e] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
A simple method, which takes place quickly in 5 min, is developed for the N-triflination of pyrazolones using CF3SO2Na (Langlois reagent) and phenyliodine(iii)bis(trifluoroacetate) (PIFA). This reaction takes place at the imine nitrogen centre instead of the more reactive C4-position, forming a new N-S bond. A variety of pyrazolone derivatives were subjected to the reaction. Unlike the previous reports on sulfenylation or sulfonylation of pyrazolone, wherein the corresponding C-S bond is formed, this new method leads to the formation of the hetero-hetero atom bond (N-S bond) at room temperature.
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Affiliation(s)
- Ahwan Panigrahi
- Department of Organic Chemistry, Indian Institute of Science, Bangalore 560 012, Karnataka, India.
| | - Nachimuthu Muniraj
- Department of Organic Chemistry, Indian Institute of Science, Bangalore 560 012, Karnataka, India.
| | - Kandikere Ramaiah Prabhu
- Department of Organic Chemistry, Indian Institute of Science, Bangalore 560 012, Karnataka, India.
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Bansode AH, Suryavanshi G. Visible‐Light‐Induced Controlled Oxidation of
N
‐Substituted 1,2,3,4‐Tetrahydroisoquinolines for the Synthesis of 3,4‐Dihydroisoquinolin‐1(2
H
)‐ones and Isoquinolin‐1(2
H
)‐ones. Adv Synth Catal 2021. [DOI: 10.1002/adsc.202001266] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Ajay H. Bansode
- Chemical Engineering & Process Development Division CSIR-National Chemical Laboratory Dr. Homi Bhabha Road Pune 411008 India
- Academy of Scientific and Innovative Research (AcSIR) Ghaziabad 201 002 India
| | - Gurunath Suryavanshi
- Chemical Engineering & Process Development Division CSIR-National Chemical Laboratory Dr. Homi Bhabha Road Pune 411008 India
- Academy of Scientific and Innovative Research (AcSIR) Ghaziabad 201 002 India
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11
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Ramavath V, Rupanawar BD, More SG, Bansode AH, Suryavanshi G. Hypervalent iodine( iii) induced oxidative olefination of benzylamines using Wittig reagents. NEW J CHEM 2021. [DOI: 10.1039/d1nj01170g] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
We have developed hypervalent iodine mediated oxidative olefination of 1° and 2° amines using 2C-Wittig reagents for the synthesis of α,β-unsaturated esters.
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Affiliation(s)
- Vijayalakshmi Ramavath
- Chemical Engineering & Process Development Division
- CSIR-National Chemical Laboratory
- Pune-411008
- India
- Academy of Scientific and Innovative Research (AcSIR)
| | - Bapurao D. Rupanawar
- Chemical Engineering & Process Development Division
- CSIR-National Chemical Laboratory
- Pune-411008
- India
- Academy of Scientific and Innovative Research (AcSIR)
| | - Satish G. More
- Chemical Engineering & Process Development Division
- CSIR-National Chemical Laboratory
- Pune-411008
- India
- Academy of Scientific and Innovative Research (AcSIR)
| | - Ajay H. Bansode
- Chemical Engineering & Process Development Division
- CSIR-National Chemical Laboratory
- Pune-411008
- India
- Academy of Scientific and Innovative Research (AcSIR)
| | - Gurunath Suryavanshi
- Chemical Engineering & Process Development Division
- CSIR-National Chemical Laboratory
- Pune-411008
- India
- Academy of Scientific and Innovative Research (AcSIR)
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12
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Schofield K, Foley C, Hulme C. 5- Endo Trig Oxidative Radical Cyclizations of Ugi-3CR Products toward 1,4-Imidazolidinones. Org Lett 2020; 23:107-112. [PMID: 33306404 DOI: 10.1021/acs.orglett.0c03785] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
A 5-endo trig oxidative radical cyclization of benzylamine-derived Ugi three-component reaction products rapidly affords imidazolidinones with three diversity elements. This adaptation of our previously described multicomponent reaction-oxidation methodology further showcases manipulation of the diversity elements in multicomponent reaction products via oxidative radical cyclizations, which generates highly decorated privileged heterocycles.
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Affiliation(s)
- Kevin Schofield
- Department of Chemistry and Biochemistry, College of Science, The University of Arizona, Tucson, Arizona 85721, United States
| | - Christopher Foley
- Department of Chemistry and Biochemistry, College of Science, The University of Arizona, Tucson, Arizona 85721, United States
| | - Christopher Hulme
- Department of Chemistry and Biochemistry, College of Science, The University of Arizona, Tucson, Arizona 85721, United States.,Department of Pharmacology and Toxicology, College of Pharmacy, The University of Arizona, Tucson, Arizona 85721, United States
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13
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Bhoite SP, Bansode AH, Suryavanshi G. Radical Rearrangement of Aryl/Alkylidene Malononitriles via Aza Michael Addition/Decynoformylation/Addition Sequence: An Access to α-Aminonitriles and α-Aminoamides. J Org Chem 2020; 85:14858-14865. [DOI: 10.1021/acs.joc.0c01358] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Shubhangi P. Bhoite
- Chemical Engineering & Process Development Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, India
- Academy of Scientific and Innovative Research (AcSIR), New Delhi 110 025, India
| | - Ajay H. Bansode
- Chemical Engineering & Process Development Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, India
- Academy of Scientific and Innovative Research (AcSIR), New Delhi 110 025, India
| | - Gurunath Suryavanshi
- Chemical Engineering & Process Development Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, India
- Academy of Scientific and Innovative Research (AcSIR), New Delhi 110 025, India
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14
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Zhuang H, Li H, Zhang S, Yin Y, Han F, Sun C, Miao C. TEMPO and its derivatives mediated reactions under transition-metal-free conditions. CHINESE CHEM LETT 2020. [DOI: 10.1016/j.cclet.2019.06.027] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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15
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Rupanawar BD, Veetil SM, Suryavanshi G. Oxidative Olefination of Benzylamine with an Active Methylene Compound Mediated by Hypervalent Iodine (III). European J Org Chem 2019. [DOI: 10.1002/ejoc.201900970] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Bapurao D. Rupanawar
- Chemical Engineering & Process Development Division; CSIR-National Chemical Laboratory; Dr. Homi Bhaba Road, Pashan, Pune- 411008 Maharashtra India
- Academy of Scientifc and Innovative Research (AcSIR); 201002 Ghaziabad, Uttar Pradesh India
| | - Sruthi M. Veetil
- CSIR-National Chemical Laboratory; Central NMR Facility; Dr. Homi Bhaba Road, Pashan, Pune- 411008 Maharashtra India
| | - Gurunath Suryavanshi
- Chemical Engineering & Process Development Division; CSIR-National Chemical Laboratory; Dr. Homi Bhaba Road, Pashan, Pune- 411008 Maharashtra India
- Academy of Scientifc and Innovative Research (AcSIR); 201002 Ghaziabad, Uttar Pradesh India
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16
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Bansode AH, Suryavanshi G. Iodine-Mediated Oxidative Rearrangement of α,β-Unsaturated Diaryl Ketones: A Facile Access to 1,2-Diaryl Diketones. ACS OMEGA 2019; 4:9636-9644. [PMID: 31460054 PMCID: PMC6648810 DOI: 10.1021/acsomega.9b00833] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 05/17/2019] [Indexed: 05/03/2023]
Abstract
A metal-free oxidative rearrangement was explored for the synthesis of 1,2-diaryl diketones by utilizing α,β-unsaturated diaryl ketones and I2/TBHP in good to high yields. The reaction proceeds via oxidative aryl migration, followed by C-C bond cleavage. A simple and high-yielding protocol was developed for the synthesis of a wide range of 1,2-diaryl diketones, which are the backbone for a variety of medicinally important molecules.
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Affiliation(s)
- Ajay H. Bansode
- Chemical
Engineering & Process Development Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, India
- Academy
of Scientific and Innovative Research (AcSIR), New Delhi 110 025, India
| | - Gurunath Suryavanshi
- Chemical
Engineering & Process Development Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, India
- Academy
of Scientific and Innovative Research (AcSIR), New Delhi 110 025, India
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17
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Mane KD, Kamble RB, Suryavanshi G. A visible light mediated, metal and oxidant free highly efficient cross dehydrogenative coupling (CDC) reaction between quinoxalin-2(1H)-ones and ethers. NEW J CHEM 2019. [DOI: 10.1039/c9nj00075e] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The white light mediated, 3C alkylation of quinoxalin-2(1H)-ones via a cross dehydrogenative coupling (CDC) reaction with cyclic ethers using eosin Y as a photocatalyst is described. The reaction proceeds via a hydrogen abstraction and transfer process.
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Affiliation(s)
- Kishor D. Mane
- Chemical Engineering and Process Development Division
- CSIR-National Chemical Laboratory
- Pune
- India
- Academy of Scientific and Innovative Research
| | - Rohit B. Kamble
- Chemical Engineering and Process Development Division
- CSIR-National Chemical Laboratory
- Pune
- India
- Academy of Scientific and Innovative Research
| | - Gurunath Suryavanshi
- Chemical Engineering and Process Development Division
- CSIR-National Chemical Laboratory
- Pune
- India
- Academy of Scientific and Innovative Research
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More SG, Suryavanshi G. Metal-free, radical 1,6-conjugated addition of cyclic ethers with para-quinone methides (p-QMs). Org Biomol Chem 2019; 17:3239-3248. [DOI: 10.1039/c9ob00127a] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
An efficient method for metal-free C–C bond formation between p-quinone methides (p-QMs) and cyclic ethers via a radical pathway to afford substituted diarylmethanes and triarylmethanes or to effect the α-alkylation of the cyclic ethers has been developed.
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Affiliation(s)
- Satish G. More
- Chemical Engineering and Process Development Division
- CSIR-National Chemical Laboratory
- Pune
- India
- Academy of Scientific and Innovative Research
| | - Gurunath Suryavanshi
- Chemical Engineering and Process Development Division
- CSIR-National Chemical Laboratory
- Pune
- India
- Academy of Scientific and Innovative Research
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