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Wang Y, Tran PM, Lahm ME, Wei P, Adams ER, Schaefer HF, Robinson GH. From Carbene-Dithiolene Zwitterion Mediated B-H Bond Activation to BH 3·SMe 2-Assisted Boron-Boron Bond Formation. Organometallics 2023; 42:3328-3333. [PMID: 38098647 PMCID: PMC10716900 DOI: 10.1021/acs.organomet.3c00361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Indexed: 12/17/2023]
Abstract
The 1:1 reaction of the carbene-stabilized dithiolene zwitterion 1 with BH3·SMe2 gave the dithiolene-based hydroborane 2 and the doubly hydrogen-capped CAAC species 3 via hydride-coupled reverse electron transfer processes. The mechanism of this transformation was probed computationally using density functional theory. The subsequent 2:1 reaction of 2 with 1 resulted in 4 and 3, suggesting that 1 can mediate the B-H bond activation not only for BH3 but also for monohydroboranes. In the presence of BH3·SMe2, 2 was unexpectedly converted to the corresponding diborane(4) complex 5 through a dehydrocoupling reaction at an elevated temperature.
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Affiliation(s)
- Yuzhong Wang
- Department of Chemistry and
Center for Computational Chemistry, The
University of Georgia, Athens, Georgia 30602-2556, United States
| | - Phuong M. Tran
- Department of Chemistry and
Center for Computational Chemistry, The
University of Georgia, Athens, Georgia 30602-2556, United States
| | - Mitchell E. Lahm
- Department of Chemistry and
Center for Computational Chemistry, The
University of Georgia, Athens, Georgia 30602-2556, United States
| | - Pingrong Wei
- Department of Chemistry and
Center for Computational Chemistry, The
University of Georgia, Athens, Georgia 30602-2556, United States
| | - Earle R. Adams
- Department of Chemistry and
Center for Computational Chemistry, The
University of Georgia, Athens, Georgia 30602-2556, United States
| | - Henry F. Schaefer
- Department of Chemistry and
Center for Computational Chemistry, The
University of Georgia, Athens, Georgia 30602-2556, United States
| | - Gregory H. Robinson
- Department of Chemistry and
Center for Computational Chemistry, The
University of Georgia, Athens, Georgia 30602-2556, United States
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2
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Tendera L, Kuehn L, Marder TB, Radius U. On the Reactivity of a NHC Nickel Bis-Boryl Complex: Reductive Elimination and Formation of Mono-Boryl Complexes. Chemistry 2023; 29:e202302310. [PMID: 37551752 DOI: 10.1002/chem.202302310] [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: 07/19/2023] [Revised: 08/07/2023] [Accepted: 08/08/2023] [Indexed: 08/09/2023]
Abstract
The synthesis of the first terminal mono-boryl complexes of nickel, which are not stabilized by a pincer ligand, is reported. The reaction of the nickel bis-boryl complex cis-[Ni(i Pr2 ImMe )2 (Bcat)2 ] 1 (cat=1,2-O2 C6 H4 ) with the small donor ligand PMe3 led to a complete ligand exchange at nickel with reductive elimination of B2 cat2 and formation of the bis-NHC adduct [B2 cat2 ⋅ (i Pr2 ImMe )2 ] 3 and [Ni(PMe3 )4 ] 2 as the metal-containing species. Electrophilic attack of MeI on complex 1 or ligand dismutation of 1 with trans-[Ni(i Pr2 ImMe )2 Br2 ] led to loss of only one boryl ligand of 1 and afforded the nickel mono-boryl complexes trans-[Ni(i Pr2 ImMe )2 (Bcat)Br] 4 a and trans-[Ni(i Pr2 ImMe )2 (Bcat)I] 4 b.
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Affiliation(s)
- Lukas Tendera
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Laura Kuehn
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Todd B Marder
- 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
| | - Udo Radius
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
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3
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Tendera L, Fantuzzi F, Marder TB, Radius U. Nickel boryl complexes and nickel-catalyzed alkyne borylation. Chem Sci 2023; 14:2215-2228. [PMID: 36845942 PMCID: PMC9945561 DOI: 10.1039/d2sc04690c] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 01/27/2023] [Indexed: 01/28/2023] Open
Abstract
The first nickel bis-boryl complexes cis-[Ni( i Pr2ImMe)2(Bcat)2], cis-[Ni( i Pr2ImMe)2(Bpin)2] and cis-[Ni( i Pr2ImMe)2(Beg)2] are reported, which were prepared via the reaction of a source of [Ni( i Pr2ImMe)2] with the diboron(4) compounds B2cat2, B2pin2 and B2eg2 ( i Pr2ImMe = 1,3-di-iso-propyl-4,5-dimethylimidazolin-2-ylidene; B2cat2 = bis(catecholato)diboron; B2pin2 = bis(pinacolato)diboron; B2eg2 = bis(ethylene glycolato)diboron). X-ray diffraction and DFT calculations strongly suggest that a delocalized, multicenter bonding scheme dictates the bonding situation of the NiB2 moiety in these square planar complexes, reminiscent of the bonding situation of "non-classical" H2 complexes. [Ni( i Pr2ImMe)2] also efficiently catalyzes the diboration of alkynes using B2cat2 as the boron source under mild conditions. In contrast to the known platinum-catalyzed diboration, the nickel system follows a different mechanistic pathway, which not only provides the 1,2-borylation product in excellent yields, but also provides an efficient approach to other products such as C-C coupled borylation products or rare tetra-borylated compounds. The mechanism of the nickel-catalyzed alkyne borylation was examined by means of stoichiometric reactions and DFT calculations. Oxidative addition of the diboron reagent to nickel is not dominant; the first steps of the catalytic cycle are coordination of the alkyne to [Ni( i Pr2ImMe)2] and subsequent borylation at the coordinated and, thus, activated alkyne to yield complexes of the type [Ni(NHC)2(η2-cis-(Bcat)(R)C[double bond, length as m-dash]C(R)(Bcat))], exemplified by the isolation and structural characterization of [Ni( i Pr2ImMe)2(η2-cis-(Bcat)(Me)C[double bond, length as m-dash]C(Me)(Bcat))] and [Ni( i Pr2ImMe)2(η2-cis-(Bcat)(H7C3)C[double bond, length as m-dash]C(C3H7)(Bcat))].
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Affiliation(s)
- Lukas Tendera
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Felipe Fantuzzi
- School of Chemistry and Forensic Science, University of KentPark Wood RdCanterburyCT2 7NHUK
| | - Todd B. Marder
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität WürzburgAm Hubland97074 WürzburgGermany,Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität WürzburgAm Hubland97074 WürzburgGermany
| | - Udo Radius
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
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4
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5
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Drescher W, Kleeberg C. Ligand properties of boryl ligands in bis-boryl rhodium(III) complexes: a case study. Dalton Trans 2022; 51:4749-4759. [PMID: 35244112 DOI: 10.1039/d1dt04276a] [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
The oxidative addition of five diborane(4) derivatives, symmetrical and unsymmetrical, to [Rh(PMe3)3Cl] was studied. Only for the more electron poor diboron derivatives, B2cat2, B2pin2 and catB-Bpin the resulting octahedral bis-boryl complexes [(PMe3)3Rh(boryl)2Cl] were obtained, while for the more electron rich congeners only the equilibrium oxidative addition (catB-Bdmab) or no significant reaction (pinB-Bdmab) was observed (pin = (OCMe2)2, cat = 1,2-O2C6H4, dmab = 1,2-(NMe)2C6H4). By abstraction of the chlorido ligand with NaBArF (BArF = tetrakis-[3,5-bis-(trifluormethyl)-phenyl]-borat) in the presence of a neutral ligand (L = PMe3, MeCN, MeNC) the corresponding cationic octahedral complexes [(PMe3)3Rh(boryl)2L]+ were obtained. All isolated complexes were fully characterised including single crystal X-ray diffraction and heteronuclear, temperature dependent NMR spectroscopy. Whilst the complexes [(PMe3)3Rh(boryl)2Cl] and [(PMe3)3Rh(boryl)2L]+ show many similarities, their detailed structural and spectroscopic properties depend crucially on the properties of both boryl ligands.
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Affiliation(s)
- Wiebke Drescher
- Institut für Anorganische und Analytische Chemie, Technische Universität Braunschweig, Hagenring 30, 38106 Braunschweig, Germany.
| | - Christian Kleeberg
- Institut für Anorganische und Analytische Chemie, Technische Universität Braunschweig, Hagenring 30, 38106 Braunschweig, Germany.
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6
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Huang M, Hu J, Krummenacher I, Friedrich A, Braunschweig H, Westcott SA, Radius U, Marder TB. Base-Mediated Radical Borylation of Alkyl Sulfones. Chemistry 2022; 28:e202103866. [PMID: 34713940 PMCID: PMC9299846 DOI: 10.1002/chem.202103866] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Indexed: 11/06/2022]
Abstract
A practical and direct method was developed for the production of versatile alkyl boronate esters via transition metal-free borylation of primary and secondary alkyl sulfones. The key to the success of the strategy is the use of bis(neopentyl glycolato) diboron (B2 neop2 ), with a stoichiometric amount of base as a promoter. The practicality and industrial potential of this protocol are highlighted by its wide functional group tolerance, the late-stage modification of complex compounds, no need for further transesterification, and operational simplicity. Radical clock, radical trap experiments, and EPR studies were conducted which show that the borylation process involves radical intermediates.
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Affiliation(s)
- Mingming Huang
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Jiefeng Hu
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Ivo Krummenacher
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Alexandra Friedrich
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Holger Braunschweig
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Stephen A. Westcott
- Department of Chemistry & BiochemistryMount Allison UniversitySackvilleNB E4L 1G8Canada
| | - Udo Radius
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Todd B. Marder
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
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7
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Okorn A, Jayaraman A, Englert L, Arrowsmith M, Swoboda T, Weigelt J, Brunecker C, Hess M, Lamprecht A, Lenczyk C, Rang M, Braunschweig H. Synthesis and hydrogenation of polycyclic aromatic hydrocarbon-substituted diborenes via uncatalysed hydrogenative B–C bond cleavage. Chem Sci 2022; 13:7566-7574. [PMID: 35872817 PMCID: PMC9242019 DOI: 10.1039/d2sc02515a] [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: 05/05/2022] [Accepted: 06/03/2022] [Indexed: 11/21/2022] Open
Abstract
In contrast to classical B–B bond-centred diborene hydrogenation, polycyclic aromatic hydrocarbon-substituted diborenes first undergo thermal intramolecular hydroarylation, followed by hydrogenation of the remaining B–B and endocyclic B–C bonds.
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Affiliation(s)
- Alexander Okorn
- 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
| | - Arumugam Jayaraman
- 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
| | - Lukas Englert
- 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
| | - Theresa Swoboda
- 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
| | - Jeanette Weigelt
- 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
| | - Carina Brunecker
- 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
| | - Merlin Hess
- 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 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
| | - Carsten Lenczyk
- 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 Rang
- 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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8
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Toffoli D, Grazioli C, Monti M, Stener M, Totani R, Richter R, Schio L, Fronzoni G, Cossaro A. Revealing the electronic properties of the B-B bond: the bis-catecholato diboron molecule. Phys Chem Chem Phys 2021; 23:23517-23525. [PMID: 34642728 DOI: 10.1039/d1cp03428f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The electronic properties of a diboron molecule, namely bis(catecholato)diboron (2-(1,3,2-benzodioxaborol-2-yl)-1,3,2-benzodioxaborole) (B2Cat2), have been studied by comparing the results of photoemission (XPS) and near edge X-ray absorption spectroscopy (NEXAFS) experiments with the outcome of DFT calculations. The B 1s, C 1s and O 1s K-edges have been investigated for both the isolated gas phase molecule and the adsorbed one on the Au(111) surface. The main features of the polarized NEXAFS spectra at each of the three edges considered are not significantly affected by the presence of the substrate, with respect to the isolated molecule, indicating that the molecule-gold interaction is weak. Moreover, the comparison between the observed dichroism in the NEXAFS spectra of the adsorbed B2Cat2 and that in the NEXAFS spectra of the isolated molecule has confirmed the orbital symmetry assigned in the gas phase absorption spectra. The transitions to π(B-B) bonding and π*(B-B) anti-bonding final states represent the most relevant probe of the chemistry of the B2Cat2 molecule. We show that their theoretical description requires that the treatment of the relaxation changes among different excited state configurations, which we successfully implemented by using ΔSCF-DFT (ΔSCF) calculations.
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Affiliation(s)
- D Toffoli
- Department of Chemical and Pharmaceutical Sciences, University of Trieste, 34127 Trieste, Italy.
| | - C Grazioli
- IOM-CNR, Istituto Officina dei Materiali-CNR, S.S.14, Km 163.5, 34149 Trieste, Italy
| | - M Monti
- Department of Chemical and Pharmaceutical Sciences, University of Trieste, 34127 Trieste, Italy.
| | - M Stener
- Department of Chemical and Pharmaceutical Sciences, University of Trieste, 34127 Trieste, Italy.
| | - R Totani
- ISM-CNR, Istituto di Struttura della Materia, LD2 Unit, 34149 Trieste, Italy
| | - R Richter
- Elettra-Sincrotrone Trieste, 34149 Basovizza, Trieste, Italy
| | - L Schio
- IOM-CNR, Istituto Officina dei Materiali-CNR, S.S.14, Km 163.5, 34149 Trieste, Italy
| | - G Fronzoni
- Department of Chemical and Pharmaceutical Sciences, University of Trieste, 34127 Trieste, Italy.
| | - A Cossaro
- Department of Chemical and Pharmaceutical Sciences, University of Trieste, 34127 Trieste, Italy. .,IOM-CNR, Istituto Officina dei Materiali-CNR, S.S.14, Km 163.5, 34149 Trieste, Italy
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9
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Drescher W, Borner C, Kleeberg C. Stability and decomposition of copper( i) boryl complexes: [(IDipp)Cu–Bneop], [(IDipp*)Cu–Bneop] and copper clusters. NEW J CHEM 2021. [DOI: 10.1039/d0nj03166f] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Synthesis and characterisation of NHC copper boryl complexes [(NHC)Cu–Bneop] and their decomposition to low-valent copper clusters.
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Affiliation(s)
- Wiebke Drescher
- Institut für Anorganische und Analytische Chemie, Technische Universität Braunschweig, Hagenring 30, 38106 Braunschweig, Germany
| | - Corinna Borner
- Institut für Anorganische und Analytische Chemie, Technische Universität Braunschweig, Hagenring 30, 38106 Braunschweig, Germany
| | - Christian Kleeberg
- Institut für Anorganische und Analytische Chemie, Technische Universität Braunschweig, Hagenring 30, 38106 Braunschweig, Germany
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10
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Manankandayalage CP, Unruh DK, Krempner C. Boronic, diboronic and boric acid esters of 1,8-naphthalenediol - synthesis, structure and formation of boronium salts. Dalton Trans 2020; 49:4834-4842. [PMID: 32215427 DOI: 10.1039/d0dt00745e] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The 1,8-naphthalenediolate [1,8-O2C10H8] supported boronic and boric acid esters of general formula X-B(1,8-O2C10H8), where X = C6H5 (1a), C6F5 (2a), 3,4,5-F3-C6H2 (3a), 2,4,6-F3-C6H2 (4a), 2,6-F2-C6H3 (5a), 2,6-Cl2-C6H3 (6a), 2,4,6-Me3-C6H2 (7a), 2,6-(MeO)3-C6H3 (8a), Bun (9a), MeO (10a), OH (11a) and Cl (13a), were synthesized, NMR spectroscopically characterized, and the solid-state structures of 1a-5a, 8a and 10a determined by X-ray crystallography. The acceptor numbers of 1a-7a and 13a were determined and found to be similar to their catecholate analogues, R-Bcat, indicating similar Lewis acidities of these two classes of boronic acid esters. The reaction of B2(NMe2)4 with 1,8-naphthalenediol, followed by addition of HCl furnished the diboronic acid ester B2(1,8-O2C10H8)4 (16a) in ca. 70% yield. Cl-B(1,8-O2C10H8) (13a) was shown to react with O[double bond, length as m-dash]PEt3, DMAP, 1,10-phenanthroline and 2,2'-bipyridine, resp., to give the boronium salts [(Et3P[double bond, length as m-dash]O)2B(1,8-O2C10H8)]Cl (18a), [(DMAP)2B(1,8-O2C10H8)]Cl (22a), [(2,2'-bipyridine)B(1,8-O2C10H8)]Cl (23a) and [(1,10-phenanthroline)B(1,8-O2C10H8)]Cl (24a), which were characterized by NMR spectroscopy and X-ray crystallography.
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Affiliation(s)
- Chamila P Manankandayalage
- Department of Chemistry and Biochemistry, Texas Tech University, Memorial Dr. & Boston, Lubbock, TX 79409, USA.
| | - Daniel K Unruh
- Department of Chemistry and Biochemistry, Texas Tech University, Memorial Dr. & Boston, Lubbock, TX 79409, USA.
| | - Clemens Krempner
- Department of Chemistry and Biochemistry, Texas Tech University, Memorial Dr. & Boston, Lubbock, TX 79409, USA.
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11
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Yao CJ, Zhao K, Long G, Li X, Gong ZL, Zhong YW, Gao W, Li Y, Ganguly R, Li G, Zhang Q. Synthesis, characterization and photophysical studies of a novel polycyclic diborane. NEW J CHEM 2019. [DOI: 10.1039/c8nj05550e] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A long polycyclic diborane (4) with a dihedral angle of 21.75° between the two naphthalene rings has been successfully prepared and fully characterized.
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12
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Transition-metal-free diboration of non-activated olefins: A reaction mechanism revisited. COMPUT THEOR CHEM 2018. [DOI: 10.1016/j.comptc.2018.03.030] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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13
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Franz D, Szilvási T, Pöthig A, Deiser F, Inoue S. Three-Coordinate Boron(III) and Diboron(II) Dications. Chemistry 2018; 24:4283-4288. [DOI: 10.1002/chem.201800609] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2018] [Indexed: 11/08/2022]
Affiliation(s)
- Daniel Franz
- Department of Chemistry, Catalysis Research Center; Institute of Silicon Chemistry; Technische Universität München; Lichtenbergstr. 4 85748 Garching bei München Germany
| | - Tibor Szilvási
- Department of Chemical and Biological Engineering; University of Wisconsin-Madison; 1415 Engineering Drive Madison WI 53706-1607 USA
| | - Alexander Pöthig
- Department of Chemistry, Catalysis Research Center; Institute of Silicon Chemistry; Technische Universität München; Lichtenbergstr. 4 85748 Garching bei München Germany
| | - Franziska Deiser
- Department of Chemistry, Catalysis Research Center; Institute of Silicon Chemistry; Technische Universität München; Lichtenbergstr. 4 85748 Garching bei München Germany
| | - Shigeyoshi Inoue
- Department of Chemistry, Catalysis Research Center; Institute of Silicon Chemistry; Technische Universität München; Lichtenbergstr. 4 85748 Garching bei München Germany
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14
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Eck M, Würtemberger-Pietsch S, Eichhorn A, Berthel JHJ, Bertermann R, Paul USD, Schneider H, Friedrich A, Kleeberg C, Radius U, Marder TB. B-B bond activation and NHC ring-expansion reactions of diboron(4) compounds, and accurate molecular structures of B 2(NMe 2) 4, B 2eg 2, B 2neop 2 and B 2pin 2. Dalton Trans 2018; 46:3661-3680. [PMID: 28252145 DOI: 10.1039/c7dt00334j] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
In this detailed study we report on the structures of the widely employed diboron(4) compounds bis(pinacolato)diboron (B2pin2) and bis(neopentyl glycolato)diboron (B2neop2), as well as bis(ethylene glycolato)diboron (B2eg2) and tetrakis(dimethylamino)diboron (B2(NMe2)4), and their reactivity, along with that of bis(catecholato)diboron (B2cat2) with backbone saturated and backbone unsaturared N-heterocyclic carbenes (NHCs) of different steric demand. Depending on the nature of the diboron(4) compound and the NHC used, Lewis-acid/Lewis-base adducts or NHC ring-expansion products stemming from B-B and C-N bond activation have been observed. The corresponding NHC adducts and NHC ring-expanded products were isolated and characterised via solid-state and solution NMR spectroscopy and X-ray diffraction. In general, we observed B-B bond and C-N bond activation at low temperature for B2eg2, at room temperature for B2neop2 and at higher temperature for B2cat2. The reactivity strongly depends on steric effects of the NHCs and the diboron(4) compounds, as well as on the corresponding Lewis-basicity and Lewis-acidity. Our results provide profound insight into the chemistry of these diboron(4) reagents with the nowadays ubiquitous NHCs, the stability of the corresponding NHC adducts and on B-B bond activation using Lewis-bases in general. We demonstrate that B-B bond activation may be triggered even at temperatures as low as -40 °C to -30 °C without any metal species involved. For example, the reactions of B2eg2 with sterically less demanding NHCs such as Me2ImMe and iPr2Im in solution led to the corresponding ring-expanded products at low temperatures. Furthermore, boronium [L2B(OR)2]+ and borenium [LB(OR)2]+ cations have been observed from the reaction of the bis-borate B2eg3 with the NHCs iPr2Im and Me2ImMe, which led to the conclusion that the activation of bis-borates with NHCs (or Lewis-bases in general) might be a facile and simple route to access such species.
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Affiliation(s)
- Martin Eck
- Institut für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
| | - Sabrina Würtemberger-Pietsch
- Institut für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
| | - Antonius Eichhorn
- Institut für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
| | - Johannes H J Berthel
- Institut für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
| | - Rüdiger Bertermann
- Institut für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
| | - Ursula S D Paul
- Institut für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
| | - Heidi Schneider
- Institut für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
| | - Alexandra Friedrich
- Institut für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
| | - Christian Kleeberg
- Institut für Anorganische und Analytische Chemie, Technische Universität Carolo-Wilhelmina zu Braunschweig, Hagenring 30, 38106 Braunschweig, Germany.
| | - Udo Radius
- Institut für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
| | - Todd B Marder
- Institut für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
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15
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Katsuma Y, Asakawa H, Yamashita M. Reactivity of highly Lewis acidic diborane(4) towards pyridine and isocyanide: formation of boraalkene-pyridine complex and ortho-functionalized pyridine derivatives. Chem Sci 2018; 9:1301-1310. [PMID: 29675176 PMCID: PMC5887101 DOI: 10.1039/c7sc04759b] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 12/10/2017] [Indexed: 12/14/2022] Open
Abstract
The reaction of pinB-BMes2 (pin = pinacolato, Mes = 2,4,6-Me3C6H2) with Xyl-NC (Xyl = 2,6-Me2C6H3) and pyridine results in the formation of a pyridine-coordinated boraalkene that exhibits an intense color caused by an intramolecular charge-transfer interaction. In the presence of an excess of pyridine, the ortho C-H bond of pyridine was selectively functionalized to afford a quinoid compound or an isocyanide-coupled product. Based on the concentration effect, the reaction stoichiometry, and previously reported DFT calculations, a reaction mechanism that involves several rearrangement reactions was proposed. Using the present method, substituted pyridines and N-heterocycles afforded the corresponding functionalized derivatives. A subsequent hydrolysis of one of the resulting products furnished an aminomethylated pyridine derivative in two steps from parent pyridine.
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Affiliation(s)
- Yuhei Katsuma
- Department of Applied Chemistry , Faculty of Science and Engineering , Chuo University , 1-13-27 Kasuga , Bunkyo-ku , 112-8551 , Tokyo , Japan
| | - Hiroki Asakawa
- Department of Applied Chemistry , Faculty of Science and Engineering , Chuo University , 1-13-27 Kasuga , Bunkyo-ku , 112-8551 , Tokyo , Japan
| | - Makoto Yamashita
- Department of Molecular and Macromolecular Chemistry , Graduate School of Engineering , Nagoya University , Furo-cho, Chikusa-ku , Nagoya , 464-8603 , Aichi , Japan .
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16
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Horn J, Widera A, Litters S, Kaifer E, Himmel HJ. Tuning the nucleophilicity of electron-rich diborane(4) compounds with bridging guanidinate substituents by substitution. Dalton Trans 2018; 47:2009-2017. [PMID: 29345706 DOI: 10.1039/c7dt04433j] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The proton affinity, HOMO energy and ionization energy of electron-rich sp3–sp3-hybridized diborane(4) compounds with bridging guanidinate substituents can be varied by substitution.
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Affiliation(s)
- Julian Horn
- Anorganisch-Chemisches Institut
- Ruprecht-Karls-Universität Heidelberg
- 69120 Heidelberg
- Germany
| | - Anna Widera
- Anorganisch-Chemisches Institut
- Ruprecht-Karls-Universität Heidelberg
- 69120 Heidelberg
- Germany
| | - Sebastian Litters
- Anorganisch-Chemisches Institut
- Ruprecht-Karls-Universität Heidelberg
- 69120 Heidelberg
- Germany
| | - Elisabeth Kaifer
- Anorganisch-Chemisches Institut
- Ruprecht-Karls-Universität Heidelberg
- 69120 Heidelberg
- Germany
| | - Hans-Jörg Himmel
- Anorganisch-Chemisches Institut
- Ruprecht-Karls-Universität Heidelberg
- 69120 Heidelberg
- Germany
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17
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Borner C, Wiecha MT, Kleeberg C. Unsymmetrical Diborane(4) Derivatives: A Comparative Study. Eur J Inorg Chem 2017. [DOI: 10.1002/ejic.201700545] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Corinna Borner
- Institut für Anorganische und Analytische Chemie Technische Universität Carolo‐Wilhelmina zu Braunschweig Hagenring 30 38106 Braunschweig Germany
| | - Maximilian T. Wiecha
- Institut für Anorganische und Analytische Chemie Technische Universität Carolo‐Wilhelmina zu Braunschweig Hagenring 30 38106 Braunschweig Germany
| | - Christian Kleeberg
- Institut für Anorganische und Analytische Chemie Technische Universität Carolo‐Wilhelmina zu Braunschweig Hagenring 30 38106 Braunschweig Germany
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18
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Neeve EC, Geier SJ, Mkhalid IAI, Westcott SA, Marder TB. Diboron(4) Compounds: From Structural Curiosity to Synthetic Workhorse. Chem Rev 2016; 116:9091-161. [PMID: 27434758 DOI: 10.1021/acs.chemrev.6b00193] [Citation(s) in RCA: 737] [Impact Index Per Article: 92.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Although known for over 90 years, only in the past two decades has the chemistry of diboron(4) compounds been extensively explored. Many interesting structural features and reaction patterns have emerged, and more importantly, these compounds now feature prominently in both metal-catalyzed and metal-free methodologies for the formation of B-C bonds and other processes.
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Affiliation(s)
- Emily C Neeve
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg , Würzburg 97074, Germany
| | - Stephen J Geier
- Mount Allison University , Department of Biochemistry and Chemistry, Sackville, New Brunswick E4L 1G8, Canada
| | | | - Stephen A Westcott
- Mount Allison University , Department of Biochemistry and Chemistry, Sackville, New Brunswick E4L 1G8, Canada
| | - Todd B Marder
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg , Würzburg 97074, Germany
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19
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Arnold N, Braunschweig H, Ewing WC, Kupfer T, Radacki K, Thiess T, Trumpp A. Controlling Regiochemistry in the Syntheses of Boraindanes from Diborane(4) Starting Materials. Chemistry 2016; 22:11441-9. [DOI: 10.1002/chem.201601522] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Indexed: 11/10/2022]
Affiliation(s)
- Nicole Arnold
- Institut für Anorganische Chemie; Julius-Maximilians-Universität Würzburg; Am Hubland 97074 Würzburg Germany
| | - Holger Braunschweig
- Institut für Anorganische Chemie; Julius-Maximilians-Universität Würzburg; Am Hubland 97074 Würzburg Germany
| | - William C. Ewing
- Institut für Anorganische Chemie; Julius-Maximilians-Universität Würzburg; Am Hubland 97074 Würzburg Germany
| | - Thomas Kupfer
- Institut für Anorganische Chemie; Julius-Maximilians-Universität Würzburg; Am Hubland 97074 Würzburg Germany
| | - Krzysztof Radacki
- Institut für Anorganische Chemie; Julius-Maximilians-Universität Würzburg; Am Hubland 97074 Würzburg Germany
| | - Torsten Thiess
- Institut für Anorganische Chemie; Julius-Maximilians-Universität Würzburg; Am Hubland 97074 Würzburg Germany
| | - Alexandra Trumpp
- Institut für Anorganische Chemie; Julius-Maximilians-Universität Würzburg; Am Hubland 97074 Würzburg Germany
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20
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Zhou J, Berthel JHJ, Kuntze-Fechner MW, Friedrich A, Marder TB, Radius U. NHC Nickel-Catalyzed Suzuki–Miyaura Cross-Coupling Reactions of Aryl Boronate Esters with Perfluorobenzenes. J Org Chem 2016; 81:5789-94. [DOI: 10.1021/acs.joc.6b01041] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jing Zhou
- Institut
für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Johannes H. J. Berthel
- Institut
für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | | | - Alexandra Friedrich
- Institut
für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Todd B. Marder
- Institut
für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Udo Radius
- Institut
für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
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21
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Schlindwein SH, Bader K, Sibold C, Frey W, Neugebauer P, Orlita M, Slageren JV, Gudat D. New Selective Synthesis of Dithiaboroles as a Viable Pathway to Functionalized Benzenedithiolenes and Their Complexes. Inorg Chem 2016; 55:6186-94. [DOI: 10.1021/acs.inorgchem.6b00821] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | | | | | | | | | - Milan Orlita
- Laboratoire National des Champs Magnétiques Intenses, 38042 Grenoble, France
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22
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Fang L, Yan L, Haeffner F, Morken JP. Carbohydrate-Catalyzed Enantioselective Alkene Diboration: Enhanced Reactivity of 1,2-Bonded Diboron Complexes. J Am Chem Soc 2016; 138:2508-11. [PMID: 26854364 PMCID: PMC4896641 DOI: 10.1021/jacs.5b13174] [Citation(s) in RCA: 94] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Catalytic enantioselective diboration of alkenes is accomplished with readily available carbohydrate-derived catalysts. Mechanistic experiments suggest the intermediacy of 1,2-bonded diboronates.
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Affiliation(s)
- Lichao Fang
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467
| | - Lu Yan
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467
| | - Fredrik Haeffner
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467
| | - James P. Morken
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467
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23
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Dewhurst RD, Neeve EC, Braunschweig H, Marder TB. sp(2)-sp(3) diboranes: astounding structural variability and mild sources of nucleophilic boron for organic synthesis. Chem Commun (Camb) 2015; 51:9594-607. [PMID: 25912808 DOI: 10.1039/c5cc02316e] [Citation(s) in RCA: 202] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Despite the widespread use of organoborane reagents in organic synthesis and catalysis, a major challenge still remains: very few boron-centered nucleophiles exist for the direct construction of B-C bonds. Perhaps the most promising emerging solution to this problem is the use of sp(2)-sp(3) diboranes, in which one boron atom of a conventional diborane(4) is quaternised by either a neutral or anionic nucleophile. These compounds, either isolated or generated in situ, serve as relatively mild and convenient sources of the boryl anion [BR2](-) for use in organic synthesis and have already proven their efficacy in metal-free as well as metal-catalysed borylation reactions. This Feature article documents the history of sp(2)-sp(3) diborane synthesis, their properties and surprising structural variability, and their burgeoning utility in organic synthesis.
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Affiliation(s)
- Rian D Dewhurst
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
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24
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Pietsch S, Paul U, Cade IA, Ingleson MJ, Radius U, Marder TB. Room temperature ring expansion of N-heterocyclic carbenes and B-B bond cleavage of diboron(4) compounds. Chemistry 2015; 21:9018-21. [PMID: 25960171 DOI: 10.1002/chem.201501498] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Indexed: 11/06/2022]
Abstract
We report the isolation and detailed structural characterization, by solid-state and solution NMR spectroscopy, of the neutral mono- and bis-NHC adducts of bis(catecholato)diboron (B2 cat2 ). The bis-NHC adduct undergoes thermally induced rearrangement, forming a six-membered -B-C=N-C=C-N-heterocyclic ring via C-N bond cleavage and ring expansion of the NHC, whereas the mono-NHC adduct is stable. Bis(neopentylglycolato)diboron (B2 neop2 ) is much more reactive than B2 cat2 giving a ring expanded product at room temperature, demonstrating that ring expansion of NHCs can be a very facile process with significant implications for their use in catalysis.
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Affiliation(s)
- Sabrina Pietsch
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg (Germany)
| | - Ursula Paul
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg (Germany)
| | - Ian A Cade
- School of Chemistry, The University of Manchester, Manchester M13 9PL (UK)
| | - Michael J Ingleson
- School of Chemistry, The University of Manchester, Manchester M13 9PL (UK).
| | - Udo Radius
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg (Germany).
| | - Todd B Marder
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg (Germany).
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25
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He G, Shynkaruk O, Lui MW, Rivard E. Small Inorganic Rings in the 21st Century: From Fleeting Intermediates to Novel Isolable Entities. Chem Rev 2014; 114:7815-80. [DOI: 10.1021/cr400547x] [Citation(s) in RCA: 156] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Gang He
- Department of Chemistry, University of Alberta, 11227 Saskatchewan
Drive, Edmonton, Alberta, Canada T6G 2G2
| | - Olena Shynkaruk
- Department of Chemistry, University of Alberta, 11227 Saskatchewan
Drive, Edmonton, Alberta, Canada T6G 2G2
| | - Melanie W. Lui
- Department of Chemistry, University of Alberta, 11227 Saskatchewan
Drive, Edmonton, Alberta, Canada T6G 2G2
| | - Eric Rivard
- Department of Chemistry, University of Alberta, 11227 Saskatchewan
Drive, Edmonton, Alberta, Canada T6G 2G2
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26
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Perras FA, Bryce DL. Boron–boron J coupling constants are unique probes of electronic structure: a solid-state NMR and molecular orbital study. Chem Sci 2014. [DOI: 10.1039/c4sc00603h] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
J couplings measured between 11B spin pairs in solid diboron compounds provide insight into electronic structure and crystallographic symmetry.
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Affiliation(s)
- Frédéric A. Perras
- Department of Chemistry and Centre for Catalysis Research and Innovation
- University of Ottawa
- Ottawa, Canada
| | - David L. Bryce
- Department of Chemistry and Centre for Catalysis Research and Innovation
- University of Ottawa
- Ottawa, Canada
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27
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Brinkmann A, Edén M. Central-transition double-quantum sideband NMR spectroscopy of half-integer quadrupolar nuclei: estimating internuclear distances and probing clusters within multi-spin networks. Phys Chem Chem Phys 2014; 16:7037-50. [DOI: 10.1039/c4cp00029c] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Clusters within quadrupolar spin networks are probed and internuclear distances between quadrupolar nuclei are estimated by central-transition double-quantum sideband NMR spectroscopy.
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Affiliation(s)
- Andreas Brinkmann
- Measurement Science and Standards
- National Research Council Canada
- Ottawa, Canada
| | - Mattias Edén
- Physical Chemistry Division
- Department of Materials and Environmental Chemistry
- Arrhenius Laboratory
- Stockholm University
- 106 91 Stockholm, Sweden
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28
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Braunschweig H, Guethlein F, Mailänder L, Marder TB. Synthesis of Catechol-, Pinacol-, and Neopentylglycolborane through the Heterogeneous Catalytic BB Hydrogenolysis of Diboranes(4). Chemistry 2013; 19:14831-5. [DOI: 10.1002/chem.201302677] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Indexed: 11/06/2022]
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29
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Perras FA, Bryce DL. Symmetry-amplified J splittings for quadrupolar spin pairs: a solid-state NMR probe of homoatomic covalent bonds. J Am Chem Soc 2013; 135:12596-9. [PMID: 23919916 PMCID: PMC3762131 DOI: 10.1021/ja407138b] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Chemically informative J couplings between pairs of quadrupolar nuclei in dimetallic and dimetalloid coordination motifs are measured using J-resolved solid-state NMR experiments. It is shown that the application of a double-quantum filter is necessary to observe the J splittings and that, under these conditions, only a simple doublet is expected. Interestingly, the splitting is amplified if the spins are magnetically equivalent, making it possible to measure highly precise J couplings and unambiguously probe the symmetry of the molecule. This is demonstrated experimentally by chemically breaking the symmetry about a pair of boron spins by reaction with an N-heterocyclic carbene to form a β-borylation reagent. The results show that the J coupling is a sensitive probe of bonding in diboron compounds and that the J values quantify the weakening of the B-B bond which occurs when forming an sp(2)-sp(3) diboron compound, which is relevant to their reactivity. Due to the prevalence of quadrupolar nuclei among transition metals, this work also provides a new approach to probe metal-metal bonding; results for Mn2(CO)10 are provided as an example.
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Affiliation(s)
- Frédéric A Perras
- Department of Chemistry and CCRI, University of Ottawa, Ottawa, Ontario, Canada K1N 6N5
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30
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Perras FA, Bryce DL. Measuring dipolar and J coupling between quadrupolar nuclei using double-rotation NMR. J Chem Phys 2013; 138:174202. [DOI: 10.1063/1.4802192] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
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31
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Rhodium complexes containing arylspiroborates derived from 3,5-di-tert-butylcatechol and their use in catalyzed hydroborations. Polyhedron 2013. [DOI: 10.1016/j.poly.2012.06.048] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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32
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Thorpe SB, Calderone JA, Santos WL. Unexpected Copper(II) Catalysis: Catalytic Amine Base Promoted β-Borylation of α,β-Unsaturated Carbonyl Compounds in Water. Org Lett 2012; 14:1918-21. [DOI: 10.1021/ol300575d] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Steven B. Thorpe
- Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Joseph A. Calderone
- Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Webster L. Santos
- Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, United States
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33
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Xie X, Haddow MF, Mansell SM, Norman NC, Russell CA. Diborane(4) compounds with bidentate diamino groups. Dalton Trans 2012; 41:2140-7. [DOI: 10.1039/c2dt11936f] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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34
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Braunschweig H, Bertermann R, Brenner P, Burzler M, Dewhurst RD, Radacki K, Seeler F. trans-[Pt(BCat′)Me(PCy3)2]: An Experimental Case Study of Reductive Elimination Processes in Pt-Boryls through Associative Mechanisms. Chemistry 2011; 17:11828-37. [DOI: 10.1002/chem.201101823] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2011] [Indexed: 11/10/2022]
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35
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Brinkmann A, Edén M. Estimating internuclear distances between half-integer quadrupolar nuclei by central-transition double-quantum sideband NMR spectroscopy. CAN J CHEM 2011. [DOI: 10.1139/v11-020] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We demonstrate the estimation of homonuclear dipolar couplings, and thereby internuclear distances, between half-integer spin quadrupolar nuclei by central-transition (CT) double-quantum (2Q) sideband nuclear magnetic resonance (NMR) spectroscopy. It is shown that the rotor-encoded sideband amplitudes from CT 2Q coherences in the indirect dimension of the two-dimensional NMR spectrum are sensitive probes of the magnitude of the homonuclear dipolar coupling, but are significantly less affected by other NMR parameters such as the magnitudes and orientations of the electric field gradient tensors. Experimental results of employing the [Formula: see text] recoupling sequence to the 11B spin pair of bis(catecholato)diboron resulted in an estimation of the internuclear B–B distance as (169.6 ± 3) pm, i.e., with a relative uncertainty of ±2%, and in excellent agreement with the distance of 167.8 pm determined by single-crystal X-ray diffraction.
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Affiliation(s)
- Andreas Brinkmann
- Steacie Institute for Molecular Sciences, National Research Council, 1200 Montreal Road, M-40, Ottawa, ON K1A 0R6, Canada
| | - Mattias Edén
- Physical Chemistry Division, Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, 106 91 Stockholm, Sweden
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Gao M, Thorpe SB, Kleeberg C, Slebodnick C, Marder TB, Santos WL. Structure and Reactivity of a Preactivated sp2–sp3 Diboron Reagent: Catalytic Regioselective Boration of α,β-Unsaturated Conjugated Compounds. J Org Chem 2011; 76:3997-4007. [DOI: 10.1021/jo2003488] [Citation(s) in RCA: 116] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ming Gao
- Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Steven B. Thorpe
- Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Christian Kleeberg
- Department of Chemistry, Durham University, South Road, Durham, DH1 3LE U.K
| | - Carla Slebodnick
- Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Todd B. Marder
- Department of Chemistry, Durham University, South Road, Durham, DH1 3LE U.K
| | - Webster L. Santos
- Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, United States
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Sun J, Perfetti MT, Santos WL. A method for the deprotection of alkylpinacolyl boronate esters. J Org Chem 2011; 76:3571-5. [PMID: 21449603 DOI: 10.1021/jo200250y] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A two-step procedure for deprotection of alkylpinacolyl boronate esters via transesterification with diethanolamine followed by hydrolysis was successfully developed with the advantages of tolerance to various functional groups, short reaction time, and ease of product isolation.
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Affiliation(s)
- Jing Sun
- Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, USA
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Vogels CM, Westcott SA. Arylspiroboronate esters: from lithium batteries to wood preservatives to catalysis. Chem Soc Rev 2011; 40:1446-58. [DOI: 10.1039/c0cs00023j] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Xie X, Haddow MF, Mansell SM, Norman NC, Russell CA. New polycyclic borazine species. Chem Commun (Camb) 2011; 47:3748-50. [DOI: 10.1039/c1cc10196j] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Huang K, Yu DG, Zheng SF, Wu ZH, Shi ZJ. Borylation of Aryl and Alkenyl Carbamates through Ni-Catalyzed CO Activation. Chemistry 2010; 17:786-91. [DOI: 10.1002/chem.201001943] [Citation(s) in RCA: 105] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2010] [Indexed: 11/12/2022]
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Appoh FE, Wheaton SL, Vogels CM, Baerlocher FJ, Decken A, Westcott SA. Synthesis, structure, and antifungal activity of dihydropyridones containing boronate esters. HETEROATOM CHEMISTRY 2009. [DOI: 10.1002/hc.20512] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Alibadi MAM, Batsanov AS, Bramham G, Charmant JPH, Haddow MF, MacKay L, Mansell SM, McGrady JE, Norman NC, Roffey A, Russell CA. 1,1- and 1,2-isomers of the diborane(4) compound B2{1,2-(NH)2C6H4}2 and a TCNQ Co-crystal of the 1,1-isomer. Dalton Trans 2009:5348-54. [DOI: 10.1039/b822225h] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Dang L, Zhao H, Lin Z, Marder TB. Understanding the Higher Reactivity of B2cat2 versus B2pin2 in Copper(I)-Catalyzed Alkene Diboration Reactions. Organometallics 2008. [DOI: 10.1021/om700999w] [Citation(s) in RCA: 101] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Li Dang
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Haitao Zhao
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Zhenyang Lin
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Todd B. Marder
- Department of Chemistry, Durham University, South Road, Durham DH1 3LE, U.K
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Fritschi CB, Wernitz SM, Vogels CM, Shaver MP, Decken A, Bell A, Westcott SA. 4,4,5,5-Tetraphenyl-1,3,2-dioxaborolane: A Bulky Borane for the Transition Metal Catalysed Hydroboration of Alkenes. Eur J Inorg Chem 2008. [DOI: 10.1002/ejic.200701066] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Mkhalid IAI, Coapes RB, Edes SN, Coventry DN, Souza FES, Thomas RL, Hall JJ, Bi SW, Lin Z, Marder TB. Rhodium catalysed dehydrogenative borylation of alkenes: Vinylboronates via C–H activation. Dalton Trans 2008:1055-64. [DOI: 10.1039/b715584k] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Charmant JPH, Fan C, Norman NC, Pringle PG. Synthesis and reactivity of dichloroboryl complexes of platinum(ii). Dalton Trans 2007:114-23. [PMID: 17160181 DOI: 10.1039/b612039n] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The reaction between [Pt(nbe)3] (nbe=norbornene), two equivalents of the phosphines PPh3, PMePh2 or PMe2Ph and 1 equivalent of BCl3 affords the platinum dichloroboryl species [PtCl(BCl2)(PPh3)2], [PtCl(BCl2)(PMePh2)2] and [PtCl(BCl2)(PMe2Ph)2]. All three complexes were characterised by X-ray crystallography and reveal that the boryl group lies trans to the chloride. With PMe3 as the phosphine, the complex [PtCl(BCl2)(PMe3)2] is isolated in high yield as a white crystalline powder although crystals suitable for X-ray crystallography were not obtained. Crystals were obtained of a product shown by X-ray crystallography to be the unusual dinuclear species [Pt2(BCl2)2(PMe3)4(micro-Cl)][BCl4] which reveals an arrangement in which two square planar platinum(II) centres are linked by a single bridging chloride which is trans to a BCl2 group on each platinum centre. The reaction of [PtCl(BCl2)(PMe3)2] with NEt3 or pyridine (py) affords the adducts [PtCl{BCl2(NEt3)}(PMe3)2] and [PtCl{BCl2(py)}(PMe3)2], respectively, both characterised spectroscopically. The reaction between [PtCl(BCl2)(PMe3)2] and either 4 equivalents of NHEt2 or piperidine (pipH) results in the mono-substituted boryl species [PtCl{BCl(NEt2)}(PMe3)2] and [PtCl{BCl(pip)}(PMe3)2], respectively, the former characterised by X-ray crystallography. Treatment of either [PtCl(BCl2)(PMe3)2] (in the presence of excess NEt3) or [PtCl{BCl(NEt2)}(PMe3)2] with catechol affords the B(cat) (cat=catecholate) derivative [PtCl{B(cat)}(PMe3)2] which is also formed in the reaction between [Pt(PMe3)4] and ClB(cat) and also from the slow decomposition of [Pt{B(cat)}2(PMe3)2] in dichloromethane over a period of months. The compound [Pt{B(cat)}2(PMe3)2] was prepared from the reaction between [Pt(PMe3)4] and B2(cat)2.
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Vogels CM, Decken A, Westcott SA. Catalyzed hydroboration of nitrostyrenes and 4-vinylaniline: a mild and selective route to aniline derivatives containing boronate esters. Tetrahedron Lett 2006. [DOI: 10.1016/j.tetlet.2006.01.144] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Wynberg NA, Leger LJ, Conrad ML, Vogels CM, Decken A, Duffy SJ, Westcott SA. Synthesis and catalysed hydroboration of styryl sulfonamides. CAN J CHEM 2005. [DOI: 10.1139/v05-078] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
We have prepared the aryl sulfonamides 4,4′-R-C6H4SO2NHC6H4CH=CH2 (R = CH3, 1a; NO2, 1b) by addition of 2 equiv. of 4-vinylaniline to the corresponding sulfonyl chlorides. The disulfonamides 4,4,4′-(R-C6H4SO2)2NC6H4CH=CH2 (R = CH3, 2a; NO2, 2b) were also prepared using 4-vinylaniline and 2 equiv. of the sulfonyl chlorides in the presence of DMAP. Although hydroborations of sulfanilamide derivatives 1 suffered from competing hydrogenation reactions, judicious choice of the transition metal catalyst gave selective formation of either the primary or secondary boronate esters in hydroborations of 2a.Key words: boronate esters, catalysed hydroborations, sulfanilamides, vinylaniline.
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