1
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Gadhave MS, Barik S, Wessels F, Biju AT. Nucleophilic Acylation-Annulation Cascade of 2-Chlorobenzonitriles Using Aldehydes Triggered by N-Heterocyclic Carbenes. Org Lett 2023; 25:8314-8319. [PMID: 37962305 DOI: 10.1021/acs.orglett.3c03376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
A general and practical route to the synthesis of functionalized isoindolin-2-ones from commercially available aldehydes and 2-chlorobenzonitriles under mild conditions initiated by N-heterocyclic carbenes is presented. The catalytically generated Breslow intermediates from aldehydes and carbenes underwent smooth SNAr with 2-chlorobenzonitriles followed by annulation triggered by adventitious water present in DMF to furnish the functionalized isoindolin-2-ones in good to excellent yields.
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Affiliation(s)
- Mahesh S Gadhave
- Department of Organic Chemistry, Indian Institute of Science, Bangalore-560012, India
| | - Soumen Barik
- Department of Organic Chemistry, Indian Institute of Science, Bangalore-560012, India
| | - Felix Wessels
- Organisch-Chemisches Institut, Universität Münster, 48149 Münster, Germany
| | - Akkattu T Biju
- Department of Organic Chemistry, Indian Institute of Science, Bangalore-560012, India
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2
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Chabuka BK, Alabugin IV. Hole Catalysis of Cycloaddition Reactions: How to Activate and Control Oxidant Upconversion in Radical-Cationic Diels-Alder Reactions. J Am Chem Soc 2023; 145:19354-19367. [PMID: 37625247 DOI: 10.1021/jacs.3c06106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/27/2023]
Abstract
In order to use holes as catalysts, the oxidized product should be able to transfer the hole to a fresh reactant. For that, the hole-catalyzed reaction must increase the oxidation potential along the reaction path, i.e., lead to "hole upconversion." If this thermodynamic requirement is satisfied, a hole injected via one-electron oxidation can persist through multiple propagation cycles and serve as a true catalyst. This work provides guidelines for the rational design of hole-catalyzed Diels-Alder (DA) reactions, the prototypical cycloaddition. After revealing the crucial role of hyperconjugation in the absence of hole upconversion in the parent DA reaction, we show how upconversion can be reactivated by proper substitution. For this purpose, we computationally evaluate the contrasting effects of substituents at the three possible positions in the two reactants. The occurrence and magnitude of hole upconversion depend strongly on the placement and nature of substituents. For example, donors at C1 in 1,3-butadiene shift the reaction to the hole-upconverted regime with an increased oxidation potential of up to 1.0 V. In contrast, hole upconversion in C2-substituted 1,3-butadienes is activated by acceptors with the oxidation potential increase up to 0.54 V. Dienophile substitution results in complex trends because the radical cation can be formed at either the dienophile or the diene. Hole upconversion is always present in the former scenario (up to 0.65 V). Finally, we report interesting stereoelectronic effects that can activate or deactivate upconversion via a conformational change.
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Affiliation(s)
- Beauty K Chabuka
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
| | - Igor V Alabugin
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
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3
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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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4
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Xu Y, Li Q, Ye R, Xu B, Zhou X. Electrochemical Oxidative C-H Amination through a Ritter-Type Reaction. J Org Chem 2023. [PMID: 37262003 DOI: 10.1021/acs.joc.3c00609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
A straightforward strategy for direct benzylic C-H bond amination via an electrochemical Ritter-type reaction is developed. The reaction demonstrates simpler and milder reaction conditions over the existing methods without extra mediator. Moderate to excellent yields up to 94% of the desired amide products were obtained with a broad substrate scope. The removal of the Ac group by a simple step can afford NH-free benzylic amines, providing a suitable approach for the late-stage functionalization of bioactive molecules.
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Affiliation(s)
- Yiwen Xu
- College of Chemistry, Sichuan University, Wangjiang Road 29, Chengdu, Sichuan 610064, China
| | - Qiang Li
- College of Chemistry, Sichuan University, Wangjiang Road 29, Chengdu, Sichuan 610064, China
| | - Runyou Ye
- College of Chemistry, Sichuan University, Wangjiang Road 29, Chengdu, Sichuan 610064, China
| | - Buyi Xu
- National Anti-Drug Laboratory Sichuan Regional Center, 36 Yunling Road, Chengdu, Sichuan 610200, P.R. China
| | - Xiangge Zhou
- College of Chemistry, Sichuan University, Wangjiang Road 29, Chengdu, Sichuan 610064, China
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5
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Duff L, Meakin H, Richardson A, Greener AJ, Smith GWA, Ocaña I, Chechik V, James MJ. Denitrative Hydroxylation of Unactivated Nitroarenes. Chemistry 2023; 29:e202203807. [PMID: 36594445 DOI: 10.1002/chem.202203807] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Accepted: 12/17/2022] [Indexed: 01/04/2023]
Abstract
A one-step method for the conversion of nitroarenes into phenols under operationally simple, transition-metal-free conditions is described. This denitrative functionalization protocol provides a concise and economical alternative to conventional three-step synthetic sequences. Experimental and computational studies suggest that nitroarenes may be substituted by an electron-catalysed radical-nucleophilic substitution (SRN 1) chain mechanism.
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Affiliation(s)
- Lee Duff
- Department of Chemistry, University of York Heslington, York, YO10 5DD, UK
| | - Harry Meakin
- Department of Chemistry, University of York Heslington, York, YO10 5DD, UK
| | - Adam Richardson
- Department of Chemistry, University of York Heslington, York, YO10 5DD, UK
| | - Andrew J Greener
- Department of Chemistry, University of York Heslington, York, YO10 5DD, UK
| | - George W A Smith
- Department of Chemistry, University of York Heslington, York, YO10 5DD, UK
| | - Ivan Ocaña
- Department of Chemistry, University of York Heslington, York, YO10 5DD, UK
| | - Victor Chechik
- Department of Chemistry, University of York Heslington, York, YO10 5DD, UK
| | - Michael J James
- Department of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK
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6
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Li A, Li C, Yang T, Yang Z, Liu Y, Li L, Tang K, Zhou C. Electrochemical Synthesis of Benzo[ d]imidazole via Intramolecular C(sp 3)-H Amination. J Org Chem 2023; 88:1928-1935. [PMID: 34918925 DOI: 10.1021/acs.joc.1c01842] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
An electrochemical dehydrogenative amination for the synthesis of benzimidazoles was developed. This electrosynthesis method could address the limitations of the C(sp3)-H intramolecular amination synthesis reaction and provide novel access to obtain 1,2-disubstituted benzimidazoles without transition metals and oxidants. Under undivided electrolytic conditions, various benzimidazole derivatives could be synthesized, exhibiting functional group tolerance.
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Affiliation(s)
- An Li
- Province Key Laboratory for Fine Petrochemical Catalysis and Separation, College of Chemistry and Chemical Engineering, Hunan Institute of Science and Technology, Yueyang, Hunan 414000, P. R. China
| | - Caohui Li
- Province Key Laboratory for Fine Petrochemical Catalysis and Separation, College of Chemistry and Chemical Engineering, Hunan Institute of Science and Technology, Yueyang, Hunan 414000, P. R. China
| | - Tao Yang
- Province Key Laboratory for Fine Petrochemical Catalysis and Separation, College of Chemistry and Chemical Engineering, Hunan Institute of Science and Technology, Yueyang, Hunan 414000, P. R. China
| | - Zan Yang
- Key Laboratory of Molecule Synthesis and Function Discovery (Fujian Province University), College of Chemistry, Fuzhou University, Fuzhou 350108, China
| | - Yu Liu
- Province Key Laboratory for Fine Petrochemical Catalysis and Separation, College of Chemistry and Chemical Engineering, Hunan Institute of Science and Technology, Yueyang, Hunan 414000, P. R. China
| | - LiJun Li
- Province Key Laboratory for Fine Petrochemical Catalysis and Separation, College of Chemistry and Chemical Engineering, Hunan Institute of Science and Technology, Yueyang, Hunan 414000, P. R. China
| | - KeWen Tang
- Province Key Laboratory for Fine Petrochemical Catalysis and Separation, College of Chemistry and Chemical Engineering, Hunan Institute of Science and Technology, Yueyang, Hunan 414000, P. R. China
| | - Congshan Zhou
- Province Key Laboratory for Fine Petrochemical Catalysis and Separation, College of Chemistry and Chemical Engineering, Hunan Institute of Science and Technology, Yueyang, Hunan 414000, P. R. China
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7
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Abstract
AIBN is a convenient electrophilic cyanation reagent for transforming ArLi into ArCN under mild conditions. The addition/fragmentation cascade is controlled by Li···N chelation in which AIBN nitrogens assist in the nearly barrierless fragmentation into the desired ArCN product. Acidic C-H bonds in the fragmented byproduct partially consume ArLi by protonation. Density functional theory calculations and isotopic labeling probe the mechanism and explain the switch to substituted hydrazones in reactions with BuLi.
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Affiliation(s)
- Quintin Elliott
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
| | - Igor V Alabugin
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
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8
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Eckhardt P, Elliot Q, Alabugin IV, Opatz T. Two Paths to Oxidative C-H Amination Under Basic Conditions: A Theoretical Case Study Reveals Hidden Opportunities Provided by Electron Upconversion. Chemistry 2022; 28:e202201637. [PMID: 35880945 PMCID: PMC9804812 DOI: 10.1002/chem.202201637] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Indexed: 01/09/2023]
Abstract
Traditionally, cross-dehydrogenative coupling (CDC) leads to C-N bond formation under basic and oxidative conditions and is proposed to proceed via a two-electron bond formation mediated by carbenium ions. However, the formation of such high-energy intermediates is only possible in the presence of strong oxidants, which may lead to undesired side reactions and poor functional group tolerance. In this work we explore if oxidation under basic conditions allows the formation of three-electron bonds (resulting in "upconverted" highly-reducing radical-anions). The benefit of this "upconversion" process is in the ability to use milder oxidants (e. g., O2 ) and to avoid high-energy intermediates. Comparison of the two- and three-electron pathways using quantum mechanical calculations reveals that not only does the absence of a strong oxidant shut down two-electron pathways in favor of a three-electron path but, paradoxically, weaker oxidants react faster with the upconverted reductants by avoiding the inverted Marcus region for electron transfer.
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Affiliation(s)
- Paul Eckhardt
- Department of ChemistryJohannes Gutenberg University MainzDuesbergweg 10–1455128MainzGermany
| | - Quintin Elliot
- Department of Chemistry and BiochemistryFlorida State UniversityTallahasseeFlorida 32306USA
| | - Igor V. Alabugin
- Department of Chemistry and BiochemistryFlorida State UniversityTallahasseeFlorida 32306USA
| | - Till Opatz
- Department of ChemistryJohannes Gutenberg University MainzDuesbergweg 10–1455128MainzGermany
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9
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Liu T, Gan KB, Zhong RL, He X, Kwong FY. A Metal-Free and Redox-Neutral Benzylic C-O Cyclization for Succinct Access of Helical Chromenes. Org Lett 2022; 24:6805-6809. [PMID: 36098713 DOI: 10.1021/acs.orglett.2c02728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A redox-neutral benzylic C-O cyclization under beneficial transition-metal-free conditions is reported. Key to the success of this process is the utilization of the Tf anion as the leaving group for achieving the redox-neutral transformation. This protocol delivers a series of captivating helical compounds having various functionality in good-to-excellent yields. It is particularly noteworthy that sterically hindered helical compounds are conformationally stable. In addition to simple helical chromenes, the bihelical multiple-ring systems which are potentially useful in material chemistry are also easily attained by employing this method. DFT calculation revealed that quinone intermediate is the key species, among four possible mechanisms, for accomplishing the desired cyclization via an oxa-6π-electrocyclization pathway.
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Affiliation(s)
- Tianyi Liu
- State Key Laboratory of Synthetic Chemistry and Department of Chemistry, The Chinese University of Hong Kong, New Territories, Hong Kong, China.,Shenzhen Municipal Key Laboratory of Chemical Synthesis of Medicinal Organic Molecules, Shenzhen Research Institute, The Chinese University of Hong Kong, No. 10, Second Yuexing Road, Shenzhen 518507, P. R. China
| | - Kin Boon Gan
- State Key Laboratory of Synthetic Chemistry and Department of Chemistry, The Chinese University of Hong Kong, New Territories, Hong Kong, China.,Shenzhen Municipal Key Laboratory of Chemical Synthesis of Medicinal Organic Molecules, Shenzhen Research Institute, The Chinese University of Hong Kong, No. 10, Second Yuexing Road, Shenzhen 518507, P. R. China
| | - Rong-Lin Zhong
- State Key Laboratory of Synthetic Chemistry and Department of Chemistry, The Chinese University of Hong Kong, New Territories, Hong Kong, China.,Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, College of Chemistry, Jilin University, Changchun 130023, P. R. China
| | - Xinwei He
- State Key Laboratory of Synthetic Chemistry and Department of Chemistry, The Chinese University of Hong Kong, New Territories, Hong Kong, China.,Key Laboratory of Functional Molecular Solids, Ministry of Education, Anhui Laboratory of Molecule-Based Materials (State Key Laboratory Cultivation Base), College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241002, P. R. China
| | - Fuk Yee Kwong
- State Key Laboratory of Synthetic Chemistry and Department of Chemistry, The Chinese University of Hong Kong, New Territories, Hong Kong, China.,Shenzhen Municipal Key Laboratory of Chemical Synthesis of Medicinal Organic Molecules, Shenzhen Research Institute, The Chinese University of Hong Kong, No. 10, Second Yuexing Road, Shenzhen 518507, P. R. China
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10
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Balycheva VA, Akyeva AY, Saverina EA, Shangin PG, Krylova IV, Korolev VA, Egorov MP, Alabugin IV, Syroeshkin MA. Electron upconversion in reactions of 1,2,4-triazoline-3,5-dione. Russ Chem Bull 2022. [DOI: 10.1007/s11172-022-3570-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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11
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Copper Catalyzed Oxidative Cascade Double Cyclization of 2‐Iodobenzamide Derivatives and Propargyl dicarbonyl Compounds for Accessing 3‐Hydroxy‐3‐furylisoindolinone derivatives. Adv Synth Catal 2022. [DOI: 10.1002/adsc.202200235] [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]
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12
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Akyeva AY, Kansuzyan AV, Vukich KS, Kuhn L, Saverina EA, Minyaev ME, Pechennikov VM, Egorov MP, Alabugin IV, Vorobyev SV, Syroeshkin MA. Remote Stereoelectronic Effects in Pyrrolidone- and Caprolactam-Substituted Phenols: Discrepancies in Antioxidant Properties Evaluated by Electrochemical Oxidation and H-Atom Transfer Reactivity. J Org Chem 2022; 87:5371-5384. [PMID: 35363496 DOI: 10.1021/acs.joc.2c00207] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
New antioxidants are commonly evaluated via two main approaches, i.e., the ability to donate an electron and the ability to intercept free radicals. We compared these approaches by evaluating the properties of 11 compounds containing both antioxidant moieties (mono- and polyphenols) and auxiliary pharmacophores (pyrrolidone and caprolactam). Several common antioxidants, such as butylated hydroxytoluene (BHT), 2,3,5-trimethylphenol (TMP), quercetin, and dihydroquercetin, were added for comparison. The antioxidant properties of these compounds were determined by their rates of reaction with 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical and their oxidation potentials from cyclic voltammetry. Although these methods test different chemical properties, their results correlate reasonably well. However, several exceptions exist where the two methods give opposite predictions! One of them is the different behavior of mono- and polyphenols: polyphenols can react with DPPH more than an order of magnitude faster than monophenols of a similar oxidation potential. The second exception stems from the size of a "bystander" lactam ring at the benzylic position. Although the phenols with a seven-membered lactam ring are harder to oxidize, the sterically nonhindered compounds react with DPPH about 2× faster than the analogous five-membered lactams. The limitations of computational methods, especially those based on a single parameter, are also evaluated and discussed.
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Affiliation(s)
- Anna Ya Akyeva
- N.D. Zelinsky Institute of Organic Chemistry, 119991 Moscow Russia
| | | | - Katarina S Vukich
- N.D. Zelinsky Institute of Organic Chemistry, 119991 Moscow Russia.,I.M. Sechenov First Moscow State Medical University, 119991 Moscow, Russia
| | - Leah Kuhn
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
| | | | | | | | - Mikhail P Egorov
- N.D. Zelinsky Institute of Organic Chemistry, 119991 Moscow Russia
| | - Igor V Alabugin
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
| | - Stepan V Vorobyev
- Gubkin Russian State University of Oil and Gas, 65 Leninsky Prospect, 119991 Moscow, Russia
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13
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Greener AJ, Ubysz P, Owens-Ward W, Smith G, Ocaña I, Whitwood AC, Chechik V, James MJ. Radical-anion coupling through reagent design: hydroxylation of aryl halides. Chem Sci 2021; 12:14641-14646. [PMID: 34881017 PMCID: PMC8580057 DOI: 10.1039/d1sc04748e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 10/20/2021] [Indexed: 01/09/2023] Open
Abstract
The design and development of an oxime-based hydroxylation reagent, which can chemoselectively convert aryl halides (X = F, Cl, Br, I) into phenols under operationally simple, transition-metal-free conditions is described. Key to the success of this approach was the identification of a reducing oxime anion which can interact and couple with open-shell aryl radicals. Experimental and computational studies support the proposed radical-nucleophilic substitution chain mechanism.
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Affiliation(s)
- Andrew J Greener
- Department of Chemistry, University of York Heslington York YO10 5DD UK
| | - Patrycja Ubysz
- Department of Chemistry, University of York Heslington York YO10 5DD UK
| | - Will Owens-Ward
- Department of Chemistry, University of York Heslington York YO10 5DD UK
| | - George Smith
- Department of Chemistry, University of York Heslington York YO10 5DD UK
| | - Ivan Ocaña
- Department of Chemistry, University of York Heslington York YO10 5DD UK
| | - Adrian C Whitwood
- Department of Chemistry, University of York Heslington York YO10 5DD UK
| | - Victor Chechik
- Department of Chemistry, University of York Heslington York YO10 5DD UK
| | - Michael J James
- Department of Chemistry, University of York Heslington York YO10 5DD UK
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14
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Yuan X, Yu X, He K, Zhang R, Xiao W, Lin J, Zhan Z, Cheng X, Shao Z, Jin Y. Dual C(sp 3)-H Functionalization of Cyclic Ethers via Singlet Oxygen-Mediated Ring Opening and Ring Closing. Org Lett 2021; 23:8267-8272. [PMID: 34633191 DOI: 10.1021/acs.orglett.1c03008] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A metal-free dual C(sp3)-H bond functionalization of saturated cyclic ethers via photooxidative singlet oxygen-mediated ring opening and ring closing has been developed, providing a method for generating hydrobenzofurans/pyrans/dioxins. Mechanistic studies have confirmed that ring-opening intermediates were effectively generated by singlet oxygen-mediated C(sp3)-H activation and efficiently reacted with aldehydes and activated methylene compounds to form a wide array of products with high diastereoselectivities (up to >95:5 dr). This study is a rare example of α,β-dual C(sp3)-H bond functionalization of ethers.
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Affiliation(s)
- Xu Yuan
- Key Laboratory of Medicinal for Natural Resource, Ministry of Education and Yunnan Province, School of Chemical Science and Technology, Yunnan University, Kunming 650091, China
| | - Xianglin Yu
- Key Laboratory of Medicinal for Natural Resource, Ministry of Education and Yunnan Province, School of Chemical Science and Technology, Yunnan University, Kunming 650091, China
| | - Kun He
- Key Laboratory of Medicinal for Natural Resource, Ministry of Education and Yunnan Province, School of Chemical Science and Technology, Yunnan University, Kunming 650091, China
| | - Ruihan Zhang
- Key Laboratory of Medicinal for Natural Resource, Ministry of Education and Yunnan Province, School of Chemical Science and Technology, Yunnan University, Kunming 650091, China
| | - Weilie Xiao
- Key Laboratory of Medicinal for Natural Resource, Ministry of Education and Yunnan Province, School of Chemical Science and Technology, Yunnan University, Kunming 650091, China
| | - Jun Lin
- Key Laboratory of Medicinal for Natural Resource, Ministry of Education and Yunnan Province, School of Chemical Science and Technology, Yunnan University, Kunming 650091, China
| | - Zhajun Zhan
- College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou 310014, P. R. China
| | - Xiaohong Cheng
- Key Laboratory of Medicinal for Natural Resource, Ministry of Education and Yunnan Province, School of Chemical Science and Technology, Yunnan University, Kunming 650091, China
| | - Zhihui Shao
- Key Laboratory of Medicinal for Natural Resource, Ministry of Education and Yunnan Province, School of Chemical Science and Technology, Yunnan University, Kunming 650091, China
| | - Yi Jin
- Key Laboratory of Medicinal for Natural Resource, Ministry of Education and Yunnan Province, School of Chemical Science and Technology, Yunnan University, Kunming 650091, China
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15
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Alabugin IV, Kuhn L, Medvedev MG, Krivoshchapov NV, Vil' VA, Yaremenko IA, Mehaffy P, Yarie M, Terent'ev AO, Zolfigol MA. Stereoelectronic power of oxygen in control of chemical reactivity: the anomeric effect is not alone. Chem Soc Rev 2021; 50:10253-10345. [PMID: 34263287 DOI: 10.1039/d1cs00386k] [Citation(s) in RCA: 66] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Although carbon is the central element of organic chemistry, oxygen is the central element of stereoelectronic control in organic chemistry. Generally, a molecule with a C-O bond has both a strong donor (a lone pair) and a strong acceptor (e.g., a σ*C-O orbital), a combination that provides opportunities to influence chemical transformations at both ends of the electron demand spectrum. Oxygen is a stereoelectronic chameleon that adapts to the varying situations in radical, cationic, anionic, and metal-mediated transformations. Arguably, the most historically important stereoelectronic effect is the anomeric effect (AE), i.e., the axial preference of acceptor groups at the anomeric position of sugars. Although AE is generally attributed to hyperconjugative interactions of σ-acceptors with a lone pair at oxygen (negative hyperconjugation), recent literature reports suggested alternative explanations. In this context, it is timely to evaluate the fundamental connections between the AE and a broad variety of O-functional groups. Such connections illustrate the general role of hyperconjugation with oxygen lone pairs in reactivity. Lessons from the AE can be used as the conceptual framework for organizing disjointed observations into a logical body of knowledge. In contrast, neglect of hyperconjugation can be deeply misleading as it removes the stereoelectronic cornerstone on which, as we show in this review, the chemistry of organic oxygen functionalities is largely based. As negative hyperconjugation releases the "underutilized" stereoelectronic power of unshared electrons (the lone pairs) for the stabilization of a developing positive charge, the role of orbital interactions increases when the electronic demand is high and molecules distort from their equilibrium geometries. From this perspective, hyperconjugative anomeric interactions play a unique role in guiding reaction design. In this manuscript, we discuss the reactivity of organic O-functionalities, outline variations in the possible hyperconjugative patterns, and showcase the vast implications of AE for the structure and reactivity. On our journey through a variety of O-containing organic functional groups, from textbook to exotic, we will illustrate how this knowledge can predict chemical reactivity and unlock new useful synthetic transformations.
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Affiliation(s)
- Igor V Alabugin
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306, USA.
| | - Leah Kuhn
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306, USA.
| | - Michael G Medvedev
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky prosp., 119991 Moscow, Russian Federation.,A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, 28 Vavilova St., 119991 Moscow, Russian Federation
| | - Nikolai V Krivoshchapov
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky prosp., 119991 Moscow, Russian Federation.,Lomonosov Moscow State University, Leninskie Gory 1 (3), Moscow, 119991, Russian Federation
| | - Vera A Vil'
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky prosp., 119991 Moscow, Russian Federation
| | - Ivan A Yaremenko
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky prosp., 119991 Moscow, Russian Federation
| | - Patricia Mehaffy
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306, USA.
| | - Meysam Yarie
- Department of Organic Chemistry, Faculty of Chemistry, Bu-Ali Sina University, Hamedan 65167, Iran
| | - Alexander O Terent'ev
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky prosp., 119991 Moscow, Russian Federation
| | - Mohammad Ali Zolfigol
- Department of Organic Chemistry, Faculty of Chemistry, Bu-Ali Sina University, Hamedan 65167, Iran
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16
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Nozawa-Kumada K, Matsuzawa Y, Ono K, Shigeno M, Kondo Y. Copper-catalyzed aerobic double functionalization of benzylic C(sp 3)-H bonds for the synthesis of 3-hydroxyisoindolinones. Chem Commun (Camb) 2021; 57:8604-8607. [PMID: 34368822 DOI: 10.1039/d1cc02870g] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
A copper-catalyzed aerobic 3-hydroxyisoindolinone synthesis was developed via the benzylic double C(sp3)-H functionalization of 2-alkylbenzamides. In this reaction, molecular oxygen was used as both an oxidant for C(sp3)-H functionalization and an oxygen source. Our method can be extended to diverse benzylic C(sp3)-H bonds and shows excellent functional group tolerance.
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Affiliation(s)
- Kanako Nozawa-Kumada
- Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3 Aoba, Aramaki, Aoba-ku, Sendai 980-8578, Japan.
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17
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Xu Z, Liu D, Yu H, Ahlquist MS, Fu Y. Mechanistic study on the photo carboxylation of benzylic C-H bonds by xanthone and Ni(0) catalysts. MOLECULAR CATALYSIS 2021. [DOI: 10.1016/j.mcat.2021.111785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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18
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Wang Y, Lu R, Yao J, Li H. 1,5,7-Triazabicyclo[4.4.0]dec-5-ene Enhances Activity of Peroxide Intermediates in Phosphine-Free α-Hydroxylation of Ketones. Angew Chem Int Ed Engl 2021; 60:6631-6638. [PMID: 33289252 DOI: 10.1002/anie.202014478] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 11/28/2020] [Indexed: 12/29/2022]
Abstract
The critical role of double hydrogen bonds was addressed for the aerobic α-hydroxylation of ketones catalyzed by 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), in the absence of either a metal catalyst or phosphine reductant. Experimental and theoretical investigations were performed to study the mechanism. In addition to initiating the reaction by proton abstraction, a more important role of TBD was revealed, that is, to enhance the oxidizing ability of peroxide intermediates, allowing DMSO to be used rather than commonly used phosphine reductants. Further characterizations with nuclear Overhauser effect spectroscopy (NOESY) confirmed the presence of double hydrogen bonds between TBD and the ketone, and kinetic studies suggested the attack of dioxygen on the TBD-enol adduct to be the rate-determining step. This work should encourage the application of TBD as a catalyst for oxidations.
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Affiliation(s)
- Yongtao Wang
- Department of Chemistry and ZJU-NHU United R&D Center, Zhejiang University, 38 Zheda Road, Hangzhou, 310027, P. R. China
| | - Rui Lu
- Department of Chemistry and ZJU-NHU United R&D Center, Zhejiang University, 38 Zheda Road, Hangzhou, 310027, P. R. China
| | - Jia Yao
- Department of Chemistry and ZJU-NHU United R&D Center, Zhejiang University, 38 Zheda Road, Hangzhou, 310027, P. R. China
| | - Haoran Li
- Department of Chemistry and ZJU-NHU United R&D Center, Zhejiang University, 38 Zheda Road, Hangzhou, 310027, P. R. China.,State Key Laboratory of Chemical Engineering and College of Chemical and Biological Engineering, Zhejiang University, 38 Zheda Road, Hangzhou, 310027, P. R. China
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19
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Wang Y, Lu R, Yao J, Li H. 1,5,7‐Triazabicyclo[4.4.0]dec‐5‐ene Enhances Activity of Peroxide Intermediates in Phosphine‐Free α‐Hydroxylation of Ketones. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202014478] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Yongtao Wang
- Department of Chemistry and ZJU-NHU United R&D Center Zhejiang University 38 Zheda Road Hangzhou 310027 P. R. China
| | - Rui Lu
- Department of Chemistry and ZJU-NHU United R&D Center Zhejiang University 38 Zheda Road Hangzhou 310027 P. R. China
| | - Jia Yao
- Department of Chemistry and ZJU-NHU United R&D Center Zhejiang University 38 Zheda Road Hangzhou 310027 P. R. China
| | - Haoran Li
- Department of Chemistry and ZJU-NHU United R&D Center Zhejiang University 38 Zheda Road Hangzhou 310027 P. R. China
- State Key Laboratory of Chemical Engineering and College of Chemical and Biological Engineering Zhejiang University 38 Zheda Road Hangzhou 310027 P. R. China
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20
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Lai X, Liu JB, Wang YC, Qiu G. Iron-catalyzed intramolecular acyl nitrene/alkyne metalation for the synthesis of pyrrolo[2,1-a]isoindol-5-ones. Chem Commun (Camb) 2021; 57:2077-2080. [DOI: 10.1039/d0cc08039j] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
In this work, by using N-methoxybenzamides as efficient acyl nitrene precursors, an iron-catalyzed acyl nitrene/alkyne metalation is reported for the synthesis of pyrrolo[2,1-a]isoindol-5-ones.
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Affiliation(s)
- Xiaojing Lai
- College of Biological
- Chemical Sciences and Engineering
- Jiaxing University
- Jiaxing 314001
- China
| | - Jin-Biao Liu
- School of Metallurgical and Chemical Engineering
- Jiangxi University of Science and Technology
- Ganzhou 341000
- China
| | - Yu-Chao Wang
- College of Biological
- Chemical Sciences and Engineering
- Jiaxing University
- Jiaxing 314001
- China
| | - Guanyinsheng Qiu
- College of Biological
- Chemical Sciences and Engineering
- Jiaxing University
- Jiaxing 314001
- China
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21
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Gao Y, Jing Y, Li L, Zhang J, Chen X, Ma YN. Synthesis of Phenanthridines through Iodine-Supported Intramolecular C–H Amination and Oxidation under Visible Light. J Org Chem 2020; 85:12187-12198. [DOI: 10.1021/acs.joc.0c01390] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Yan Gao
- School of Chemistry and Chemical Engineering, Henan Key Laboratory of Boron Chemistry and Advanced Energy Materials, Henan Normal University, Xinxiang, Henan 453007, China
| | - Yi Jing
- School of Chemistry and Chemical Engineering, Henan Key Laboratory of Boron Chemistry and Advanced Energy Materials, Henan Normal University, Xinxiang, Henan 453007, China
| | - Lixin Li
- College of Chemistry and Chemical Engineering, Xinyang Normal University, Xinyang, Henan 464000, China
| | - Jie Zhang
- School of Chemistry and Chemical Engineering, Henan Key Laboratory of Boron Chemistry and Advanced Energy Materials, Henan Normal University, Xinxiang, Henan 453007, China
| | - Xuenian Chen
- School of Chemistry and Chemical Engineering, Henan Key Laboratory of Boron Chemistry and Advanced Energy Materials, Henan Normal University, Xinxiang, Henan 453007, China
- College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou, Henan 450001, China
| | - Yan-Na Ma
- School of Chemistry and Chemical Engineering, Henan Key Laboratory of Boron Chemistry and Advanced Energy Materials, Henan Normal University, Xinxiang, Henan 453007, China
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22
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Burykina JV, Shlapakov NS, Gordeev EG, König B, Ananikov VP. Selectivity control in thiol-yne click reactions via visible light induced associative electron upconversion. Chem Sci 2020; 11:10061-10070. [PMID: 34094267 PMCID: PMC8162103 DOI: 10.1039/d0sc01939a] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Accepted: 07/22/2020] [Indexed: 12/02/2022] Open
Abstract
An associative electron upconversion is proposed as a key step determining the selectivity of thiol-yne coupling. The developed synthetic approach provided an efficient tool to access a comprehensive range of products - four types of vinyl sulfides were prepared in high yields and selectivity. We report practically important transition-metal-free regioselective thiol-yne addition and formation of the demanding Markovnikov-type product by a radical photoredox process. The photochemical process was directly monitored by mass-spectrometry in a specially designed ESI-MS device with green laser excitation in the spray chamber. The proposed reaction mechanism is supported by experiments and DFT calculations.
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Affiliation(s)
- Julia V Burykina
- Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences Leninsky Prospect 47 Moscow 119991 Russia
| | - Nikita S Shlapakov
- Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences Leninsky Prospect 47 Moscow 119991 Russia
- Institut für Organische Chemie, Universität Regensburg Universitätstrasse 31 93053 Regensburg Germany
| | - Evgeniy G Gordeev
- Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences Leninsky Prospect 47 Moscow 119991 Russia
| | - Burkhard König
- Institut für Organische Chemie, Universität Regensburg Universitätstrasse 31 93053 Regensburg Germany
| | - Valentine P Ananikov
- Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences Leninsky Prospect 47 Moscow 119991 Russia
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