1
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Kim S, Treacy JW, Nelson YA, Gonzalez JAM, Gembicky M, Houk KN, Spokoyny AM. Arene C-H borylation strategy enabled by a non-classical boron cluster-based electrophile. Nat Commun 2023; 14:1671. [PMID: 36966132 PMCID: PMC10039867 DOI: 10.1038/s41467-023-37258-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Accepted: 03/08/2023] [Indexed: 03/27/2023] Open
Abstract
Introducing a tri-coordinate boron-based functional group (e.g., boronic ester) into an unactivated C-H bond in the absence of directing groups is an ongoing challenge in synthetic chemistry. Despite previous developments in transition metal-catalyzed and -free approaches, C-H borylation of sterically hindered arenes remains a largely unsolved problem to date. Here, we report a synthetic strategy of a two-step, precious metal-free electrophilic C-H borylation of sterically hindered alkyl- and haloarenes to generate aryl boronic esters. The first step relies on electrophilic aromatic substitution (EAS) induced by cage-opening of Cs2[closo-B10H10], forming a 6-Ar-nido-B10H13 product containing a B-C bond, followed by a cage deconstruction of arylated decaboranes promoted by diols. The combination of these two steps allows for the preparation of aryl boronic esters that are hardly accessible by current direct C-H borylation approaches. This reaction does not require any precious metals, highly-engineered ligands, pre-functionalized boron reagents, or inert conditions. In addition, the unique properties of a non-classical boron cluster electrophile intermediate, B10H13+, afford a regioselectivity with unique steric and electronic control without the undesirable side reactions.
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Affiliation(s)
- Sangmin Kim
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Joseph W Treacy
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Yessica A Nelson
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Jordan A M Gonzalez
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Milan Gembicky
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA, 92093, USA
| | - K N Houk
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Alexander M Spokoyny
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, 90095, USA.
- California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA, 90095, USA.
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2
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Luo L, Tang S, Wu J, Jin S, Zhang H. Transition Metal-Free Aromatic C-H, C-N, C-S and C-O Borylation. CHEM REC 2023; 23:e202300023. [PMID: 36850026 DOI: 10.1002/tcr.202300023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2023] [Revised: 02/10/2023] [Indexed: 03/01/2023]
Abstract
Aromatic organoboron compounds are highly valuable building blocks in organic chemistry. They were mainly synthesized through aromatic C-H and C-Het borylation, in which transition metal-catalysis dominate. In the past decade, with increasing attention to sustainable chemistry, numerous transition metal-free C-H and C-Het borylation transformations have been developed and emerged as efficient methods towards the synthesis of aromatic organoboron compounds. This account mainly focuses on recent advances in transition metal-free aromatic C-H, C-N, C-S, and C-O borylation transformations and provides insights to where further developments are required.
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Affiliation(s)
- Lu Luo
- Key Laboratory of Catalysis and Energy Materials Chemistry of Ministry of Education & Hubei Key Laboratory of Catalysis and Materials Science & Key Laboratory of Analytical Chemistry of the State Ethnic Affairs Commission, School of Chemistry and Materials Science, South-Central Minzu University, Wuhan, 430074, China
| | - Shuai Tang
- Key Laboratory of Catalysis and Energy Materials Chemistry of Ministry of Education & Hubei Key Laboratory of Catalysis and Materials Science & Key Laboratory of Analytical Chemistry of the State Ethnic Affairs Commission, School of Chemistry and Materials Science, South-Central Minzu University, Wuhan, 430074, China
| | - Jiangyue Wu
- Key Laboratory of Catalysis and Energy Materials Chemistry of Ministry of Education & Hubei Key Laboratory of Catalysis and Materials Science & Key Laboratory of Analytical Chemistry of the State Ethnic Affairs Commission, School of Chemistry and Materials Science, South-Central Minzu University, Wuhan, 430074, China
| | - Shiwei Jin
- Key Laboratory of Catalysis and Energy Materials Chemistry of Ministry of Education & Hubei Key Laboratory of Catalysis and Materials Science & Key Laboratory of Analytical Chemistry of the State Ethnic Affairs Commission, School of Chemistry and Materials Science, South-Central Minzu University, Wuhan, 430074, China
| | - Hua Zhang
- Key Laboratory of Catalysis and Energy Materials Chemistry of Ministry of Education & Hubei Key Laboratory of Catalysis and Materials Science & Key Laboratory of Analytical Chemistry of the State Ethnic Affairs Commission, School of Chemistry and Materials Science, South-Central Minzu University, Wuhan, 430074, China.,Key Laboratory of Organosilicon Chemistry and Material Technology of Ministry of Education, Hangzhou Normal University, Hangzhou, 311121, China
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3
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Tan X, Wang X, Li ZH, Wang H. Borenium-Ion-Catalyzed C-H Borylation of Arenes. J Am Chem Soc 2022; 144:23286-23291. [PMID: 36524876 DOI: 10.1021/jacs.2c12151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Non-metal-catalyzed C-H borylation of arenes represents a sustainable and environment-friendly approach for the functionalization of arenes. Despite its promise as an alternative to traditional transition-metal systems, its substrate scope is generally limited to electron-rich arenes, thus hindering its application in organic synthesis. Herein, we report the development of a borenium-ion catalyst which can borylate unactivated arenes under ambient conditions with 4-chlorocatecholborane (HBcatCl) as borylation reagent. This metal-free catalytic system is suitable for the borylation of C-H bonds in sterically encumbered positions, which has been a challenging task for transition-metal systems. Additionally, this catalytic system allows para-selective one-pot borylation of phenols, which has not been achieved by using transition-metal systems. Our mechanistic investigations and computational studies support a synergistic activation of the H-BcatCl bond by the arene substrate and the borenium-ion catalyst. This generates a Wheland intermediate and a neutral hydroborane species and is followed by deprotonation of the Wheland intermediate with the hydroborane species. The latter step of C-H bond cleavage is likely the rate-limiting step.
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Affiliation(s)
- Xinyue Tan
- Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Department of Chemistry, Fudan University, Songhu Road 2005, Shanghai 200438, China
| | - Xi Wang
- Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Department of Chemistry, Fudan University, Songhu Road 2005, Shanghai 200438, China
| | - Zhen Hua Li
- Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Department of Chemistry, Fudan University, Songhu Road 2005, Shanghai 200438, China
| | - Huadong Wang
- Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Department of Chemistry, Fudan University, Songhu Road 2005, Shanghai 200438, China
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4
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Rej S, Chatani N. Regioselective Transition‐Metal‐Free C(sp
2
)−H Borylation: A Subject of Practical and Ongoing Interest in Synthetic Organic Chemistry. Angew Chem Int Ed Engl 2022; 61:e202209539. [DOI: 10.1002/anie.202209539] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Indexed: 12/22/2022]
Affiliation(s)
- Supriya Rej
- Department of Applied Chemistry Faculty of Engineering and Research Center for Environmental Preservation Osaka University Suita, Osaka 565-0871 Japan
- Institut für Chemie Technische Universität Berlin Strasse des 17. Juni 115 10623 Berlin Germany
| | - Naoto Chatani
- Department of Applied Chemistry Faculty of Engineering and Research Center for Environmental Preservation Osaka University Suita, Osaka 565-0871 Japan
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5
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Rej S, Chatani N. Regio‐Selective Transition‐Metal‐Free C(sp2)‒H Borylation: A Subject of Practical and Ongoing Interest in Synthetic Organic Chemistry. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202209539] [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)
- Supriya Rej
- Osaka University School of Engineering Graduate School of Engineering: Osaka Daigaku Kogakubu Daigakuin Kogaku Kenkyuka Applied Chemistry JAPAN
| | - Naoto Chatani
- Osaka University School of Engineering Graduate School of Engineering: Osaka Daigaku Kogakubu Daigakuin Kogaku Kenkyuka Applied Chemistry 2-1 Yamadaoka 566-0871 Suita, Osaka JAPAN
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6
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Pahl J, Noone E, Uzelac M, Yuan K, Ingleson MJ. Borylation Directed Borylation of Indoles Using Pyrazabole Electrophiles: A One-Pot Route to C7-Borylated-Indolines. Angew Chem Int Ed Engl 2022; 61:e202206230. [PMID: 35686751 PMCID: PMC9401042 DOI: 10.1002/anie.202206230] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Indexed: 12/23/2022]
Abstract
Pyrazabole (1) is a readily accessible diboron compound that can be transformed into ditopic electrophiles. In 1 (and derivatives), the B⋅⋅⋅B separation is ca. 3 Å, appropriate for one boron centre bonding to N and one to the C7 of indoles and indolines. This suitable B⋅⋅⋅B separation enables double E-H (E=N/C) functionalisation of indoles and indolines. Specifically, the activation of 1 with HNTf2 generates an electrophile that transforms N-H indoles and indolines into N/C7-diborylated indolines, with N-H borylation directing subsequent C7-H borylation. Indole reduction to indoline occurs before C-H borylation and our studies indicate this proceeds via hydroboration-C3-protodeboronation to produce an intermediate that then undergoes C7 borylation. The borylated products can be converted in situ into C7-BPin-N-H-indolines. Overall, this represents a transient directed C-H borylation to form useful C7-BPin-indolines.
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Affiliation(s)
- Jürgen Pahl
- School of Chemistry, University of Edinburgh, Edinburgh, EH9 3FJ, UK
| | - Emily Noone
- School of Chemistry, University of Edinburgh, Edinburgh, EH9 3FJ, UK
| | - Marina Uzelac
- School of Chemistry, University of Edinburgh, Edinburgh, EH9 3FJ, UK
| | - Kang Yuan
- School of Chemistry, University of Edinburgh, Edinburgh, EH9 3FJ, UK
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7
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Jin T, Kunze L, Breimaier S, Bolte M, Lerner HW, Jäkle F, Winter RF, Braun M, Mewes JM, Wagner M. Exploring Structure-Property Relations of B,S-Doped Polycyclic Aromatic Hydrocarbons through the Trinity of Synthesis, Spectroscopy, and Theory. J Am Chem Soc 2022; 144:13704-13716. [PMID: 35868238 DOI: 10.1021/jacs.2c04516] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Polycyclic aromatic hydrocarbons (PAHs) are prominent lead structures for organic optoelectronic materials. This work describes the synthesis of three B,S-doped PAHs with heptacene-type scaffolds via nucleophilic aromatic substitution reactions between fluorinated arylborane precursors and 1,2-(Me3SiS)2C6H4/1,8-diazabicyclo[5.4.0]undec-7-ene (72-92% yield). All compounds contain tricoordinate B atoms at their 7,16-positions, kinetically protected by mesityl (Mes) substituents. PAHs 1/2 feature two/four S atoms at their 5,18-/5,9,14,18-positions; PAH 3 is a 6,8,15,17-tetrafluoro derivative of 2. For comparison, we also prepared the skewed naphtho[2,3-c]pentaphene-type isomer 4. The simultaneous presence of electron-accepting B atoms and electron-donating S atoms results in a redox-ambiphilic behavior; the radical cations [1•]+ and [2•]+ were characterized by electron paramagnetic resonance spectroscopy. Several low-lying charge-transfer states exist, some of which (especially S-to-B and Mes-to-B transitions) compete on the excited-state potential-energy surface. Consistent with the calculated state characters and oscillator strengths, this competition results in a spread of fluorescence quantum yields (2-27%). The optoelectronic properties of 1 change drastically upon addition of Ag+ ions: while the color of 1 in CH2Cl2 changes bathochromically from yellow to red (λmax from 463 to 486 nm; -0.13 eV), the emission band shifts hypsochromically from 606 to 545 nm (+0.23 eV), and the fluorescence quantum yield increases from 12 to 43%. According to titration experiments, higher order adducts [Agn1m]n+ are formed. As a suitable system for modeling Ag+ complexation, our calculations predict a dimer structure (n = m = 2) with Ag2S4 core, approximately linear S-Ag-S fragments, and Ag-Ag interaction. The computed optoelectronic properties of [Ag212]2+ agree well with the experimentally observed ones.
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Affiliation(s)
- Tao Jin
- Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt, Max-von-Laue-Str. 7, D-60438 Frankfurt am Main, Germany
| | - Lukas Kunze
- Mulliken Center for Theoretical Chemistry, Institut für Physikalische und Theoretische Chemie, Universität Bonn, Beringstraße 4, 53115 Bonn, Germany
| | - Stefanie Breimaier
- Fachbereich Chemie, Universität Konstanz, Universitätsstraße 10, D-78453 Konstanz, Germany
| | - Michael Bolte
- Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt, Max-von-Laue-Str. 7, D-60438 Frankfurt am Main, Germany
| | - Hans-Wolfram Lerner
- Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt, Max-von-Laue-Str. 7, D-60438 Frankfurt am Main, Germany
| | - Frieder Jäkle
- Department of Chemistry, Rutgers University-Newark, 73 Warren Street, Newark, New Jersey 07102, United States
| | - Rainer F Winter
- Fachbereich Chemie, Universität Konstanz, Universitätsstraße 10, D-78453 Konstanz, Germany
| | - Markus Braun
- Institut für Physikalische und Theoretische Chemie, Goethe-Universität Frankfurt, Max-von-Laue-Str. 7, D-60438 Frankfurt (Main), Germany
| | - Jan-Michael Mewes
- Mulliken Center for Theoretical Chemistry, Institut für Physikalische und Theoretische Chemie, Universität Bonn, Beringstraße 4, 53115 Bonn, Germany
| | - Matthias Wagner
- Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt, Max-von-Laue-Str. 7, D-60438 Frankfurt am Main, Germany
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8
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Pahl J, Noone E, Uzelac M, Yuan K, Ingleson M. Borylation Directed Borylation of Indoles Using Pyrazabole Electrophiles: A One‐Pot Route to C7‐Borylated‐Indolines. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202206230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- J. Pahl
- University of Edinburgh Chemistry UNITED KINGDOM
| | - E. Noone
- University of Edinburgh Chemistry UNITED KINGDOM
| | - M. Uzelac
- University of Edinburgh Chemistry UNITED KINGDOM
| | - K. Yuan
- University of Edinburgh Chemistry UNITED KINGDOM
| | - Michael Ingleson
- University of Edinburgh Chemistry South Bridge EH8 9YL Edinburgh UNITED KINGDOM
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9
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Saraswat A, Sharma A. Mini-review on the functionalization of C–H bond to C-X linkage via metalla-electrocatalyzed tool. J INDIAN CHEM SOC 2021. [DOI: 10.1016/j.jics.2021.100247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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10
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Zhang B, Zou Y, Wang L, Zhang H. Zinc catalysed C3-H borylation of indoles and 1,1-diboration of terminal alkynes. Chem Commun (Camb) 2021; 57:11185-11188. [PMID: 34622253 DOI: 10.1039/d1cc04497d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
A low catalyst loading Zn(OTf)2-catalysed C3-H borylation of indoles with pinacolborane was developed. This transformation represents the use of an abundant, cheap and environmentally benign zinc catalyst in catalytic direct aromatic C-H borylation and offers a simple and prompt route towards the synthesis of C3-borylated indoles. The 1,1-diboration of terminal alkynes was also achieved using the same catalytic system to produce 1,1-diborylated alkenes.
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Affiliation(s)
- Binfeng Zhang
- Key Laboratory of Catalysis and Energy Materials Chemistry of Ministry of Education & Hubei Key Laboratory of Catalysis and Materials Science, South-Central University for Nationalities, Wuhan 430074, China. .,College of Chemistry, Nanchang University, Nanchang 330031, China
| | - Youliang Zou
- Key Laboratory of Catalysis and Energy Materials Chemistry of Ministry of Education & Hubei Key Laboratory of Catalysis and Materials Science, South-Central University for Nationalities, Wuhan 430074, China. .,College of Chemistry, Nanchang University, Nanchang 330031, China
| | - Li Wang
- Key Laboratory of Catalysis and Energy Materials Chemistry of Ministry of Education & Hubei Key Laboratory of Catalysis and Materials Science, South-Central University for Nationalities, Wuhan 430074, China. .,College of Chemistry, Nanchang University, Nanchang 330031, China
| | - Hua Zhang
- Key Laboratory of Catalysis and Energy Materials Chemistry of Ministry of Education & Hubei Key Laboratory of Catalysis and Materials Science, South-Central University for Nationalities, Wuhan 430074, China. .,College of Chemistry, Nanchang University, Nanchang 330031, China
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11
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Miura H, Hirata R, Tomoya T, Shishido T. Electrophilic C(sp
2
)−H Silylation by Supported Gold Catalysts. ChemCatChem 2021. [DOI: 10.1002/cctc.202101123] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Hiroki Miura
- Department of Applied Chemistry for Environment Graduate School of Urban Environmental Sciences Tokyo Metropolitan University 1-1 Minami-Osawa Hachioji, Tokyo 192-0397 Japan
- Research Center for Hydrogen Energy-based Society 1-1 Minami-Osawa Hachioji, Tokyo 192-0397 Japan
- Elements Strategy Initiative for Catalysts & Batteries Kyoto University 1-30 Goryo-Ohara Nishikyo-ku, Kyoto 615-8245 Japan
| | - Ryuji Hirata
- Department of Applied Chemistry for Environment Graduate School of Urban Environmental Sciences Tokyo Metropolitan University 1-1 Minami-Osawa Hachioji, Tokyo 192-0397 Japan
| | - Toyomasu Tomoya
- Department of Applied Chemistry for Environment Graduate School of Urban Environmental Sciences Tokyo Metropolitan University 1-1 Minami-Osawa Hachioji, Tokyo 192-0397 Japan
| | - Tetsuya Shishido
- Department of Applied Chemistry for Environment Graduate School of Urban Environmental Sciences Tokyo Metropolitan University 1-1 Minami-Osawa Hachioji, Tokyo 192-0397 Japan
- Research Center for Hydrogen Energy-based Society 1-1 Minami-Osawa Hachioji, Tokyo 192-0397 Japan
- Elements Strategy Initiative for Catalysts & Batteries Kyoto University 1-30 Goryo-Ohara Nishikyo-ku, Kyoto 615-8245 Japan
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12
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Klare HFT, Albers L, Süsse L, Keess S, Müller T, Oestreich M. Silylium Ions: From Elusive Reactive Intermediates to Potent Catalysts. Chem Rev 2021; 121:5889-5985. [PMID: 33861564 DOI: 10.1021/acs.chemrev.0c00855] [Citation(s) in RCA: 107] [Impact Index Per Article: 35.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The history of silyl cations has all the makings of a drama but with a happy ending. Being considered reactive intermediates impossible to isolate in the condensed phase for decades, their actual characterization in solution and later in solid state did only fuel the discussion about their existence and initially created a lot of controversy. This perception has completely changed today, and silyl cations and their donor-stabilized congeners are now widely accepted compounds with promising use in synthetic chemistry. This review provides a comprehensive summary of the fundamental facts and principles of the chemistry of silyl cations, including reliable ways of their preparation as well as their physical and chemical properties. The striking features of silyl cations are their enormous electrophilicity and as such reactivity as super Lewis acids as well as fluorophilicity. Known applications rely on silyl cations as reactants, stoichiometric reagents, and promoters where the reaction success is based on their steady regeneration over the course of the reaction. Silyl cations can even be discrete catalysts, thereby opening the next chapter of their way into the toolbox of synthetic methodology.
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Affiliation(s)
- Hendrik F T Klare
- Institut für Chemie, Technische Universität Berlin, Strasse des 17 Juni 115, 10623 Berlin, Germany
| | - Lena Albers
- Institut für Chemie, Carl von Ossietzky Universität Oldenburg, Carl von Ossietzky-Strasse 9-11, 26129 Oldenburg, Germany
| | - Lars Süsse
- Institut für Chemie, Technische Universität Berlin, Strasse des 17 Juni 115, 10623 Berlin, Germany
| | - Sebastian Keess
- Institut für Chemie, Technische Universität Berlin, Strasse des 17 Juni 115, 10623 Berlin, Germany
| | - Thomas Müller
- Institut für Chemie, Carl von Ossietzky Universität Oldenburg, Carl von Ossietzky-Strasse 9-11, 26129 Oldenburg, Germany
| | - Martin Oestreich
- Institut für Chemie, Technische Universität Berlin, Strasse des 17 Juni 115, 10623 Berlin, Germany
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13
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Zou Y, Zhang B, Wang L, Zhang H. Benzoic Acid-Promoted C2-H Borylation of Indoles with Pinacolborane. Org Lett 2021; 23:2821-2825. [PMID: 33733795 DOI: 10.1021/acs.orglett.1c00809] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A benzoic acid-promoted C2-H borylation of indoles with pinacolborane to afford C2-borylated indoles is developed. Preliminary mechanistic studies indicate BH3-related borane species formed via the decomposition of pinacolborane to be the probable catalyst. This transformation provides a prompt route toward the synthesis of diverse C2-functionalized indoles.
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Affiliation(s)
- Youliang Zou
- Key Laboratory of Catalysis and Energy Materials Chemistry of Ministry of Education and Hubei Key Laboratory of Catalysis and Materials Science, School of Chemistry and Materials Science, South-Central University for Nationalities, Wuhan 430074, China.,College of Chemistry, Nanchang University, Nanchang 330031, China
| | - Binfeng Zhang
- Key Laboratory of Catalysis and Energy Materials Chemistry of Ministry of Education and Hubei Key Laboratory of Catalysis and Materials Science, School of Chemistry and Materials Science, South-Central University for Nationalities, Wuhan 430074, China.,College of Chemistry, Nanchang University, Nanchang 330031, China
| | - Li Wang
- Key Laboratory of Catalysis and Energy Materials Chemistry of Ministry of Education and Hubei Key Laboratory of Catalysis and Materials Science, School of Chemistry and Materials Science, South-Central University for Nationalities, Wuhan 430074, China.,College of Chemistry, Nanchang University, Nanchang 330031, China
| | - Hua Zhang
- Key Laboratory of Catalysis and Energy Materials Chemistry of Ministry of Education and Hubei Key Laboratory of Catalysis and Materials Science, School of Chemistry and Materials Science, South-Central University for Nationalities, Wuhan 430074, China.,College of Chemistry, Nanchang University, Nanchang 330031, China
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14
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Ma Y, Lou SJ, Hou Z. Electron-deficient boron-based catalysts for C-H bond functionalisation. Chem Soc Rev 2021; 50:1945-1967. [PMID: 33325932 DOI: 10.1039/d0cs00380h] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
In contrast to transition metal-catalysed C-H functionalisation, highly efficient construction of C-C and C-X (X = N, O, S, B, Si, etc.) bonds through metal-free catalytic C-H functionalisation remains one of the most challenging tasks for synthetic chemists. In recent years, electron-deficient boron-based catalyst systems have exhibited great potential for C-H bond transformations. Such emerging systems may greatly enrich the chemistry of C-H functionalisation and main-group element catalysis, and will also provide enormous opportunities in synthetic chemistry, materials chemistry, and chemical biology. This article aims to give a timely comprehensive overview to recognise the current status of electron-deficient boron-based catalysis in C-H functionalisation and stimulate the development of more efficient catalytic systems.
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Affiliation(s)
- Yuanhong Ma
- Key Laboratory of Chemical Biology and Traditional Chinese Medicine (Ministry of Educational of China), Key Laboratory of Phytochemistry R&D of Hunan Province, and Key Laboratory of the Assembly and Application of Organic Functional Molecules of Hunan Province, College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, P. R. China.
| | - Shao-Jie Lou
- Advanced Catalysis Research Group, RIKEN Center for Sustainable Resource Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
| | - Zhaomin Hou
- Advanced Catalysis Research Group, RIKEN Center for Sustainable Resource Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan. and Organometallic Chemistry Laboratory, RIKEN Cluster for Pioneering Research, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
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15
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16
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Lipshultz JM, Fu Y, Liu P, Radosevich AT. Organophosphorus-catalyzed relay oxidation of H-Bpin: electrophilic C-H borylation of heteroarenes. Chem Sci 2020; 12:1031-1037. [PMID: 34163869 PMCID: PMC8179051 DOI: 10.1039/d0sc05620k] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A nontrigonal phosphorus triamide (1, P{N[o-NMe-C6H4]2}) is shown to catalyze C–H borylation of electron-rich heteroarenes with pinacolborane (HBpin) in the presence of a mild chloroalkane reagent. C–H borylation proceeds for a range of electron-rich heterocycles including pyrroles, indoles, and thiophenes of varied substitution. Mechanistic studies implicate an initial P–N cooperative activation of HBpin by 1 to give P-hydrido diazaphospholene 2, which is diverted by Atherton–Todd oxidation with chloroalkane to generate P-chloro diazaphospholene 3. DFT calculations suggest subsequent oxidation of pinacolborane by 3 generates chloropinacolborane (ClBpin) as a transient electrophilic borylating species, consistent with observed substituent effects and regiochemical outcomes. These results illustrate the targeted diversion of established reaction pathways in organophosphorus catalysis to enable a new mode of main group-catalyzed C–H borylation. A nontrigonal phosphorus triamide (1, P{N[o-NMe-C6H4]2}) is shown to catalyze C–H borylation of electron-rich heteroarenes with pinacolborane (HBpin) in the presence of a mild chloroalkane reagent.![]()
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Affiliation(s)
- Jeffrey M Lipshultz
- Department of Chemistry, Massachusetts Institute of Technology 77 Massachusetts Avenue Cambridge MA 02139 USA
| | - Yue Fu
- Department of Chemistry, University of Pittsburgh 219 Parkman Avenue Pittsburgh PA 15260 USA
| | - Peng Liu
- Department of Chemistry, University of Pittsburgh 219 Parkman Avenue Pittsburgh PA 15260 USA
| | - Alexander T Radosevich
- Department of Chemistry, Massachusetts Institute of Technology 77 Massachusetts Avenue Cambridge MA 02139 USA
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17
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Kakiuchi F, Kochi T. New Strategy for Catalytic Oxidative C–H Functionalization: Efficient Combination of Transition-metal Catalyst and Electrochemical Oxidation. CHEM LETT 2020. [DOI: 10.1246/cl.200475] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Fumitoshi Kakiuchi
- Department of Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa 223-8522, Japan
| | - Takuya Kochi
- Department of Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa 223-8522, Japan
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18
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Wu Y, Huang YH, Chen XY, Wang P. Site-Selective Silylation of Arenes Mediated by Thianthrene S-Oxide. Org Lett 2020; 22:6657-6661. [DOI: 10.1021/acs.orglett.0c02458] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Yichen Wu
- State Key Laboratory of Organometallic Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, CAS, 345 Lingling Road, Shanghai 200032, China
| | - Yu-Hao Huang
- State Key Laboratory of Organometallic Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, CAS, 345 Lingling Road, Shanghai 200032, China
| | - Xiao-Yue Chen
- State Key Laboratory of Organometallic Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, CAS, 345 Lingling Road, Shanghai 200032, China
| | - Peng Wang
- State Key Laboratory of Organometallic Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, CAS, 345 Lingling Road, Shanghai 200032, China
- CAS Key Laboratory of Energy Regulation Materials, Shanghai Institute of Organic Chemistry, CAS, 345 Lingling Road, Shanghai 200032, China
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19
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Prybil J, Wallace R, Warren A, Klingman J, Vaillant R, Hall MB, Yang X, Brennessel WW, Chin RM. Silylation of Pyridine, Picolines, and Quinoline with a Zinc Catalyst. ACS OMEGA 2020; 5:1528-1539. [PMID: 32010826 PMCID: PMC6990635 DOI: 10.1021/acsomega.9b03317] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Accepted: 12/30/2019] [Indexed: 06/10/2023]
Abstract
Zn(OTf)2 (OTf- = trifluoromethanesulfonate) catalyzes the silylation of pyridine, 3-picoline, and quinoline to afford the silylated products, where the silyl groups are meta to the nitrogen. The isolated yields of the products range from 41 to 26%. The 2- and 4-picolines yielded the silylmethylpyridines, where the CH3 groups were silylated instead of the ring. The pyridine silylation can occur via two separate pathways, involving either a 1,4- or a 1,2-hydrosilylation of pyridine as the first step. A byproduct of the pyridine silylation is a head-to-tail dimerization of N-silyl-1,4-dihydropyridine to form a diazaditwistane molecule.
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Affiliation(s)
- Joshua
W. Prybil
- Department
of Chemistry and Biochemistry, University
of Northern Iowa, Cedar
Falls, Iowa 50614-0423, United States
| | - Rodney Wallace
- Department
of Chemistry and Biochemistry, University
of Northern Iowa, Cedar
Falls, Iowa 50614-0423, United States
| | - Alexandra Warren
- Department
of Chemistry and Biochemistry, University
of Northern Iowa, Cedar
Falls, Iowa 50614-0423, United States
| | - Jordan Klingman
- Department
of Chemistry and Biochemistry, University
of Northern Iowa, Cedar
Falls, Iowa 50614-0423, United States
| | - Romane Vaillant
- École
nationale supérieure de chimie de Rennes, Sciences Chimiques
de Rennes, Rennes, Bretagne 35700, France
| | - Michael B. Hall
- Department
of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Xin Yang
- Department
of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - William W. Brennessel
- Department
of Chemistry, University of Rochester, Rochester, New York 14627, United States
| | - Robert M. Chin
- Department
of Chemistry and Biochemistry, University
of Northern Iowa, Cedar
Falls, Iowa 50614-0423, United States
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20
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Iqbal SA, Cid J, Procter RJ, Uzelac M, Yuan K, Ingleson MJ. Acyl-Directed ortho-Borylation of Anilines and C7 Borylation of Indoles using just BBr 3. Angew Chem Int Ed Engl 2019; 58:15381-15385. [PMID: 31461213 PMCID: PMC6856876 DOI: 10.1002/anie.201909786] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Indexed: 01/04/2023]
Abstract
Indoles are privileged heterocycles found in many biologically active pharmaceuticals and natural products. However, the selective functionalization of the benzenoid moiety in indoles in preference to the more reactive pyrrolic unit is a significant challenge. Herein we report that N-acyl directing groups enable the C7-selective C-H borylation of indoles using just BBr3 . This transformation shows some functional-group tolerance and notably proceeds with C6 substituted indoles. The directing group can be readily removed in situ and the products isolated as the pinacol boronate esters. Acyl-directed electrophilic borylation can be extended to carbazoles and anilines with excellent ortho selectivity. 4-amino-indoles are amenable to this process, with acyl group installation and directed electrophilic C-H borylation enabling selective formation of C5-BPin-indoles.
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Affiliation(s)
- Saqib A. Iqbal
- School of ChemistryUniversity of EdinburghEdinburghEH9 3FJUK
| | - Jessica Cid
- Dept. of ChemistryUniversity of ManchesterManchesterM13 9PLUK
| | | | - Marina Uzelac
- School of ChemistryUniversity of EdinburghEdinburghEH9 3FJUK
| | - Kang Yuan
- School of ChemistryUniversity of EdinburghEdinburghEH9 3FJUK
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21
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Iqbal SA, Cid J, Procter RJ, Uzelac M, Yuan K, Ingleson MJ. Acyl‐Directed
ortho
‐Borylation of Anilines and C7 Borylation of Indoles using just BBr
3. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201909786] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Saqib A. Iqbal
- School of Chemistry University of Edinburgh Edinburgh EH9 3FJ UK
| | - Jessica Cid
- Dept. of Chemistry University of Manchester Manchester M13 9PL UK
| | | | - Marina Uzelac
- School of Chemistry University of Edinburgh Edinburgh EH9 3FJ UK
| | - Kang Yuan
- School of Chemistry University of Edinburgh Edinburgh EH9 3FJ UK
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