1
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Fan J, Xu J, Ma Q, Yao S, Zhao L, Frenking G, Driess M. Silylene-Stabilized Neutral Dibora-Aromatics with a B═B Bond. J Am Chem Soc 2024; 146:20458-20467. [PMID: 38980827 PMCID: PMC11273343 DOI: 10.1021/jacs.4c06579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2024] [Revised: 06/27/2024] [Accepted: 06/28/2024] [Indexed: 07/11/2024]
Abstract
The unprecedented silylene-supported dibenzodiboraoxepin 2 and 9,10-diboraphenanthrene complexes 6 and 8 were synthesized. The (NHSi)2B2(xanthene) [NHSi = PhC(NtBu)2(Me2N)Si:] 2 results from debromination of the bis(NHSi)-stabilized bis(dibromoboryl)xanthene 1 with potassium graphite (KC8); 2 is capable of activating white phosphorus and ammonia to form the B2P4 cage compound 3 and H2N-B-B-H diborane species 4, respectively. The thermal rearrangement of 2 affords the 9,10-dihydro-9,10-diboraphenanthrene 5 through a bis(NHSi)-assisted intramolecular reductive C-O-C deoxygenation process. Notably, the 9,10-diboraphenanthrene derivatives 6 and 8 could be generated by deoxygenation of 2 with KC8 and 1,3,4,5-tetramethylimidazol-2-ylidene, respectively. The aromaticity of 6 and 8 was confirmed by computational studies. Strikingly, the NHSi ligand in 8 engenders the monodeoxygenation of carbon dioxide in toluene at room temperature to form the CO-stabilized 9,10-diboraphenanthrene derivative 9 via the silaoxadiborinanone intermediate 10.
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Affiliation(s)
- Jun Fan
- Department
of Chemistry: Metalorganics and Inorganic Materials, Technische Universität Berlin, Strasse des 17. Juni 115, Sekr. C2, Berlin 10623, Germany
| | - Jian Xu
- Department
of Chemistry: Metalorganics and Inorganic Materials, Technische Universität Berlin, Strasse des 17. Juni 115, Sekr. C2, Berlin 10623, Germany
| | - Qin Ma
- State
Key Laboratory of Materials-Oriented Chemical Engineering, School
of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing 211816, China
| | - Shenglai Yao
- Department
of Chemistry: Metalorganics and Inorganic Materials, Technische Universität Berlin, Strasse des 17. Juni 115, Sekr. C2, Berlin 10623, Germany
| | - Lili Zhao
- State
Key Laboratory of Materials-Oriented Chemical Engineering, School
of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing 211816, China
| | - Gernot Frenking
- State
Key Laboratory of Materials-Oriented Chemical Engineering, School
of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing 211816, China
- Fachbereich
Chemie, Philipps-Universität Marburg, Marburg 35032, Germany
| | - Matthias Driess
- Department
of Chemistry: Metalorganics and Inorganic Materials, Technische Universität Berlin, Strasse des 17. Juni 115, Sekr. C2, Berlin 10623, Germany
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2
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Uhlmann C, Münzfeld L, Hauser A, Ruan TT, Kumar Kuppusamy S, Jin C, Ruben M, Fink K, Moreno-Pineda E, Roesky PW. Unique Double and Triple Decker Arrangements of Rare-Earth 9,10-Diborataanthracene Complexes Featuring Single-Molecule Magnet Characteristics. Angew Chem Int Ed Engl 2024; 63:e202401372. [PMID: 38390783 DOI: 10.1002/anie.202401372] [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: 01/19/2024] [Revised: 02/07/2024] [Accepted: 02/09/2024] [Indexed: 02/24/2024]
Abstract
Herein, we present the first report on the synthesis of rare-earth complexes featuring a 9,10-diborataanthracene ligand. This 14-π-electron ligand is highly reductive and was previously used in small-molecule activation. Salt elimination reactions between dipotassium 9,10-diethyl-9,10-diborataanthracene [K2(DEDBA)] and [LnIII(η8-CotTIPS)(BH4)(thf)x] (CotTIPS=1,4-(iPr3Si)2C8H6) in a 1 : 1 ratio yielded heteroleptic sandwich complexes [K(η8-CotTIPS)LnIII(η6-DEDBA)] (Ln=Y, Dy, Er). These compounds form Lewis-base-free one-dimensional coordination polymers when crystallised from toluene. In contrast, reaction of [K2(DEDBA)] and [LnIII(η8-CotTIPS)(BH4)(thf)x] in a 1 : 2 ratio led to the formation of heteroleptic triple-decker complexes [(η8-CotTIPS)LnIII(μ-η6:η6-DEDBA)LnIII(η8-CotTIPS)] (Ln=Y, Dy, Er). Notably, these are not only the first lanthanide triple-decker compounds featuring a six-membered ring as a deck but also the first trivalent lanthanide triple-decker featuring a heterocycle in the coordination sphere. Magnetic investigations reveal that [K(η8-CotTIPS)LnIII(η6-DEDBA)] (Ln=Dy, Er) and [(η8-CotTIPS)ErIII(μ-η6:η6-DEDBA)ErIII(η8-CotTIPS)] exhibit Single-Molecule Magnet (SMM) behaviour. In the case of [(η8-CotTIPS)LnIII(μ-η6:η6-DEDBA)LnIII(η8-CotTIPS)] (Ln=Dy, Er), the introduction of a second near lanthanide ion results in strong antiferromagnetic interactions, allowing the enhancement of the magnetic characteristic of the system, compared to the quasi isolated counterpart. This research renews the overlooked coordination chemistry of the DBA ligand and expands it to encompass rare-earth elements.
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Affiliation(s)
- Cedric Uhlmann
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstraße 15, 76131, Karlsruhe
| | - Luca Münzfeld
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstraße 15, 76131, Karlsruhe
| | - Adrian Hauser
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstraße 15, 76131, Karlsruhe
| | - Ting-Ting Ruan
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Kaiserstraße 12, 76131, Karlsruhe, Germany
| | - Senthil Kumar Kuppusamy
- Institute of Quantum Materials and Technologies (IQMT), Karlsruhe Institute of Technology (KIT), 76344, Eggenstein-Leopoldshafen, Germany
| | - Chengyu Jin
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Kaiserstraße 12, 76131, Karlsruhe, Germany
| | - Mario Ruben
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Kaiserstraße 12, 76131, Karlsruhe, Germany
- Institute of Quantum Materials and Technologies (IQMT), Karlsruhe Institute of Technology (KIT), 76344, Eggenstein-Leopoldshafen, Germany
- Centre Européen de Science Quantique (CESQ), Institut de Science et d'Ingénierie Supramoléculaires (ISIS, UMR 7006), CNRS-Université de Strasbourg, 8 allée Gaspard Monge BP, 70028 67083, Strasbourg Cedex, France
| | - Karin Fink
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Kaiserstraße 12, 76131, Karlsruhe, Germany
| | - Eufemio Moreno-Pineda
- Universidad de Panamá, Facultad de Ciencias Naturales, Exactas y Tecnología, Depto. de Química-Física, Panamá, 0824, Panamá
- Universidad de Panamá, Facultad de Ciencias Naturales, Exactas y Tecnología, Grupo de Investigación de Materiales, Panamá, 0824, Panamá
| | - Peter W Roesky
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstraße 15, 76131, Karlsruhe
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3
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Das A, Elvers BJ, Chrysochos N, Uddin SI, Gangber T, Krummenacher I, Borah D, Mishra A, Shanmugam M, Yildiz CB, Braunschweig H, Schulzke C, Jana A. Dianionic and Neutral Diboron-Centered Classical Diradicaloids. J Am Chem Soc 2024; 146:9004-9011. [PMID: 38502925 DOI: 10.1021/jacs.3c13310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/21/2024]
Abstract
Herein, we report the syntheses and electronic structures of crystalline dianionic as well as neutral diboron-centered classical diradicaloids as boron analogues of classical Thiele, Chichibabin, and Müller (this only for dianionic diradicaloids!) hydrocarbons. These are based on borane radical anion and NHC-stabilized boryl radical spin carriers, respectively. All these dianionic diboron-centered diradicaloids exhibit triplet population at room temperature regardless of the π-conjugated spacer: p-phenylene, p,p'-biphenylene, or p,p″-terphenylene. In the case of neutral diboron-centered diradicaloids, the employed π-conjugated spacer plays a crucial role for the triplet population at room temperature: EPR inactive for p-phenylene vs EPR active for p,p'-biphenylene. The findings emphasize the importance of the spin carriers for the resulting ground-state: borane radical anion vs NHC-stabilized boryl radical along with the pivotal role of the π-conjugated spacer as spin-coupler between two spins. Notably, 100 years (a century) after the first report by Krause of the triphenyl borane radical-anion, being isoelectronic to the triphenylmethyl radical, we convey borane radical anion-based diradicaloids. Furthermore, while donor-stabilized boryl radicals were introduced in the 1980s by Giles and Roberts, said concept is herewith being extended to NHC-stabilized boryl radical-based diradicaloids.
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Affiliation(s)
- Ayan Das
- Tata Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad 500046, India
| | - Benedict J Elvers
- Institut für Biochemie, Universität Greifswald, Greifswald D-17489, Germany
| | - Nicolas Chrysochos
- Tata Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad 500046, India
| | - Sk Imraj Uddin
- Tata Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad 500046, India
| | - Tejaswinee Gangber
- Tata Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad 500046, India
| | - Ivo Krummenacher
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron (ICB), Julius-Maximilians-Universität Würzburg, Am Hubland, Würzburg 97074, Germany
| | - Dipanti Borah
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400 076, India
| | - Anshika Mishra
- Tata Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad 500046, India
| | - Maheswaran Shanmugam
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400 076, India
| | - Cem B Yildiz
- Department of Aromatic and Medicinal Plants, Aksaray University, Aksaray 68100, Turkey
| | - Holger Braunschweig
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron (ICB), Julius-Maximilians-Universität Würzburg, Am Hubland, Würzburg 97074, Germany
| | - Carola Schulzke
- Institut für Biochemie, Universität Greifswald, Greifswald D-17489, Germany
| | - Anukul Jana
- Tata Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad 500046, India
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4
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Yeganeh-Salman A, Yeung J, Miao L, Stephan DW. Coordination chemistry and FLP reactivity of 1,1- and 1,2-bis-boranes. Dalton Trans 2024; 53:1178-1189. [PMID: 38108120 DOI: 10.1039/d3dt03660j] [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
Coordination chemistry and frustrated Lewis pair (FLP) chemistry have been most commonly studied using monodentate Lewis acids. In this paper, we examine the corresponding reactions employing the 1,1- and 1,2-bis-boranes, PhCH2CH(B(C6F5)2)21 and Me3SiCH(B(C6F5)2)CH2B(C6F5)22, respectively. Coordination of isocyanide to these species results in the formation of the products RCH(B(C6F5)2CNtBu)CH2(B(C6F5)2CNtBu) (R = Ph 3, Me3Si 4). The rearrangement of 1 to give the 1,2-bis-borane adduct 3 was probed and attributed to a donor-induced retrohydroboration and subsequent hydroboration. The analogous reaction of 1 is evident in efforts to use the Gutman-Beckett method to assess its Lewis acidity. However, in combination with tBu3P, bis-boranes 1 and 2 form FLPs and react with H2 to give [tBu3PH][PhCH2CH(B(C6F5)2)2(μ-H)] 5a and [tBu3PH][Me3SiCH(B(C6F5)2)CH2(B(C6F5)2)(μ-H)] 6, respectively. Reactions of 1 and 2 with various donors and PhCCH were shown to give deprotonation and addition products, depending on the nature of the base. However, in the case of 1, products resulting from retrohydroboration, and subsequent hydroboration are evident. Several of these alkyne products are crystallographically characterized.
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Affiliation(s)
- Amir Yeganeh-Salman
- Department of Chemistry, University of Toronto, 80 St. George St, Toronto, ON, M5S3H6, Canada.
| | - Jason Yeung
- Department of Chemistry, University of Toronto, 80 St. George St, Toronto, ON, M5S3H6, Canada.
| | - Linkun Miao
- Department of Chemistry, University of Toronto, 80 St. George St, Toronto, ON, M5S3H6, Canada.
| | - Douglas W Stephan
- Department of Chemistry, University of Toronto, 80 St. George St, Toronto, ON, M5S3H6, Canada.
- Institute of Drug Discovery Technology, Ningbo University, Zhejiang, P. R. China
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5
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Lamprecht A, Arrowsmith M, Dietz M, Fuchs S, Rempel A, Härterich M, Braunschweig H. Synthesis, reduction and C-H activation chemistry of azaborinines with redox-active organoboryl substituents. Dalton Trans 2024; 53:1004-1013. [PMID: 38088750 DOI: 10.1039/d3dt03826b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2024]
Abstract
The 2,3,4,5,6-pentaphenyl-1,2-azaborinin-1-yl (PPAB) potassium complex 1 undergoes facile salt metathesis with 9,10-dibromo-9,10-dihydroboraanthracene (DBABr2), 5-bromodibenzo[b,d]borole (DBBBr), 1-chlorotetraphenylborole (TPBCl) and dibromo(phenyl)borane (BBr2Ph) to yield the corresponding N-borylated azaborinines N-DBABr-PPAB (2, which hydrolyses and dimerises to the oxo-bridged N,N'-O(DBA)2-(PPAB)2, 3), N,N'-DBA-(PPAB)2 (4), N-DBB-PPAB (5), N-PPB-PPAB (7) and N-BBrPh-PPBA (9). Stepwise reduction of 4 yields the corresponding stable radical anion 4˙- and dianion 42-. One-electron reduction of 5 with KC8 yields the purple radical anion 5˙-, which forms a highly insoluble coordination polymer. 5˙- undergoes very slow radical intramolecular ortho-C-H activation at the C4-phenyl substituent of the PPAB moiety, yielding a BN-analogue of the 5,5'-spiro-bi[dibenzoborole] anion, [6]K. Compound 7 cannot be isolated and undergoes spontaneous and diastereoselective 2,5-anti-addition of the ortho-C-H bond of the PPAB C4-phenyl substituent to yield a novel BNB-analogue of the triply fused dihydrocyclopenta[l]phenanthrene cation, compound 8. Finally the one-electron reduction of 9 results in the ortho-C-H activation of the PPAB C4-phenyl substituent at an in situ-generated dicoordinate boryl anion (10), resulting in the formation of a BNB-analogue of 9H-fluorene, the borate 11-. DFT calculations provide a rationale for the diverse C-H activations observed in these reactions.
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Affiliation(s)
- Anna Lamprecht
- 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
| | - Merle Arrowsmith
- 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
| | - Sonja Fuchs
- 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
| | - Anna Rempel
- 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
| | - 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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6
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Dietz M, Arrowsmith M, Braunschweig H. CAAC-stabilised 9,10-diboraanthracene: an electronically and structurally flexible platform for small-molecule activation and metal complexation. Dalton Trans 2024; 53:449-453. [PMID: 38062986 DOI: 10.1039/d3dt03787h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2024]
Abstract
A biradical cyclic alkyl(amino)carbene-stabilised 9,10-diboraanthracene (DBA) activates small molecules such as hydrogen, phenyl azide or TEMPO (2,2,6,6-tetramethylpiperidin-1-oxyl) across its two boron atoms, while reactions with [(MeCN)3M(CO)3] (M = Cr, Mo, W) yield the first half-sandwich DBA complexes of the form [(η6-DBA)M(CO)3].
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Affiliation(s)
- 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
| | - Merle Arrowsmith
- 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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7
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Metzler M, Virovets A, Lerner HW, Wagner M. B 2,N 4-Doped Heptacenes: Ambipolar Charge-Transfer Compounds with Deep LUMO Levels. J Am Chem Soc 2023; 145:23824-23831. [PMID: 37862629 DOI: 10.1021/jacs.3c09029] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2023]
Abstract
The B2,N4-doped heptacene H4 in which two N,N'-dihydrophenazine units are linked by two BMes bridges (Mes = mesityl) was synthesized via fourfold Buchwald-Hartwig coupling between 2,3,6,7-tetrachloro-9,10-dimesityl-9,10-dihydro-9,10-diboraanthracene and o-phenylenediamine (tBuXPhos-Pd-G3, DBU/NaOTf, 2-MeTHF, 50 °C, 16 h). Upon exposure to ambient air, H4 is oxidized to its N,N'-dihydro form H2; further oxidation with MnO2 furnishes the di(phenazine) derivative H0. Stirring under a blanket of H2 in the presence of Pd/C hydrogenates H0 back to H2 and ultimately H4. Yellow-colored H0 is a remarkably good electron acceptor with a LUMO-energy level of -3.9 eV; upon irradiation with a 405 nm LED in the presence of THF or 1,4-cyclohexadiene, H0 accepts two H atoms to furnish H2. One-electron reduction of H0 yields the isolable radical-anion salt Li[H0] (lithium naphthalenide, THF, -30 °C to rt). The ambipolar compounds H2 and H4 possess a navy blue and deep purple color, respectively, due to charge-transfer interactions from the electron-rich N,N'-dihydrophenazine donor(s) to the electron-accepting B2C4 core.
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Affiliation(s)
- Maurice Metzler
- Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt, Max-von-Laue-Straße 7, D-60438 Frankfurt (Main), Germany
| | - Alexander Virovets
- Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt, Max-von-Laue-Straße 7, D-60438 Frankfurt (Main), Germany
| | - Hans-Wolfram Lerner
- Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt, Max-von-Laue-Straße 7, D-60438 Frankfurt (Main), Germany
| | - Matthias Wagner
- Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt, Max-von-Laue-Straße 7, D-60438 Frankfurt (Main), Germany
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8
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Metzler M, Bolte M, Virovets A, Lerner HW, Wagner M. Vicinal Vinylation of Boron-Doped Acenes via Heck Coupling. Org Lett 2023; 25:5827-5832. [PMID: 37523592 DOI: 10.1021/acs.orglett.3c02086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/02/2023]
Abstract
Silylated and halogenated benzenes 1,2-(Me3Si)2-4,5-X2-C6H2 [X = Br (3), I (4)] are versatile synthetic building blocks. 3 was prepared from known 1,2-(Me3Si)2-4,5-Cl2-C6H2 via C-Cl borylation/bromodeboronation; CuI-catalyzed Br/I exchange on 3 affords 4. 3 or 4 and BBr3 yield 9,10-dibromo-9,10-dihydro-9,10-diboraanthracenes (DBAs) 7 or 8. The B centers were protected with mesityl (Mes; 9, 10) or 2,4,6-tris(trifluoromethyl)phenyl (FMes; 11, 12) groups. Heck coupling of 9 and styrene/2,3,4,5,6-pentafluorostyrene furnishes the two tetravinyl-substituted green/blue emitters 13/14.
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Affiliation(s)
- Maurice Metzler
- Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt, Max-von-Laue-Straße 7, D-60438 Frankfurt (Main), Germany
| | - Michael Bolte
- Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt, Max-von-Laue-Straße 7, D-60438 Frankfurt (Main), Germany
| | - Alexander Virovets
- Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt, Max-von-Laue-Straße 7, D-60438 Frankfurt (Main), Germany
| | - Hans-Wolfram Lerner
- Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt, Max-von-Laue-Straße 7, D-60438 Frankfurt (Main), Germany
| | - Matthias Wagner
- Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt, Max-von-Laue-Straße 7, D-60438 Frankfurt (Main), Germany
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9
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Prey SE, Gilmer J, Teichmann SV, Čaić L, Wenisch M, Bolte M, Virovets A, Lerner HW, Fantuzzi F, Wagner M. Synthesis, bridgehead functionalization, and photoisomerization of 9,10-diboratatriptycene dianions. Chem Sci 2023; 14:5316-5322. [PMID: 37234897 PMCID: PMC10207881 DOI: 10.1039/d3sc00555k] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 03/02/2023] [Indexed: 04/02/2024] Open
Abstract
9,10-Diboratatriptycene salts M2[RB(μ-C6H4)3BR] (R = H, Me; M+ = Li+, K+, [n-Bu4N]+) have been synthesized via [4 + 2] cycloaddition between doubly reduced 9,10-dihydro-9,10-diboraanthracenes M2[DBA] and benzyne, generated in situ from C6H5F and C6H5Li or LiN(i-Pr)2. [HB(μ-C6H4)3BH]2- reacts with CH2Cl2 to form quantitatively the bridgehead-derivatized [ClB(μ-C6H4)3BCl]2-, while twofold H- abstraction with B(C6F5)3 in the presence of SMe2 leads cleanly to the diadduct (Me2S)B(μ-C6H4)3B(SMe2). Photoisomerization of K2[HB(μ-C6H4)3BH] (THF, medium-pressure Hg lamp) provides facile access to diborabenzo[a]fluoranthenes, a little explored form of boron-doped polycyclic aromatic hydrocarbons. According to DFT calculations, the underlying reaction mechanism consists of three main steps: (i) photoinduced di-π-borate rearrangement, (ii) "walk reaction" of a BH unit, and (iii) boryl anion-like C-H activation.
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Affiliation(s)
- Sven E Prey
- Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt Max-von-Laue-Straße 7 D-60438 Frankfurt am Main Germany
| | - Jannik Gilmer
- Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt Max-von-Laue-Straße 7 D-60438 Frankfurt am Main Germany
| | - Samira V Teichmann
- Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt Max-von-Laue-Straße 7 D-60438 Frankfurt am Main Germany
| | - Luis Čaić
- Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt Max-von-Laue-Straße 7 D-60438 Frankfurt am Main Germany
| | - Mischa Wenisch
- Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt Max-von-Laue-Straße 7 D-60438 Frankfurt am Main Germany
| | - Michael Bolte
- Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt Max-von-Laue-Straße 7 D-60438 Frankfurt am Main Germany
| | - Alexander Virovets
- Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt Max-von-Laue-Straße 7 D-60438 Frankfurt am Main Germany
| | - Hans-Wolfram Lerner
- Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt Max-von-Laue-Straße 7 D-60438 Frankfurt am Main Germany
| | - Felipe Fantuzzi
- School of Chemistry and Forensic Science, University of Kent Park Wood Rd Canterbury CT2 7NH UK
| | - Matthias Wagner
- Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt Max-von-Laue-Straße 7 D-60438 Frankfurt am Main Germany
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10
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Barker JE, Obi AD, Dickie DA, Gilliard RJ. Boron-Doped Pentacenes: Isolation of Crystalline 5,12- and 5,7-Diboratapentacene Dianions. J Am Chem Soc 2023; 145:2028-2034. [PMID: 36689632 DOI: 10.1021/jacs.2c11494] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The syntheses, molecular structures, reactivities, and computational assessment of dipotassium diboratapentacene isomers are described (1 and 2). These compounds represent the first examples of aromatized diboraacenes where the boron atoms are spatially separated in different rings of the acene framework. Both 1 and 2 react with carbon dioxide (CO2) via diastereoselective carboxylation of the pentacene backbone that likely proceeds by a frustrated Lewis pair-like mechanism. The placement of the boron atoms and the reactivity studies provide a platform for later stage functionalization of diboraacenes beyond the central ring of the polycyclic aromatic hydrocarbon core.
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Affiliation(s)
- Joshua E Barker
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Akachukwu D Obi
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Diane A Dickie
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Robert J Gilliard
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
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11
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Prey SE, Herok C, Fantuzzi F, Bolte M, Lerner HW, Engels B, Wagner M. Multifaceted behavior of a doubly reduced arylborane in B-H-bond activation and hydroboration catalysis. Chem Sci 2023; 14:849-860. [PMID: 36755708 PMCID: PMC9890859 DOI: 10.1039/d2sc05518j] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 12/02/2022] [Indexed: 12/12/2022] Open
Abstract
Alkali-metal salts of 9,10-dimethyl-9,10-dihydro-9,10-diboraanthrancene (M2[DBA-Me2]; M+ = Li+, Na+, K+) activate the H-B bond of pinacolborane (HBpin) in THF already at room temperature. For M+ = Na+, K+, the addition products M2[4] are formed, which contain one new H-B and one new B-Bpin bond; for M+ = Li+, the H- ion is instantaneously transferred from the DBA-Me2 unit to another equivalent of HBpin to afford Li[5]. Although Li[5] might commonly be considered a [Bpin]- adduct of neutral DBA-Me2, it donates a [Bpin]+ cation to Li[SiPh3], generating the silyl borane Ph3Si-Bpin; Li2[DBA-Me2] with an aromatic central B2C4 ring acts as the leaving group. Furthermore, Li2[DBA-Me2] catalyzes the hydroboration of various unsaturated substrates with HBpin in THF. Quantum-chemical calculations complemented by in situ NMR spectroscopy revealed two different mechanistic scenarios that are governed by the steric demand of the substrate used: in the case of the bulky Ph(H)C[double bond, length as m-dash]NtBu, the reaction requires elevated temperatures of 100 °C, starts with H-Bpin activation which subsequently generates Li[BH4], so that the mechanism eventually turns into "hidden borohydride catalysis". Ph(H)C[double bond, length as m-dash]NPh, Ph2C[double bond, length as m-dash]O, Ph2C[double bond, length as m-dash]CH2, and iPrN[double bond, length as m-dash]C[double bond, length as m-dash]NiPr undergo hydroboration already at room temperature. Here, the active hydroboration catalyst is the [4 + 2] cycloadduct between the respective substrate and Li2[DBA-Me2]: in the key step, attack of HBpin on the bridging unit opens the bicyclo[2.2.2]octadiene scaffold and gives the activated HBpin adduct of the Lewis-basic moiety that was previously coordinated to the DBA-B atom.
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Affiliation(s)
- Sven E. Prey
- Institut für Anorganische und Analytische Chemie, Goethe-Universität FrankfurtFrankfurt am Main D-60438Germany
| | - Christoph Herok
- Institut für Physikalische und Theoretische Chemie, Julius-Maximilians-Universität Würzburg Würzburg D-97074 Germany
| | - Felipe Fantuzzi
- Institut für Physikalische und Theoretische Chemie, Julius-Maximilians-Universität Würzburg Würzburg D-97074 Germany .,School of Chemistry and Forensic Science, University of Kent Canterbury CT2 7NH UK
| | - Michael Bolte
- Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt Frankfurt am Main D-60438 Germany
| | - Hans-Wolfram Lerner
- Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt Frankfurt am Main D-60438 Germany
| | - Bernd Engels
- Institut für Physikalische und Theoretische Chemie, Julius-Maximilians-Universität Würzburg Würzburg D-97074 Germany
| | - Matthias Wagner
- Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt Frankfurt am Main D-60438 Germany
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12
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Gilmer J, Bolte M, Virovets A, Lerner HW, Fantuzzi F, Wagner M. A Hydride-Substituted Homoleptic Silylborate: How Similar is it to its Diborane(6)-Dianion Isostere? Chemistry 2023; 29:e202203119. [PMID: 36210643 PMCID: PMC10100083 DOI: 10.1002/chem.202203119] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Indexed: 11/05/2022]
Abstract
The B-nucleophilic 9H-9-borafluorene dianion reacts with 9-chloro-9-silafluorene to afford air- and moisture-stable silylborate salts M[Ar2 (H)B-Si(H)Ar2 ] (M[HBSiH], M=Li, Na). Li[HBSiH] and Me3 SiCl give the B-pyridine adduct Ar2 (py)B-Si(H)Ar2 ((py)BSiH) or the chlorosilane Li[Ar2 (H)B-Si(Cl)Ar2 ] (Li[HBSiCl]) in C6 H6 -pyridine or THF. In both cases, the first step is H- abstraction at the B center. The resulting free borane subsequently binds a py or thf ligand. While the py adduct is stable at room temperature, the thf adduct undergoes a 1,2-H shift via the cyclic B(μ-H)Si intermediate BHSi, which is afterwards attacked at the Si atom by a Cl- ion to give Li[HBSiCl]. DFT calculations were employed to support the proposed reaction mechanism and to characterize the electronic structure of BHSi. Treatment of Li[HBSiCl] with the N-heterocyclic carbene IMe introduces the neutral donor at the Si atom and leads to Ar2 (H)B-Si(IMe)Ar2 (HBSi(IMe)), a donor-acceptor-stabilized silylene.
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Affiliation(s)
- Jannik Gilmer
- Institut für Anorganische und Analytische Chemie, J. W. Goethe-Universität Frankfurt, Max-von-Laue-Str. 7, 60438, Frankfurt (Main), Germany
| | - Michael Bolte
- Institut für Anorganische und Analytische Chemie, J. W. Goethe-Universität Frankfurt, Max-von-Laue-Str. 7, 60438, Frankfurt (Main), Germany
| | - Alexander Virovets
- Institut für Anorganische und Analytische Chemie, J. W. Goethe-Universität Frankfurt, Max-von-Laue-Str. 7, 60438, Frankfurt (Main), Germany
| | - Hans-Wolfram Lerner
- Institut für Anorganische und Analytische Chemie, J. W. Goethe-Universität Frankfurt, Max-von-Laue-Str. 7, 60438, Frankfurt (Main), Germany
| | - Felipe Fantuzzi
- School of Chemistry and Forensic Science, University of Kent, Park Wood Rd, Canterbury, CT2 7NH, UK
| | - Matthias Wagner
- Institut für Anorganische und Analytische Chemie, J. W. Goethe-Universität Frankfurt, Max-von-Laue-Str. 7, 60438, Frankfurt (Main), Germany
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13
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Millet CRP, Pahl J, Noone E, Yuan K, Nichol GS, Uzelac M, Ingleson MJ. Synthesis of Electrophiles Derived from Dimeric Aminoboranes and Assessing Their Utility in the Borylation of π Nucleophiles. Organometallics 2022; 41:2638-2647. [PMID: 36185396 PMCID: PMC9516688 DOI: 10.1021/acs.organomet.2c00393] [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: 08/02/2022] [Indexed: 11/30/2022]
Abstract
![]()
Dimeric aminoboranes,
[H2BNR2]2 (R = Me or CH2CH2) containing B2N2 cores, can
be activated by I2, HNTf2 (NTf2 =
[N(SO2CF3)2]), or [Ph3C][B(C6F5)4] to form isolable H2B(μ-NR2)2BHX (for X = I or NTf2). For X = [B(C6F5)4]− further reactivity, presumably
between [H2B(μ-NMe2)2BH][B(C6F5)4] and aminoborane, forms a B3N3-based monocation containing a three-center two
electron B-(μ-H)-B moiety. The structures of H2B(μ-NMe2)2BH(I) and [(μ-NMe2)BH(NTf2)]2 indicated a sterically crowded environment
around boron, and this leads to the less common O-bound mode of NTf2 binding. While the iodide congener reacted very slowly with
alkynes, the NTf2 analogues were more reactive, with hydroboration
of internal alkynes forming (vinyl)2BNR2 species
and R2NBH(NTf2) as the major products. Further
studies indicated that the B2N2 core is maintained
during the first hydroboration, and that it is during subsequent steps
that B2N2 dissociation occurs. In the mono-boron
systems, for example, iPr2NBH(NTf2), NTf2 is N-bound; thus, they have less steric
crowding around boron relative to the B2N2 systems.
Notably, the monoboron systems are much less reactive in alkyne hydroboration
than the B2N2-based bis-boranes, despite the
former being three coordinate at boron while the latter are four coordinate
at boron. Finally, these B2N2 electrophiles
are much more prone to dissociate into mono-borane species than pyrazabole
[H2B(μ-N2C3H3)]2 analogues, making them less useful for the directed diborylation
of a single substrate.
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Affiliation(s)
| | - Jürgen Pahl
- School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, U.K
| | - Emily Noone
- School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, U.K
| | - Kang Yuan
- School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, U.K
| | - Gary S. Nichol
- School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, U.K
| | - Marina Uzelac
- School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, U.K
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14
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Morris LJ, Rajeshkumar T, Okumura A, Maron L, Okuda J. Solvent-Dependent Oxidative Addition and Reductive Elimination of H 2 Across a Gallium-Zinc Bond. Angew Chem Int Ed Engl 2022; 61:e202208855. [PMID: 35833688 PMCID: PMC9544028 DOI: 10.1002/anie.202208855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Indexed: 11/09/2022]
Abstract
H2 adds reversibly across the metal-metal bond of [(BDI)Ga(H)-Zn(tmeda)(thf)][BAr4 F ] (BDI=[HC{C(CH3 )N(2,6-iPr2 -C6 H3 )}2 ]- , TMEDA=N,N,N',N'-tetramethylethylenediamine, BAr4 F- =[B(C6 H3 -3,5-(CF3 )2 )4 ]- ). Due to the stabilising effect of solvent coordination, hydrogenation products [(BDI)GaH2 ] and [(tmeda)ZnH(thf)][BAr4 F ] are favoured in THF solution, but THF-free mixtures of [(BDI)GaH2 ] and [(tmeda)ZnH(OEt2 )][BAr4 F ] are predisposed towards entropically driven dehydrogenation to [(BDI)Ga(H)-Zn(tmeda)][BAr4 F ] in fluorobenzene solution.
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Affiliation(s)
- Louis J. Morris
- Institute for Inorganic ChemistryRWTH Aachen University52062AachenGermany
- Chemistry Research LaboratoryUniversity of OxfordOxfordOX1 3TAUK
| | - Thayalan Rajeshkumar
- CNRSINSAUPSUMR 5215LPCNOUniversité de Toulouse135 Avenue de Rangueil31077ToulouseFrance
| | - Akira Okumura
- Institute for Inorganic ChemistryRWTH Aachen University52062AachenGermany
| | - Laurent Maron
- CNRSINSAUPSUMR 5215LPCNOUniversité de Toulouse135 Avenue de Rangueil31077ToulouseFrance
| | - Jun Okuda
- Institute for Inorganic ChemistryRWTH Aachen University52062AachenGermany
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15
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Zhang C, Liu X, Wang J, Ye Q. A Three-Dimensional Inorganic Analogue of 9,10-Diazido-9,10-Diboraanthracene: A Lewis Superacidic Azido Borane with Reactivity and Stability. Angew Chem Int Ed Engl 2022; 61:e202205506. [PMID: 35713166 PMCID: PMC9541227 DOI: 10.1002/anie.202205506] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Indexed: 12/16/2022]
Abstract
Herein, we report the facile synthesis of a three-dimensional (3D) inorganic analogue of 9,10-diazido-9,10-dihydrodiboraantracene, which turned out to be a monomer in both the solid and solution state, and thermally stable up to 230 °C, representing a rare example of azido borane with boosted Lewis acidity and stability in one. Apart from the classical acid-base and Staudinger reactions, E-H bond activation (E=B, Si, Ge) was investigated. While the reaction with B-H (9-borabicyclo[3.3.1]nonane) led directly to the 1,1-addition on Nα upon N2 elimination, the Si-H (Et3 SiH, PhMe2 SiH) activation proceeded stepwise via 1,2-addition, with the key intermediates 5int and 6int being isolated and characterized. In contrast, the cooperative Ge-H was reversible and stayed at the 1,2-addition step.
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Affiliation(s)
- Chonghe Zhang
- Department of ChemistrySouthern University of Science and Technology518055ShenzhenP. R. China
| | - Xiaocui Liu
- Department of ChemistrySouthern University of Science and Technology518055ShenzhenP. R. China
| | - Junyi Wang
- Department of ChemistrySouthern University of Science and Technology518055ShenzhenP. R. China
- Department of ChemistryThe Hong Kong University of Science and TechnologyClear Water Bay, KowloonHong KongHong Kong
| | - Qing Ye
- Department of ChemistrySouthern University of Science and Technology518055ShenzhenP. R. China
- Institute for Inorganic ChemistryJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
- Institute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
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16
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Pahl J, Noone E, Uzelac M, Yuan K, Ingleson MJ. Borylation Directed Borylation of Indoles Using Pyrazabole Electrophiles: A One-Pot Route to C7-Borylated-Indolines. Angew Chem Int Ed Engl 2022; 61:e202206230. [PMID: 35686751 PMCID: PMC9401042 DOI: 10.1002/anie.202206230] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Indexed: 12/23/2022]
Abstract
Pyrazabole (1) is a readily accessible diboron compound that can be transformed into ditopic electrophiles. In 1 (and derivatives), the B⋅⋅⋅B separation is ca. 3 Å, appropriate for one boron centre bonding to N and one to the C7 of indoles and indolines. This suitable B⋅⋅⋅B separation enables double E-H (E=N/C) functionalisation of indoles and indolines. Specifically, the activation of 1 with HNTf2 generates an electrophile that transforms N-H indoles and indolines into N/C7-diborylated indolines, with N-H borylation directing subsequent C7-H borylation. Indole reduction to indoline occurs before C-H borylation and our studies indicate this proceeds via hydroboration-C3-protodeboronation to produce an intermediate that then undergoes C7 borylation. The borylated products can be converted in situ into C7-BPin-N-H-indolines. Overall, this represents a transient directed C-H borylation to form useful C7-BPin-indolines.
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Affiliation(s)
- Jürgen Pahl
- School of Chemistry, University of Edinburgh, Edinburgh, EH9 3FJ, UK
| | - Emily Noone
- School of Chemistry, University of Edinburgh, Edinburgh, EH9 3FJ, UK
| | - Marina Uzelac
- School of Chemistry, University of Edinburgh, Edinburgh, EH9 3FJ, UK
| | - Kang Yuan
- School of Chemistry, University of Edinburgh, Edinburgh, EH9 3FJ, UK
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17
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Sun Q, Daniliuc CG, Mück‐Lichtenfeld C, Kehr G, Erker G. Formation of a Hybrid 1‐Bora‐3‐boratabenzene Heteroarene Anion Derivative. Angew Chem Int Ed Engl 2022; 61:e202205565. [DOI: 10.1002/anie.202205565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Indexed: 11/12/2022]
Affiliation(s)
- Qiu Sun
- Organisch-Chemisches Institut Westfälische Wilhelms-Universität Münster Corrensstraße 40 48149 Münster Germany
| | - Constantin G. Daniliuc
- Organisch-Chemisches Institut Westfälische Wilhelms-Universität Münster Corrensstraße 40 48149 Münster Germany
| | - Christian Mück‐Lichtenfeld
- Organisch-Chemisches Institut Westfälische Wilhelms-Universität Münster Corrensstraße 40 48149 Münster Germany
| | - Gerald Kehr
- Organisch-Chemisches Institut Westfälische Wilhelms-Universität Münster Corrensstraße 40 48149 Münster Germany
| | - Gerhard Erker
- Organisch-Chemisches Institut Westfälische Wilhelms-Universität Münster Corrensstraße 40 48149 Münster Germany
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18
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Solvent‐Dependent Oxidative Addition and Reductive Elimination of H2 Across a Gallium─Zinc Bond. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202208855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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19
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Zhang C, Liu X, Wang J, Ye Q. A Three‐Dimensional Inorganic Analogue of 9,10‐Diazido‐9,10‐Diboraanthracene – A Lewis Superacidic Azido Borane with Reactivity and Stability. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202205506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Chonghe Zhang
- Southern University of Science and Technology Department of Chemistry CHINA
| | - Xiaocui Liu
- Southern University of Science and Technology Department of Chemistry CHINA
| | - Junyi Wang
- Southern University of Science and Technology Department of Chemistry CHINA
| | - Qing Ye
- Julius-Maximilians-Universität Würzburg: Julius-Maximilians-Universitat Wurzburg Institut für Anorganische Chemie Am Hubland 97074 Würzburg GERMANY
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20
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Pahl J, Noone E, Uzelac M, Yuan K, Ingleson M. Borylation Directed Borylation of Indoles Using Pyrazabole Electrophiles: A One‐Pot Route to C7‐Borylated‐Indolines. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202206230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- J. Pahl
- University of Edinburgh Chemistry UNITED KINGDOM
| | - E. Noone
- University of Edinburgh Chemistry UNITED KINGDOM
| | - M. Uzelac
- University of Edinburgh Chemistry UNITED KINGDOM
| | - K. Yuan
- University of Edinburgh Chemistry UNITED KINGDOM
| | - Michael Ingleson
- University of Edinburgh Chemistry South Bridge EH8 9YL Edinburgh UNITED KINGDOM
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21
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Sun Q, Daniliuc CG, Mück-Lichtenfeld C, Kehr G, Erker G. Formation of a Hybrid 1‐Bora‐3‐boratabenzene Heteroarene Anion Derivative. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202205565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Qiu Sun
- Westfälische Wilhelms-Universität Münster: Westfalische Wilhelms-Universitat Munster Organisch-Chemisches Institut GERMANY
| | - Constantin G. Daniliuc
- Westfälische Wilhelms-Universität Münster: Westfalische Wilhelms-Universitat Munster Organisch-Chemsiches Institut GERMANY
| | | | - Gerald Kehr
- Westfälische Wilhelms-Universität Münster: Westfalische Wilhelms-Universitat Munster Organisch-Chemisches Institut GERMANY
| | - Gerhard Erker
- Universität Münster Organisch-Chemisches Institut Corrensstr. 40 48149 Münster GERMANY
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22
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Ding Z, Liu Z, Wang Z, Yu T, Xu M, Wen J, Yang K, Zhang H, Xu L, Li P. Catalysis with Diboron(4)/Pyridine: Application to the Broad-Scope [3 + 2] Cycloaddition of Cyclopropanes and Alkenes. J Am Chem Soc 2022; 144:8870-8882. [PMID: 35532758 DOI: 10.1021/jacs.2c03673] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
In contrast to the extensive but non-recyclable use of tetraalkoxydiboron(4) compounds as stoichiometric reagents in diverse reactions, this article reports an atom-economical reaction using a commercial diboron(4) as the catalyst. The key to success was designing a catalytic cycle for radical [3 + 2] cycloaddition involving a pyridine cocatalyst to generate from the diboron(4) catalyst and reversibly mediate the transfer of boronyl radicals. In comparison with known [3 + 2] cycloaddition with transition metal-based catalysts, the current reaction features not only metal-free conditions, inexpensive and stable catalysts, and simple operation but also remarkably broadened substrate scope. In particular, previously unusable cyclopropyl ketones without an activating group and/or alkenes with 1,2-disubstitution and 1,1,2-trisubstitution patterns were successfully used for the first time. Consequently, challenging cyclopentane compounds with various levels of substitution (65 examples, 57 new products, up to six substituents at all five ring atoms) were readily prepared in generally high to excellent yield and diastereoselectivity. The reaction was also successfully applied in concise formal synthesis of an anti-obesity drug and building natural product-like complex bridged or spirocyclic compounds. Mechanistic experiments and computational investigation support the proposed radical relay catalysis featuring a pyridine-assisted boronyl radical catalyst. Overall, this work demonstrates the first approach to use tetraalkoxydiboron(4) compounds as catalysts and may lead to the development of new, green, and efficient transition metal-like boron-catalyzed organic reactions.
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Affiliation(s)
- Zhengwei Ding
- Department of Medicinal Chemistry, School of Pharmacy, Xi'an Jiaotong University, Xi'an 710061, China
| | - Zhi Liu
- Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an 710054, China
| | - Zhijun Wang
- School of Chemistry and Chemical Engineering/Key Laboratory for Green Processing of Chemical Engineering of Xinjiang Bingtuan, Shihezi University, Shihezi 832003, China
| | - Tao Yu
- Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an 710054, China
| | - Ming Xu
- Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an 710054, China
| | - Jingru Wen
- Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an 710054, China
| | - Kaiyan Yang
- Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an 710054, China
| | - Hailong Zhang
- Department of Medicinal Chemistry, School of Pharmacy, Xi'an Jiaotong University, Xi'an 710061, China
| | - Liang Xu
- School of Chemistry and Chemical Engineering/Key Laboratory for Green Processing of Chemical Engineering of Xinjiang Bingtuan, Shihezi University, Shihezi 832003, China
| | - Pengfei Li
- Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an 710054, China.,State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, China
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23
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Tao J, Bolte M, Lerner HW, Wagner M. Nucleophilic aromatic substitution approach to phosphanyl-substituted diboraanthracenes: biphilic compounds with tunable electron affinities. Org Chem Front 2022. [DOI: 10.1039/d2qo01199a] [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
9,10-Dimesityl-9,10-dihydro-9,10-diboraanthracenes (Mes2DBAs) bearing one (1), two (2), or four (3) Ph2P-substituents were prepared from Ph2PSiMe3 and tetrafluorinated Mes2DBAs via a nucleophilic aromatic substitution protocol. Using compound 1 as the model...
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24
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Budy H, Prey SE, Buch CD, Bolte M, Lerner HW, Wagner M. Nucleophilic borylation of fluorobenzenes with reduced arylboranes. Chem Commun (Camb) 2021; 58:254-257. [PMID: 34881754 DOI: 10.1039/d1cc06225e] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Two challenging but rewarding topics in chemical synthesis are C-F-bond activation and the development of B-centered nucleophiles. We have now tackled both subjects simultaneously by forming aryl-B bonds via SNAr-type reactions on fluorobenzenes under mild conditions using Na2[FluBBFlu], Li2[HBFlu], and Li2[Me2DBA] (BFlu = 9-borafluorenyl, Me2DBA = 9,10-dimethyl-9,10-dihydro-9,10-diboraanthracene).
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Affiliation(s)
- Hendrik Budy
- Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt, Max-von-Laue-Straße 7, Frankfurt (Main) D-60438, Germany.
| | - Sven E Prey
- Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt, Max-von-Laue-Straße 7, Frankfurt (Main) D-60438, Germany.
| | - Christoph D Buch
- Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt, Max-von-Laue-Straße 7, Frankfurt (Main) D-60438, Germany.
| | - Michael Bolte
- Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt, Max-von-Laue-Straße 7, Frankfurt (Main) D-60438, Germany.
| | - Hans-Wolfram Lerner
- Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt, Max-von-Laue-Straße 7, Frankfurt (Main) D-60438, Germany.
| | - Matthias Wagner
- Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt, Max-von-Laue-Straße 7, Frankfurt (Main) D-60438, Germany.
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25
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Liu J, Wu S, Wang Y, Qin Y, Wu J, Wang L, Tian G, Zhao X, Yang X. A Zeolite‐confined Pd/Acid Sites for High Efficiency of B−H Cleavage. Z Anorg Allg Chem 2021. [DOI: 10.1002/zaac.202000482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Jia‐Wen Liu
- School of Chemical Engineering and Technology & School of Materials Sun Yat-sen University Guangzhou 510275 China
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing & School of Materials Science and Engineer & International School of Material science and Engineering Wuhan University of Technology 122 Luoshi Road Wuhan 430070 China
| | - Si‐Ming Wu
- School of Chemical Engineering and Technology & School of Materials Sun Yat-sen University Guangzhou 510275 China
- School of Engineering and Applied Sciences Harvard University Cambridge MA 02138 USA
| | - Yi‐Tian Wang
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing & School of Materials Science and Engineer & International School of Material science and Engineering Wuhan University of Technology 122 Luoshi Road Wuhan 430070 China
| | - Yuan Qin
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing & School of Materials Science and Engineer & International School of Material science and Engineering Wuhan University of Technology 122 Luoshi Road Wuhan 430070 China
| | - Jing‐Xian Wu
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing & School of Materials Science and Engineer & International School of Material science and Engineering Wuhan University of Technology 122 Luoshi Road Wuhan 430070 China
| | - Li‐Ying Wang
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics National Center for Magnetic Resonance in Wuhan Wuhan Institute of Physics and Mathematics Innovation Academy for Precision Measurement Science and Technology Chinese Academy of Sciences Wuhan 430071
| | - Ge Tian
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing & School of Materials Science and Engineer & International School of Material science and Engineering Wuhan University of Technology 122 Luoshi Road Wuhan 430070 China
| | - Xiao‐Fang Zhao
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing & School of Materials Science and Engineer & International School of Material science and Engineering Wuhan University of Technology 122 Luoshi Road Wuhan 430070 China
| | - Xiao‐Yu Yang
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing & School of Materials Science and Engineer & International School of Material science and Engineering Wuhan University of Technology 122 Luoshi Road Wuhan 430070 China
- School of Engineering and Applied Sciences Harvard University Cambridge MA 02138 USA
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26
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Trageser T, Bebej D, Bolte M, Lerner HW, Wagner M. B-B vs. B-H Bond Activation in a (μ-Hydrido)diborane(4) Anion upon Cycloaddition with CO 2 , Isocyanates, or Carbodiimides. Angew Chem Int Ed Engl 2021; 60:13500-13506. [PMID: 33740318 PMCID: PMC8252796 DOI: 10.1002/anie.202103427] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Indexed: 11/11/2022]
Abstract
The intriguing (μ‐hydrido)diboranes(4) with their prominent pristine representative [B2H5]− have mainly been studied theoretically. We now describe the behavior of the planarized tetraaryl (μ‐hydrido)diborane(4) anion [1H]− in cycloaddition reactions with the homologous series of heterocumulenes CO2, iPrNCO, and iPrNCNiPr. We show that a C=O bond of CO2 selectively activates the B−B bond of [1H]−, while the μ‐H ligand is left untouched ([2H]−). The carbodiimide iPrNCNiPr, in contrast, neglects the B−B bond and rather adds the B‐bonded H− ion to its central C atom to generate a formamidinate bridge across the B2 pair ([3]−). As a hybrid, the isocyanate iPrNCO combines the reactivity patterns of both its congeners and gives two products: one of them ([4H]−) is related to [2H]−, the other ([5]−) is an analog of [3]−. We finally propose a mechanistic scenario that rationalizes the individual reaction outcomes and combines them to a coherent picture of B–B vs. B–H bond activation.
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Affiliation(s)
- Timo Trageser
- Institut für Anorganische Chemie, Goethe-Universität Frankfurt, Max-von-Laue-Strasse 7, 60438, Frankfurt (Main), Germany
| | - Dariusz Bebej
- 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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27
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Trageser T, Bebej D, Bolte M, Lerner H, Wagner M. B–B vs. B–H Bond Activation in a (μ‐Hydrido)diborane(4) Anion upon Cycloaddition with CO
2
, Isocyanates, or Carbodiimides. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202103427] [Citation(s) in RCA: 6] [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
| | - Dariusz Bebej
- 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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28
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Zhang C, Wang J, Su W, Lin Z, Ye Q. Synthesis, Characterization, and Density Functional Theory Studies of Three-Dimensional Inorganic Analogues of 9,10-Diboraanthracene-A New Class of Lewis Superacids. J Am Chem Soc 2021; 143:8552-8558. [PMID: 33984238 DOI: 10.1021/jacs.1c03057] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The three-dimensional inorganic analogues of 9,10-diboraanthracene, B2X2(C2B10H10)2 (X = Cl, 1; X = Br, 2), were attained by salt elimination of Li2C2B10H10 and trihaloboranes. The methyl- and phenyl-substituted compounds B2Me2(C2B10H10)2 (3) and B2Ph2(C2B10H10)2 (4) were obtained by treating 1 or 2 with the corresponding Grignard reagents. These compounds were fully characterized by NMR, cyclic voltammetry (CV), IR, and single-crystal X-ray diffraction analyses. Experimental (CV and Gutmann-Beckett method) and computational (fluoride ion affinity, hydride ion affinity and LUMO energy) results suggest that the order of Lewis acidity is 2 > 1 > 4 > 3 > SbF5. Treatment of 1 or 2 with HSiEt3 gave a rare neutral borane-silane adduct, (Et3SiH)2B2H2(C2B10H10)2 (5). The equilibrium of 5 in solution was thoroughly investigated by spectroscopy and quantum calculations.
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Affiliation(s)
- Chonghe Zhang
- Department of Chemistry, Southern University of Science and Technology, Shenzhen 518055, P. R. China
| | - Junyi Wang
- Department of Chemistry, Southern University of Science and Technology, Shenzhen 518055, P. R. China.,Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Wei Su
- Department of Chemistry, Southern University of Science and Technology, Shenzhen 518055, P. R. China
| | - Zhenyang Lin
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Qing Ye
- Department of Chemistry, Southern University of Science and Technology, Shenzhen 518055, P. R. China
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29
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Lipshultz JM, Li G, Radosevich AT. Main Group Redox Catalysis of Organopnictogens: Vertical Periodic Trends and Emerging Opportunities in Group 15. J Am Chem Soc 2021; 143:1699-1721. [PMID: 33464903 PMCID: PMC7934640 DOI: 10.1021/jacs.0c12816] [Citation(s) in RCA: 131] [Impact Index Per Article: 43.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
A growing number of organopnictogen redox catalytic methods have emerged-especially within the past 10 years-that leverage the plentiful reversible two-electron redox chemistry within Group 15. The goal of this Perspective is to provide readers the context to understand the dramatic developments in organopnictogen catalysis over the past decade with an eye toward future development. An exposition of the fundamental differences in the atomic structure and bonding of the pnictogens, and thus the molecular electronic structure of organopnictogen compounds, is presented to establish the backdrop against which organopnictogen redox reactivity-and ultimately catalysis-is framed. A deep appreciation of these underlying periodic principles informs an understanding of the differing modes of organopnictogen redox catalysis and evokes the key challenges to the field moving forward. We close by addressing forward-looking directions likely to animate this area in the years to come. What new catalytic manifolds can be developed through creative catalyst and reaction design that take advantage of the intrinsic redox reactivity of the pnictogens to drive new discoveries in catalysis?
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Affiliation(s)
- Jeffrey M Lipshultz
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Gen Li
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Alexander T Radosevich
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
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30
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Shao Y, Huang M, Gu F, Zhao C, Qu LB, Ke Z. Diazadiborinine as an ambiphilic catalyst for metal-free hydrogenation: a computational study on the structural design and reaction mechanism. Org Chem Front 2021. [DOI: 10.1039/d0qo01510e] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The reactivity and mechanism of hydrogenation by a metal-free ambiphilic catalyst.
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Affiliation(s)
- Youxiang Shao
- School of Materials Science and Engineering
- PCFM Lab
- Sun Yat-sen University
- Guangzhou 510275
- P. R. China
| | - Ming Huang
- School of Clinical Pharmacy
- Guangdong Pharmaceutical University
- Guangzhou 510006
- P. R. China
| | - Fenglong Gu
- MOE Key Laboratory of Theoretical Chemistry of the Environment
- School of Chemistry and Environment
- South China Normal University
- Guangzhou 510006
- P. R. China
| | - Cunyuan Zhao
- School of Materials Science and Engineering
- PCFM Lab
- Sun Yat-sen University
- Guangzhou 510275
- P. R. China
| | - Ling-Bo Qu
- College of Chemistry and Molecular Engineering
- Zhengzhou University
- Zhengzhou 450001
- P. R. China
| | - Zhuofeng Ke
- School of Materials Science and Engineering
- PCFM Lab
- Sun Yat-sen University
- Guangzhou 510275
- P. R. China
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31
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Prey SE, Wagner M. Threat to the Throne: Can Two Cooperating Boron Atoms Rival Transition Metals in Chemical Bond Activation and Catalysis? Adv Synth Catal 2020. [DOI: 10.1002/adsc.202001356] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Sven E. Prey
- Institut für Anorganische Chemie Goethe-Universität Frankfurt am Main Max-von-Laue-Str. 7 60438 Frankfurt (Main) Germany
| | - Matthias Wagner
- Institut für Anorganische Chemie Goethe-Universität Frankfurt am Main Max-von-Laue-Str. 7 60438 Frankfurt (Main) Germany
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32
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Taylor JW, Harman WH. H 2 evolution from H 2O via O-H oxidative addition across a 9,10-diboraanthracene. Chem Commun (Camb) 2020; 56:13804-13807. [PMID: 33078792 DOI: 10.1039/d0cc05261b] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The water reactivity of the boroauride complex ([Au(B2P2)][K(18-c-6)]; (B2P2, 9,10-bis(2-(diisopropylphosphino)-phenyl)-9,10-dihydroboranthrene) and its corresponding two-electron oxidized complex, Au(B2P2)Cl, are presented. Au(B2P2)Cl is tolerant to H2O and forms the hydroxide complex Au(B2P2)OH in the presence of H2O and triethylamine. [Au(B2P2)]Cl and [Au(B2P2)]OH are poor Lewis acids as judged by the Gutmann-Becket method, with [Au(B2P2)]OH displaying facile hydroxide exchange between B atoms of the DBA ring as evidenced by variable temperature NMR spectroscopy. The reduced boroauride complex [Au(B2P2)]- reacts with 1 equivalent of H2O to produce a hydride/hydroxide product, [Au(B2P2)(H)(OH)]-, that rapidly evolves H2 upon further H2O reaction to yield the dihydroxide compound, [Au(B2P2)(OH)2]-. [Au(B2P2)]Cl can be regenerated from [Au(B2P2)(OH)2]-via HCl·Et2O, providing a synthetic cycle for H2 evolution from H2O enabled by O-H oxidative addition at a diboraanthracene unit.
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Affiliation(s)
- Jordan W Taylor
- Department of Chemistry, University of California, Riverside, Riverside, CA 92521, USA.
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33
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Budy H, Gilmer J, Trageser T, Wagner M. Anionic Organoboranes: Delicate Flowers Worth Caring for. Eur J Inorg Chem 2020. [DOI: 10.1002/ejic.202000786] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Hendrik Budy
- Institut für Anorganische Chemie Goethe‐Universität Frankfurt Max‐von‐Laue‐Str. 7 60438 Frankfurt (Main) Germany
| | - Jannik Gilmer
- Institut für Anorganische Chemie Goethe‐Universität Frankfurt Max‐von‐Laue‐Str. 7 60438 Frankfurt (Main) Germany
| | - Timo Trageser
- Institut für Anorganische Chemie Goethe‐Universität Frankfurt Max‐von‐Laue‐Str. 7 60438 Frankfurt (Main) Germany
| | - Matthias Wagner
- Institut für Anorganische Chemie Goethe‐Universität Frankfurt Max‐von‐Laue‐Str. 7 60438 Frankfurt (Main) Germany
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34
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Prat JR, Gaggioli CA, Cammarota RC, Bill E, Gagliardi L, Lu CC. Bioinspired Nickel Complexes Supported by an Iron Metalloligand. Inorg Chem 2020; 59:14251-14262. [PMID: 32954721 DOI: 10.1021/acs.inorgchem.0c02041] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Nature utilizes multimetallic sites in metalloenzymes to enable multielectron chemical transformations at ambient conditions and low overpotentials. One such example of multimetallic cooperativity can be found in the C-cluster of Ni-carbon monoxide dehydrogenase (CODH), which interconverts CO and CO2. Toward a potential functional model of the C-cluster, a family of Ni-Fe bimetallic complexes was synthesized that contain direct metal-metal bonding interactions. The complexes were characterized by X-ray crystallography, various spectroscopies (NMR, EPR, UV-vis, Mössbauer), and theoretical calculations. The Ni-Fe bimetallic system has a reversible Fe(III)/Fe(II) redox couple at -2.10 V (vs Fc+/Fc). The Fe-based "redox switch" can turn on CO2 reactivity at the Ni(0) center by leveraging the Ni→Fe dative interaction to attenuate the Ni(0) electron density. The reduced Ni(0)Fe(II) species mediated the formal two-electron reduction of CO2 to CO, providing a Ni-CO adduct and CO32- as products. During the reaction, an intermediate was observed that is proposed to be a Ni-CO2 species.
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Affiliation(s)
| | | | | | - Eckhard Bill
- Max-Planck-Institut für Chemische Energiekonversion, Stiftstraße 34-36, 45470 Mülheim an der Ruhr, Germany
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35
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He Z, Liu L, Zhao Z, Mellerup SK, Ge Y, Wang X, Wang N, Wang S. Divergent and Multi-Stage Photoisomerization of Four-Coordinated Boron Compounds with a Naphthyl-Pyridyl/Thiazolyl Backbone. Chemistry 2020; 26:12403-12410. [PMID: 32311174 DOI: 10.1002/chem.202000775] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 04/15/2020] [Indexed: 11/10/2022]
Abstract
Examination of the photoreactivity of a new class of N,C-chelate organoboron compounds, including a series of unsymmetrically substituted boron molecules, B(naph-pyridyl)(Ar1 )(Ar2 ) and B(naph-thiazolyl)(Ar1 )(Ar2 ), led to the discovery of new and divergent photothermal isomerization phenomena. These include the clean and regioselective photoisomerization by unsymmetrical boron, forming borepin isomers, some of which further isomerize to the corresponding boratanorcaradiene diastereomer pairs as a result of the generation of two chiral centers. Significantly, the boratanorcaradienes involving a 3-thienyl substituent on boron were found to thermally convert to BN-fluoranthene annulated borapentalene via an unprecedented reversible boratacyclopropane-boratacyclopentene rearrangement. Changing the pyridyl donor to a thiazolyl donor on the boron was found to provide the B(naph-thiazolyl)(Mes)2 compounds with a distinct new photoisomerization pathway-instead of borepin, forming new blue fluorescent polycyclic azaborinine species. This work illustrates the richness and complexity of boron photochemistry.
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Affiliation(s)
- Zhechang He
- Department of Chemistry, Queen's University, 90 Bader Lane, Kingston, Ontario, K7L 3N6, Canada
| | - Lijie Liu
- Beijing Key Laboratory of Photoelectronic/Electrophotonic, Conversion Materials, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, 5 South Zhongguancun Street, Beijing, P. R. China
| | - Zhenhui Zhao
- Beijing Key Laboratory of Photoelectronic/Electrophotonic, Conversion Materials, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, 5 South Zhongguancun Street, Beijing, P. R. China
| | - Soren K Mellerup
- Department of Chemistry, Queen's University, 90 Bader Lane, Kingston, Ontario, K7L 3N6, Canada
| | - Yuxin Ge
- Department of Chemistry, Queen's University, 90 Bader Lane, Kingston, Ontario, K7L 3N6, Canada
| | - Xiang Wang
- Department of Chemistry, Queen's University, 90 Bader Lane, Kingston, Ontario, K7L 3N6, Canada
| | - Nan Wang
- Beijing Key Laboratory of Photoelectronic/Electrophotonic, Conversion Materials, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, 5 South Zhongguancun Street, Beijing, P. R. China
| | - Suning Wang
- Department of Chemistry, Queen's University, 90 Bader Lane, Kingston, Ontario, K7L 3N6, Canada
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36
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Wu M, Jing Y, Wong AA, Fell EM, Jin S, Tang Z, Gordon RG, Aziz MJ. Extremely Stable Anthraquinone Negolytes Synthesized from Common Precursors. Chem 2020. [DOI: 10.1016/j.chempr.2020.03.021] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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37
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Novoseltseva P, Li H, Wang X, Sauriol F, Wang S. Structural Dynamics and Stereoselectivity of Chiral Benzylideneamine N,C-Chelate Borane Photo-Thermal Isomerization. Chemistry 2020; 26:2276-2284. [PMID: 31899573 DOI: 10.1002/chem.201905312] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2019] [Revised: 12/17/2019] [Indexed: 11/10/2022]
Abstract
New chiral N,C-chelate organoboron compounds based on benzylideneamines (bza) with the general formula of B(bza-R)Mes2 (R=H or Me; Mes=mesityl) are reported. A chiral substituent group R- or S-CH(CH3 )Ph (Ph=phenyl) was introduced to the imine center, which imposed a previously unobserved pseudo- or axial-chirality on the BMes2 , creating distinct diastereomers. NMR spectroscopic studies established that the diastereomers undergo slow exchange in solution at ambient temperature. The chiral N,C-chelate B(bza-R)Mes2 molecules undergo photoisomerization in the same manner as their non-chiral analogues, generating chiral BN-cyclooctatriene (BN-COT) derivatives. Most significantly, by tracking the photoisomerization with circular dichroism (CD) and 1 H NMR spectra along with time-dependent density functional theory (TD-DFT) computational studies, the photoisomerization was established to proceed in a highly stereoselective manner, that is, one diastereomer converts exclusively to the corresponding diastereomer product in the photoreaction.
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Affiliation(s)
- Polina Novoseltseva
- Department of Chemistry, Queen's University, 90 Bader Lane, Kingston, Ontario, K7L 3N6, Canada
| | - Haijun Li
- Department of Chemistry, Queen's University, 90 Bader Lane, Kingston, Ontario, K7L 3N6, Canada
| | - Xiang Wang
- Department of Chemistry, Queen's University, 90 Bader Lane, Kingston, Ontario, K7L 3N6, Canada
| | - Francoise Sauriol
- Department of Chemistry, Queen's University, 90 Bader Lane, Kingston, Ontario, K7L 3N6, Canada
| | - Suning Wang
- Department of Chemistry, Queen's University, 90 Bader Lane, Kingston, Ontario, K7L 3N6, Canada
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38
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Taylor JW, Harman WH. CO scission and reductive coupling of organic carbonyls by a redox-active diboraanthracene. Chem Commun (Camb) 2020; 56:4480-4483. [PMID: 32201869 DOI: 10.1039/d0cc01142h] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
A gold-stabilized diboraanthracene mediates reductive transformations of carbonyls, including C–O and C–C bond formation, and deoxygenation of acetone to propene and hydroxide.
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Affiliation(s)
| | - W. Hill Harman
- Department of Chemistry
- University of California
- Riverside
- USA
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39
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Taylor JW, McSkimming A, Essex LA, Harman WH. CO 2 reduction with protons and electrons at a boron-based reaction center. Chem Sci 2019; 10:9084-9090. [PMID: 31827750 PMCID: PMC6889837 DOI: 10.1039/c9sc02792k] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 07/30/2019] [Indexed: 11/21/2022] Open
Abstract
Borohydrides are widely used reducing agents in chemical synthesis and have emerging energy applications as hydrogen storage materials and reagents for the reduction of CO2. Unfortunately, the high energy cost associated with the multistep preparation of borohydrides starting from alkali metals precludes large scale implementation of these latter uses. One potential solution to this issue is the direct synthesis of borohydrides from the protonation of reduced boron compounds. We herein report reactions of the redox series [Au(B2P2)] n (n = +1, 0, -1) (B2P2, 9,10-bis(2-(diisopropylphosphino)phenyl)-9,10-dihydroboranthrene) and their conversion into corresponding mono- and diborohydride complexes. Crucially, the monoborohydride can be accessed via protonation of [Au(B2P2)]-, a masked borane dianion equivalent accessible at relatively mild potentials (-2.05 V vs. Fc/Fc+). This species reduces CO2 to produce the corresponding formate complex. Cleavage of the formate complex can be achieved by reduction (ca. -1.7 V vs. Fc/Fc+) or by the addition of electrophiles including H+. Additionally, direct reaction of [Au(B2P2)]- with CO2 results in reductive disproportion to release CO and generate a carbonate complex. Together, these reactions constitute a synthetic cycle for CO2 reduction at a boron-based reaction center that proceeds through a B-H unit generated via protonation of a reduced borane with weak organic acids.
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Affiliation(s)
- Jordan W Taylor
- Department of Chemistry , University of California , Riverside , California 92521 , USA .
| | - Alex McSkimming
- Department of Chemistry , University of California , Riverside , California 92521 , USA .
| | - Laura A Essex
- Department of Chemistry , University of California , Riverside , California 92521 , USA .
| | - W Hill Harman
- Department of Chemistry , University of California , Riverside , California 92521 , USA .
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Teerasarunyanon R, Wilkins LC, Park G, Gabbaï FP. Synthesis, structure and anion binding properties of 1,8-bis(dimesitylboryl)anthracene and its monoborylated analog. Dalton Trans 2019; 48:14777-14782. [PMID: 31552969 DOI: 10.1039/c9dt03238j] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Two boranes, 1-(dimesitylboryl)anthracene (1) and 1,8-bis(dimesitylboryl)anthracene (2), have been synthesized with the spectrophysical properties showing how the inclusion of one or two boron atoms progressively perturbs the π-system of the anthracene backbone. This perturbation is caused by conjugation of the anthracene-π* orbital with the vacant p-orbital on boron. Additionally, both 1 and 2 have a high affinity for fluoride and cyanide anions which are complexed in a 1 : 1 guest-host ratio. The mono-borane 1 is particularly well-suited for cyanide binding, displaying a binding constant of 3 × 107 in THF. Furthermore, as a result of their unique electronic structures, these boranes display a fluorescence response to fluoride anion characterized by a blue shift in the case of 1 and a red shift in the case of 2.
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Exploring the reactivity of carbene supported diboraanthracene towards dihydrogen activation. Polyhedron 2019. [DOI: 10.1016/j.poly.2019.06.043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Kirschner S, Uecker I, Bolte M, Lerner HW, Wagner M. How π Extension or Structural Bending Alters the Properties of Boron-Doped Phenylene-Containing Oligoacenes. Organometallics 2019. [DOI: 10.1021/acs.organomet.9b00330] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Sven Kirschner
- Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt (Main), Max-von-Laue-Straße 7, 60438 Frankfurt (Main), Germany
| | - Ise Uecker
- Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt (Main), Max-von-Laue-Straße 7, 60438 Frankfurt (Main), Germany
| | - Michael Bolte
- Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt (Main), Max-von-Laue-Straße 7, 60438 Frankfurt (Main), Germany
| | - Hans-Wolfram Lerner
- Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt (Main), Max-von-Laue-Straße 7, 60438 Frankfurt (Main), Germany
| | - Matthias Wagner
- Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt (Main), Max-von-Laue-Straße 7, 60438 Frankfurt (Main), Germany
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Kirschner S, Bao SS, Fengel MK, Bolte M, Lerner HW, Wagner M. Aryl-aryl coupling in a polycyclic aromatic hydrocarbon with embedded tetracoordinate boron centre. Org Biomol Chem 2019; 17:5060-5065. [PMID: 31066422 DOI: 10.1039/c9ob00618d] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The addition of 2 eq. of MesLi to the biphenylene-containing 9,10-dihydro-9,10-diboraanthracene (DBA) 2 results in the formation of the corresponding oxaboraphenanthrene 3 after column chromatography under ambient conditions. In the initial step, the anionic B-Mes monoadduct of 2 is generated, which eliminates a formal [Mes2B:]- ion with concomitant C-C-bond formation (room temperature, 18 h). The resulting biphenylene-containing borafluorene 4 is still sufficiently Lewis acidic to add the second equivalent of MesLi ([4Mes]-). Using pristine 9-mesityl-9-borafluorene as a model system, we confirmed that both 4 and [4Mes]- should be capable of inserting an oxygen atom to furnish the observed oxaboraphenanthrene scaffold. The biphenylene-containing oxaboraphenanthrene 3 is a yellow compound with an absorption maximum at λmax = 450 nm. Similar to its DBA analogue 2, 3 shows no photoluminescence.
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Affiliation(s)
- Sven Kirschner
- Institut für Anorganische Chemie, Goethe-Universität Frankfurt, Max-von-Laue Strasse 7, 60438 Frankfurt am Main, Germany.
| | - Song-Song Bao
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, P.R. China
| | - Melina K Fengel
- Institut für Anorganische Chemie, Goethe-Universität Frankfurt, Max-von-Laue Strasse 7, 60438 Frankfurt am Main, Germany.
| | - Michael Bolte
- Institut für Anorganische Chemie, Goethe-Universität Frankfurt, Max-von-Laue Strasse 7, 60438 Frankfurt am Main, Germany.
| | - Hans-Wolfram Lerner
- Institut für Anorganische Chemie, Goethe-Universität Frankfurt, Max-von-Laue Strasse 7, 60438 Frankfurt am Main, Germany.
| | - Matthias Wagner
- Institut für Anorganische Chemie, Goethe-Universität Frankfurt, Max-von-Laue Strasse 7, 60438 Frankfurt am Main, Germany.
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