1
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Hamaguchi N, Kubota T, Yamada M, Kimura H, Tsuji H. Post-Formation of Fused Pentagonal Structure on Fjord Region of Polyaromatic Hydrocarbons under Hydrothermal Conditions. Chemistry 2024; 30:e202400987. [PMID: 38629239 DOI: 10.1002/chem.202400987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2024] [Indexed: 05/23/2024]
Abstract
This study explores the synthesis of cyclopenta-fused polyaromatic hydrocarbons (CP-PAHs) via Pt-catalyzed cyclization in water, focusing on the formation of fused pentagonal rings within heavily fused PAH frameworks. Utilizing platinum catalysts at lower temperatures (200-260 °C) in water, led to the successful synthesis of singly cyclized CP-PAHs. The reaction conditions facilitated the mono-cyclization of substrates such as dibenzo[g,p]chrysene and its isomers, yielding the desired products while suppressing the formation of bis-cyclized compounds. The use of Fe2O3 as an additive in conjunction with PtO2 was effective to suppress hydrogenation of the substrates and products. The products exhibited a redshift in UV-visible absorption and photoluminescence bands due to a decrease in the HOMO-LUMO energy gap. These findings highlight the potential of Pt-catalyzed cyclization for the controlled synthesis of CP-PAHs, with implications for various applications in materials science.
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Affiliation(s)
- Naoto Hamaguchi
- Department of Chemistry, Faculty of Science, Kanagawa University, 3-27-1 Rokkaku-bashi, Kanagawa-ku, Yokohama, 221-8686, Japan
| | - Takumi Kubota
- Department of Chemistry, Faculty of Science, Kanagawa University, 3-27-1 Rokkaku-bashi, Kanagawa-ku, Yokohama, 221-8686, Japan
| | - Masaaki Yamada
- Department of Chemistry, Faculty of Science, Kanagawa University, 3-27-1 Rokkaku-bashi, Kanagawa-ku, Yokohama, 221-8686, Japan
| | - Hikaru Kimura
- Department of Chemistry, Faculty of Science, Kanagawa University, 3-27-1 Rokkaku-bashi, Kanagawa-ku, Yokohama, 221-8686, Japan
| | - Hayato Tsuji
- Department of Chemistry, Faculty of Science, Kanagawa University, 3-27-1 Rokkaku-bashi, Kanagawa-ku, Yokohama, 221-8686, Japan
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2
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Misselwitz E, Spengler J, Rominger F, Kivala M. Indenoannulated Tridecacyclene: An All-Carbon Seven-Stage Redox-Amphoter. Chemistry 2024; 30:e202400696. [PMID: 38563636 DOI: 10.1002/chem.202400696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2024] [Accepted: 04/01/2024] [Indexed: 04/04/2024]
Abstract
We disclose an indenoannulated tridecacyclene comprising a central cyclooctatetraene moiety with multiple adjacent pentagonal rings which is accessible in a concise synthetic sequence. The saddle-shaped geometry of the non-benzenoid polycyclic scaffold and its unique packing behavior in the solid state were characterized by X-ray crystallography. In electrochemical studies, the compound undergoes seven reversible redox events comprising five reductions and two oxidations. The dicationic and dianionic species obtained by chemical oxidation and reduction, respectively, were characterized spectroscopically in solution. Density functional theory calculations were applied to provide insights into aromaticity evolution in the respective charged species, highlighting the beneficial effect of the non-benzenoid moieties on charge stabilization.
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Affiliation(s)
- Erik Misselwitz
- Organisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Jonas Spengler
- Organisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Frank Rominger
- Organisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Milan Kivala
- Organisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
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3
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Fu W, Tian J, Ding Y, Wang X, Wang M, Wang Z. Copper-Catalyzed Site-Selective Electrophilic Aromatic Alkylation of Monosubstituted Simple Arenes. Org Lett 2024; 26:2546-2551. [PMID: 38522077 DOI: 10.1021/acs.orglett.4c00475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/26/2024]
Abstract
A copper-catalyzed highly para-selective electrophilic aromatic alkylation of monosubstituted simple arenes has been accomplished. This method provides a practical platform for the transformation from simple commercial arenes to well-defined di- and multisubstituted aromatics with high added value. Control experiments and DFT calculations reveal that the achievement of the excellent site-selectivity is ascribed to the controlled deprotonation of the Wheland intermediates. Remarkably, the type of alkylating regent has been shown to have a significant impact on site-selectivity.
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Affiliation(s)
- Wanting Fu
- College of Chemistry and Materials Science, Hebei University, Baoding 071002, China
| | - Jing Tian
- College of Chemistry and Materials Science, Hebei University, Baoding 071002, China
| | - Yuanli Ding
- College of Chemistry and Materials Science, Hebei University, Baoding 071002, China
| | - Xi Wang
- College of Chemistry and Materials Science, Hebei University, Baoding 071002, China
| | - Meiyan Wang
- Institute of Theoretical Chemistry, College of Chemistry, Jilin University, Changchun 130023, China
| | - Zikun Wang
- College of Chemistry and Materials Science, Hebei University, Baoding 071002, China
- State Key Laboratory of New Pharmaceutical Preparations and Excipients, Hebei University, Baoding 071002, China
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4
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Türkmen YE. Recent advances in the synthesis and applications of fluoranthenes. Org Biomol Chem 2024; 22:2719-2733. [PMID: 38470856 DOI: 10.1039/d4ob00083h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/14/2024]
Abstract
As an important subclass of polycyclic aromatic hydrocarbons (PAHs), fluoranthenes continue to attract significant attention in synthetic organic chemistry and materials science. In this article, an overview of recent advances in the synthesis of fluoranthene derivatives along with selected applications is provided. First, methods for fluoranthene synthesis with a classification based on strategic bond disconnections are discussed. Then, the total syntheses of natural products featuring the benzo[j]fluoranthene skeleton are covered. Finally, examples of important applications of a variety of fluoranthenes are summarized.
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Affiliation(s)
- Yunus Emre Türkmen
- Department of Chemistry, Faculty of Science, Bilkent University, Ankara 06800, Türkiye.
- UNAM - National Nanotechnology Research Center, Institute of Materials Science and Nanotechnology, Bilkent University, Ankara 06800, Türkiye
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5
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Ketata N, Liu L, Ben Salem R, Doucet H. Mono or double Pd-catalyzed C-H bond functionalization for the annulative π-extension of 1,8-dibromonaphthalene: a one pot access to fluoranthene derivatives. Beilstein J Org Chem 2024; 20:427-435. [PMID: 38410779 PMCID: PMC10896227 DOI: 10.3762/bjoc.20.37] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Accepted: 02/08/2024] [Indexed: 02/28/2024] Open
Abstract
The Pd-catalyzed annulative π-extension of 1,8-dibromonaphthalene for the preparation of fluoranthenes in a single operation has been investigated. With specific arenes such as fluorobenzenes, the Pd-catalyzed double functionalization of C-H bonds yields the desired fluoranthenes. The reaction proceeds via a palladium-catalyzed direct intermolecular arylation, followed by a direct intramolecular arylation step. As the C-H bond activation of several benzene derivatives remains very challenging, the preparation of fluoranthenes from 1,8-dibromonaphthalene via Suzuki coupling followed by intramolecular C-H activation has also been investigated to provide a complementary method. Using the most appropriate synthetic route and substrates, it is possible to introduce the desired functional groups at positions 7-10 on fluoranthenes.
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Affiliation(s)
- Nahed Ketata
- University of Rennes, CNRS, ISCR-UMR 6226, F-35000 Rennes, France
- Organic chemistry laboratory, LR17ES08, Department of Chemistry, Faculty of Sciences, University of Sfax, B.P. 1171, 3038, Sfax, Tunisia
| | - Linhao Liu
- University of Rennes, CNRS, ISCR-UMR 6226, F-35000 Rennes, France
| | - Ridha Ben Salem
- Organic chemistry laboratory, LR17ES08, Department of Chemistry, Faculty of Sciences, University of Sfax, B.P. 1171, 3038, Sfax, Tunisia
| | - Henri Doucet
- University of Rennes, CNRS, ISCR-UMR 6226, F-35000 Rennes, France
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6
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Su X, Wang Y, Feng Q, Sun J. Heterodifunctionalization of Electron-Rich Alkynes Catalyzed by in Situ Generated Silylium Ions. Org Lett 2024; 26:421-426. [PMID: 38166166 DOI: 10.1021/acs.orglett.3c04208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2024]
Abstract
Silylium ions are versatile Lewis acids in organic synthesis. While they have been well-known for the activation of σ donors, catalysis initiated by the activation of π donors remains underdeveloped, particularly for alkynes. Herein, we demonstrate an example of silylium-catalyzed alkyne heterodifunctionalization. The silylium ion generated in situ from HNTf2 and the silyl reagent serve as superior catalysts in the efficient silylphosphination and silylcyanation of electron-rich alkynes with excellent regio- and stereoselectivity. The compatibility of this protocol with strongly coordinating ligands (Ph2P and CN) not only complements the metal-catalyzed systems but also expands the scope of silylium-catalyzed reactions.
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Affiliation(s)
- Xiang Su
- School of Biomedical and Pharmaceutical Sciences, Guangdong University of Technology, Guangzhou 510006, China
| | - Yong Wang
- Department of Chemistry and the Hong Kong Branch of Chinese National Engineering Research Centre for Tissue Restoration and Reconstruction, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong Special Administrative Region, China
| | - Qiang Feng
- Department of Chemistry and the Hong Kong Branch of Chinese National Engineering Research Centre for Tissue Restoration and Reconstruction, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong Special Administrative Region, China
| | - Jianwei Sun
- Department of Chemistry and the Hong Kong Branch of Chinese National Engineering Research Centre for Tissue Restoration and Reconstruction, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong Special Administrative Region, China
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7
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Jiang HJ, Zuo H, Zhu M, Sharanov I, Irran E, Klare HFT, Tshepelevitsh S, Lõkov M, Leito I, Oestreich M. Chiral Carborane Acids Decorated with Binol-Based Phosphonates: Synthesis, Characterization, and Application. J Org Chem 2024; 89:756-760. [PMID: 38109189 DOI: 10.1021/acs.joc.3c02162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
The syntheses of hexabrominated closo-carborates decorated with different chiral Binol-derived phosphonates and their conjugate acids are described. X-ray diffraction analysis reveals a polymeric structure for the sodium salt with the anionic units connected by [B-Br-Na-O═P]+ linkages. For the acid, coordination of the proton to the phosphonate's P═O oxygen atom is assumed. The pKa value was estimated by combining experiments and computations. Application of these Brønsted acids as chiral catalysts in an imino-ene and a Mukaiyama-Mannich reaction was moderately successful.
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Affiliation(s)
- Hua-Jie Jiang
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623 Berlin, Germany
| | - Honghua Zuo
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623 Berlin, Germany
| | - Min Zhu
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623 Berlin, Germany
| | - Illia Sharanov
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623 Berlin, Germany
| | - Elisabeth Irran
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623 Berlin, Germany
| | - Hendrik F T Klare
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623 Berlin, Germany
| | - Sofja Tshepelevitsh
- Institute of Chemistry, University of Tartu, Ravila 14a, 50411 Tartu, Estonia
| | - Märt Lõkov
- Institute of Chemistry, University of Tartu, Ravila 14a, 50411 Tartu, Estonia
| | - Ivo Leito
- Institute of Chemistry, University of Tartu, Ravila 14a, 50411 Tartu, Estonia
| | - Martin Oestreich
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623 Berlin, Germany
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8
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Hooker LV, Bandar JS. Synthetic Advantages of Defluorinative C-F Bond Functionalization. Angew Chem Int Ed Engl 2023; 62:e202308880. [PMID: 37607025 PMCID: PMC10843719 DOI: 10.1002/anie.202308880] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 08/20/2023] [Accepted: 08/21/2023] [Indexed: 08/24/2023]
Abstract
Much progress has been made in the development of methods to both create compounds that contain C-F bonds and to functionalize C-F bonds. As such, C-F bonds are becoming common and versatile synthetic functional handles. This review summarizes the advantages of defluorinative functionalization reactions for small molecule synthesis. The coverage is organized by the type of carbon framework the fluorine is attached to for mono- and polyfluorinated motifs. The main challenges, opportunities and advances of defluorinative functionalization are discussed for each class of organofluorine. Most of the text focuses on case studies that illustrate how defluorofunctionalization can improve routes to synthetic targets or how the properties of C-F bonds enable unique mechanisms and reactions. The broader goal is to showcase the opportunities for incorporating and exploiting C-F bonds in the design of synthetic routes, improvement of specific reactions and advent of new methods.
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Affiliation(s)
- Leidy V Hooker
- Department of Chemistry, Colorado State University, Fort Collins, CO, 80523, USA
| | - Jeffrey S Bandar
- Department of Chemistry, Colorado State University, Fort Collins, CO, 80523, USA
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9
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Zanetti D, Matuszewska O, Giorgianni G, Pezzetta C, Demitri N, Bonifazi D. Photoredox Annulation of Polycyclic Aromatic Hydrocarbons. JACS AU 2023; 3:3045-3054. [PMID: 38034957 PMCID: PMC10685425 DOI: 10.1021/jacsau.3c00438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 09/22/2023] [Accepted: 09/25/2023] [Indexed: 12/02/2023]
Abstract
The rise of interest in using polycyclic aromatic hydrocarbons (PAHs) and molecular graphenoids in optoelectronics has recently stimulated the growth of modern synthetic methodologies giving access to intramolecular aryl-aryl couplings. Here, we show that a radical-based annulation protocol allows expansion of the planarization approaches to prepare functionalized molecular graphenoids. The enabler of this reaction is peri-xanthenoxanthene, the photocatalyst which undergoes photoinduced single electron transfer with an ortho-oligoarylenyl precursor bearing electron-withdrawing and nucleofuge groups. Dissociative electron transfer enables the formation of persistent aryl radical intermediates, the latter undergoing intramolecular C-C bond formation, allowing the planarization reaction to occur. The reaction conditions are mild and compatible with various electron-withdrawing and -donating substituents on the aryl rings as well as heterocycles and PAHs. The method could be applied to induce double annulation reactions, allowing the synthesis of π-extended scaffolds with different edge peripheries.
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Affiliation(s)
- Davide Zanetti
- Institute
of Organic Chemistry, Faculty of Chemistry, University of Vienna, Währinger Straße 38, 1090 Vienna, Austria
| | - Oliwia Matuszewska
- School
of Chemistry, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, U.K.
| | - Giuliana Giorgianni
- Institute
of Organic Chemistry, Faculty of Chemistry, University of Vienna, Währinger Straße 38, 1090 Vienna, Austria
| | - Cristofer Pezzetta
- School
of Chemistry, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, U.K.
| | - Nicola Demitri
- Elettra—Sincrotrone
Trieste, S.S. 14 Km 163.5
in Area Science Park, 34149 Basovizza, Trieste, Italy
| | - Davide Bonifazi
- Institute
of Organic Chemistry, Faculty of Chemistry, University of Vienna, Währinger Straße 38, 1090 Vienna, Austria
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10
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Jayarani A, Deepa M, Khan HA, Koothradan FF, Yoganandhini S, Sreelakshmi V, Sivasankar C. Ruthenium-Catalyzed Chemo-Selective Carbene Insertion into C-H Bond of Styrene over Cyclopropanation: C-C Bond Formation. J Org Chem 2023; 88:15817-15831. [PMID: 37934176 DOI: 10.1021/acs.joc.3c01881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2023]
Abstract
The C-C bond formation reactions are important in organic synthesis. Heck reaction is known to arylate the terminal carbon of olefins; however, direct alkylation of the terminal carbon of olefin is limited. Herein, we report a novel ruthenium-catalyzed selective cross-coupling reaction of styrene and α-diazoesters to form a new C-C bond over cyclopropanation via the C-H insertion process for the first time. Using this novel methodology, a wide variety of substrates have been utilized and a variety of α-vinylated benzylic esters and densely functionalized olefins have been synthesized with good stereoselectivity under mild reaction conditions. The overall reaction process proceeds through the carbene insertion into styrene to form the desired products in good to excellent yields with proper stereoselectivity. The selective C-H inserted product, wide substrate scope, and excellent functional group tolerance are the best features of this work.
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Affiliation(s)
- Arumugam Jayarani
- Catalysis and Energy Laboratory, Department of Chemistry, Pondicherry University (A Central University), Puducherry, Puducherry 605014, India
| | - Masilamani Deepa
- Postgraduate and Research Department of Chemistry, Muthurangam Government Arts College, Vellore, Tamil Nadu 632002, India
| | - Hilal Ahmad Khan
- Catalysis and Energy Laboratory, Department of Chemistry, Pondicherry University (A Central University), Puducherry, Puducherry 605014, India
| | - Fathima Febin Koothradan
- Catalysis and Energy Laboratory, Department of Chemistry, Pondicherry University (A Central University), Puducherry, Puducherry 605014, India
| | - Sekar Yoganandhini
- Postgraduate and Research Department of Chemistry, Muthurangam Government Arts College, Vellore, Tamil Nadu 632002, India
| | - Vinod Sreelakshmi
- Catalysis and Energy Laboratory, Department of Chemistry, Pondicherry University (A Central University), Puducherry, Puducherry 605014, India
| | - Chinnappan Sivasankar
- Catalysis and Energy Laboratory, Department of Chemistry, Pondicherry University (A Central University), Puducherry, Puducherry 605014, India
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11
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He T, Klare HFT, Oestreich M. Arenium-ion-catalysed halodealkylation of fully alkylated silanes. Nature 2023; 623:538-543. [PMID: 37821704 DOI: 10.1038/s41586-023-06646-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2023] [Accepted: 09/14/2023] [Indexed: 10/13/2023]
Abstract
'Organic silicon' is not found in nature but modern chemistry is hard to imagine without silicon bound to carbon. Although silicon-containing commodity chemicals such as those emerging from the 'direct process'1-4 look simple, it is not trivial to selectively prepare aryl-substituted and alkyl-substituted (functionalized) silicon compounds, known as silanes. Chlorosilanes such as Me4-nSiCln (n = 1-3) as well as SiCl4 (n = 4) are common starting points for the synthesis of silicon-containing molecules. Yet these methods often suffer from challenging separation problems5. Conversely, silanes with four alkyl groups are considered synthetic dead ends. Here we introduce an arenium-ion-catalysed halodealkylation that effectively converts Me4Si and related quaternary silanes into a diverse range of functionalized derivatives. The reaction uses an alkyl halide and an arene (co)solvent: the alkyl halide is the halide source that eventually engages in a Friedel-Crafts alkylation with the arene to regenerate the catalyst6, whereas the arenium ion acts as a strong Brønsted acid for the protodealkylation step7. The advantage of the top-down halodealkylation methodology over reported bottom-up procedures is demonstrated, for example, in the synthesis of a silicon drug precursor. Moreover, chemoselective chlorodemethylation of the rather inert Me3Si group attached to an alkyl chain followed by oxidative degradation is shown to be an entry into Tamao-Fleming-type alcohol formation8,9.
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Affiliation(s)
- Tao He
- Institut für Chemie, Technische Universität Berlin, Berlin, Germany
| | - Hendrik F T Klare
- Institut für Chemie, Technische Universität Berlin, Berlin, Germany.
| | - Martin Oestreich
- Institut für Chemie, Technische Universität Berlin, Berlin, Germany.
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12
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Saatlo RE, Matiba JP, Rudolph M, Rominger F, Hashmi ASK. Gold(I)-Mediated Cyclizations of Triene-Yne Systems: An Easy Access to Cyclopenta-Fused Anthracenes. Chemistry 2023; 29:e202301671. [PMID: 37283554 DOI: 10.1002/chem.202301671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 06/06/2023] [Accepted: 06/06/2023] [Indexed: 06/08/2023]
Abstract
The direct synthesis of cyclopenta-fused anthracenes (CP-anthracenes) through a gold(I)-catalyzed cyclization reaction of easily available triene-yne systems bearing a benzofulvene substructure, is reported. The targets are of great interest due to the potential use as organic materials and the preparation of these compounds is gaining huge importance. The applied starting materials are readily available through a three-step synthesis, which further contributes to the advantages of this route. In addition, UV-Vis and fluorescent spectra of the obtained CP-anthracenes were recorded.
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Affiliation(s)
- Rebeka Eshagh Saatlo
- Organisch-Chemisches Institut, Heidelberg University, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Jan P Matiba
- Organisch-Chemisches Institut, Heidelberg University, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Matthias Rudolph
- Organisch-Chemisches Institut, Heidelberg University, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Frank Rominger
- Organisch-Chemisches Institut, Heidelberg University, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - A Stephen K Hashmi
- Organisch-Chemisches Institut, Heidelberg University, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
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13
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Toyota S, Ban S, Hara M, Kawamura M, Ikeda H, Tsurumaki E. Synthesis and Properties of Rubicene-Based Aromatic π-Conjugated Compounds as Five-Membered Ring Embedded Planar Nanographenes. Chemistry 2023; 29:e202301346. [PMID: 37278362 DOI: 10.1002/chem.202301346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 06/05/2023] [Accepted: 06/06/2023] [Indexed: 06/07/2023]
Abstract
Polycyclic aromatic hydrocarbons consisting of two or three rubicene substructures were designed as π-conjugated compounds embedding five-membered rings. The target compounds with t-butyl groups were synthesized by the Scholl reaction of precursors consisting of 9,10-diphenylanthracene units, even though a partially precyclized precursor was required for the synthesis of the trimer. These compounds were isolated as stable and dark blue solids. Single-crystal X-ray analysis and DFT calculations revealed the planar aromatic framework of these compounds. In the electronic spectra, the absorption and emission bands were considerably red-shifted compared with those of the reference rubicene compound. In particular, the emission band of the trimer extended to the near-IR region while retaining the emissive property. The narrowed HOMO-LUMO gap with the extension of the π-conjugation was confirmed by cyclic voltammetry and DFT calculations.
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Affiliation(s)
- Shinji Toyota
- Department of Chemistry, School of Science, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo, 152-8551, Japan
| | - Sayaka Ban
- Department of Chemistry, School of Science, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo, 152-8551, Japan
| | - Muneyasu Hara
- Department of Chemistry, School of Science, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo, 152-8551, Japan
| | - Masahiko Kawamura
- Department of Chemistry, School of Science, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo, 152-8551, Japan
| | - Hiroshi Ikeda
- Department of Chemistry, School of Science, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo, 152-8551, Japan
- Tokyo Metropolitan College of Industrial Technology, 1-10-40 Higashi-Oi, Shinagawa-ku, Tokyo, 140-0011, Japan
| | - Eiji Tsurumaki
- Department of Chemistry, School of Science, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo, 152-8551, Japan
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14
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Yoshida S. C-F Transformations of Benzotrifluorides by the Activation of Ortho-Hydrosilyl Group. CHEM REC 2023; 23:e202200308. [PMID: 36762730 DOI: 10.1002/tcr.202200308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 01/23/2023] [Indexed: 02/11/2023]
Abstract
Single C-F transformations of aromatic trifluoromethyl compounds are challenging issues due to the strong C-F bond. We have recently developed selective methods for single C-F transformations such as allylation of o-hydrosilyl-substituted benzotrifluorides through the hydride abstraction with trityl cations. Single C-F thiolation and azidation of o-(hydrosilyl)benzotrifluorides were achieved using trityl sulfides and trityl azide catalyzed by Yb(OTf)3 . Treatment of o-(hydrosilyl)benzotrifluorides with trityl chloride resulted in single C-F chlorination. The resulting fluorosilyl group served in further transformations including protonation, halogenation, and Hiyama cross-coupling with C-Si cleavage. We also synthesized benzyl fluorides by LiAlH4 -reduction of the resulting fluorosilanes and further C-F transformations. These methods enabled us to prepare a broad range of organofluorines from simple benzotrifluorides through C-F and C-Si transformations.
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Affiliation(s)
- Suguru Yoshida
- Department of Biological Science and Technology, Faculty of Advanced Engineering, Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo, 125-8585, Japan
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15
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Dajnak A, Shi L, Altınbaş Özpınar G, Lenk R, Saffon-Merceron N, Baceiredo A, Kato T, Müller T, Maerten E. Imine-stabilized silylium ions: synthesis, structure and application in catalysis. Dalton Trans 2023; 52:3052-3058. [PMID: 36779626 DOI: 10.1039/d3dt00168g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Novel norbornene-based imine-stabilized silylium ions 2 have been synthesized via the simple reaction of sulfide-stabilized silylium ion 1 with carbonyl derivatives. Those silylium ions were fully characterized in solution and in the solid state by NMR spectroscopy and X-ray diffraction analysis as well as DFT calculations. Unlike the previously reported phosphine-stabilized silylium ion VI, behaving as a Lewis pair, calculations show that 2 have a strong Lewis acid character. Indeed, imine-stabilized silylium ions 2 are able to activate Si-H bonds and catalyzed the hydrosilylation of carbonyl derivatives under mild conditions.
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Affiliation(s)
- Aymeric Dajnak
- Université de Toulouse, UPS, and CNRS, LHFA UMR 5069, 118 route de Narbonne, 31062 Toulouse, France.
| | - Limiao Shi
- Université de Toulouse, UPS, and CNRS, LHFA UMR 5069, 118 route de Narbonne, 31062 Toulouse, France.
| | - Gül Altınbaş Özpınar
- Institute of Chemistry, Carl von Ossietzky University, Oldenburg, D-26129 Oldenburg, Germany
| | - Romaric Lenk
- Université de Toulouse, UPS, and CNRS, LHFA UMR 5069, 118 route de Narbonne, 31062 Toulouse, France.
| | - Nathalie Saffon-Merceron
- Université de Toulouse, UPS, and CNRS, ICT UAR2599, 118 route de Narbonne, 31062 Toulouse, France
| | - Antoine Baceiredo
- Université de Toulouse, UPS, and CNRS, LHFA UMR 5069, 118 route de Narbonne, 31062 Toulouse, France.
| | - Tsuyoshi Kato
- Université de Toulouse, UPS, and CNRS, LHFA UMR 5069, 118 route de Narbonne, 31062 Toulouse, France.
| | - Thomas Müller
- Institute of Chemistry, Carl von Ossietzky University, Oldenburg, D-26129 Oldenburg, Germany
| | - Eddy Maerten
- Université de Toulouse, UPS, and CNRS, LHFA UMR 5069, 118 route de Narbonne, 31062 Toulouse, France.
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16
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He T, Klare HFT, Oestreich M. Catalytically Generated Meerwein's Salt-Type Oxonium Ions for Friedel-Crafts C(sp 2)-H Methylation with Methanol. J Am Chem Soc 2023; 145:3795-3801. [PMID: 36724501 DOI: 10.1021/jacs.2c13341] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
A catalytic protocol for a Friedel-Crafts-type direct C(sp2)-H methylation of various arenes with methanol is disclosed. The reaction is initiated by counteranion-stabilized silylium or arenium ions, which form Meerwein's salt-like oxonium ions with methanol as the active methylating agents. The silylated methyloxonium ions are stronger electrophiles than their protonated congeners, allowing the Friedel-Crafts alkylation to proceed more efficiently and at a lower reaction temperature. The regeneration of these superelectrophiles within the catalytic cycle is accomplished by the addition of a tetraorganosilane additive, i.e., trimethyl(phenyl)silane or tetraethylsilane, that releases a silylium ion through protodesilylation by the Brønsted acidic Wheland intermediate, thereby acting as a productive "proton-into-silylium ion" generator. By this method, even the C-H methylation of electronically deactivated aryl halides with methanol is achieved. The protocol is also applicable to nonactivated primary as well as π-activated benzylic alcohols. Dialkyl ethers are also competent alkylating agents in the presence of the quaternary phenylsilane additive.
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Affiliation(s)
- Tao He
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623 Berlin, Germany
| | - Hendrik F T Klare
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623 Berlin, Germany
| | - Martin Oestreich
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623 Berlin, Germany
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17
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Rej S, Klare HFT, Oestreich M. The [3]Dendralene Motif as an Entry into Nazarov Cyclizations by Silylium-Ion Initiation. Org Lett 2023; 25:426-431. [PMID: 36603195 DOI: 10.1021/acs.orglett.2c04166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Geminal alkenes bearing an aryl and an allenyl group contain the motif of [3]dendralenes. The central alkene double bond in these cross-conjugated polyenes can be reacted with a silylium ion, thereby initiating a Nazarov cyclization. The cationic intermediate emerging from the electrocyclic ring closure is captured by hydride in the presence of excess hydrosilane. The resulting benzannulated methylenecyclopentene derivatives bearing a silylalkyl group then engage in silylium-ion regeneration followed by an unusual endo-selective intramolecular hydrosilylation. This cascade eventually leads to the formation of a silicon-containing bicyclo[3.2.1]octane skeleton.
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Affiliation(s)
- Supriya Rej
- Institut für Chemie, Technische Universität Berlin, Straße des 17. Juni 115, 10623 Berlin, Germany
| | - Hendrik F T Klare
- Institut für Chemie, Technische Universität Berlin, Straße des 17. Juni 115, 10623 Berlin, Germany
| | - Martin Oestreich
- Institut für Chemie, Technische Universität Berlin, Straße des 17. Juni 115, 10623 Berlin, Germany
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18
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Abe R, Nagashima Y, Tanaka J, Tanaka K. Room Temperature Fluoranthene Synthesis through Cationic Rh(I)/H 8-BINAP-Catalyzed [2 + 2 + 2] Cycloaddition: Unexpected Acceleration due to Noncovalent Interactions. ACS Catal 2023. [DOI: 10.1021/acscatal.2c05683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Ryota Abe
- Department of Chemical Science and Engineering, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo 152-8550, Japan
| | - Yuki Nagashima
- Department of Chemical Science and Engineering, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo 152-8550, Japan
| | - Jin Tanaka
- Department of Chemical Science and Engineering, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo 152-8550, Japan
| | - Ken Tanaka
- Department of Chemical Science and Engineering, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo 152-8550, Japan
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19
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Falk A, Bauer JO. Structural and Electronic Effects on Phosphine Chalcogenide Stabilized Silicon Centers in Four-Membered Heterocyclic Cations. Inorg Chem 2022; 61:15576-15588. [PMID: 36130169 DOI: 10.1021/acs.inorgchem.2c02360] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Understanding the interplay of structural and electronic parameters in the stabilization of Lewis acidic silicon centers is crucial for stereochemical questions and applications in bond activation and catalytic transformations. Phosphine chalcogenide functionalized (Ch = O, S, and Se) hydrosilanes having tert-butyl and 2,4,6-trimethoxyphenyl (TMP) substituents on the silicon atom were synthesized, and the ring-closing reactions to afford the heterocyclic four-membered CPChSi cations were investigated. Synthetic access was only achieved for the sulfur- and selenium-based cations. A thorough study by means of single-crystal X-ray structure determination, NMR spectroscopic data, and density functional theory (DFT) calculations provided insight into important electronic and structural parameters affecting the stability of the intramolecularly stabilized cations. Detailed structural considerations were made on the contributions to the ring strain (angular strain and steric repulsion). Thermochemical investigations showed that the substituents on the silicon and phosphorus atoms play an important role for the stability of the cationic heterocycles. In the absence of large steric repulsions through bulky substituents (methyl groups on silicon and tert-butyl groups on phosphorus), an intrinsic stability sequence of the intramolecular Ch-Si coordination depending on the chalcogen atom in the direction Se ≤ S < O can be observed. However, the order is reversed (O < S < Se) in the case of strong repulsions between sterically demanding substituents (tert-butyl groups on both silicon and phosphorus atoms). Natural bond orbital (NBO) analysis supported the explanations for the observed deshielding trends in 31P NMR spectroscopy and revealed that the O-Si bond is more ionic in nature compared to the S-Si and Se-Si bonds, with the latter exhibiting higher covalent character due to a more efficient charge transfer through a σ-type nCh → pSi interaction.
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Affiliation(s)
- Alexander Falk
- Institut für Anorganische Chemie, Fakultät für Chemie und Pharmazie, Universität Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Jonathan O Bauer
- Institut für Anorganische Chemie, Fakultät für Chemie und Pharmazie, Universität Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
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20
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Sun F, Tan S, Cao H, Xu J, Bregadze VI, Tu D, Lu C, Yan H. Palladium‐Catalyzed Hydroboration of Alkynes with Carboranes: Facile Construction of a Library of Boron Cluster‐Based AIE‐Active Luminogens. Angew Chem Int Ed Engl 2022; 61:e202207125. [DOI: 10.1002/anie.202207125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2022] [Indexed: 11/07/2022]
Affiliation(s)
- Fangxiang Sun
- State Key Laboratory of Coordination Chemistry School of Chemistry and Chemical Engineering Nanjing University Nanjing 210023 P. R. China
| | - Shuaimin Tan
- State Key Laboratory of Coordination Chemistry School of Chemistry and Chemical Engineering Nanjing University Nanjing 210023 P. R. China
| | - Hou‐Ji Cao
- State Key Laboratory of Coordination Chemistry School of Chemistry and Chemical Engineering Nanjing University Nanjing 210023 P. R. China
| | - Jingkai Xu
- State Key Laboratory of Coordination Chemistry School of Chemistry and Chemical Engineering Nanjing University Nanjing 210023 P. R. China
| | - Vladimir I. Bregadze
- A. N. Nesmeyanov Institute of Organoelement Compounds (INEOS) Russian Academy of Sciences Moscow 119991 Russia
| | - Deshuang Tu
- State Key Laboratory of Coordination Chemistry School of Chemistry and Chemical Engineering Nanjing University Nanjing 210023 P. R. China
| | - Changsheng Lu
- State Key Laboratory of Coordination Chemistry School of Chemistry and Chemical Engineering Nanjing University Nanjing 210023 P. R. China
| | - Hong Yan
- State Key Laboratory of Coordination Chemistry School of Chemistry and Chemical Engineering Nanjing University Nanjing 210023 P. R. China
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21
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Abstract
A convergent synthesis of dibenzochrysenes and diindenochrysenes that proceeds from difluorofluorenes and acetoxyenone 15 has been used to prepare 5,6,11,12-tetrabromosemibuckminsterfullerene (31). The synthesis is highly modular and is distinguished by proceeding through an unsymmetrical intermediate. Our work will enable the straightforward preparation of semibuckminsterfullerenes from diindenochrysenes that lack bilateral symmetry using common reagents and nonpyrolytic conditions.
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Affiliation(s)
- Cody F Dickinson
- Chemistry Department, University of Hawaii at Manoa, Honolulu, Hawaii 96822, United States
| | - Justin K Yang
- Chemistry Department, University of Hawaii at Manoa, Honolulu, Hawaii 96822, United States
| | - Glenn P A Yap
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
| | - Marcus A Tius
- Chemistry Department, University of Hawaii at Manoa, Honolulu, Hawaii 96822, United States
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22
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Sun F, Tan S, Cao HJ, Xu J, Bregadze V, Tu D, Lu C, Yan H. Palladium‐Catalyzed Hydroboration of Alkynes with Carboranes: Facile Construction of a Library of Boron Cluster‐Based AIE‐Active Luminogens. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202207125] [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)
- Fangxiang Sun
- Nanjing University School of Chemistry and Chemical Engineering CHINA
| | - Shuaimin Tan
- Nanjing University School of Chemistry and Chemical Engineering CHINA
| | - Hou-Ji Cao
- Nanjing University School of Chemistry and Chemical Engineering CHINA
| | - Jingkai Xu
- Nanjing University School of Chemistry and Chemical Engineering CHINA
| | - Vladimir Bregadze
- Russian Academy of Science A. N. Nesmeyanov Institute of Organoelement Compounds (INEOS) RUSSIAN FEDERATION
| | - Deshuang Tu
- Nanjing University School of Chemistry and Chemical Engineering CHINA
| | - Changsheng Lu
- Nanjing University School of Chemistry and Chemical Engineering CHINA
| | - Hong Yan
- Nanjing University School of Chemistry and Chemical Engineering 22 Hankou Rd. 210093 Nanjing CHINA
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23
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Akhmetov V, Feofanov M, Ruppenstein C, Lange J, Sharapa D, Krstić M, Hampel F, Kataev EA, Amsharov K. Acenaphthenoannulation Induced by the Dual Lewis Acidity of Alumina. Chemistry 2022; 28:e202200584. [PMID: 35313382 PMCID: PMC9321853 DOI: 10.1002/chem.202200584] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Indexed: 01/06/2023]
Abstract
We have discovered a dual (i. e., soft and hard) Lewis acidity of alumina that enables rapid one‐pot π‐extension through the activation of terminal alkynes followed by C−F activation. The tandem reaction introduces an acenaphthene fragment – an essential moiety of geodesic polyarenes. This reaction provides quick access to elusive non‐alternant polyarenes such as π‐extended buckybowls and helicenes through three‐point annulation of the 1‐(2‐ethynyl‐6‐fluorophenyl)naphthalene moiety. The versatility of the developed method was demonstrated by the synthesis of unprecedented structural fragments of elusive geodesic graphene nanoribbons.
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Affiliation(s)
- Vladimir Akhmetov
- Martin-Luther-Universität Halle-Wittenberg Institute of Chemistry, Organic Chemistry Kurt-Mothes-Strasse 2 06120 Halle Germany
| | - Mikhail Feofanov
- Martin-Luther-Universität Halle-Wittenberg Institute of Chemistry, Organic Chemistry Kurt-Mothes-Strasse 2 06120 Halle Germany
| | - Cordula Ruppenstein
- Martin-Luther-Universität Halle-Wittenberg Institute of Chemistry, Organic Chemistry Kurt-Mothes-Strasse 2 06120 Halle Germany
| | - Josefine Lange
- Martin-Luther-Universität Halle-Wittenberg Institute of Chemistry, Organic Chemistry Kurt-Mothes-Strasse 2 06120 Halle Germany
| | - Dmitry Sharapa
- Karlsruhe Institute of Technology Institute of Catalysis Research and Technology Helmholtz-Platz 1 76344 Eggenstein-Leopoldshafen Germany
| | - Marjan Krstić
- Karlsruhe Institute of Technology Institute of Theoretical Solid State Physics Wolfgang-Gaede-Strasse 1 76131 Karlsruhe Germany
| | - Frank Hampel
- Friedrich-Alexander University Erlangen–Nuernberg Department of Chemistry and Pharmacy, Organic Chemistry II Nikolaus-Fiebiger Strasse 10 91058 Erlangen Germany
| | - Evgeny A. Kataev
- Friedrich-Alexander University Erlangen–Nuernberg Department of Chemistry and Pharmacy, Organic Chemistry II Nikolaus-Fiebiger Strasse 10 91058 Erlangen Germany
| | - Konstantin Amsharov
- Martin-Luther-Universität Halle-Wittenberg Institute of Chemistry, Organic Chemistry Kurt-Mothes-Strasse 2 06120 Halle Germany
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24
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Gunther SO, Lee CI, Song E, Bhuvanesh N, Ozerov OV. Isolable fluorinated triphenylmethyl cation salts of [HCB 11Cl 11] -: demonstration of remarkable hydride affinity. Chem Sci 2022; 13:4972-4976. [PMID: 35655874 PMCID: PMC9067617 DOI: 10.1039/d1sc05936j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 04/02/2022] [Indexed: 12/29/2022] Open
Abstract
Significantly fluorinated triarylmethyl cations have long attracted attention as potentially accessible highly reactive carbocations, but their isolation in a convenient form has proved elusive. We show that abstraction of chloride with a cationic silylium reagent leads to the facile formation of di-, tetra-, and hexafluorinated trityl cations, which could be isolated as analytically pure salts with the [HCB11Cl11]- counterion and are compatible with (halo)arene solvents. The F6Tr+ cation carrying six meta-F substituents was computationally predicted to possess up to 20% higher hydride affinity than the parent triphenylmethyl cation Tr+. We report that indeed F6Tr+ displays reactivity unmatched by Tr+. F6Tr+ at ambient temperature abstracts hydrides from the C-H bonds in tetraethylsilane, mesitylene, methylcyclohexane, and catalyzes Friedel-Crafts alkylation of arenes with ethylene, while Tr+ does none of these.
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Affiliation(s)
- S Olivia Gunther
- Department of Chemistry, Texas A&M University 3255 TAMU College Station Texas 77842 USA
| | - Chun-I Lee
- Department of Chemistry, Texas A&M University 3255 TAMU College Station Texas 77842 USA
| | - Ellen Song
- Department of Chemistry, Texas A&M University 3255 TAMU College Station Texas 77842 USA
| | - Nattamai Bhuvanesh
- Department of Chemistry, Texas A&M University 3255 TAMU College Station Texas 77842 USA
| | - Oleg V Ozerov
- Department of Chemistry, Texas A&M University 3255 TAMU College Station Texas 77842 USA
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25
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Singh S, Mahato R, Sharma P, Yadav N, Vodnala N, Kumar Hazra C. Development of Transition-Metal-Free Lewis Acid-Initiated Double Arylation of Aldehyde: A Facile Approach Towards the Total Synthesis of Anti-Breast-Cancer Agent. Chemistry 2022; 28:e202104545. [PMID: 35060647 DOI: 10.1002/chem.202104545] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Indexed: 12/21/2022]
Abstract
This work describes a mild and robust double hydroarylation strategy for the synthesis of symmetrical /unsymmetrical diaryl- and triarylmethanes in excellent yields using Lambert salt (0.2-1.0 mol%). Despite the anticipated challenges associated with controlling selective product formation, unsymmetrical diaryl- and triarylmethanes products are obtained unprecedentedly. A highly efficient gram scale reaction has also been reported (TON for symmetrical product=475 and for unsymmetrical product=390). The synthetic utility of the methodology is demonstrated by the preparation of several unexplored diaryl- and triarylmethane-based biologically relevant molecules, such as arundine, vibrindole A, turbomycin B, and certain anti-inflammatory agents. A total synthesis of an anti-breast-cancer agent is also demonstrated. Control experiments, Hammett analysis, HRMS and GC-MS studies reveal the reaction intermediates and reaction mechanism.
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Affiliation(s)
- Sanjay Singh
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, 110016, India
| | - Rina Mahato
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, 110016, India
| | - Pragya Sharma
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, 110016, India
| | - Naveen Yadav
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, 110016, India
| | - Nagaraju Vodnala
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, 110016, India
| | - Chinmoy Kumar Hazra
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, 110016, India
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26
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Arii H, Nakao K, Masuda H, Kawashima T. Synthesis of 1-Silabenzo[ d, e]isochromanes via Electrophilic Aromatic Substitution of Aldehydes Activated by Silylium Ion. ACS OMEGA 2022; 7:5166-5175. [PMID: 35187332 PMCID: PMC8851623 DOI: 10.1021/acsomega.1c06228] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 01/18/2022] [Indexed: 06/14/2023]
Abstract
A strong Lewis acid silylium ion was utilized for dehydrogenative annulation between dialkyl(1-naphthyl)silanes 1 and aldehydes 2. Silane 1a was reacted with [Ph3C][B(C6F5)4] in the presence of 2,6-di-tert-butyl-4-methylpyridine and aldehydes 2 to afford the annulation product, 1-silabenzo[d,e]isochromanes 3, in moderate isolated yields. The annulation occurred only at the 8-position on the 1-naphthyl group. The silylium ion-promoted hydrosilylation proceeded competitively to afford silyl ethers 4 via the same intermediates, silylcarboxonium ions, in the dehydrogenative annulation. The ratio of 3 and 4 was affected by solvents and the electronic properties of aromatic aldehydes; for example, the use of less polar solvents and that of benzaldehydes with an electron-withdrawing group at the para-position predominantly yielded 3. This annulation reaction was applicable to aldehydes bearing a heteroaromatic group and aliphatic alkyl groups. Judging from these results, both the formation of silylcarboxonium ions by in situ-generated silylium ions and the electrophilic aromatic substitution are important for this annulation reaction.
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Affiliation(s)
- Hidekazu Arii
- Faculty
of Education, University of Miyazaki, 1-1 Gakuen Kibanadai Nishi, Miyazaki 889-2192, Japan
| | - Kenichi Nakao
- Department
of Life Science and Applied Chemistry, Nagoya
Institute of Technology, Gokiso-cho,
Showa-ku, Nagoya 466-8555, Japan
| | - Hideki Masuda
- Department
of Life Science and Applied Chemistry, Nagoya
Institute of Technology, Gokiso-cho,
Showa-ku, Nagoya 466-8555, Japan
| | - Takayuki Kawashima
- Graduate
School of Science and Technology, Gunma
University, 1-5-1 Tenjin-cho, Kiryu, 376-8515 Gunma, Japan
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27
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Fontana N, Espinosa-Jalapa NA, Seidl M, Bauer JO. Hidden silylium-type reactivity of a siloxane-based phosphonium-hydroborate ion pair. Chem Commun (Camb) 2022; 58:2144-2147. [PMID: 35050278 DOI: 10.1039/d1cc07016a] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A new class of siloxane-based cations with hidden silylium-type reactivity is provided, which, in combination with an arylborate counteranion, initiates a highly selective para-C(sp2)-F defunctionalization of a perfluorinated aryl group. The hydrodefluorinated aryl borane is obtained as a crystalline solid via continuous sublimation during the reaction. The heterocyclic six-membered cation could be obtained single-crystalline after dehydrogenative anion exchange. DFT calculations give insight into the bonding within the siloxane-based cation and the mechanism of the ion pair reaction.
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Affiliation(s)
- Nicolò Fontana
- Institut für Anorganische Chemie, Fakultät für Chemie und Pharmazie, Universität Regensburg, Universitätsstraße 31, Regensburg D-93053, Germany.
| | - Noel Angel Espinosa-Jalapa
- Institut für Anorganische Chemie, Fakultät für Chemie und Pharmazie, Universität Regensburg, Universitätsstraße 31, Regensburg D-93053, Germany.
| | - Michael Seidl
- Institut für Anorganische Chemie, Fakultät für Chemie und Pharmazie, Universität Regensburg, Universitätsstraße 31, Regensburg D-93053, Germany.
| | - Jonathan O Bauer
- Institut für Anorganische Chemie, Fakultät für Chemie und Pharmazie, Universität Regensburg, Universitätsstraße 31, Regensburg D-93053, Germany.
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28
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Dajnak A, Özpınar GA, Lenk R, Saffon-Merceron N, Baceiredo A, Kato T, Müller T, Maerten E. Norbornene based-sulfide-stabilized silylium ions: synthesis, structure and application in catalysis. Dalton Trans 2022; 51:1407-1414. [PMID: 34994754 DOI: 10.1039/d1dt04009j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A norbornene-based sulfide stabilized silylium ion 4 has been synthesized. The S-Si interaction was studied in solution and in the solid state by NMR spectroscopy and X-ray diffraction analysis as well as DFT calculations. Unlike the previously reported phosphine-stabilized silylium ion VII, behaving as a Lewis pair, calculations predict that 4 should behave as a Lewis acid toward acrylate derivatives. Indeed, the base-stabilized silylium ion 4 has emerged as an easy-to-handle silylium ion-based Lewis acid catalyst, particularly for the Diels-Alder cycloaddition, with poorly reactive dienes, and hydrodefluorination reactions.
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Affiliation(s)
- Aymeric Dajnak
- Université de Toulouse, UPS, and CNRS, LHFA UMR 5069, 118 route de Narbonne, 31062 Toulouse, France.
| | - Gül Altınbaş Özpınar
- Institute of Chemistry, Carl von Ossietzky University of Oldenburg, D-26129 Oldenburg, Germany
| | - Romaric Lenk
- Université de Toulouse, UPS, and CNRS, LHFA UMR 5069, 118 route de Narbonne, 31062 Toulouse, France.
| | - Nathalie Saffon-Merceron
- Université de Toulouse, UPS, and CNRS, ICT UAR2599 118 route de Narbonne, 31062 Toulouse, France
| | - Antoine Baceiredo
- Université de Toulouse, UPS, and CNRS, LHFA UMR 5069, 118 route de Narbonne, 31062 Toulouse, France.
| | - Tsuyoshi Kato
- Université de Toulouse, UPS, and CNRS, LHFA UMR 5069, 118 route de Narbonne, 31062 Toulouse, France.
| | - Thomas Müller
- Institute of Chemistry, Carl von Ossietzky University of Oldenburg, D-26129 Oldenburg, Germany
| | - Eddy Maerten
- Université de Toulouse, UPS, and CNRS, LHFA UMR 5069, 118 route de Narbonne, 31062 Toulouse, France.
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29
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Zhang H, Wang W, Wang B, Tan H, Jiao N, Song S. Electrophilic amidomethylation of arenes with DMSO/MeCN reagents. Org Chem Front 2022. [DOI: 10.1039/d2qo00181k] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An efficient electrophilic amidomethylation of aromatics was described with DMSO as the CH2 source and nitrile as the nitrogen source.
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Affiliation(s)
- Hongliang Zhang
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Xue Yuan Road 38, Beijing 100191, China
| | - Weijin Wang
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Xue Yuan Road 38, Beijing 100191, China
| | - Bingding Wang
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Xue Yuan Road 38, Beijing 100191, China
| | - Hui Tan
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Xue Yuan Road 38, Beijing 100191, China
| | - Ning Jiao
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Xue Yuan Road 38, Beijing 100191, China
| | - Song Song
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Xue Yuan Road 38, Beijing 100191, China
- State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Jiangsu 210023, China
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30
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Tej V, McArthur S, Banda I, Gregory A, Fisher SP, McArthur S, Lavallo V. Fusing 10-vertex closo-Carborane Anions with N-Heterocyclic Carbenes. Chem Commun (Camb) 2022; 58:10580-10582. [DOI: 10.1039/d2cc02596e] [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
Discovered by Knöth in 1964, the 10-vertex closo-carborane anion [HCB9H91-] is a classical bicapped square antiprism that contains an unusual pentacoordinate carbon center. Compared to its larger icosahedral cousin [HCB11H111-],...
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31
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Dickinson CF, Yang JK, Tius MA. Fluorine on fluorenes. Org Biomol Chem 2022; 20:8615-8617. [DOI: 10.1039/d2ob01798a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Fluorinated fluorenones can be elaborated to polyhalogenated dibenzochrysenes in 4 steps.
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Affiliation(s)
- Cody F. Dickinson
- Chemistry Department, University of Hawaii at Manoa, 2545 The Mall, Honolulu, HI 96822, USA
| | - Justin K. Yang
- Chemistry Department, University of Hawaii at Manoa, 2545 The Mall, Honolulu, HI 96822, USA
| | - Marcus A. Tius
- Chemistry Department, University of Hawaii at Manoa, 2545 The Mall, Honolulu, HI 96822, USA
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32
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Yata T, Nishimoto Y, Yasuda M. Carboboration-Driven Generation of a Silylium Ion for Vinylic C-F Bond Functionalization by B(C 6 F 5 ) 3 Catalysis. Chemistry 2021; 28:e202103852. [PMID: 34837264 DOI: 10.1002/chem.202103852] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Indexed: 11/05/2022]
Abstract
Strong main-group Lewis acids such as silylium ions are known to effectively promote heterolytic C(sp3 )-F bond cleavage. However, carrying out the C(sp2 )-F bond transformation of vinylic C-F bonds has remained an unmet challenge. Herein, we describe our development of a new and simple strategy for vinylic C-F bond transformation of α-fluorostyrenes with silyl ketene acetals catalyzed by B(C6 F5 )3 under mild conditions. Our theoretical calculations revealed that a stabilized silylium ion, which is generated from silyl ketene acetals by carboboration, cleaves the C-F bond of α-fluorostyrenes. A comparative study of α-chloro or bromostyrenes demonstrated that our reaction can be applied only to α-fluorostyrenes because the strong silicon-fluorine affinity facilitates an intramolecular interaction of silylium ions with fluorine atom to cleave the C-F bond. A broad range of α-fluorostyrenes as well as a range of silyl ketene acetals underwent this C-F bond transformation.
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Affiliation(s)
- Tetsuji Yata
- Department of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Yoshihiro Nishimoto
- Department of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka, 565-0871, Japan.,Innovative Catalysis Science Division, Institute for Open and Transdisciplinary, Research Initiatives (ICS-OTRI), Osaka University, Suita, Osaka, 565-0871, Japan
| | - Makoto Yasuda
- Department of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka, 565-0871, Japan.,Innovative Catalysis Science Division, Institute for Open and Transdisciplinary, Research Initiatives (ICS-OTRI), Osaka University, Suita, Osaka, 565-0871, Japan
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33
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Feofanov M, Förtsch A, Amsharov K, Akhmetov V. Solid-state construction of zigzag periphery via intramolecular C-H insertion induced by alumina-mediated C-F activation. Chem Commun (Camb) 2021; 57:12325-12328. [PMID: 34735559 DOI: 10.1039/d1cc05233k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Caryl-F bond activation has become an important and quickly developing method for construction of carbon-based materials. We report that alumina-mediated C-F bond activation (AmCFA) enables construction of PAHs with zigzag periphery. This method includes formal Csp3-H activation and opens an avenue for generation of carbon-based nanomagnets directly on technologically relevant surfaces.
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Affiliation(s)
- Mikhail Feofanov
- Institute of Chemistry, Organic Chemistry, Martin-Luther-University Halle-Wittenberg, Kurt-Mothes-Strasse 2, D-06120 Halle, Germany. .,Friedrich-Alexander University Erlangen-Nuernberg, Department of Chemistry and Pharmacy, Organic Chemistry II, Nikolaus-Fiebiger Str. 10, 91058 Erlangen, Germany
| | - Andreas Förtsch
- Institute of Chemistry, Organic Chemistry, Martin-Luther-University Halle-Wittenberg, Kurt-Mothes-Strasse 2, D-06120 Halle, Germany.
| | - Konstantin Amsharov
- Institute of Chemistry, Organic Chemistry, Martin-Luther-University Halle-Wittenberg, Kurt-Mothes-Strasse 2, D-06120 Halle, Germany. .,South Ural State University, pr. Lenina 76, 454080 Chelyabinsk, Russia
| | - Vladimir Akhmetov
- Institute of Chemistry, Organic Chemistry, Martin-Luther-University Halle-Wittenberg, Kurt-Mothes-Strasse 2, D-06120 Halle, Germany. .,Friedrich-Alexander University Erlangen-Nuernberg, Department of Chemistry and Pharmacy, Organic Chemistry II, Nikolaus-Fiebiger Str. 10, 91058 Erlangen, Germany
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34
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Ham H, Shin S, Ko GH, Han SH, Han GU, Maeng C, Kim TH, Noh HC, Lee K, Kim H, Yang H, Lee PH. Direct and Regioselective Palladium(II)-Catalyzed B(4)-H Monoacyloxylation and B(4,5)-H Diacetoxylation of o-Carborane Acids with Phenyliodonium Dicarboxylates. J Org Chem 2021; 86:15153-15163. [PMID: 34592103 DOI: 10.1021/acs.joc.1c01804] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
A direct B(4)-H monoacyloxylation via a Pd-catalyzed regioselective B(4)-H activation of o-carborane acids with phenyliodonium dicarboxylates was developed, and a series of B(4)-H monoacyloxylated o-carboranes decorated with active groups were synthesized with moderate to good yields as well as excellent selectivity. In addition, a direct B(4,5)-H diacetoxylation from o-carborane acids with phenyliodonium diacetate was demonstrated.
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Affiliation(s)
- Hyeongcheol Ham
- Department of Chemistry, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Seohyun Shin
- Department of Chemistry, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Gi Hoon Ko
- Department of Chemistry, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Sang Hoon Han
- Department of Chemistry, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Gi Uk Han
- Department of Chemistry, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Chanyoung Maeng
- Department of Chemistry, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Tae Hyeon Kim
- Department of Chemistry, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Hee Chan Noh
- Department of Chemistry, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Kyungsup Lee
- Department of Chemistry, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Hanjoong Kim
- Department of Chemistry, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Heejin Yang
- Department of Chemistry, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Phil Ho Lee
- Department of Chemistry, Kangwon National University, Chuncheon 24341, Republic of Korea
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35
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Zhao M, Pun SH, Gong Q, Miao Q. Carbazole‐Fused Polycyclic Aromatics Enabled by Regioselective Scholl Reactions. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202107373] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Mengna Zhao
- Department of Chemistry The Chinese University of Hong Kong, Shatin, New Territories Hong Kong China
| | - Sai Ho Pun
- Department of Chemistry The Chinese University of Hong Kong, Shatin, New Territories Hong Kong China
| | - Qi Gong
- Department of Chemistry The Chinese University of Hong Kong, Shatin, New Territories Hong Kong China
| | - Qian Miao
- Department of Chemistry The Chinese University of Hong Kong, Shatin, New Territories Hong Kong China
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36
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Zhao M, Pun SH, Gong Q, Miao Q. Carbazole-Fused Polycyclic Aromatics Enabled by Regioselective Scholl Reactions. Angew Chem Int Ed Engl 2021; 60:24124-24130. [PMID: 34519417 DOI: 10.1002/anie.202107373] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Indexed: 12/13/2022]
Abstract
The synthesis of new carbazole-fused polycyclic aromatics with interesting geometry and useful properties was explored using Scholl reactions. As found from the Scholl reactions of substrates having two carbazole units linked at different positions through o-phenylene, oxidative coupling of carbazole units occurred in a regioselective manner with new carbon-carbon bonds preferably formed at C3 and C4 in N-alkyl carbazoles. A new N-containing aromatic bowl was characterized by single-crystal X-ray crystallography, and new p-type organic semiconductors exhibited field effect mobility of up to 0.070 cm2 V-1 s-1 in solution-processed thin-film transistors.
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Affiliation(s)
- Mengna Zhao
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Sai Ho Pun
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Qi Gong
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Qian Miao
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
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37
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Klare HFT, Oestreich M. The Power of the Proton: From Superacidic Media to Superelectrophile Catalysis. J Am Chem Soc 2021; 143:15490-15507. [PMID: 34520196 DOI: 10.1021/jacs.1c07614] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Superacidic media became famous in connection with carbocations. Yet not all reactive intermediates can be generated, characterized, and eventually isolated from these Brønsted acid/Lewis acid cocktails. The counteranion, that is the conjugate base, in these systems is often too nucleophilic and/or engages in redox chemistry with the newly formed cation. The Brønsted acidity, especially superacidity, is in fact often not even crucial unless protonation of extremely weak bases needs to be achieved. Instead, it is the chemical robustness of the aforementioned counteranion that determines the success of the protolysis. The advent of molecular Brønsted superacids derived from weakly coordinating, redox-inactive counteranions that do withstand the enormous reactivity of superelectrophiles such as silicon cations completely changed the whole field. This Perspective summarizes general aspects of medium and molecular Brønsted acidity and shows how applications of molecular Brønsted superacids have advanced from stoichiometric reactions to catalytic processes involving protons and in situ generated superelectrophiles.
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Affiliation(s)
- Hendrik F T Klare
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623 Berlin, Germany
| | - Martin Oestreich
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623 Berlin, Germany
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38
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He T, Klare HFT, Oestreich M. Silylium-Ion Regeneration by Protodesilylation Enables Friedel–Crafts Alkylation with Less Isomerization and No Defunctionalization. ACS Catal 2021. [DOI: 10.1021/acscatal.1c03602] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Tao He
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623 Berlin, Germany
| | - Hendrik F. T. Klare
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623 Berlin, Germany
| | - Martin Oestreich
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623 Berlin, Germany
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39
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Huang R, Zhao W, Xu S, Xu J, Li C, Lu C, Yan H. Photoredox B-H functionalization to selective B-N(sp 3) coupling of nido-carborane with primary and secondary amines. Chem Commun (Camb) 2021; 57:8580-8583. [PMID: 34369517 DOI: 10.1039/d1cc03326c] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Access to nido-carborane site-selective B-N(sp3) coupling by photoredox catalysed B-H activation has been achieved for the first time, which leads to the synthesis of a series of nitrogen-containing nido-carboranes with moderate to good yields. This protocol is applicable to primary and secondary amines containing alkyl, or heteroaryl groups as well as sulfonamides. Furthermore, the open to air and metal-free conditions with excellent site-selectivity represent a significant improvement for B-H functionalization of nido-carboranes with organic functionalities.
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Affiliation(s)
- Ronghui Huang
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, China.
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40
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Fujita T, Morioka R, Fukuda T, Suzuki N, Ichikawa J. Acid-mediated intermolecular C-F/C-H cross-coupling of 2-fluorobenzofurans with arenes: synthesis of 2-arylbenzofurans. Chem Commun (Camb) 2021; 57:8500-8503. [PMID: 34351333 DOI: 10.1039/d1cc03453g] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Transition-metal-free acid-promoted biaryl construction was achieved via intermolecular C-F/C-H cross-coupling. By treating 2-fluorobenzofurans with arenes in the presence of AlCl3, 2-arylbenzofurans were obtained. This protocol was successfully applied to the short-step orthogonal synthesis of a bioactive 2-arylbenzofuran natural product, which allows independent transformations of C-F and C-Br bonds. Mechanistic studies indicated that α-fluorine-stabilized carbocations, generated via the protonation of 2-fluorobenzofurans, served as key intermediates. The Friedel-Crafts-type C-C bond formation between the α-fluorocarbocations and arenes, followed by hydrogen fluoride elimination, afforded 2-arylbenzofurans.
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Affiliation(s)
- Takeshi Fujita
- Division of Chemistry, Faculty of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8571, Japan.
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41
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Abstract
AbstractThe unique properties of fluorine-containing organic compounds make fluorine substitution attractive for the development of pharmaceuticals and various specialty materials, which have inspired the evolution of diverse C-F bond activation techniques. Although many advances have been made in functionalizations of activated C-F bonds utilizing transition metal complexes, there are fewer approaches available for nonactivated C-F bonds due to the difficulty in oxidative addition of transition metals to the inert C-F bonds. In this regard, using Lewis acid to abstract the fluoride and light/radical initiator to generate the radical intermediate have emerged as powerful tools for activating those inert C-F bonds. Meanwhile, these transition-metal-free processes are greener, economical, and for the pharmaceutical industry, without heavy metal residues. This review provides an overview of recent C-F bond activations and functionalizations under transition-metal-free conditions. The key mechanisms involved are demonstrated and discussed in detail. Finally, a brief discussion on the existing limitations of this field and our perspective are presented.
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42
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Ebner F, Greb L. An isolable, crystalline complex of square-planar silicon(IV). Chem 2021; 7:2151-2159. [PMID: 34435162 PMCID: PMC8367297 DOI: 10.1016/j.chempr.2021.05.002] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 03/01/2021] [Accepted: 05/04/2021] [Indexed: 12/16/2022]
Abstract
The structure and reactivity of silicon(IV), the second most abundant element in our Earth's crust, is determined by its invariant tetrahedral coordination geometry. Silicon(IV) with a square-planar configuration (ptSi IV ) represents a transition state. Quantum theory supported the feasibility of stabilizing ptSi IV by structural constraint, but its isolation has not been achieved yet. Here, we present the synthesis and full characterization of the first square-planar coordinated silicon(IV). The planarity provokes an extremely low-lying unoccupied molecular orbital that induces unusual silicon redox chemistry and CH-agostic interactions. The small separation of the frontier molecular orbitals enables visible-light ligand-element charge transfer and bond-activation reactivity. Previously, such characteristics have been reserved for d-block metals or low-valent p-block elements. Planarization transfers them, for the first time, to a p-block element in the normal valence state.
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Affiliation(s)
- Fabian Ebner
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 275, 69120 Heidelberg, Germany
| | - Lutz Greb
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 275, 69120 Heidelberg, Germany
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43
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Burton KI, Elser I, Waked AE, Wagener T, Andrews RJ, Glorius F, Stephan DW. Bipyridinium and Phenanthrolinium Dications for Metal-Free Hydrodefluorination: Distinctive Carbon-Based Reactivity. Chemistry 2021; 27:11730-11737. [PMID: 34107119 DOI: 10.1002/chem.202101534] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Indexed: 01/06/2023]
Abstract
The development of novel Lewis acids derived from bipyridinium and phenanthrolinium dications is reported. Calculations of Hydride Ion Affinity (HIA) values indicate high carbon-based Lewis acidity at the ortho and para positions. This arises in part from extensive LUMO delocalization across the aromatic backbones. Species [C10 H6 R2 N2 CH2 CH2 ]2+ (R=H [1 a]2+ , Me [1 f]2+ , tBu [1 g]2+ ), and [C12 H4 R4 N2 CH2 CH2 ]2+ (R=H [2 a]2+ , Me [2 b]2+ ) were prepared and evaluated for use in the initiation of hydrodefluorination (HDF) catalysis. Compound [2 a]2+ proved highly effective towards generating catalytically active silylium cations via Lewis acid-mediated hydride abstraction from silane. This enabled the HDF of a range of aryl- and alkyl- substituted sp3 (C-F) bonds under mild conditions. The protocol was also adapted to effect the deuterodefluorination of cis-2,4,6-(CF3 )3 C6 H9 . The dications are shown to act as hydride acceptors with the isolation of neutral species C16 H14 N2 (3 a) and C16 H10 Me4 N2 (3 b) and monocationic species [C14 H13 N2 ]+ ([4 a]+ ) and [C18 H21 N2 ]+ ([4 b]+ ). Experimental and computational data provide further support that the dications are initiators in the generation of silylium cations.
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Affiliation(s)
- Katherine I Burton
- Department of Chemistry, Davenport Research Laboratories, University of Toronto, Toronto, Ontario, M5S 3H6, Canada
| | - Iris Elser
- Department of Chemistry, Davenport Research Laboratories, University of Toronto, Toronto, Ontario, M5S 3H6, Canada
| | - Alexander E Waked
- Department of Chemistry, Davenport Research Laboratories, University of Toronto, Toronto, Ontario, M5S 3H6, Canada
| | - Tobias Wagener
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Correnstraβe 40, 48149, Münster, Germany
| | - Ryan J Andrews
- Department of Chemistry, Davenport Research Laboratories, University of Toronto, Toronto, Ontario, M5S 3H6, Canada
| | - Frank Glorius
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Correnstraβe 40, 48149, Münster, Germany
| | - Douglas W Stephan
- Department of Chemistry, Davenport Research Laboratories, University of Toronto, Toronto, Ontario, M5S 3H6, Canada
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44
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Kumar N, Laye C, Robert F, Landais Y. Quinoline‐Based Silylium Ions: Synthesis, Structure and Lewis Acidity. European J Org Chem 2021. [DOI: 10.1002/ejoc.202100604] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Nivesh Kumar
- Univ. Bordeaux, CNRS Institut des Sciences Moléculaires (ISM), UMR-5255 33400 Talence France
| | - Claire Laye
- Univ. Bordeaux, CNRS Institut des Sciences Moléculaires (ISM), UMR-5255 33400 Talence France
| | - Frédéric Robert
- Univ. Bordeaux, CNRS Institut des Sciences Moléculaires (ISM), UMR-5255 33400 Talence France
| | - Yannick Landais
- Univ. Bordeaux, CNRS Institut des Sciences Moléculaires (ISM), UMR-5255 33400 Talence France
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45
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Long PW, Oestreich M. B(C 6F 5) 3-Catalyzed Diastereoselective Formal (4 + 1)-Cycloaddition of Vinylcyclopropanes and Et 2SiH 2. Org Lett 2021; 23:4834-4837. [PMID: 34076451 DOI: 10.1021/acs.orglett.1c01565] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A formal (4 + 1)-cycloaddition of vinylcyclopropanes and Et2SiH2 to afford 3,4-disubstituted silolanes is reported. The reaction sequence commences with the known B(C6F5)3-catalyzed alkene hydrosilylation with dihydrosilanes. Cleavage of the remaining Si-H bond in the hydrosilylation product assisted by B(C6F5)3 leads to formation of a cyclopropane-stabilized silylium ion. The activated cyclopropane ring is then opened by the in situ-generated borohydride accompanied by ring closure to the silolane. The diastereoselectivity is rationalized by a mechanistic model.
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Affiliation(s)
- Peng-Wei Long
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623 Berlin, Germany
| | - Martin Oestreich
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623 Berlin, Germany
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46
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Abstract
![]()
Practical, efficient,
and general methods for the diversification
of N-heterocycles have been a recurrent goal in chemical
synthesis due to the ubiquitous influence of these motifs within bioactive
frameworks. Here, we describe a direct, catalytic, and selective functionalization
of azines via silylium activation. Our catalyst design enables mild
conditions and a remarkable functional group tolerance in a one-pot
setup.
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Affiliation(s)
- Carla Obradors
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, Mülheim an der Ruhr, 45470, Germany
| | - Benjamin List
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, Mülheim an der Ruhr, 45470, Germany
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47
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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: 97] [Impact Index Per Article: 32.3] [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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48
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Shuler WG, Parvathaneni SP, Rodriguez JB, Lewis TN, Berges AJ, Bardeen CJ, Krische MJ. Synthesis and Photophysical Properties of Soluble N-Doped Rubicenes via Ruthenium-Catalyzed Transfer Hydrogenative Benzannulation. Chemistry 2021; 27:4898-4902. [PMID: 33576516 DOI: 10.1002/chem.202100134] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Indexed: 11/10/2022]
Abstract
Ruthenium-catalyzed butadiene-mediated benzannulation enabled the first synthesis of 3,10-(di-tert-butyl)rubicene and its N-doped derivatives as well as preliminary studies on their photophysical properties. Unlike the parent rubicene and 3,10-(di-tert-butyl)rubicene, which adopt classical herringbone-type packing motifs in the solid state, the N-doped congener 7 b displayed columnar packing with an alternating co-facial arrangement of aromatic and heteroaromatic substructures.
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Affiliation(s)
- William G Shuler
- Department of Chemistry, University of Texas at Austin, 105 E 24th St. (A5300), Austin, TX, 78712-1167, USA
| | - Sai P Parvathaneni
- Department of Chemistry, University of Texas at Austin, 105 E 24th St. (A5300), Austin, TX, 78712-1167, USA
| | - Jacob B Rodriguez
- Department of Materials Science and Engineering, University of California, 501 Big Springs Road, Riverside, CA, 92521, USA
| | - Taylor N Lewis
- Department of Chemistry, University of California, 501 Big Springs Road, Riverside, CA, 92521, USA
| | - Adam J Berges
- Department of Chemistry, University of California, 501 Big Springs Road, Riverside, CA, 92521, USA
| | - Christopher J Bardeen
- Department of Materials Science and Engineering, University of California, 501 Big Springs Road, Riverside, CA, 92521, USA.,Department of Chemistry, University of California, 501 Big Springs Road, Riverside, CA, 92521, USA
| | - Michael J Krische
- Department of Chemistry, University of Texas at Austin, 105 E 24th St. (A5300), Austin, TX, 78712-1167, USA
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49
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Shi Q, Shi X, Feng C, Wu Y, Zheng N, Liu J, Wu X, Chen H, Peng A, Li J, Jiang L, Fu H, Xie Z, Marder SR, Blakey SB, Huang H. Synthetic Routes for Heteroatom-Containing Alkylated/Arylated Polycyclic Aromatic Hydrocarbons. Angew Chem Int Ed Engl 2021; 60:2924-2928. [PMID: 33107179 DOI: 10.1002/anie.202014108] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Indexed: 01/27/2023]
Abstract
Synthetic routes for heteroatom-containing polycyclic aromatic hydrocarbons (H-PAHs) with alkyl and aryl substitution are demonstrated. Three H-PAHs, including heteroatom-containing rubicenes (H-rubicenes), angular-benzothiophenes (ABTs), and indenothiophene (IDTs) were successfully synthesized by two key steps, including polysubstituted olefin formation and cyclization. Specifically, ABT and H-rubicenes were comprehensively investigated by single-crystal X-ray diffraction, NMR spectroscopy, UV-vis absorption, cyclic voltammetry, transient absorption, and single-crystal OFET measurements.
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Affiliation(s)
- Qinqin Shi
- Center of Materials Science and Optoelectronics Engineering, College of Materials Science and Opto-Electronic Technology & CAS Center for Excellence in Topological Quantum Computation & CAS Key Laboratory of Vacuum Physic, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Xiaosong Shi
- Key Laboratory of Organic Solids, Beijing National Laboratory for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Changfu Feng
- Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing, 100048, P. R. China
| | - Yishi Wu
- Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing, 100048, P. R. China
| | - Nan Zheng
- State Key Laboratory of Luminescent Materials and Devices, School of Materials Science and Engineering, South China University of Technology, Guangzhou, 510640, P. R. China
| | - Jie Liu
- Key Laboratory of Organic Solids, Beijing National Laboratory for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Xiaoxi Wu
- Center of Materials Science and Optoelectronics Engineering, College of Materials Science and Opto-Electronic Technology & CAS Center for Excellence in Topological Quantum Computation & CAS Key Laboratory of Vacuum Physic, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Hao Chen
- Center of Materials Science and Optoelectronics Engineering, College of Materials Science and Opto-Electronic Technology & CAS Center for Excellence in Topological Quantum Computation & CAS Key Laboratory of Vacuum Physic, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Aidong Peng
- Center of Materials Science and Optoelectronics Engineering, College of Materials Science and Opto-Electronic Technology & CAS Center for Excellence in Topological Quantum Computation & CAS Key Laboratory of Vacuum Physic, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Jianfeng Li
- Center of Materials Science and Optoelectronics Engineering, College of Materials Science and Opto-Electronic Technology & CAS Center for Excellence in Topological Quantum Computation & CAS Key Laboratory of Vacuum Physic, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Lang Jiang
- Key Laboratory of Organic Solids, Beijing National Laboratory for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Hongbing Fu
- Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing, 100048, P. R. China
| | - Zengqi Xie
- State Key Laboratory of Luminescent Materials and Devices, School of Materials Science and Engineering, South China University of Technology, Guangzhou, 510640, P. R. China
| | - Seth R Marder
- School of Chemistry and Biochemistry and Center for Organic Photonics and Electronics, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Simon B Blakey
- Department of Chemistry, Emory University, Atlanta, GA, 30322, USA
| | - Hui Huang
- Center of Materials Science and Optoelectronics Engineering, College of Materials Science and Opto-Electronic Technology & CAS Center for Excellence in Topological Quantum Computation & CAS Key Laboratory of Vacuum Physic, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
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50
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Fontana N, Espinosa‐Jalapa NA, Seidl M, Bauer JO. Easy Access to Enantiomerically Pure Heterocyclic Silicon-Chiral Phosphonium Cations and the Matched/Mismatched Case of Dihydrogen Release. Chemistry 2021; 27:2649-2653. [PMID: 33264430 PMCID: PMC7898527 DOI: 10.1002/chem.202005171] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Indexed: 11/17/2022]
Abstract
Phosphonium ions are widely used in preparative organic synthesis and catalysis. The provision of new types of cations that contain both functional and chiral information is a major synthetic challenge and can open up new horizons in asymmetric cation-directed and Lewis acid catalysis. We discovered an efficient methodology towards new Si-chiral four-membered CPSSi* heterocyclic cations. Three synthetic approaches are presented. The stereochemical sequence of anchimerically assisted cation formation with B(C6 F5 )3 and subsequent hydride addition was fully elucidated and proceeds with excellent preservation of the chiral information at the stereogenic silicon atom. Also the mechanism of dihydrogen release from a protonated hydrosilane was studied in detail by the help of Si-centered chirality as stereochemical probe. Chemoselectivity switch (dihydrogen release vs. protodesilylation) can easily be achieved through slight modifications of the solvent. A matched/mismatched case was identified and the intermolecularity of this reaction supported by spectroscopic, kinetic, deuterium-labeling experiments, and quantum chemical calculations.
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Affiliation(s)
- Nicolò Fontana
- Institut für Anorganische ChemieFakultät für Chemie und PharmazieUniversität RegensburgUniversitätsstraße 3193053RegensburgGermany
| | - Noel Angel Espinosa‐Jalapa
- Institut für Anorganische ChemieFakultät für Chemie und PharmazieUniversität RegensburgUniversitätsstraße 3193053RegensburgGermany
| | - Michael Seidl
- Institut für Anorganische ChemieFakultät für Chemie und PharmazieUniversität RegensburgUniversitätsstraße 3193053RegensburgGermany
| | - Jonathan O. Bauer
- Institut für Anorganische ChemieFakultät für Chemie und PharmazieUniversität RegensburgUniversitätsstraße 3193053RegensburgGermany
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