1
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Lu W, Hensiek N, Saha K, Dewhurst RD, Härterich M, Pranckevicius C, Hagspiel S, Dietz M, Krummenacher I, Braunschweig H. Electron-Precise Dicationic Tetraboranes: Syntheses, Structures and Rearrangement to an Alkylidene Borate-Borenium Zwitterion and a 1,3-Azaborinine. Chemistry 2023; 29:e202300644. [PMID: 37272320 DOI: 10.1002/chem.202300644] [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: 03/03/2023] [Revised: 06/02/2023] [Accepted: 06/02/2023] [Indexed: 06/06/2023]
Abstract
Carbene-stabilized symmetrical and unsymmetrical dicationic tetraboranes, featuring an electron-precise tetraborane chain, were synthesized and fully characterized. Reactions of these tetraboranes with reductants/bases give rise to different outcomes according to the conditions employed, including: 1) reduction and rearrangement of the tetraborane chain to give a zwitterionic alkylidene borate-borenium species; 2) cleavage of the tetraborane chain to afford a 1,3-azaborinine; and 3) reduction of the supporting ligands to provide a diamino dipotassium salt. The zwitterionic alkylidene borate-borenium species can be viewed as an analogue of the base-stabilized diborenes. NMR spectroscopy and DFT calculations reveal a highly polarized B-B bond in the zwitterionic alkylidene borate-borenium, in which the formal oxidation states of the boron atoms can be considered as -1 and +2. These results suggest the considerable potential of tetraboranes as synthons for low-valent boron species.
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Affiliation(s)
- Wei Lu
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
- Key Laboratory of Green Chemistry & Technology of Ministry of Education, College of Chemistry, Sichuan University, 29 Wangjiang Road, Chengdu, 610064, P. R. China
| | - Nicola Hensiek
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Koushik Saha
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Rian D Dewhurst
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Marcel Härterich
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Conor Pranckevicius
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Stephan Hagspiel
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Maximilian Dietz
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Ivo Krummenacher
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Holger Braunschweig
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
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2
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Wang Y, Zhang X, Han J, Li Q, Wei R, Ruiz DA, Liu LL, Tung C, Kong L. Crystalline Neutral Diboron Analogues of Cyclopropanes. Angew Chem Int Ed Engl 2022; 61:e202117053. [DOI: 10.1002/anie.202117053] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Indexed: 11/09/2022]
Affiliation(s)
- Yu Wang
- School of Chemistry and Chemical Engineering Shandong University Jinan 250100 P. R. China
| | - Xin Zhang
- Department of Chemistry and Shenzhen Grubbs Institute, Southern University of Science and Technology Shenzhen 518055 P. R. China
| | - Jixing Han
- School of Chemistry and Chemical Engineering Shandong University Jinan 250100 P. R. China
| | - Qianli Li
- School of Chemistry and Chemical Engineering Liaocheng University Liaocheng 252059 P. R. China
| | - Rui Wei
- Department of Chemistry and Shenzhen Grubbs Institute, Southern University of Science and Technology Shenzhen 518055 P. R. China
| | - David A. Ruiz
- Department of Chemistry and Shenzhen Grubbs Institute, Southern University of Science and Technology Shenzhen 518055 P. R. China
| | - Liu Leo Liu
- Department of Chemistry and Shenzhen Grubbs Institute, Southern University of Science and Technology Shenzhen 518055 P. R. China
| | - Chen‐Ho Tung
- School of Chemistry and Chemical Engineering Shandong University Jinan 250100 P. R. China
| | - Lingbing Kong
- School of Chemistry and Chemical Engineering Shandong University Jinan 250100 P. R. China
- State Key Laboratory of Elemento-Organic Chemistry Nankai University Tianjin 300071 P. R. China
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3
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Kistner L, Kowatsch D, Marz A, Kaifer E, Himmel H. Directed Synthesis and Chemistry of Unsymmetric Dicationic Diboranes and Their Use in Frustrated Lewis Pair‐like Chemistry. Chemistry 2022; 28:e202104016. [PMID: 35061309 PMCID: PMC9305129 DOI: 10.1002/chem.202104016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Indexed: 11/15/2022]
Abstract
The chemistry of dicationic diboranes with two BII atoms that are engaged in direct B−B bonding is by enlarge unexplored, although these molecules have intriguing properties due to their combined Lewis acidic and electron‐donor properties. Unsymmetric dicationic diboranes are extremely rare, but especially attractive due to their polarized B−B bond. In this work we report the directed synthesis of several stable unsymmetric dicationic diboranes by reaction between the electron‐rich ditriflato‐diborane B2(hpp)2(OTf)2 (hpp=1,3,4,6,7,8‐hexahydro‐2H‐pyrimido[1,2‐α]pyrimidinate) and phosphino‐pyridines, establishing B−N and B−P bonds with the diborane concomitant with triflate elimination. In the case of 2‐((ditertbutylphosphino)methyl)pyridine, the B−N bond is formed instantly, but the B−P bond formation requires (due to steric constraints) several days at ambient conditions for completion, creating an intermediate that could be used for frustrated Lewis pair (FLP)‐like chemistry. Here we test its reaction with an aldehyde, and propose a new type of FLP‐like chemistry.
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Affiliation(s)
- Lucas Kistner
- Anorganisch-Chemisches Institut Ruprecht-Karls Universität Heidelberg Im Neuenheimer Feld 270 69120 Heidelberg Germany
| | - Dario Kowatsch
- Anorganisch-Chemisches Institut Ruprecht-Karls Universität Heidelberg Im Neuenheimer Feld 270 69120 Heidelberg Germany
| | - Andreas Marz
- Anorganisch-Chemisches Institut Ruprecht-Karls Universität Heidelberg Im Neuenheimer Feld 270 69120 Heidelberg Germany
| | - Elisabeth Kaifer
- Anorganisch-Chemisches Institut Ruprecht-Karls Universität Heidelberg Im Neuenheimer Feld 270 69120 Heidelberg Germany
| | - Hans‐Jörg Himmel
- Anorganisch-Chemisches Institut Ruprecht-Karls Universität Heidelberg Im Neuenheimer Feld 270 69120 Heidelberg Germany
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4
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Wang Y, Zhang X, Han J, Li Q, Wei R, Ruiz DA, Liu LL, Tung CH, Kong L. Crystalline Neutral Diboron Analogues of Cyclopropanes. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202117053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Yu Wang
- Shandong University School of Chemistry and Chemical Engineering CHINA
| | - Xin Zhang
- Southern University of Science and Technology Department of Chemistry CHINA
| | - Jixing Han
- Shandong University School of Chemistry and Chemical Engineering CHINA
| | - Qianli Li
- Liaocheng University Department of Chemistry and Chemical Engineering CHINA
| | - Rui Wei
- Southern University of Science and Technology Department of Chemistry CHINA
| | - David A Ruiz
- Southern University of Science and Technology Department of Chemistry CHINA
| | - Liu Leo Liu
- Southern University of Science and Technology Department of Chemistry CHINA
| | - Chen-Ho Tung
- Shandong University School of Chemistry and Chemical Engineering CHINA
| | - Lingbing Kong
- Shandong University School of Chemistry and Chemical Engineering 27 Shanda Nanlu 250100 Jinan CHINA
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5
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Filbeck E, Widera A, Kaifer E, Himmel HJ. Polycationic Redox-Active Cyclophanes with Integrated Electron-Rich Diboron Units. Chemistry 2021; 27:15737-15750. [PMID: 34459521 PMCID: PMC9291520 DOI: 10.1002/chem.202102656] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Indexed: 11/29/2022]
Abstract
Cationic cyclophanes are widely used in a variety of applications in supramolecular chemistry and materials science. In this work the authors systematically study the integration of electron‐rich diboron units with BII atoms into polycationic cyclophanes with viologen‐like electron‐acceptor units. They also report a first hexacationic cage‐compound in which three diboron units connect two tris(4‐pyridyl)triazine acceptor units. Moreover, di‐ and tetracationic open‐structure compounds, in which one diboron unit connects two bispyridyl groups, were synthesized and the properties compared to those of the corresponding closed structures (cyclophanes). The combination of diboron electron‐donor units and bi‐ or oligopyridyl electron‐acceptor units leads to intriguing optical and redox properties.
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Affiliation(s)
- Erik Filbeck
- Institute of Inorganic Chemistry, Ruprecht-Karls University of Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Anna Widera
- Institute of Inorganic Chemistry, Ruprecht-Karls University of Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Elisabeth Kaifer
- Institute of Inorganic Chemistry, Ruprecht-Karls University of Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Hans-Jörg Himmel
- Institute of Inorganic Chemistry, Ruprecht-Karls University of Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
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6
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Kar S, Bairagi S, Kar K, Roisnel T, Dorcet V, Ghosh S. Metal Coordinated Tri‐ and Tetraborane Analogues. Eur J Inorg Chem 2021. [DOI: 10.1002/ejic.202100687] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Sourav Kar
- Department of Chemistry Indian Institute of Technology Madras Chennai 600036 India
| | - Subhash Bairagi
- Department of Chemistry Indian Institute of Technology Madras Chennai 600036 India
| | - Ketaki Kar
- Department of Chemistry Indian Institute of Technology Madras Chennai 600036 India
| | - Thierry Roisnel
- ISCR (Institut des Sciences Chimiques de Rennes) Univ Rennes CNRS UMR 6226 35000 Rennes France
| | - Vincent Dorcet
- ISCR (Institut des Sciences Chimiques de Rennes) Univ Rennes CNRS UMR 6226 35000 Rennes France
| | - Sundargopal Ghosh
- Department of Chemistry Indian Institute of Technology Madras Chennai 600036 India
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7
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Steuer L, Kaifer E, Himmel HJ. On the metal-ligand bonding in dinuclear complexes with redox-active guanidine ligands. Dalton Trans 2021; 50:9467-9482. [PMID: 34136887 DOI: 10.1039/d1dt01354h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Coordination compounds with redox-active ligands are currently intensively studied. Within this research theme, redox-active guanidines have been established as a new, eminent class of redox-active ligands. In this work the variation of metal-guanidine bonding in dinuclear transition metal complexes with bridging redox-active tetrakisguanidine ligands is analysed. A series of dinuclear complexes with different metals (Mn, Fe, Co, Ni, Cu and Zn) is synthesized, using either newly prepared redox-active tetrakisguanidino-dioxine or previously reported tetrakisguanidino-benzene ligands. The discussion of the bond properties in this work is predominantly based on the trends of structural parameters, derived from determination of single-crystal structures by X-ray diffraction and quantum chemical calculations. In addition, the trends in the redox potentials and magnetometric (SQUID) measurements on some of the complexes are included. Due to their combined σ- and π-electron donor capability, redox-active guanidine ligands are weak-field ligands; the σ- and π-bonding contributions vary with the metal. The results highlight the peculiarity of copper-guanidine bonding with a high π-bond contribution to metal-guanidine bonding, enabled by structural distortion of the coordination mode from tetrahedral in the direction of square-planar, short copper-guanidine bonds and minor displacement of the copper atoms from the ligand aromatic plane.
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Affiliation(s)
- Lena Steuer
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany.
| | - Elisabeth Kaifer
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany.
| | - Hans-Jörg Himmel
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany.
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8
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Affiliation(s)
- Anna Widera
- Anorganisch‐Chemisches Institut Ruprecht‐Karls‐Universität Heidelberg Im Neuenheimer Feld 270 69120 Heidelberg Germany
| | - Erik Filbeck
- Anorganisch‐Chemisches Institut Ruprecht‐Karls‐Universität Heidelberg Im Neuenheimer Feld 270 69120 Heidelberg Germany
| | - Hans‐Jörg Himmel
- Anorganisch‐Chemisches Institut Ruprecht‐Karls‐Universität Heidelberg Im Neuenheimer Feld 270 69120 Heidelberg Germany
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9
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Li N, Wu B, Yu C, Li T, Zhang W, Xi Z. Trishomoaromatic (B
3
N
3
Ph
6
) Dianion: Characterization and Two‐Electron Reduction. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.201916651] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Nan Li
- Beijing National Laboratory for Molecular Sciences (BNLMS) Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education College of Chemistry Peking University Beijing 100871 China
| | - Botao Wu
- Beijing National Laboratory for Molecular Sciences (BNLMS) Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education College of Chemistry Peking University Beijing 100871 China
| | - Chao Yu
- Beijing National Laboratory for Molecular Sciences (BNLMS) Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education College of Chemistry Peking University Beijing 100871 China
| | - Tianyu Li
- College of Chemistry Beijing Normal University China
| | - Wen‐Xiong Zhang
- Beijing National Laboratory for Molecular Sciences (BNLMS) Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education College of Chemistry Peking University Beijing 100871 China
| | - Zhenfeng Xi
- Beijing National Laboratory for Molecular Sciences (BNLMS) Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education College of Chemistry Peking University Beijing 100871 China
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10
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Trageser T, Bolte M, Lerner HW, Wagner M. B-B Bond Nucleophilicity in a Tetraaryl μ-Hydridodiborane(4) Anion. Angew Chem Int Ed Engl 2020; 59:7726-7731. [PMID: 32058652 PMCID: PMC7317828 DOI: 10.1002/anie.202000292] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Indexed: 11/15/2022]
Abstract
The tetraaryl μ‐hydridodiborane(4) anion [2H]− possesses nucleophilic B−B and B−H bonds. Treatment of K[2H] with the electrophilic 9‐H‐9‐borafluorene (HBFlu) furnishes the B3 cluster K[3], with a triangular boron core linked through two BHB two‐electron, three‐center bonds and one electron‐precise B−B bond, reminiscent of the prominent [B3H8]− anion. Upon heating or prolonged stirring at room temperature, K[3] rearranges to a slightly more stable isomer K[3 a]. The reaction of M[2H] (M+=Li+, K+) with MeI or Me3SiCl leads to equimolar amounts of 9‐R‐9‐borafluorene and HBFlu (R=Me or Me3Si). Thus, [2H]− behaves as a masked [:BFlu]− nucleophile. The HBFlu by‐product was used in situ to establish a tandem substitution‐hydroboration reaction: a 1:1 mixture of M[2H] and allyl bromide gave the 1,3‐propylene‐linked ditopic 9‐borafluorene 5 as sole product. M[2H] also participates in unprecedented [4+1] cycloadditions with dienes to furnish dialkyl diaryl spiroborates, M[R2BFlu].
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Affiliation(s)
- Timo Trageser
- Institut für Anorganische Chemie, Goethe-Universität Frankfurt, Max-von-Laue-Strasse 7, 60438, Frankfurt (Main), Germany
| | - Michael Bolte
- Institut für Anorganische Chemie, Goethe-Universität Frankfurt, Max-von-Laue-Strasse 7, 60438, Frankfurt (Main), Germany
| | - Hans-Wolfram Lerner
- Institut für Anorganische Chemie, Goethe-Universität Frankfurt, Max-von-Laue-Strasse 7, 60438, Frankfurt (Main), Germany
| | - Matthias Wagner
- Institut für Anorganische Chemie, Goethe-Universität Frankfurt, Max-von-Laue-Strasse 7, 60438, Frankfurt (Main), Germany
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11
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Li N, Wu B, Yu C, Li T, Zhang WX, Xi Z. Trishomoaromatic (B 3 N 3 Ph 6 ) Dianion: Characterization and Two-Electron Reduction. Angew Chem Int Ed Engl 2020; 59:8868-8872. [PMID: 32133711 DOI: 10.1002/anie.201916651] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Revised: 02/19/2020] [Indexed: 01/08/2023]
Abstract
Benzene, a common aromatic compound, can be converted into an unstable antiaromatic 8π-electron intermediate through two-electron reduction. However, as an isoelectronic equivalent of benzene, borazine (B3 N3 Ph6 ), having weak aromaticity, undergoes a totally different two-electron reduction to afford (B3 N3 R6 )2- homoaromatic compounds. Reported here is the synthesis of homoaromatic (B3 N3 Ph6 )2- by the reduction of B3 N3 Ph6 with either potassium or rubidium in the presence of 18-crown-6 ether. Theoretical investigations illustrate that two electrons delocalize over the three boron atoms in (B3 N3 Ph6 )2- , which is formed by the geometric and orbital reorganization and exhibits (π,σ)-mixed homoaromaticity. Moreover, (B3 N3 Ph6 )2- can act as a robust 2e reductant for unsaturated compounds, such as anthracene, chalcone, and tanshinones. This 2e reduction is of high efficiency and selectivity, proceeds under mild reaction conditions, and can regenerate neutral borazine.
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Affiliation(s)
- Nan Li
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, Peking University, Beijing, 100871, China
| | - Botao Wu
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, Peking University, Beijing, 100871, China
| | - Chao Yu
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, Peking University, Beijing, 100871, China
| | - Tianyu Li
- College of Chemistry, Beijing Normal University, China
| | - Wen-Xiong Zhang
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, Peking University, Beijing, 100871, China
| | - Zhenfeng Xi
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, Peking University, Beijing, 100871, China
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12
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Trageser T, Bolte M, Lerner H, Wagner M. B−B Bond Nucleophilicity in a Tetraaryl μ‐Hydridodiborane(4) Anion. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202000292] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Timo Trageser
- Institut für Anorganische Chemie Goethe-Universität Frankfurt Max-von-Laue-Strasse 7 60438 Frankfurt (Main) Germany
| | - Michael Bolte
- Institut für Anorganische Chemie Goethe-Universität Frankfurt Max-von-Laue-Strasse 7 60438 Frankfurt (Main) Germany
| | - Hans‐Wolfram Lerner
- Institut für Anorganische Chemie Goethe-Universität Frankfurt Max-von-Laue-Strasse 7 60438 Frankfurt (Main) Germany
| | - Matthias Wagner
- Institut für Anorganische Chemie Goethe-Universität Frankfurt Max-von-Laue-Strasse 7 60438 Frankfurt (Main) Germany
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13
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Widera A, Filbeck E, Wadepohl H, Kaifer E, Himmel H. Electron-Rich, Lewis Acidic Diborane Meets N-Heterocyclic Aromatics: Formation and Electron Transfer in Cyclophane Boranes. Chemistry 2020; 26:3435-3440. [PMID: 31943435 PMCID: PMC7155121 DOI: 10.1002/chem.202000189] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Indexed: 01/17/2023]
Abstract
Herein reported are the reactions of an electron-rich, Lewis acidic diborane with N-heterocyclic aromatics to give first members of an unprecedented family of highly charged cationic cyclophanes with diboranyl units. Tetracationic cyclophanes with 4,4'-bipyridine/ 1,2-bis(4-pyridyl)ethylene and diboranyl units were synthesized and their redox chemistry was studied. Cyclisation of two diboranyl and two pyrazine units is accompanied by electron transfer from the diboranyl unit to the pyrazine. Our results pave the way for the integration of redox-active diboranyl units into cyclophanes and supramolecular structures.
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Affiliation(s)
- Anna Widera
- Anorganisch-Chemisches InstitutRuprecht-Karls-Universität HeidelbergIm Neuenheimer Feld 27069121HeidelbergGermany
| | - Erik Filbeck
- Anorganisch-Chemisches InstitutRuprecht-Karls-Universität HeidelbergIm Neuenheimer Feld 27069121HeidelbergGermany
| | - Hubert Wadepohl
- Anorganisch-Chemisches InstitutRuprecht-Karls-Universität HeidelbergIm Neuenheimer Feld 27069121HeidelbergGermany
| | - Elisabeth Kaifer
- Anorganisch-Chemisches InstitutRuprecht-Karls-Universität HeidelbergIm Neuenheimer Feld 27069121HeidelbergGermany
| | - Hans‐Jörg Himmel
- Anorganisch-Chemisches InstitutRuprecht-Karls-Universität HeidelbergIm Neuenheimer Feld 27069121HeidelbergGermany
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14
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Vogler D, Wolf N, Kaifer E, Himmel HJ. Electron transfer in complexes of B II cations with organic π-acceptors: a combined experimental and quantum-chemical study. Dalton Trans 2019; 48:14354-14366. [PMID: 31513209 DOI: 10.1039/c9dt03151k] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Due to their combined Lewis acidity and electron-donor capability, BII cations exhibit an interesting reactivity, which is almost unexplored so far. In this work, we compare the reduction in a dicationic diborane of a series of vicinal diones with different redox potentials, namely 3,5-di-tert-butylbenzoquinone, 3,4,5,6-tetrachlorobenzoquinone, 1,2-naphthalene-dione, 9,10-phenanthrene-dione, 2,2'-dichlorobenzil, benzil and 1,2-acenaphthylene-dione. The experimental work is complemented by quantum-chemical calculations, illuminating the electron-transfer step in the reactions.
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Affiliation(s)
- Daniel Vogler
- Anorganisch-Chemisches Institut, Ruprecht-Karls-University of Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany.
| | - Nina Wolf
- Anorganisch-Chemisches Institut, Ruprecht-Karls-University of Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany.
| | - Elisabeth Kaifer
- Anorganisch-Chemisches Institut, Ruprecht-Karls-University of Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany.
| | - Hans-Jörg Himmel
- Anorganisch-Chemisches Institut, Ruprecht-Karls-University of Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany.
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