1
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Frey NC, Hollister KK, Müller P, Dickie DA, Webster CE, Gilliard RJ. Borafluorene-Mediated Sulfur Activation: Isolation of Boryl-Linked S 7 and S 8 Catenates and Related Chalcogenide Molecules. Inorg Chem 2024. [PMID: 39239900 DOI: 10.1021/acs.inorgchem.4c02459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/07/2024]
Abstract
Although the activation of elemental sulfur by main group compounds is well-documented in the literature, the products of such reactions are often heterocyclic in nature. However, the isolation and characterization of sulfur catenates (i.e., acyclic sulfur chains) is significantly less common. In this study, we report the activation of elemental sulfur by the 9-CAAC-9-borafluorene radical (1) and anion (2) (CAAC = (2,6-diisopropylphenyl)-4,4-diethyl-2,2-dimethyl-pyrrolidin-5-ylidene) to form boron-sulfur catenates (3-6). From the isolation of the octasulfide-bridged compound 3, a sulfur extrusion reaction using 1,3,4,5-tetramethylimidazol-2-ylidene (IMe4) was used to decrease the sulfide chain length from eight to seven (4). Bonding analysis of compounds 3-6 was performed using density functional theory, which elucidated the nature of the sulfur-sulfur bonding observed within these compounds. We also report the synthesis of a series of borafluorene-chalcogenide species (7-9), via diphenyl dichalcogenide activation, which portray characteristics described by an internal heavy atom effect. Compounds 7-9 each exhibit blue fluorescence, with the lowest energy emissive process (S2 → S0) at 436 nm (7 and 8) and 431 nm (9). The S1 → S0 emission is not observed experimentally due to a Laporte forbidden transition. Density functional theory was employed to investigate the frontier molecular orbitals and absorption and emission profiles of compounds 7-9.
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Affiliation(s)
- Nathan C Frey
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Building 18-596, Cambridge, Massachusetts 02139-4307, United States
| | - Kimberly K Hollister
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Building 18-596, Cambridge, Massachusetts 02139-4307, United States
| | - Peter Müller
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Building 18-596, Cambridge, Massachusetts 02139-4307, United States
| | - Diane A Dickie
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
| | - Charles Edwin Webster
- Department of Chemistry, Mississippi State University, Box 9573, Mississippi State, Mississippi 39762, United States
| | - Robert J Gilliard
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Building 18-596, Cambridge, Massachusetts 02139-4307, United States
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2
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Hollister KK, Molino A, Jones N, Le VV, Dickie DA, Cafiso DS, Wilson DJD, Gilliard RJ. Unlocking Biradical Character in Diborepins. J Am Chem Soc 2024; 146:6506-6515. [PMID: 38420913 DOI: 10.1021/jacs.3c08297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2024]
Abstract
Systems that possess open- and closed-shell behavior attract significant attention from researchers due to their inherent redox and charge transport properties. Herein, we report the synthesis of the first diborepin biradicals. They display tunable biradical character based on the steric and electronic profile of the stabilizing ligand and the resulting geometric deviation of the diborepin core from planarity. While there are numerous all-carbon-based biradical systems, boron-based biradical compounds are comparatively rare, particularly ones in which the radical sites are disjointed. Calculations using density functional theory (DFT) and multireference methods demonstrate that the fused diborepin scaffold exhibits high biradical character, up to 95%. Use of a nonsterically demanding diaminocarbene promotes the planarization of the pentacyclic framework, resulting in the synthetic realization of a diborepin containing a dibora-quinoidal core, which possesses a closed-shell ground state and thermally accessible triplet state. The biradicals were structurally authenticated and characterized by both solution and solid-state electron paramagnetic resonance (EPR) spectroscopy. Half-field transitions were observed at low temperatures (about 170 K), confirming the presence of the triplet state. Initial reactivity studies of the biradicals led to the isolation and structural characterization of bis(borepin hydride) and bis(borepin dianion).
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Affiliation(s)
- Kimberly K Hollister
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Building 18-596, Cambridge, Massachusetts 02139-4307, United States
| | - Andrew Molino
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne 3086, Victoria, Australia
| | - Nula Jones
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
| | - VuongVy V Le
- 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
| | - David S Cafiso
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States
| | - David J D Wilson
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne 3086, Victoria, Australia
| | - Robert J Gilliard
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Building 18-596, Cambridge, Massachusetts 02139-4307, United States
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3
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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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4
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Bennaamane S, Rialland B, Khrouz L, Fustier-Boutignon M, Bucher C, Clot E, Mézailles N. Ammonia Synthesis at Room Temperature and Atmospheric Pressure from N 2 : A Boron-Radical Approach. Angew Chem Int Ed Engl 2023; 62:e202209102. [PMID: 36301016 PMCID: PMC10107438 DOI: 10.1002/anie.202209102] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 09/09/2022] [Accepted: 10/24/2022] [Indexed: 11/06/2022]
Abstract
Ammonia, NH3 , is an essential molecule, being part of fertilizers. It is currently synthesized via the Haber-Bosch process, from the very stable dinitrogen molecule, N2 and dihydrogen, H2 . This process requires high temperatures and pressures, thereby generating ca 1.6 % of the global CO2 emissions. Alternative strategies are needed to realize the functionalization of N2 to NH3 under mild conditions. Here, we show that boron-centered radicals provide a means of activating N2 at room temperature and atmospheric pressure whilst allowing a radical process to occur, leading to the production of borylamines. Subsequent hydrolysis released NH4 + , the acidic form of NH3 . EPR spectroscopy supported the intermediacy of radicals in the process, corroborated by DFT calculations, which rationalized the mechanism of the N2 functionalization by R2 B radicals.
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Affiliation(s)
- Soukaina Bennaamane
- Laboratoire Hétérochimie Fondamentale et Appliquée, Université Paul Sabatier, CNRS, 118 Route de Narbonne, 31062, Toulouse, France
| | - Barbara Rialland
- Laboratoire Hétérochimie Fondamentale et Appliquée, Université Paul Sabatier, CNRS, 118 Route de Narbonne, 31062, Toulouse, France
| | - Lhoussain Khrouz
- Univ Lyon, ENS Lyon, CNRS, Universite Lyon 1, Laboratoire de Chimie, UMR 5182, 46 allée d'Italie, 69364, Lyon, France
| | - Marie Fustier-Boutignon
- Laboratoire Hétérochimie Fondamentale et Appliquée, Université Paul Sabatier, CNRS, 118 Route de Narbonne, 31062, Toulouse, France
| | - Christophe Bucher
- Univ Lyon, ENS Lyon, CNRS, Universite Lyon 1, Laboratoire de Chimie, UMR 5182, 46 allée d'Italie, 69364, Lyon, France
| | - Eric Clot
- ICGM, Univ. Montpellier, CNRS, ENSCM, 34000, Montpellier, France
| | - Nicolas Mézailles
- Laboratoire Hétérochimie Fondamentale et Appliquée, Université Paul Sabatier, CNRS, 118 Route de Narbonne, 31062, Toulouse, France
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5
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Mao X, Zhang J, Lu Z, Xie Z. A (μ-hydrido)diborane(4) anion and its coordination chemistry with coinage metals. Chem Sci 2022; 13:3009-3013. [PMID: 35382458 PMCID: PMC8905795 DOI: 10.1039/d2sc00318j] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 02/10/2022] [Indexed: 11/21/2022] Open
Abstract
A tetra(o-tolyl) (μ-hydrido)diborane(4) anion 1, an analogue of [B2H5]- species, was facilely prepared through the reaction of tetra(o-tolyl)diborane(4) with sodium hydride. Unlike common sp2-sp3 diborane species, 1 exhibited a σ-B-B bond nucleophilicity towards NHC-coordinated transition-metal (Cu, Ag, and Au) halides, resulting in the formation of η2-B-B bonded complexes 2 as confirmed by single-crystal X-ray analyses. Compared with 1, the structural data of 2 imply significant elongations of B-B bonds, following the order Au > Cu > Ag. DFT studies show that the diboron ligand interacts with the coinage metal through a three-center-two-electron B-M-B bonding mode. The fact that the B-B bond of the gold complex is much prolonged than the related Cu and Ag compounds might be ascribed to the superior electrophilicity of the gold atom.
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Affiliation(s)
- Xiaofeng Mao
- Department of Chemistry, State Key Laboratory of Synthetic Chemistry, The Chinese University of Hong Kong Shatin, N. T. Hong Kong China
| | - Jie Zhang
- Department of Chemistry, State Key Laboratory of Synthetic Chemistry, The Chinese University of Hong Kong Shatin, N. T. Hong Kong China
| | - Zhenpin Lu
- Department of Chemistry, State Key Laboratory of Synthetic Chemistry, The Chinese University of Hong Kong Shatin, N. T. Hong Kong China
| | - Zuowei Xie
- Department of Chemistry, State Key Laboratory of Synthetic Chemistry, The Chinese University of Hong Kong Shatin, N. T. Hong Kong China
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6
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Zhong M, Zhang J, Lu Z, Xie Z. Diboration of alkenes and alkynes with a carborane-fused four-membered boracycle bearing an electron-precise B-B bond. Dalton Trans 2021; 50:17150-17155. [PMID: 34780587 DOI: 10.1039/d1dt03665c] [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
Small ring compounds are fascinating molecules and have been used as valuable compounds in organic synthesis. In this study, a carborane-fused four-membered boracycle bearing an electron precise B-B bond, 1,2-[BBrSMe2]2-o-C2B10H10, was synthesized via the reaction of 1,2-Li2-o-carborane with B2Br4(SMe2)2. This novel boracycle can be used as a "strain-release" compound to achieve diboration of alkenes and alkynes, leading to the generation of ring-expansion products. Interestingly, when bis(trimethylsilyl) acetylene was employed, an allene-functionalized six-membered boracycle was obtained. Moreover, DFT calculations were conducted to shed light on the reaction mechanism.
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Affiliation(s)
- Minling Zhong
- Department of Chemistry and State Key Laboratory of Synthetic Chemistry, The Chinese University of Hong Kong, Shatin, N. T., Hong Kong, China.
| | - Jie Zhang
- Department of Chemistry and State Key Laboratory of Synthetic Chemistry, The Chinese University of Hong Kong, Shatin, N. T., Hong Kong, China.
| | - Zhenpin Lu
- Department of Chemistry and State Key Laboratory of Synthetic Chemistry, The Chinese University of Hong Kong, Shatin, N. T., Hong Kong, China.
| | - Zuowei Xie
- Department of Chemistry and State Key Laboratory of Synthetic Chemistry, The Chinese University of Hong Kong, Shatin, N. T., Hong Kong, China.
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7
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Efficient synthesis of primary and secondary amides via reacting esters with alkali metal amidoboranes. Nat Commun 2021; 12:5964. [PMID: 34645807 PMCID: PMC8514480 DOI: 10.1038/s41467-021-25836-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 09/03/2021] [Indexed: 11/08/2022] Open
Abstract
Amides are one of the most important organic compounds that are widely applied in medicine, biochemistry, and materials science. To find an efficient synthetic method of amides is a challenge for organic chemistry. We report here a facile synthesis method of primary and secondary amides through a direct amidation of esters with sodium amidoboranes (NaNHRBH3, R = H, Me), at room temperature without using catalysts and other reagents. This process is rapid and chemoselective, and features quantitative conversion and wide applicability for esters tolerating different functional groups. The experimental and theoretical studies reveal a reaction mechanism with nucleophilic addition followed by a swift proton transfer-induced elimination reaction.
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8
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Chen X, Liu XR, Wang X, Chen XM, Jing Y, Wei D. A safe and efficient synthetic method for alkali metal octahydrotriborates, unravelling a general mechanism for constructing the delta B3 unit of polyhedral boranes. Dalton Trans 2021; 50:13676-13679. [PMID: 34590666 DOI: 10.1039/d1dt01892b] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A safe and efficient synthetic method for MB3H8 (M = Na, K, Rb and Cs) has been developed with excellent yields by directly reacting the corresponding MBH4 with the dimethyl sulfide borane complex (DMS·BH3). A general mechanism for constructing B3H8-, a basic unit for building polyhedral boranes, has been unravelled.
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Affiliation(s)
- Xuenian Chen
- Green Catalysis Center and College of Chemistry, Zhengzhou University, Zhengzhou, Henan 450001, China. .,Henan Key Laboratory of Boron Chemistry and Advanced Energy Materials, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan 453007, China
| | - Xin-Ran Liu
- Henan Key Laboratory of Boron Chemistry and Advanced Energy Materials, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan 453007, China
| | - Xinghua Wang
- Green Catalysis Center and College of Chemistry, Zhengzhou University, Zhengzhou, Henan 450001, China.
| | - Xi-Meng Chen
- Henan Key Laboratory of Boron Chemistry and Advanced Energy Materials, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan 453007, China
| | - Yi Jing
- Henan Key Laboratory of Boron Chemistry and Advanced Energy Materials, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan 453007, China
| | - Donghui Wei
- Green Catalysis Center and College of Chemistry, Zhengzhou University, Zhengzhou, Henan 450001, China.
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9
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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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10
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Budy H, Kaese T, Bolte M, Lerner H, Wagner M. A Chemiluminescent Tetraaryl Diborane(4) Tetraanion. Angew Chem Int Ed Engl 2021; 60:19397-19405. [PMID: 34161639 PMCID: PMC8456833 DOI: 10.1002/anie.202106980] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 06/22/2021] [Indexed: 12/13/2022]
Abstract
Two subvalent, redox-active diborane(4) anions, [3]4- and [3]2- , carrying exceptionally high negative charge densities are reported: Reduction of 9-methoxy-9-borafluorene with Li granules without stirring leads to the crystallization of the B(sp3 )-B(sp2 ) diborane(5) anion salt Li[5]. [5]- contains a 2,2'-biphenyldiyl-bridged B-B core, a chelating 2,2'-biphenyldiyl moiety, and a MeO substituent. Reduction of Li[5] with Na metal gives the Na+ salt of the tetraanion [3]4- in which two doubly reduced 9-borafluorenyl fragments are linked via a B-B single bond. Comproportionation of Li[5] and Na4 [3] quantitatively furnishes the diborane(4) dianion salt Na2 [3], the doubly boron-doped congener of 9,9'-bis(fluorenylidene). Under acid catalysis, Na2 [3] undergoes a formal Stone-Wales rearrangement to yield a dibenzo[g,p]chrysene derivative with B=B core. Na2 [3] shows boron-centered nucleophilicity toward n-butyl chloride. Na4 [3] produces bright blue chemiluminescence when exposed to air.
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Affiliation(s)
- Hendrik Budy
- Institut für Anorganische ChemieGoethe-Universität FrankfurtMax-von-Laue-Strasse 760438Frankfurt (Main)Germany
| | - Thomas Kaese
- Institut für Anorganische ChemieGoethe-Universität FrankfurtMax-von-Laue-Strasse 760438Frankfurt (Main)Germany
| | - Michael Bolte
- Institut für Anorganische ChemieGoethe-Universität FrankfurtMax-von-Laue-Strasse 760438Frankfurt (Main)Germany
| | - Hans‐Wolfram Lerner
- Institut für Anorganische ChemieGoethe-Universität FrankfurtMax-von-Laue-Strasse 760438Frankfurt (Main)Germany
| | - Matthias Wagner
- Institut für Anorganische ChemieGoethe-Universität FrankfurtMax-von-Laue-Strasse 760438Frankfurt (Main)Germany
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11
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Budy H, Kaese T, Bolte M, Lerner H, Wagner M. A Chemiluminescent Tetraaryl Diborane(4) Tetraanion. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202106980] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Hendrik Budy
- Institut für Anorganische Chemie Goethe-Universität Frankfurt Max-von-Laue-Strasse 7 60438 Frankfurt (Main) Germany
| | - Thomas Kaese
- 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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12
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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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13
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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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14
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Su X, Bartholome TA, Tidwell JR, Pujol A, Yruegas S, Martinez JJ, Martin CD. 9-Borafluorenes: Synthesis, Properties, and Reactivity. Chem Rev 2021; 121:4147-4192. [DOI: 10.1021/acs.chemrev.0c01068] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Xiaojun Su
- Department of Chemistry and Biochemistry, Baylor University, One Bear Place #97348, Waco, Texas 76798, United States
| | - Tyler A. Bartholome
- Department of Chemistry and Biochemistry, Baylor University, One Bear Place #97348, Waco, Texas 76798, United States
| | - John R. Tidwell
- Department of Chemistry and Biochemistry, Baylor University, One Bear Place #97348, Waco, Texas 76798, United States
| | - Alba Pujol
- Department of Chemistry and Biochemistry, Baylor University, One Bear Place #97348, Waco, Texas 76798, United States
| | - Sam Yruegas
- Department of Chemistry and Biochemistry, Baylor University, One Bear Place #97348, Waco, Texas 76798, United States
| | - Jesse J. Martinez
- Department of Chemistry and Biochemistry, Baylor University, One Bear Place #97348, Waco, Texas 76798, United States
| | - Caleb D. Martin
- Department of Chemistry and Biochemistry, Baylor University, One Bear Place #97348, Waco, Texas 76798, United States
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15
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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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He J, Rauch F, Finze M, Marder TB. (Hetero)arene-fused boroles: a broad spectrum of applications. Chem Sci 2020; 12:128-147. [PMID: 34163585 PMCID: PMC8178973 DOI: 10.1039/d0sc05676f] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
(Hetero)arene-fused boroles are a class of compounds containing a 5-membered boron diene-ring. Based on their molecular framework, the (hetero)arene-fused boroles can be considered as boron-doped polycyclic antiaromatic hydrocarbons and are thus of great interest. Due to the vacant pz orbital on the 3-coordinate boron atom, the antiaromaticity and strain of the 5-membered borole ring, (hetero)arene-fused boroles possess strong electron accepting abilities and Lewis acidity. By functionalization, they can be tuned to optimize different properties for specific applications. Herein, we summarize synthetic methodologies, different strategies for their functionalization, and applications of (hetero)arene-fused boroles. (Hetero)arene-fused boroles, ‘antiaromatic’ 2n-electron π-systems, more stable and more functionalizable than boroles, offer greater potential for a variety of applications.![]()
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Affiliation(s)
- Jiang He
- Institute for Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron (ICB), Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Florian Rauch
- Institute for Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron (ICB), Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Maik Finze
- Institute for Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron (ICB), Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Todd B Marder
- Institute for Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron (ICB), Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
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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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18
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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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