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Beagan DM, Rivera C, Szymczak NK. Appended Lewis Acids Enable Dioxygen Reactivity and Catalytic Oxidations with Ni(II). J Am Chem Soc 2024; 146:12375-12385. [PMID: 38661576 PMCID: PMC11148854 DOI: 10.1021/jacs.3c12399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
We disclose a suite of Ni(II) complexes featuring secondary sphere Lewis acids of varied Lewis acidity and tether lengths. Several of these complexes feature atypical behavior of Ni(II): reactivity with O2 that occurs only in the presence of a tethered Lewis acid. In situ UV-vis spectroscopy revealed that, although adducts are stable at -40 °C, complexes containing 9-borabicyclo[3.3.1]nonane (9-BBN) Lewis acids underwent irreversible oxidative deborylation when warmed to room temperature. We computationally and experimentally identified that oxidative instability of appended 9-BBN moieties can be mitigated using weaker Lewis acids such as pinacolborane (BPin). These insights enabled the realization of catalytic reactions: hydrogen atom abstraction from phenols and room temperature oxygen atom transfer to PPh3.
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Affiliation(s)
- Daniel M Beagan
- University of Michigan, 930 N. University Ave., Ann Arbor, Michigan 48109, United States
| | - Carolina Rivera
- University of Michigan, 930 N. University Ave., Ann Arbor, Michigan 48109, United States
| | - Nathaniel K Szymczak
- University of Michigan, 930 N. University Ave., Ann Arbor, Michigan 48109, United States
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Philipp MSM, Bertermann R, Radius U. Activation of Ge-H and Sn-H Bonds with N-Heterocyclic Carbenes and a Cyclic (Alkyl)(amino)carbene. Chemistry 2023; 29:e202202493. [PMID: 36177710 PMCID: PMC10100474 DOI: 10.1002/chem.202202493] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Indexed: 01/14/2023]
Abstract
A study of the reactivity of several N-heterocyclic carbenes (NHCs) and the cyclic (alkyl)(amino)carbene 1-(2,6-di-iso-propylphenyl)-3,3,5,5-tetramethyl-pyrrolidin-2-ylidene (cAACMe ) with the group 14 hydrides GeH2 Mes2 and SnH2 Me2 (Me=CH3 , Mes=1,3,5-(CH3 )3 C6 H2 ) is presented. The reaction of GeH2 Mes2 with cAACMe led to the insertion of cAACMe into one Ge-H bond to give cAACMe H-GeHMes2 (1). If 1,3,4,5-tetramethyl-imidazolin-2-ylidene (Me2 ImMe ) was used as the carbene, NHC-mediated dehydrogenative coupling occurred, which led to the NHC-stabilized germylene Me2 ImMe ⋅GeMes2 (2). The reaction of SnH2 Me2 with cAACMe also afforded the insertion product cAACMe H-SnHMe2 (3), and reaction of two equivalents Me2 ImMe with SnH2 Me2 gave the NHC-stabilized stannylene Me2 ImMe ⋅SnMe2 (4). If the sterically more demanding NHCs Me2 ImMe , 1,3-di-isopropyl-4,5-dimethyl-imidazolin-2-ylidene (iPr2 ImMe ) and 1,3-bis-(2,6-di-isopropylphenyl)-imidazolin-2-ylidene (Dipp2 Im) were employed, selective formation of cyclic oligomers (SnMe2 )n (5; n=5-8) in high yield was observed. These cyclic oligomers were also obtained from the controlled decomposition of cAACMe H-SnHMe2 (3).
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Affiliation(s)
- Michael S. M. Philipp
- Institute of Inorganic ChemistryJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Rüdiger Bertermann
- Institute of Inorganic ChemistryJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Udo Radius
- Institute of Inorganic ChemistryJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
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3
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Sharma G, Newman PD, Platts JA. A review of quantum chemical studies of Frustrated Lewis Pairs. J Mol Graph Model 2021; 105:107846. [DOI: 10.1016/j.jmgm.2021.107846] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 01/13/2021] [Accepted: 01/20/2021] [Indexed: 11/16/2022]
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Prieschl D, Arrowsmith M, Dietz M, Rempel A, Müller M, Braunschweig H. Synthesis of polyheterocyclic 1,1-diboryltriazenes by γ-nitrogen insertion of azides into activated B-B single bonds. Chem Commun (Camb) 2020; 56:5681-5684. [PMID: 32319468 DOI: 10.1039/d0cc02305a] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The γ-nitrogen insertion of arylazides into the B-B bond of electron-rich cyclic μ-hydridodiboranes stabilised by one N-heterocyclic carbene (NHC) ligand leads to the expansion of the central C3B2 ring, yielding unsymmetrical polyheterocyclic 1,1-diboryltriazenes. The 2-benzyl-bridged analogues undergo further NHC ring expansion and thermally induced loss of N2.
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Affiliation(s)
- Dominic Prieschl
- Institute for Inorganic Chemistry and the Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg Am Hubland, 97074 Würzburg, Germany.
| | - Merle Arrowsmith
- Institute for Inorganic Chemistry and the Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg Am Hubland, 97074 Würzburg, Germany.
| | - Maximilian Dietz
- Institute for Inorganic Chemistry and the Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg Am Hubland, 97074 Würzburg, Germany.
| | - Anna Rempel
- Institute for Inorganic Chemistry and the Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg Am Hubland, 97074 Würzburg, Germany.
| | - Marcel Müller
- Institute for Inorganic Chemistry and the Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg Am Hubland, 97074 Würzburg, Germany.
| | - Holger Braunschweig
- Institute for Inorganic Chemistry and the Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg Am Hubland, 97074 Würzburg, Germany.
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Taguchi J, Matsuura S, Seki T, Ito H. Synthesis and Tunable Optical Properties of C,N-Chelated Borate Luminophores Derived from Potassium Acyltrifluoroborates. Chemistry 2020; 26:2450-2455. [PMID: 31863512 DOI: 10.1002/chem.201904983] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Indexed: 12/12/2022]
Abstract
A new class of borate luminophores has been synthesized by a simple two-step reaction using potassium acyltrifluoroborates (KATs) as starting materials. The hydrazones obtained from reactions between KATs and 2-hydrazinopyridines followed by a cyclization resulted in the unprecedented formation of C,N-chelated six-membered bora-heterocycles. Under consideration of the results of DFT and TD-DFT calculations, four luminophores based on such bora-heterocycles are designed and synthesized, which exhibit a tunable fluorescence range from blue to red in the solid state. Moreover, one of the luminophores exhibits mechanofluorochromism from blue to yellow/green. As a result of the aforementioned mechanochromism of one of these luminophores, white-color emission was achieved by simply mixing the four luminophores.
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Affiliation(s)
- Jumpei Taguchi
- Division of Applied Chemistry, Graduate School of Engineering, Hokkaido University, Kita 13 Nishi 8 Kita-ku, Sapporo, Hokkaido, 060-8628, Japan
| | - Satsuki Matsuura
- Division of Applied Chemistry, Graduate School of Engineering, Hokkaido University, Kita 13 Nishi 8 Kita-ku, Sapporo, Hokkaido, 060-8628, Japan
| | - Tomohiro Seki
- Division of Applied Chemistry, Graduate School of Engineering, Hokkaido University, Kita 13 Nishi 8 Kita-ku, Sapporo, Hokkaido, 060-8628, Japan
| | - Hajime Ito
- Division of Applied Chemistry, Graduate School of Engineering, Hokkaido University, Kita 13 Nishi 8 Kita-ku, Sapporo, Hokkaido, 060-8628, Japan.,Institute for Chemical Reaction Design and Discovery (WPI-ICReDD), Hokkaido University, Kita 13 Nishi 8 Kita-ku, Sapporo, Hokkaido, 060-8628, Japan
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Thiess T, Mellerup SK, Braunschweig H. B-B Cleavage and Ring-Expansion of a 1,4,2,3-Diazadiborinine with N-Heterocyclic Carbenes. Chemistry 2019; 25:13572-13578. [PMID: 31429506 PMCID: PMC6856839 DOI: 10.1002/chem.201903259] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 08/19/2019] [Indexed: 11/28/2022]
Abstract
A 1,4,2,3-diazadiborinine derivative was found to form Lewis adducts with strong two-electron donors such as N-heterocyclic and cyclic (alkyl)(amino)carbenes. Depending on the donor, some of these Lewis pairs are thermally unstable, converting to sole B,N-embedded products upon gentle heating. The products of these reactions, which have been fully characterized by NMR spectroscopy, elemental analysis, and single-crystal X-ray diffraction, were identified as B,N-heterocycles with fused 1,5,2,4-diazadiborepine and 1,4,2-diazaborinine rings. Computational modelling of the reaction mechanism provides insight into the formation of these unique structures, suggesting that a series of B-H, C-N, and B-B bond activation steps are responsible for these "intercalation" reactions between the 1,4,2,3-diazadiborinine and NHCs.
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Affiliation(s)
- Torsten Thiess
- Institute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
- Institute for Inorganic ChemistryJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Soren K. Mellerup
- Institute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
- Institute for Inorganic ChemistryJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Holger Braunschweig
- Institute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
- Institute for Inorganic ChemistryJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
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Smith CA, Narouz MR, Lummis PA, Singh I, Nazemi A, Li CH, Crudden CM. N-Heterocyclic Carbenes in Materials Chemistry. Chem Rev 2019; 119:4986-5056. [PMID: 30938514 DOI: 10.1021/acs.chemrev.8b00514] [Citation(s) in RCA: 353] [Impact Index Per Article: 70.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
N-Heterocyclic carbenes (NHCs) have become one of the most widely studied class of ligands in molecular chemistry and have found applications in fields as varied as catalysis, the stabilization of reactive molecular fragments, and biochemistry. More recently, NHCs have found applications in materials chemistry and have allowed for the functionalization of surfaces, polymers, nanoparticles, and discrete, well-defined clusters. In this review, we provide an in-depth look at recent advances in the use of NHCs for the development of functional materials.
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Affiliation(s)
- Christene A Smith
- Department of Chemistry , Queen's University , 90 Bader Lane , Kingston , Ontario , Canada , K7L 3N6
| | - Mina R Narouz
- Department of Chemistry , Queen's University , 90 Bader Lane , Kingston , Ontario , Canada , K7L 3N6
| | - Paul A Lummis
- Department of Chemistry , Queen's University , 90 Bader Lane , Kingston , Ontario , Canada , K7L 3N6
| | - Ishwar Singh
- Department of Chemistry , Queen's University , 90 Bader Lane , Kingston , Ontario , Canada , K7L 3N6
| | - Ali Nazemi
- Department of Chemistry , Queen's University , 90 Bader Lane , Kingston , Ontario , Canada , K7L 3N6
| | - Chien-Hung Li
- Department of Chemistry , Queen's University , 90 Bader Lane , Kingston , Ontario , Canada , K7L 3N6
| | - Cathleen M Crudden
- Department of Chemistry , Queen's University , 90 Bader Lane , Kingston , Ontario , Canada , K7L 3N6.,Institute of Transformative Bio-Molecules, ITbM-WPI , Nagoya University , Nagoya , Chikusa 464-8601 , Japan
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