1
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Werner L, Radius U. NHC aluminum chemistry on the rise. Dalton Trans 2024. [PMID: 39225565 DOI: 10.1039/d4dt01660b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/04/2024]
Abstract
This perspective highlights recent developments of the use of N-heterocyclic carbenes (NHCs) and cyclic (alkyl)(amino)carbenes (cAACs) in alane and aluminum organyl chemistry. Especially in the last few years this flourishing research field led to some remarkable discoveries including various substitution patterns at the central aluminum atom, different oxidation states, neutral and charged compounds with varying coordination numbers and unique reactivities. Thereby NHCs play a vital role in the stabilization of these otherwise highly reactive compounds, which would not be realizable without the use of this intriguing class of ligands. Nevertheless, main group hydrides and especially NHC ligated alanes also tend to undergo NHC decomposition reactions, which are part of ongoing research and provide important information for NHC research in general.
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Affiliation(s)
- Luis Werner
- Institute for Inorganic Chemistry, 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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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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Chrysochos N, Pätsch S, Elvers BJ, Krummenacher I, Nandeshwar M, Prabusankar G, Braunschweig H, Schulzke C, Ravat P, Jana A. Introducing an orthogonally polarized electron-rich alkene: synthesis of a zwitterionic boron-containing π-conjugated system. Chem Commun (Camb) 2023; 59:12350-12353. [PMID: 37767978 DOI: 10.1039/d3cc03975g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/29/2023]
Abstract
The synthesis of an alkene is reported which is concurrently twisted (twist angle = 86.6(8)°), push-pull (dipole moment = 7.48 D), and electron-rich (E1/2 = -1.45 V and -0.52 V vs. Fc/Fc+) in nature, comprising a unique trinity combination for the alkene class of compounds. Subsequently, this newly synthesized alkene-motif was used as a donor for the synthesis of a zwitterionic boron-containing π-conjugated compound (dipole moment = 12.17 D) through an intramolecular charge transfer process exploiting the π-conjugated donor-acceptor system.
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Affiliation(s)
- Nicolas Chrysochos
- Tata Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad-500107, India.
| | - Sebastian Pätsch
- Institut für Biochemie, Universität Greifswald, Felix-Hausdorff-Straße 4, D-17489, Greifswald, Germany.
| | - Benedict J Elvers
- Institut für Biochemie, Universität Greifswald, Felix-Hausdorff-Straße 4, D-17489, Greifswald, Germany.
| | - Ivo Krummenacher
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
| | - Muneshwar Nandeshwar
- Department of Chemistry, Indian Institute of Technology Hyderabad, Kandi-502284, India.
| | - Ganesan Prabusankar
- Department of Chemistry, Indian Institute of Technology Hyderabad, Kandi-502284, India.
| | - Holger Braunschweig
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
| | - Carola Schulzke
- Institut für Biochemie, Universität Greifswald, Felix-Hausdorff-Straße 4, D-17489, Greifswald, Germany.
| | - Prince Ravat
- Institute of Organic Chemistry, University of Würzburg, Am Hubland, 97074 Würzburg, Germany.
| | - Anukul Jana
- Tata Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad-500107, India.
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4
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Horrer G, Luff MS, Radius U. N-Heterocyclic carbene and cyclic (alkyl)(amino)carbene ligated half-sandwich complexes of chromium(II) and chromium(I). Dalton Trans 2023; 52:13244-13257. [PMID: 37667868 DOI: 10.1039/d3dt02123h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/06/2023]
Abstract
The synthesis and characterization of a series of Cr(II) N-Heterocyclic Carbene (NHC) complexes of the type [{Cr(NHC)Cl(μ-Cl)}2] and [(Cyp)Cr(NHC)X] (Cyp = η5-C5H5, cyclopentadienyl; η5-C5Me5, pentamethylcyclopentadienyl; X = Cl, η3-C3H5; NHC = IMeMe, IiPrMe, IMes, IDipp) as well as the cyclic (alkyl)(amino)carbene cAACMe ligated complexes [(η5-C5H5)Cr(cAACMe)X] (X = Cl, NPh2), [(η5-C9H7)Cr(cAACMe)Cl] (C9H7 = Ind, indenyl) and [(η5-C13H9)Cr(cAACMe)Cl] (C13H9 = Fl, fluorenyl) are reported. The reduction of [(η5-C5Me5)Cr(IMeMe)Cl] with KC8 in the presence of CO afforded the NHC ligated Cr(I) metallo-radical [(η5-C5Me5)Cr(IMeMe)(CO)2]. Quantum chemical calculations performed on [(η5-C5Me5)Cr(IMeMe)(CO)2] confirm for this complex a predominantly chromium centered radical.
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Affiliation(s)
- Günther Horrer
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
| | - Martin S Luff
- 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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5
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Herbstritt D, Tomar P, Braun T. Activation of SF 5CF 3 by the N-Heterocyclic Carbene SIMes. Molecules 2023; 28:6693. [PMID: 37764468 PMCID: PMC10535660 DOI: 10.3390/molecules28186693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 09/06/2023] [Accepted: 09/14/2023] [Indexed: 09/29/2023] Open
Abstract
The greenhouse gas SF5CF3 was photochemically activated with SIMes (1,3-Bis(2,4,6-trimethylphenyl)-4,5-dihydroimidazol-2-ylidene) to give 1,3-dimesityl-2,2-difluoroimidazolidine (SIMesF2), and 1,3-dimesitylimidazolidine-2-sulfide, as well as the trifluoromethylated carbene derivative 1,3-dimesityl-2-fluoro-2-trifluoromethylimidazolidine. CF3 radicals, as well as SF4, serve presumably as intermediates of the conversions. In addition, the photochemical activation of SF5CF3 was performed in the presence of triphenylphosphine. The formation of triphenyldifluorophosphorane and triphenylphosphine sulfide was observed.
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Affiliation(s)
| | | | - Thomas Braun
- Department of Chemistry, Humboldt–Universität zu Berlin, Brook-Taylor-Str. 2, 12489 Berlin, Germany
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6
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Baguli S, Kundu A, Nath S, Adhikari D, Mukherjee D. A Donor-Acceptor Cyclopropane by Intramolecular C(sp 3)-H Activation at a Cyclic(alkyl)(amino)carbene Center and Its Fascinating Ring-Opening Chemistry. Org Lett 2023; 25:3141-3145. [PMID: 37093744 DOI: 10.1021/acs.orglett.3c01072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2023]
Abstract
Virtually irreversible intramolecular C-H activations are deleterious for aza-carbenes. A picolyl-tethered cyclic(alkyl)(amino)carbene (CAAC) isomerizes into a donor-acceptor cyclopropane in this manner but restores the CAAC status by retro-C-H activation in the presence of trapping agents like Se or CuCl. The same DA cyclopropane is readily hydrolyzed to a pyrrolidin-2-ol that acts as another picoCAAC precursor by undergoing 1,1-dehydration in the presence of Se or CuCl. The chemistry is distinct from the N-heterocyclic carbene analogue throughout.
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Affiliation(s)
- Sudip Baguli
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata Mohanpur, Nadia, West Bengal 741246, India
| | - Abhishek Kundu
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, SAS Nagar, Manauli, Punjab 140306, India
| | - Soumajit Nath
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata Mohanpur, Nadia, West Bengal 741246, India
| | - Debashis Adhikari
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, SAS Nagar, Manauli, Punjab 140306, India
| | - Debabrata Mukherjee
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata Mohanpur, Nadia, West Bengal 741246, India
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7
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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: 9] [Impact Index Per Article: 9.0] [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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8
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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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9
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Nayak MK, Sarkar P, Elvers BJ, Mehta S, Zhang F, Chrysochos N, Krummenacher I, Vijayakanth T, Narayanan RS, Dolai R, Roy B, Malik V, Rawat H, Mondal A, Boomishankar R, Pati SK, Braunschweig H, Schulzke C, Ravat P, Jana A. A bis-NHC-CAAC dimer derived dicationic diradical. Chem Sci 2022; 13:12533-12539. [PMID: 36382295 PMCID: PMC9629079 DOI: 10.1039/d2sc03937k] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Accepted: 09/21/2022] [Indexed: 08/11/2023] Open
Abstract
The isolation of carbon-centered diradicals is always challenging due to synthetic difficulties and their limited stability. Herein we report the synthesis of a trans-1,4-cyclohexylene bridged bis-NHC-CAAC dimer derived thermally stable dicationic diradical. The diradical character of this compound was confirmed by EPR spectroscopy. The variable temperature EPR study suggests the singlet state to be marginally more stable than the triplet state (2J = -5.5 cm-1 (ΔE ST = 0.065 kJ mol-1)). The presence of the trans-1,4-cyclohexylene bridge is instrumental for the successful isolation of this dicationic diradical. Notably, in the case of ethylene or propylene bridged bis-NHC-CAAC dimers, the corresponding dicationic diradicals are transient and rearrange to hydrogen abstracted products.
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Affiliation(s)
| | - Pallavi Sarkar
- Theoretical Sciences Unit, Jawaharlal Nehru Centre for Advanced Scientific Research Bangalore-560064 India
| | - Benedict J Elvers
- Institut für Biochemie, Universität Greifswald Felix-Hausdorff-Straße 4 D-17489, Greifswald Germany
| | - Sakshi Mehta
- Solid State and Structural Chemistry Unit, Indian Institute of Science Bangalore 560012 India
| | - Fangyuan Zhang
- Institute of Organic Chemistry, University of Würzburg Am Hubland 97074 Würzburg Germany
| | - Nicolas Chrysochos
- Tata Institute of Fundamental Research Hyderabad Gopanpally Hyderabad-500107 India
| | - Ivo Krummenacher
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Thangavel Vijayakanth
- Department of Chemistry, Indian Institute of Science Education and Research Pune Dr Homi Bhabha Road Pune 411008 India
| | | | - Ramapada Dolai
- Tata Institute of Fundamental Research Hyderabad Gopanpally Hyderabad-500107 India
| | - Biswarup Roy
- Tata Institute of Fundamental Research Hyderabad Gopanpally Hyderabad-500107 India
| | - Vishal Malik
- Tata Institute of Fundamental Research Hyderabad Gopanpally Hyderabad-500107 India
| | - Hemant Rawat
- Tata Institute of Fundamental Research Hyderabad Gopanpally Hyderabad-500107 India
| | - Abhishake Mondal
- Solid State and Structural Chemistry Unit, Indian Institute of Science Bangalore 560012 India
| | - Ramamoorthy Boomishankar
- Department of Chemistry, Indian Institute of Science Education and Research Pune Dr Homi Bhabha Road Pune 411008 India
| | - Swapan K Pati
- Theoretical Sciences Unit, Jawaharlal Nehru Centre for Advanced Scientific Research Bangalore-560064 India
| | - Holger Braunschweig
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Carola Schulzke
- Institut für Biochemie, Universität Greifswald Felix-Hausdorff-Straße 4 D-17489, Greifswald Germany
| | - Prince Ravat
- Institute of Organic Chemistry, University of Würzburg Am Hubland 97074 Würzburg Germany
| | - Anukul Jana
- Tata Institute of Fundamental Research Hyderabad Gopanpally Hyderabad-500107 India
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10
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Philipp MSM, Bertermann R, Radius U. N-heterocyclic carbene and cyclic (alkyl)(amino)carbene adducts of plumbanes and plumbylenes. Dalton Trans 2022; 51:13488-13498. [PMID: 35997066 DOI: 10.1039/d2dt02462d] [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
Lewis-acid/base adducts of N-heterocyclic carbenes (NHCs) and the cyclic (alkyl)(amino)carbene cAACMe (1-(2,6-di-iso-propylphenyl)-3,3,5,5-tetramethyl-pyrrolidin-2-ylidene) with selected lead(II) and lead(IV) compounds are presented. The reaction of the NHCs Me2ImMe (1,3,4,5-tetramethyl-imidazolin-2-ylidene), iPr2ImMe (1,3-di-isopropyl-4,5-dimethyl-imidazolin-2-ylidene), Dipp2Im (1,3-bis-(2,6-di-isopropylphenyl)-imidazolin-2-ylidene) and cAACMe (1-(2,6-di-iso-propylphenyl)-3,3,5,5-tetramethyl-pyrrolidin-2-ylidene) with PbI2 yielded the NHC-containing plumbylenes NHC·PbI2 (NHC = Me2ImMe (1), iPr2ImMe (2), Dipp2Im (3) and cAACMe·PbI2 (4)). Using the Pb(IV) compound PbCl2Ph2, the plumbane adducts NHC·PbCl2Ph2 (NHC = Me2ImMe (5), iPr2ImMe (6), Dipp2Im (7)) and cAACMe·PbCl2Ph2 (8)) were isolated in high yields. Reduction of the lead(IV) adducts 5 and 6 with excess KC8 afforded the diaryl substituted plumbylenes Me2ImMe·PbPh2 (9) and iPr2ImMe·PbPh2 (10), which are stable in the solid state but decompose in solution.
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Affiliation(s)
- Michael S M Philipp
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
| | - Rüdiger Bertermann
- Institute for Inorganic Chemistry, 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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11
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Philipp MSM, Bertermann R, Radius U. N‐Heterocyclic Carbene and Cyclic (Alkyl)(amino)carbene Adducts of Germanium(IV) and Tin(IV) Chlorides and Organyl Chlorides. Eur J Inorg Chem 2022. [DOI: 10.1002/ejic.202200429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Michael S. M. Philipp
- Julius-Maximilians-Universität Würzburg: Julius-Maximilians-Universitat Wurzburg Inorganic Chemistry GERMANY
| | - Rüdiger Bertermann
- Julius-Maximilians-Universität Würzburg: Julius-Maximilians-Universitat Wurzburg Inorganic Chemistry GERMANY
| | - Udo Radius
- Julius-Maximilians-Universität Würzburg: Julius-Maximilians-Universitat Wurzburg Institut für Anorganische Chemie Am Hubland 97074 Würzburg GERMANY
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12
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Das A, Elvers BJ, Nayak MK, Chrysochos N, Anga S, Kumar A, Rao DK, Narayanan TN, Schulzke C, Yildiz CB, Jana A. Realizing 1,1-Dehydration of Secondary Alcohols to Carbenes: Pyrrolidin-2-ols as a Source of Cyclic (Alkyl)(Amino)Carbenes. Angew Chem Int Ed Engl 2022; 61:e202202637. [PMID: 35362643 PMCID: PMC9400972 DOI: 10.1002/anie.202202637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Indexed: 11/30/2022]
Abstract
Herein we report secondary pyrrolidin-2-ols as a source of cyclic (alkyl)(amino)carbenes (CAAC) for the synthesis of CAAC-CuI -complexes and cyclic thiones when reacted with CuI -salts and elemental sulfur, respectively, under reductive elimination of water from the carbon(IV)-center. This result demonstrates a convenient and facile access to CAAC-based CuI -salts, which are well known catalysts for different organic transformations. It further establishes secondary alcohols to be a viable source of carbenes-realizing after 185 years Dumas' dream who tried to prepare the parent carbene (CH2 ) by 1,1-dehydration of methanol. Addressed is also the reactivity of water towards CAACs, which proceeds through an oxidative addition of the O-H bond to the carbon(II)-center. This emphasizes the ability of carbon-compounds to mimic the reactivity of transition-metal complexes: reversible oxidative addition and reductive elimination of the O-H bond to/from the C(II)/C(IV)-centre.
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Affiliation(s)
- Ayan Das
- Tata Institute of Fundamental Research Hyderabad, GopanpallyHyderabad 500046TelanganaIndia
| | - Benedict J. Elvers
- Institut für BiochemieUniversität GreifswaldFelix-Hausdorff-Straße 417489GreifswaldGermany
| | - Mithilesh Kumar Nayak
- Tata Institute of Fundamental Research Hyderabad, GopanpallyHyderabad 500046TelanganaIndia
| | - Nicolas Chrysochos
- Tata Institute of Fundamental Research Hyderabad, GopanpallyHyderabad 500046TelanganaIndia
| | - Srinivas Anga
- Tata Institute of Fundamental Research Hyderabad, GopanpallyHyderabad 500046TelanganaIndia
| | - Amar Kumar
- Tata Institute of Fundamental Research Hyderabad, GopanpallyHyderabad 500046TelanganaIndia
| | - D. Krishna Rao
- Tata Institute of Fundamental Research Hyderabad, GopanpallyHyderabad 500046TelanganaIndia
| | | | - Carola Schulzke
- Institut für BiochemieUniversität GreifswaldFelix-Hausdorff-Straße 417489GreifswaldGermany
| | - Cem B. Yildiz
- Department of Aromatic and Medicinal PlantsAksaray UniversityAksaray68100Turkey
| | - Anukul Jana
- Tata Institute of Fundamental Research Hyderabad, GopanpallyHyderabad 500046TelanganaIndia
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13
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Serrato MR, Melaimi M, Bertrand G. Cyclic (amino)(barrelene)carbenes: an original family of CAACs through a novel synthetic pathway. Chem Commun (Camb) 2022; 58:7519-7521. [PMID: 35699417 DOI: 10.1039/d2cc02565e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
A novel family of cyclic (alkyl)(amino)carbenes, which we name cyclic (amino)(barrelene)carbenes (CABCs) is reported. The key synthetic step involves an intramolecular [4+2] cyclization of an anthracene derivative with an alkyne. This synthetic approach allows for the attachment of both aryl and alkyl groups on the nitrogen atom. When used as ligand, two of the barrelene hydrogens are in close contact with the metal, which could stabilize low valent catalytic intermediates.
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Affiliation(s)
- Melinda R Serrato
- UCSD-CNRS Joint Research Laboratory (IRL 3555), Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California, 92093, USA.
| | - Mohand Melaimi
- UCSD-CNRS Joint Research Laboratory (IRL 3555), Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California, 92093, USA.
| | - Guy Bertrand
- UCSD-CNRS Joint Research Laboratory (IRL 3555), Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California, 92093, USA.
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14
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Radius U, Philipp MS. A Versatile Route To Cyclic (Alkyl)(Amino)Carbene‐stabilized Stibinidenes. Z Anorg Allg Chem 2022. [DOI: 10.1002/zaac.202200085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Udo Radius
- Universität Würzburg Institut für Anorganische Chemie Am Hubland 97074 Würzburg GERMANY
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15
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Das A, Elvers BJ, Nayak MK, Chrysochos N, Anga S, Kumar A, Rao DK, Narayanan TN, Schulzke C, Yildiz CB, Jana A. Realizing the 1,1‐Dehydration of Secondary Alcohols to Carbenes: Pyrrolidin‐2‐ols as a Source of Cyclic (Alkyl)(Amino)Carbenes. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202202637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Ayan Das
- Tata Institute of Fundamental Research Hyderabad Chemistry INDIA
| | | | | | | | - Srinivas Anga
- Tata Institute of Fundamental Research Hyderabad Chemistry INDIA
| | - Amar Kumar
- Tata Institute of Fundamental Research Hyderabad Chemistry INDIA
| | - D. Krishna Rao
- Tata Institute of Fundamental Research Hyderabad Chemistry INDIA
| | | | | | - Cem B. Yildiz
- Aksaray Universitesi Aromatic and Medicinal Plants TURKEY
| | - Anukul Jana
- TIFR Centre for Interdisciplinary Sciences Chemical Science 21, Brundavan Colony, Narsingi 500075 Hyderabad INDIA
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16
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He Y, Wang Y, Li SJ, Lan Y, Wang X. Deoxygenative Cross-Coupling of Aromatic Amides with Polyfluoroarenes. Angew Chem Int Ed Engl 2022; 61:e202115497. [PMID: 35014163 DOI: 10.1002/anie.202115497] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Indexed: 01/17/2023]
Abstract
Considering the ubiquitous nature and ready synthesis of amides, and the great significance of organofluorine-containing species, the cross-coupling of amides and polyfluoroarenes, leading to new carbon-carbon bond-forming methodologies, would find useful applications in synthesis, late-stage functionalization, and rapid generation of molecular diversity. Herein, we present a novel synthesis of α-polyfluoroaryl amines via Sm/SmI2 -mediated deoxygenative cross-coupling of aromatic amides with polyfluoroarenes through direct C-H functionalization. The structural and functional diversity of these readily available precursors provides a versatile and flexible strategy for the streamlined synthesis of α-polyfluoroaryl amines. Combining experimental and theoretical studies, a novel plausible mechanism of the α-aminocarbene-mediated C-H insertion has been revealed, which may stimulate future work for the development of novel methods in amine synthesis.
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Affiliation(s)
- Youliang He
- State Key Laboratory of Organometallic Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China
| | - Yuxiao Wang
- State Key Laboratory of Organometallic Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China
| | - Shi-Jun Li
- Green Catalysis Center, and College of Chemistry, Zhengzhou University, Zhengzhou, 450001, China
| | - Yu Lan
- Green Catalysis Center, and College of Chemistry, Zhengzhou University, Zhengzhou, 450001, China.,School of Chemistry and Chemical Engineering, Chongqing Key Laboratory of Theoretical and Computational Chemistry, Chongqing University, Chongqing, 400030, China
| | - Xiaoming Wang
- State Key Laboratory of Organometallic Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China.,School of Chemistry and Materials Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, 1 Sub-lane Xiangshan, Hangzhou, 310024, China
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17
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He Y, Wang Y, Li S, Lan Y, Wang X. Deoxygenative Cross‐Coupling of Aromatic Amides with Polyfluoroarenes. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202115497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Youliang He
- State Key Laboratory of Organometallic Chemistry Center for Excellence in Molecular Synthesis Shanghai Institute of Organic Chemistry University of Chinese Academy of Sciences Chinese Academy of Sciences 345 Lingling Road Shanghai 200032 China
| | - Yuxiao Wang
- State Key Laboratory of Organometallic Chemistry Center for Excellence in Molecular Synthesis Shanghai Institute of Organic Chemistry University of Chinese Academy of Sciences Chinese Academy of Sciences 345 Lingling Road Shanghai 200032 China
| | - Shi‐Jun Li
- Green Catalysis Center, and College of Chemistry Zhengzhou University Zhengzhou 450001 China
| | - Yu Lan
- Green Catalysis Center, and College of Chemistry Zhengzhou University Zhengzhou 450001 China
- School of Chemistry and Chemical Engineering Chongqing Key Laboratory of Theoretical and Computational Chemistry Chongqing University Chongqing 400030 China
| | - Xiaoming Wang
- State Key Laboratory of Organometallic Chemistry Center for Excellence in Molecular Synthesis Shanghai Institute of Organic Chemistry University of Chinese Academy of Sciences Chinese Academy of Sciences 345 Lingling Road Shanghai 200032 China
- School of Chemistry and Materials Science Hangzhou Institute for Advanced Study University of Chinese Academy of Sciences 1 Sub-lane Xiangshan Hangzhou 310024 China
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18
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Muthuvel K, Gandhi T. C–F Bond Activation and Functionalizations enabled by Metal‐free NHCs and Their Metal Complexes. ChemCatChem 2022. [DOI: 10.1002/cctc.202101579] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Karthick Muthuvel
- Vellore Institute of Technology: VIT University Department of Chemistry INDIA
| | - Thirumanavelan Gandhi
- VIT University Materials Chemistry Division, School of Advanced Sciences VIT University 632014 Vellore INDIA
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19
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Philipp MSM, Krahfuss MJ, Radacki K, Radius U. N‐Heterocyclic Carbene and Cyclic (Alkyl)(amino)carbene Adducts of Antimony(III). Eur J Inorg Chem 2021. [DOI: 10.1002/ejic.202100632] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Michael S. M. Philipp
- Institute of Inorganic Chemistry Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Mirjam J. Krahfuss
- Institute of Inorganic Chemistry Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Krzysztof Radacki
- Institute of Inorganic Chemistry Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Udo Radius
- Institute of Inorganic Chemistry Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
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20
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Naumann RA, Ziller JW, Liberman-Martin AL. Crystal structure of 2-(2,6-diiso-propyl-phen-yl)- N, N-diethyl-3,3-dimethyl-2-aza-spiro-[4.5]decan-1-amine: a di-ethyl-amine adduct of a cyclic(alk-yl)(amino)-carbene (CAAC). Acta Crystallogr E Crystallogr Commun 2021; 77:903-906. [PMID: 34584759 PMCID: PMC8423011 DOI: 10.1107/s2056989021007854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 07/30/2021] [Indexed: 11/25/2022]
Abstract
The structure of the title compound, C27H46N2, at 93 K has monoclinic (P21/n) symmetry. The title compound was prepared by treatment of 2-(2,6-diiso-propyl-phenyl)-3,3-dimethyl-2-aza-spiro-[4.5]dec-1-en-2-ium hydrogen dichloride with two equivalents of lithium di-ethyl-amide. Characterization of the title compound by single-crystal X-ray diffraction and 1H and 13C NMR spectroscopy is presented. Formation of the di-ethyl-amine adduct of the cyclic(alk-yl)(amino)-carbene (CAAC) was unexpected, as deprotonation using lithium diiso-propyl-amide results in free CAAC formation.
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Affiliation(s)
- Roxanne A. Naumann
- Chemistry and Biochemistry Program, Schmid College of Science and Technology, Chapman University, 1 University Drive, Orange, CA 92866, USA
| | - Joseph W. Ziller
- Department of Chemistry, University of California, Irvine, Natural Sciences II, Irvine, CA 92697, USA
| | - Allegra L. Liberman-Martin
- Chemistry and Biochemistry Program, Schmid College of Science and Technology, Chapman University, 1 University Drive, Orange, CA 92866, USA
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21
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Zhang L, Huang X, Wang J, He W. Hypervalent Iodine‐Mediated and Traceless Fluorine‐Oriented: Synthesis of 5‐Methyl‐1,2,3,4‐tetrahydropyridine from Unactivated Alkenes. ASIAN J ORG CHEM 2021. [DOI: 10.1002/ajoc.202100290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Lu‐Wen Zhang
- Department of Chemistry School of Pharmacy The Fourth Military Medical University Xi'an 710032 P. R. China
| | - Xie Huang
- State Key Laboratory of Trauma Burns and Combined Injury Institute of Combined Injury Chongqing Engineering Research Center for Nanomedicine Department College of Preventive Medicine Third Military Medical University Chongqing 400038 P. R. China
| | - Jia‐Qi Wang
- Department of Chemistry School of Pharmacy The Fourth Military Medical University Xi'an 710032 P. R. China
| | - Wei He
- Department of Chemistry School of Pharmacy The Fourth Military Medical University Xi'an 710032 P. R. China
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22
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Föhrenbacher SA, Zeh V, Krahfuss MJ, Ignat'ev NV, Finze M, Radius U. Tris(pentafluoroethyl)difluorophosphorane and
N
‐Heterocyclic Carbenes: Adduct Formation and Frustrated
Lewis
Pair Reactivity. Eur J Inorg Chem 2021. [DOI: 10.1002/ejic.202100183] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Steffen A. Föhrenbacher
- Institute of Inorganic Chemistry Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Vivien Zeh
- Institute of Inorganic Chemistry Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Mirjam J. Krahfuss
- Institute of Inorganic Chemistry Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Nikolai V. Ignat'ev
- Institute of Inorganic Chemistry Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
- Institute for Sustainable Chemistry & Catalysis with Boron (ICB) Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
- Consultant Merck KGaA Frankfurter Straße 250 64293 Darmstadt Germany
| | - Maik Finze
- Institute of Inorganic Chemistry Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
- Institute for Sustainable Chemistry & Catalysis with Boron (ICB) Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Udo Radius
- Institute of Inorganic Chemistry Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
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23
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Schmid P, Fantuzzi F, Klopf J, Schröder NB, Dewhurst RD, Braunschweig H, Engel V, Engels B. Twisting versus Delocalization in CAAC- and NHC-Stabilized Boron-Based Biradicals: The Roles of Sterics and Electronics. Chemistry 2021; 27:5160-5170. [PMID: 33225473 PMCID: PMC8048672 DOI: 10.1002/chem.202004619] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 11/12/2020] [Indexed: 11/06/2022]
Abstract
Twisted boron-based biradicals featuring unsaturated C2 R2 (R=Et, Me) bridges and stabilization by cyclic (alkyl)(amino)carbenes (CAACs) were recently prepared. These species show remarkable geometrical and electronic differences with respect to their unbridged counterparts. Herein, a thorough computational investigation on the origin of their distinct electrostructural properties is performed. It is shown that steric effects are mostly responsible for the preference for twisted over planar structures. The ground-state multiplicity of the twisted structure is modulated by the σ framework of the bridge, and different R groups lead to distinct multiplicities. In line with the experimental data, a planar structure driven by delocalization effects is observed as global minimum for R=H. The synthetic elusiveness of C2 R2 -bridged systems featuring N-heterocyclic carbenes (NHCs) was also investigated. These results could contribute to the engineering of novel main group biradicals.
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Affiliation(s)
- Paul Schmid
- Institute for Physical and Theoretical ChemistryJulius-Maximilians-Universität WürzburgEmil-Fischer-Strasse 4297074WürzburgGermany
| | - Felipe Fantuzzi
- Institute for Physical and Theoretical ChemistryJulius-Maximilians-Universität WürzburgEmil-Fischer-Strasse 4297074WürzburgGermany
- Institute for Inorganic ChemistryJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
- Institute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Jonas Klopf
- Institute for Physical and Theoretical ChemistryJulius-Maximilians-Universität WürzburgEmil-Fischer-Strasse 4297074WürzburgGermany
| | - Niklas B. Schröder
- Institute for Physical and Theoretical ChemistryJulius-Maximilians-Universität WürzburgEmil-Fischer-Strasse 4297074WürzburgGermany
| | - Rian D. Dewhurst
- Institute for Inorganic ChemistryJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
- Institute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Holger Braunschweig
- Institute for Inorganic ChemistryJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
- Institute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Volker Engel
- Institute for Physical and Theoretical ChemistryJulius-Maximilians-Universität WürzburgEmil-Fischer-Strasse 4297074WürzburgGermany
| | - Bernd Engels
- Institute for Physical and Theoretical ChemistryJulius-Maximilians-Universität WürzburgEmil-Fischer-Strasse 4297074WürzburgGermany
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24
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Werner L, Horrer G, Philipp M, Lubitz K, Kuntze‐Fechner MW, Radius U. A General Synthetic Route to NHC‐Phosphinidenes: NHC‐mediated Dehydrogenation of Primary Phosphines. Z Anorg Allg Chem 2021. [DOI: 10.1002/zaac.202000405] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Luis Werner
- Institut für Anorganische Chemie Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Günther Horrer
- Institut für Anorganische Chemie Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Michael Philipp
- Institut für Anorganische Chemie Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Katharina Lubitz
- 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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25
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Föhrenbacher SA, Krahfuss MJ, Zapf L, Friedrich A, Ignat'ev NV, Finze M, Radius U. Tris(pentafluoroethyl)difluorophosphorane: A Versatile Fluoride Acceptor for Transition Metal Chemistry. Chemistry 2021; 27:3504-3516. [PMID: 33241855 PMCID: PMC7898530 DOI: 10.1002/chem.202004885] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 11/23/2020] [Indexed: 12/13/2022]
Abstract
Fluoride abstraction from different types of transition metal fluoride complexes [Ln MF] (M=Ti, Ni, Cu) by the Lewis acid tris(pentafluoroethyl)difluorophosphorane (C2 F5 )3 PF2 to yield cationic transition metal complexes with the tris(pentafluoroethyl)trifluorophosphate counterion (FAP anion, [(C2 F5 )3 PF3 ]- ) is reported. (C2 F5 )3 PF2 reacted with trans-[Ni(iPr2 Im)2 (ArF )F] (iPr2 Im=1,3-diisopropylimidazolin-2-ylidene; ArF =C6 F5 , 1 a; 4-CF3 -C6 F4 , 1 b; 4-C6 F5 -C6 F4 , 1 c) through fluoride transfer to form the complex salts trans-[Ni(iPr2 Im)2 (solv)(ArF )]FAP (2 a-c[solv]; solv=Et2 O, CH2 Cl2 , THF) depending on the reaction medium. In the presence of stronger Lewis bases such as carbenes or PPh3 , solvent coordination was suppressed and the complexes trans-[Ni(iPr2 Im)2 (PPh3 )(C6 F5 )]FAP (trans-2 a[PPh3 ]) and cis-[Ni(iPr2 Im)2 (Dipp2 Im)(C6 F5 )]FAP (cis-2 a[Dipp2 Im]) (Dipp2 Im=1,3-bis(2,6-diisopropylphenyl)imidazolin-2-ylidene) were isolated. Fluoride abstraction from [(Dipp2 Im)CuF] (3) in CH2 Cl2 or 1,2-difluorobenzene led to the isolation of [{(Dipp2 Im)Cu}2 ]2+ 2 FAP- (4). Subsequent reaction of 4 with PPh3 and different carbenes resulted in the complexes [(Dipp2 Im)Cu(LB)]FAP (5 a-e, LB=Lewis base). In the presence of C6 Me6 , fluoride transfer afforded [(Dipp2 Im)Cu(C6 Me6 )]FAP (5 f), which serves as a source of [(Dipp2 Im)Cu)]+ . Fluoride abstraction of [Cp2 TiF2 ] (7) resulted in the formation of dinuclear [FCp2 Ti(μ-F)TiCp2 F]FAP (8) (Cp=η5 -C5 H5 ) with one terminal fluoride ligand at each titanium atom and an additional bridging fluoride ligand.
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Affiliation(s)
- Steffen A. Föhrenbacher
- Institute of Inorganic ChemistryJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Mirjam J. Krahfuss
- Institute of Inorganic ChemistryJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Ludwig Zapf
- Institute of Inorganic ChemistryJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
- Institute for Sustainable Chemistry & Catalysis with Boron (ICB)Julius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Alexandra Friedrich
- Institute of Inorganic ChemistryJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
- Institute for Sustainable Chemistry & Catalysis with Boron (ICB)Julius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Nikolai V. Ignat'ev
- Institute of Inorganic ChemistryJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
- Institute for Sustainable Chemistry & Catalysis with Boron (ICB)Julius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
- ConsultantMerck KGaAFrankfurter Strasse 25064293DarmstadtGermany
| | - Maik Finze
- Institute of Inorganic ChemistryJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
- Institute for Sustainable Chemistry & Catalysis with Boron (ICB)Julius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Udo Radius
- Institute of Inorganic ChemistryJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
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26
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Nayak MK, Suhr S, Chrysochos N, Rawat H, Schulzke C, Chandrasekhar V, Sarkar B, Jana A. Tethered CAAC-CAAC dimers: oxidation to persistent radical cations and bridging-unit dependent reactivity/stability of the dications. Chem Commun (Camb) 2021; 57:1210-1213. [PMID: 33416055 DOI: 10.1039/d0cc07385g] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Herein, we report tethered cyclic(alkyl)(amino)carbene (CAAC) dimers in which two CAAC-motifs are connected by an ethylene-, trans-1,2-cyclohexylene- and propylene-spacer through their N-centres. The 1-electron oxidized radical cations are isolable, whereas a significant influence of the bridging unit on the chemical reactivity becomes apparent in and with the 2-electron oxidized products.
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Affiliation(s)
- Mithilesh Kumar Nayak
- Tata Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad-500046, Telangana, India.
| | - Simon Suhr
- Institut für Chemie und Biochemie, Freie Universität Berlin, Fabeckstraße 34-36, 14195 Berlin, Germany and Universität Stuttgart, Fakultät Chemie, Lehrstuhl für Anorganische Koordinationschemie, Institut für Anorganische Chemie, Pfaffenwaldring 55, Stuttgart, D-70569, Germany.
| | - Nicolas Chrysochos
- Institut für Biochemie, Universität Greifswald, Felix-Hausdorff-Straße 4, Greifswald, D-17489, Germany.
| | - Hemant Rawat
- Tata Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad-500046, Telangana, India.
| | - Carola Schulzke
- Institut für Biochemie, Universität Greifswald, Felix-Hausdorff-Straße 4, Greifswald, D-17489, Germany.
| | - Vadapalli Chandrasekhar
- Tata Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad-500046, Telangana, India. and Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur-208016, India.
| | - Biprajit Sarkar
- Institut für Chemie und Biochemie, Freie Universität Berlin, Fabeckstraße 34-36, 14195 Berlin, Germany and Universität Stuttgart, Fakultät Chemie, Lehrstuhl für Anorganische Koordinationschemie, Institut für Anorganische Chemie, Pfaffenwaldring 55, Stuttgart, D-70569, Germany.
| | - Anukul Jana
- Tata Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad-500046, Telangana, India.
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27
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Messelberger J, Kumar M, Goodner SJ, Munz D. Wanzlick's equilibrium in tri- and tetraaminoolefins. Org Chem Front 2021. [DOI: 10.1039/d1qo01320c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
How to isolate small carbenes, previously reported to from dimers instantaneously, and how to split triaminoolefins into free carbenes.
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Affiliation(s)
- Julian Messelberger
- Saarland University, Inorganic Chemistry: Coordination Chemistry, Campus C4.1, D-66123 Saarbrücken, Germany
| | - Manoj Kumar
- Saarland University, Inorganic Chemistry: Coordination Chemistry, Campus C4.1, D-66123 Saarbrücken, Germany
| | - Stephen J. Goodner
- Saarland University, Inorganic Chemistry: Coordination Chemistry, Campus C4.1, D-66123 Saarbrücken, Germany
- Friedrich-Alexander Universität Erlangen-Nürnberg, Department of Chemistry and Pharmacy: Chair of Inorganic and General Chemistry, Egerlandstraße 1, D-91058 Erlangen, Germany
| | - Dominik Munz
- Saarland University, Inorganic Chemistry: Coordination Chemistry, Campus C4.1, D-66123 Saarbrücken, Germany
- Friedrich-Alexander Universität Erlangen-Nürnberg, Department of Chemistry and Pharmacy: Chair of Inorganic and General Chemistry, Egerlandstraße 1, D-91058 Erlangen, Germany
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28
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Ertler D, Kuntze-Fechner MW, Dürr S, Lubitz K, Radius U. C–F bond activation of perfluorinated arenes using NHC-stabilized cobalt half-sandwich complexes. NEW J CHEM 2021. [DOI: 10.1039/d0nj06137a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
A study on the reactivity of cobalt half-sandwich complexes [Cp(*)Co(NHC)(olefin)] with perfluoroarenes demonstrates that C–F activation occurs along a one-electron oxidative addition pathway.
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Affiliation(s)
- Daniel Ertler
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Maximilian W. Kuntze-Fechner
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Simon Dürr
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Katharina Lubitz
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Udo Radius
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
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29
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Krahfuss MJ, Radius U. N-Heterocyclic silylenes as ambiphilic activators and ligands. Dalton Trans 2021; 50:6752-6765. [DOI: 10.1039/d1dt00617g] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Recent developments of the use of N-heterocyclic silylenes (NHSis), higher homologues of Arduengo-carbenes, as ambiphilic activators and ligands are highlighted and a comparison of NHSi ligands with NHC and phosphine ligands is provided.
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Affiliation(s)
- Mirjam J. Krahfuss
- Institut für Anorganische Chemie
- Julius-Maximilians-Universität Würzburg
- D-97074 Würzburg
- Germany
| | - Udo Radius
- Institut für Anorganische Chemie
- Julius-Maximilians-Universität Würzburg
- D-97074 Würzburg
- Germany
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30
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Kundu G, Ajithkumar VS, Bisai MK, Tothadi S, Das T, Vanka K, Sen SS. Diverse reactivity of carbenes and silylenes towards fluoropyridines. Chem Commun (Camb) 2021; 57:4428-4431. [PMID: 33949460 DOI: 10.1039/d1cc01401c] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The reaction of IDipp with C5F5N led to functionalization of all three carbon atoms of the imidazole ring with HF2- as the counter-anion (1). Reactivity with 2,3,5,6-tetrafluoropyridine gives only C-F bond activation leaving C-H bonds intact (5b). The reaction of SIDipp with C5F5N in the presence of BF3 afforded the ring cleavage product (3). Analogous reactions with silylene led to oxidative addition at the Si(ii) center.
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Affiliation(s)
- Gargi Kundu
- Inorganic Chemistry and Catalysis Division, CSIR-National Chemical Laboratory, Dr Homi Bhabha Road, Pashan, Pune 411008, India. and Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
| | - V S Ajithkumar
- Inorganic Chemistry and Catalysis Division, CSIR-National Chemical Laboratory, Dr Homi Bhabha Road, Pashan, Pune 411008, India. and Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
| | - Milan Kumar Bisai
- Inorganic Chemistry and Catalysis Division, CSIR-National Chemical Laboratory, Dr Homi Bhabha Road, Pashan, Pune 411008, India. and Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
| | - Srinu Tothadi
- Organic Chemistry Division, CSIR-National Chemical Laboratory, Dr Homi Bhabha Road, Pashan, Pune 411008, India
| | - Tamal Das
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India and Physical and Material Chemistry Division, CSIR-National Chemical Laboratory, Dr Homi Bhabha Road, Pashan, Pune 411008, India
| | - Kumar Vanka
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India and Physical and Material Chemistry Division, CSIR-National Chemical Laboratory, Dr Homi Bhabha Road, Pashan, Pune 411008, India
| | - Sakya S Sen
- Inorganic Chemistry and Catalysis Division, CSIR-National Chemical Laboratory, Dr Homi Bhabha Road, Pashan, Pune 411008, India. and Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
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31
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Krahfuss MJ, Radius U. N
‐Heterocyclic Silylene Main Group Element Chemistry: Adduct Formation, Insertion into E−X Bonds and Cyclization of Organoazides. Eur J Inorg Chem 2020. [DOI: 10.1002/ejic.202000942] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Mirjam J. Krahfuss
- 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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32
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Kuntze-Fechner MW, Verplancke H, Tendera L, Diefenbach M, Krummenacher I, Braunschweig H, Marder TB, Holthausen MC, Radius U. Coligand role in the NHC nickel catalyzed C-F bond activation: investigations on the insertion of bis(NHC) nickel into the C-F bond of hexafluorobenzene. Chem Sci 2020; 11:11009-11023. [PMID: 34094350 PMCID: PMC8162383 DOI: 10.1039/d0sc04237d] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
The reaction of [Ni(Mes2Im)2] (1) (Mes2Im = 1,3-dimesityl-imidazolin-2-ylidene) with polyfluorinated arenes as well as mechanistic investigations concerning the insertion of 1 and [Ni(iPr2Im)2] (1ipr) (iPr2Im = 1,3-diisopropyl-imidazolin-2-ylidene) into the C–F bond of C6F6 is reported. The reaction of 1 with different fluoroaromatics leads to formation of the nickel fluoroaryl fluoride complexes trans-[Ni(Mes2Im)2(F)(ArF)] (ArF = 4-CF3-C6F42, C6F53, 2,3,5,6-C6F4N 4, 2,3,5,6-C6F4H 5, 2,3,5-C6F3H26, 3,5-C6F2H37) in fair to good yields with the exception of the formation of the pentafluorophenyl complex 3 (less than 20%). Radical species and other diamagnetic side products were detected for the reaction of 1 with C6F6, in line with a radical pathway for the C–F bond activation step using 1. The difluoride complex trans-[Ni(Mes2Im)2(F)2] (9), the bis(aryl) complex trans-[Ni(Mes2Im)2(C6F5)2] (15), the structurally characterized nickel(i) complex trans-[NiI(Mes2Im)2(C6F5)] (11) and the metal radical trans-[NiI(Mes2Im)2(F)] (12) were identified. Complex 11, and related [NiI(Mes2Im)2(2,3,5,6-C6F4H)] (13) and [NiI(Mes2Im)2(2,3,5-C6F3H2)] (14), were synthesized independently by reaction of trans-[Ni(Mes2Im)2(F)(ArF)] with PhSiH3. Simple electron transfer from 1 to C6F6 was excluded, as the redox potentials of the reaction partners do not match and [Ni(Mes2Im)2]+, which was prepared independently, was not detected. DFT calculations were performed on the insertion of [Ni(iPr2Im)2] (1ipr) and [Ni(Mes2Im)2] (1) into the C–F bond of C6F6. For 1ipr, concerted and NHC-assisted pathways were identified as having the lowest kinetic barriers, whereas for 1, a radical mechanism with fluoride abstraction and an NHC-assisted pathway are both associated with almost the same kinetic barrier. A combined experimental and theoretical study on the mechanism of the C–F bond activation of C6F6 with [Ni(NHC)2] is provided.![]()
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Affiliation(s)
- Maximilian W Kuntze-Fechner
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Hendrik Verplancke
- Institute for Inorganic and Analytical Chemistry, Goethe-Universität Frankfurt Max-von-Laue-Strasse 7 60438 Frankfurt Germany
| | - Lukas Tendera
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Martin Diefenbach
- Institute for Inorganic and Analytical Chemistry, Goethe-Universität Frankfurt Max-von-Laue-Strasse 7 60438 Frankfurt Germany
| | - Ivo Krummenacher
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany .,Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Holger Braunschweig
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany .,Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - 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
| | - Max C Holthausen
- Institute for Inorganic and Analytical Chemistry, Goethe-Universität Frankfurt Max-von-Laue-Strasse 7 60438 Frankfurt Germany
| | - Udo Radius
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
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33
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Krahfuß MJ, Nitsch J, Bickelhaupt FM, Marder TB, Radius U. N-Heterocyclic Silylenes as Ligands in Transition Metal Carbonyl Chemistry: Nature of Their Bonding and Supposed Innocence. Chemistry 2020; 26:11276-11292. [PMID: 32233000 PMCID: PMC7497151 DOI: 10.1002/chem.202001062] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 03/28/2020] [Indexed: 11/07/2022]
Abstract
A study on the reactivity of the N-heterocyclic silylene Dipp2 NHSi (1,3-bis(diisopropylphenyl)-1,3-diaza-2-silacyclopent-4-en-2-yliden) with the transition metal complexes [Ni(CO)4 ], [M(CO)6 ] (M=Cr, Mo, W), [Mn(CO)5 (Br)] and [(η5 -C5 H5 )Fe(CO)2 (I)] is reported. We demonstrate that N-heterocyclic silylenes, the higher homologues of the now ubiquitous NHC ligands, show a remarkably different behavior in coordination chemistry compared to NHC ligands. Calculations on the electronic features of these ligands revealed significant differences in the frontier orbital region which lead to some peculiarities of the coordination chemistry of silylenes, as demonstrated by the synthesis of the dinuclear, NHSi-bridged complex [{Ni(CO)2 (μ-Dipp2 NHSi)}2 ] (2), complexes [M(CO)5 (Dipp2 NHSi)] (M=Cr 3, Mo 4, W 5), [Mn(CO)3 (Dipp2 NHSi)2 (Br)] (9) and [(η5 -C5 H5 )Fe(CO)2 (Dipp2 NHSi-I)] (10). DFT calculations on several model systems [Ni(L)], [Ni(CO)3 (L)], and [W(CO)5 (L)] (L=NHC, NHSi) reveal that carbenes are typically the much better donor ligands with a larger intrinsic strength of the metal-ligand bond. The decrease going from the carbene to the silylene ligand is mainly caused by favorable electrostatic contributions for the NHC ligand to the total bond strength, whereas the orbital interactions were often found to be higher for the silylene complexes. Furthermore, we have demonstrated that the contribution of σ- and π-interaction depends significantly on the system under investigation. The σ-interaction is often much weaker for the NHSi ligand compared to NHC but, interestingly, the π-interaction prevails for many NHSi complexes. For the carbonyl complexes, the NHSi ligand is the better σ-donor ligand, and contributions of π-symmetry play only a minor role for the NHC and NHSi co-ligands.
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Affiliation(s)
- Mirjam J. Krahfuß
- Institut für Anorganische ChemieJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Jörn Nitsch
- Institut für Anorganische ChemieJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - F. Matthias Bickelhaupt
- Department of Theoretical ChemistryAmsterdam Center for, Multiscale Modeling (ACMM)Vrije Universiteit AmsterdamDe Boelelaan 10831081 HVAmsterdamThe Netherlands
- Institute for Molecules and Materials (IMM)Radboud UniversityHeyendaalseweg 1356525 AJNijmegenThe Netherlands
| | - Todd B. Marder
- Institut für Anorganische ChemieJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
- Institute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Udo Radius
- Institut für Anorganische ChemieJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
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34
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Mandal D, Stein F, Chandra S, Neuman NI, Sarkar P, Das S, Kundu A, Sarkar A, Rawat H, Pati SK, Chandrasekhar V, Sarkar B, Jana A. Trisubstituted geminal diazaalkene derived transient 1,2-carbodications. Chem Commun (Camb) 2020; 56:8233-8236. [PMID: 32558832 DOI: 10.1039/d0cc02807j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The coulombic repulsion between two adjacent cation centres of 1,2-carbodications is known to decrease with π- and/or n-donor substituents by a positive charge delocalization. Here we report the delocalization of the positive charge of transient 1,2-carbodications having one H-substituent by an intramolecular base-coordination. N-heterocyclic olefin (NHO) derived 2-pyrrolidinyl appended trisubstituted geminal diazaalkenes were used for the generation of transient 1,2-carbodications through a 2-e chemical oxidation process. We have also studied the 1-e oxidation reaction of trisubstituted geminal diazaalkenes (electrochemically and chemically) and also studied them using in situ EPR spectroscopy.
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Affiliation(s)
- Debdeep Mandal
- Tata Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad 500107, Telangana, India.
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35
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Ghosh B, Phukan AK. Probing the potential of metalla-N-heterocyclic carbenes towards activation of enthalpically strong bonds. Dalton Trans 2020; 49:9505-9515. [PMID: 32608419 DOI: 10.1039/d0dt01363c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Density functional theory calculations are employed to explore the reactivity of metalla-N-heterocyclic carbenes (MNHCs) towards activation of a variety of small molecules (H2, NH3, PH3, SiH3Ph and CH4). All the MNHCs considered are found to have a stable singlet ground state and possess suitable electronic properties for their application in small molecule activation. The calculated energy barriers of E-H (E = H, C, N, Si, P) activation for the MNHCs are found to be in agreement with those of the experimentally evaluated cyclic alkyl(amino)carbene (CAAC) and diamidocarbenes (DACs), thereby indicating the activating effect of the incorporation of an ancillary metal center within a cyclic NHC, and highlighting a new, underexplored strategy in achieving difficult bond activations with carbenes.
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Affiliation(s)
- Bijoy Ghosh
- Department of Chemical Sciences, Tezpur University, Napaam 784028, Assam, India.
| | - Ashwini K Phukan
- Department of Chemical Sciences, Tezpur University, Napaam 784028, Assam, India.
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36
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Mandal D, Chandra S, Neuman NI, Mahata A, Sarkar A, Kundu A, Anga S, Rawat H, Schulzke C, Mote KR, Sarkar B, Chandrasekhar V, Jana A. Activation of Aromatic C-F Bonds by a N-Heterocyclic Olefin (NHO). Chemistry 2020; 26:5951-5955. [PMID: 32027063 PMCID: PMC7317942 DOI: 10.1002/chem.202000276] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Indexed: 11/09/2022]
Abstract
A N-heterocyclic olefin (NHO), a terminal alkene selectively activates aromatic C-F bonds without the need of any additional catalyst. As a result, a straightforward methodology was developed for the formation of different fluoroaryl-substituted alkenes in which the central carbon-carbon double bond is in a twisted geometry.
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Affiliation(s)
- Debdeep Mandal
- Tata Institute of Fundamental Research HyderabadGopanpally, Hyderabad500107India
| | - Shubhadeep Chandra
- Institut für Chemie und BiochemieAnorganische ChemieFreie Universität BerlinFabeckstrasse 34–3614195BerlinGermany
- Institut für Anorganische ChemieLehrstuhl für Anorganische KoordinationschemieUniversität StuttgartPfaffenwaldring 5570569StuttgartGermany
| | - Nicolás I. Neuman
- Institut für Chemie und BiochemieAnorganische ChemieFreie Universität BerlinFabeckstrasse 34–3614195BerlinGermany
- Instituto de Desarrollo Tecnológico para la Industria QuímicaCCT Santa Fe CONICET-UNLColectora Ruta Nacional 168, Km 472, Paraje El Pozo3000Santa FeArgentina
| | - Alok Mahata
- Tata Institute of Fundamental Research HyderabadGopanpally, Hyderabad500107India
| | - Arighna Sarkar
- Tata Institute of Fundamental Research HyderabadGopanpally, Hyderabad500107India
| | - Abhinanda Kundu
- Tata Institute of Fundamental Research HyderabadGopanpally, Hyderabad500107India
| | - Srinivas Anga
- Tata Institute of Fundamental Research HyderabadGopanpally, Hyderabad500107India
| | - Hemant Rawat
- Tata Institute of Fundamental Research HyderabadGopanpally, Hyderabad500107India
| | - Carola Schulzke
- Institut für BiochemieUniversität GreifswaldFelix-Hausdorff-Strasse 417487GreifswaldGermany
| | - Kaustubh R. Mote
- Tata Institute of Fundamental Research HyderabadGopanpally, Hyderabad500107India
| | - Biprajit Sarkar
- Institut für Chemie und BiochemieAnorganische ChemieFreie Universität BerlinFabeckstrasse 34–3614195BerlinGermany
- Institut für Anorganische ChemieLehrstuhl für Anorganische KoordinationschemieUniversität StuttgartPfaffenwaldring 5570569StuttgartGermany
| | - Vadapalli Chandrasekhar
- Tata Institute of Fundamental Research HyderabadGopanpally, Hyderabad500107India
- Department of ChemistryIndian Institute of Technology KanpurKanpur208016India
| | - Anukul Jana
- Tata Institute of Fundamental Research HyderabadGopanpally, Hyderabad500107India
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37
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Lee E, Pietrasiak E. Activation of C–F, Si–F, and S–F Bonds by N-Heterocyclic Carbenes and Their Isoelectronic Analogues. Synlett 2020. [DOI: 10.1055/s-0040-1707106] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Reactions involving C–F, Si–F, and S–F bond cleavage with N-heterocyclic carbenes and isoelectronic species are reviewed. Most examples involve activation of aromatic C–F bond via an SNAr pathway and nucleophilic substitution of fluorine in electron-deficient olefins. The mechanism of the C–F bond activation depends on the reaction partners and the reaction can proceed via addition–elimination, oxidative addition (concerted or stepwise) or metathesis. The adducts formed upon substitution find applications in organic synthesis, as ligands and as stable radical precursors, but in most cases, their full potential remains unexplored.1 Introduction1.1 The C–F Bond1.2 C–F Bond Activation: A Short Summary1.3 C–F Bond Activation: A Special Case of SNAr1.4 N-Heterocyclic Carbenes (NHCs)1.5 The Purpose of this Article2 C–F bond Activation in Acyl Fluorides3 Activation of Vinylic C–F Bonds4 Activation of Aromatic C–F Bonds5 X–F Bond Activation (X = S or Si)6 C–F Bond Activation by Main Group Compounds Isoelectronic with NHCs7 Conclusions and Outlook
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Affiliation(s)
- Eunsung Lee
- Department of Chemistry, Pohang University of Science and Technology
- Division of Advanced Materials Science, Pohang University of Science and Technology
| | - Ewa Pietrasiak
- Department of Chemistry, Pohang University of Science and Technology
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38
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Berthel JHJ, Krahfuß MJ, Radius U. Nickel Tetracarbonyl as Starting Material for the Synthesis of NHC‐stabilized Nickel(II) Allyl Complexes. Z Anorg Allg Chem 2020. [DOI: 10.1002/zaac.201900326] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Johannes H. J. Berthel
- Institut für Anorganische Chemie Julius‐Maximilians‐Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Mirjam J. Krahfuß
- 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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39
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Dutta S, De S, Bose S, Mahal E, Koley D. Cooperative Donor-Acceptor Interactions in Stabilizing Carbene-Borane and Carbene-Alane Compounds: A Theoretical Insight. Eur J Inorg Chem 2020. [DOI: 10.1002/ejic.201901163] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Sayan Dutta
- Department of Chemical Sciences; Indian Institute of Science Education and Research (IISER) Kolkata; 741 246 Mohanpur India
| | - Sriman De
- Department of Chemical Sciences; Indian Institute of Science Education and Research (IISER) Kolkata; 741 246 Mohanpur India
| | - Sanjoy Bose
- Department of Chemical Sciences; Indian Institute of Science Education and Research (IISER) Kolkata; 741 246 Mohanpur India
| | - Eti Mahal
- Department of Chemical Sciences; Indian Institute of Science Education and Research (IISER) Kolkata; 741 246 Mohanpur India
| | - Debasis Koley
- Department of Chemical Sciences; Indian Institute of Science Education and Research (IISER) Kolkata; 741 246 Mohanpur India
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40
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Kundu G, De S, Tothadi S, Das A, Koley D, Sen SS. Saturated N-Heterocyclic Carbene Based Thiele's Hydrocarbon with a Tetrafluorophenylene Linker. Chemistry 2019; 25:16533-16537. [PMID: 31609519 DOI: 10.1002/chem.201904421] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 10/06/2019] [Indexed: 01/24/2023]
Abstract
The synthesis of a SIPr [1,3-bis(2,6-diisopropylphenyl)-imidazolin-2-ylidene] derived Kekulé diradicaloid with a tetrafluorophenylene spacer (3) has been described. Two synthetic routes have been reported to access 3. The cleavage of C-F bond of C6 F6 by SIPr in the presence of BF3 led to double C-F activated compound with two tetrafluoro borate counter anions (2), which upon reduction by lithium metal afforded 3. Alternatively, 3 can be directly accessed in one step by reacting SIPr with C6 F6 in presence of Mg metal. Compounds 2 and 3 were well characterized spectroscopically and by single-crystal X-ray diffraction studies. Experimental and computational studies support the cumulenic closed-shell singlet state of 3 with a singlet-triplet energy gap (ΔES-T ) of 23.7 kcal mol-1 .
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Affiliation(s)
- Gargi Kundu
- Inorganic Chemistry and Catalysis Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pashan, Pune, 411008, India.,Academy of Scientific and Innovative Research (AcSIR), New Ghaziabad, 201002, India
| | - Sriman De
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur, 741246, India
| | - Srinu Tothadi
- Organic Chemistry Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pashan, Pune, 411008, India
| | - Abhishek Das
- Indian Association for the Cultivation of Science, 2A & 2B Raja S. C. Mullick Road, Kolkata, 700032, India
| | - Debasis Koley
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur, 741246, India
| | - Sakya S Sen
- Inorganic Chemistry and Catalysis Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pashan, Pune, 411008, India.,Academy of Scientific and Innovative Research (AcSIR), New Ghaziabad, 201002, India
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41
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Manar KK, Porwal VK, Kamte RS, Adhikari M, Thakur SK, Bawari D, Choudhury AR, Singh S. Reactions of a BICAAC with hydroboranes: propensity for Lewis adduct formation and carbene insertion into the B-H bond. Dalton Trans 2019; 48:17472-17478. [PMID: 31714564 DOI: 10.1039/c9dt03382c] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The reactivity of a bicyclic (alkyl)(amino)carbene (BICAAC) towards different boranes has been examined in the present work. The reactions with boranes BX3·SMe2 (X = H, Cl, Br), BF3·OEt2 and BCl3 yield Lewis adducts [BICAAC·BH3] (1), [BICAAC·BHCl2] (2), [BICAAC·BH2Cl] (3), [BICAAC·BF3] (4), [BICAAC·BCl3] (5) and [BICAAC·BBr3] (6) respectively, whereas more hydridic boranes, 9-borabicyclo[3.3.1]nonane (9-BBN) and catecholborane (HBcat), enable the insertion of the carbene carbon into the B-H bond to form [BICAAC(H)-(9-BBN)] (7) and [BICAAC(H)-Bcat] (8). These complexes are the first examples of BICAAC-boron compounds and have been characterized using IR, multinuclear NMR spectroscopy, HRMS spectrometry and single crystal X-ray diffraction. Computational analyses were also performed to gain insight into the mechanism of B-H bond activation and adduct formation. Furthermore, the reactions of the BICAAC with boranes have been compared with the known reactions of CAACs and NHCs.
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Affiliation(s)
- Krishna K Manar
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, Knowledge City, Sector 81, SAS Nagar, Mohali 140306, Punjab, India.
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Lorkowski J, Krahfuß M, Kubicki M, Radius U, Pietraszuk C. Intramolecular Ring-Expansion Reaction (RER) and Intermolecular Coordination of In Situ Generated Cyclic (Amino)(aryl)carbenes (cAArCs). Chemistry 2019; 25:11365-11374. [PMID: 31276243 PMCID: PMC6771577 DOI: 10.1002/chem.201902630] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Indexed: 01/07/2023]
Abstract
Cyclic (amino)(aryl)carbenes (cAArCs) based on the isoindoline core were successfully generated in situ by α-elimination of 3-alkoxyisoindolines at high temperatures or by deprotonation of isoindol-2-ium chlorides with sodium or copper(I) acetates at low temperatures. 3-Alkoxy-isoindolines 2 a,b-OR (R=Me, Et, iPr) have been prepared in high yields by the addition of a solution of 2-aryl-1,1-diphenylisoindol-2-ium triflate (1 a,b-OTf; a: aryl=Dipp=2,6-diisopropylphenyl; b: Mesityl-, Mes=2,4,6-trimethylphenyl) to the corresponding alcohol (ROH) with NEt3 at room temperature. Furthermore, the reaction of 2 a,b-OMe in diethyl ether with a tenfold excess of hydrochloric acid led to the isolation of the isoindol-2-ium chlorides 1 a,b-Cl in high yields. The thermally generated cAArC reacts with sulfur to form the thioamide 3 a. Without any additional trapping reagent, in situ generation of 1,1-diphenylisoidolin-3-ylidenes does not lead to the isolation of these compounds, but to the reaction products of the insertion of the carbene carbon atom into an ortho C-H bond of a phenyl substituent, followed by ring-expansion reaction; namely, anthracene derivatives 9-N(H)aryl-10-Ph-C14 H8 4 a,b (a: Dipp; b: Mes). These compounds are conveniently synthesized by deprotonation of the isoindol-2-ium chlorides with sodium acetate in high yields. Deprotonation of 1 a-Cl with copper(I) acetate at low temperatures afforded a mixture of 4 a and the corresponding cAArC copper(I) chloride 5 a, and allowed the isolation and structural characterization of the first example of a cAArC copper complex of general formula [(cAArC)CuCl].
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Affiliation(s)
- Jan Lorkowski
- Faculty of ChemistryDepartment of Organometallic ChemistryAdam Mickiewicz University in Poznańul. Uniwersytetu Poznańskiego 861-614PoznańPoland
- Institut für Anorganische ChemieJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Mirjam Krahfuß
- Institut für Anorganische ChemieJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Maciej Kubicki
- Faculty of ChemistryDepartment of Organometallic ChemistryAdam Mickiewicz University in Poznańul. Uniwersytetu Poznańskiego 861-614PoznańPoland
| | - Udo Radius
- Institut für Anorganische ChemieJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Cezary Pietraszuk
- Faculty of ChemistryDepartment of Organometallic ChemistryAdam Mickiewicz University in Poznańul. Uniwersytetu Poznańskiego 861-614PoznańPoland
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Kieser JM, Kinney ZJ, Gaffen JR, Evariste S, Harrison AM, Rheingold AL, Protasiewicz JD. Three Ways Isolable Carbenes Can Modulate Emission of NH-Containing Fluorophores. J Am Chem Soc 2019; 141:12055-12063. [PMID: 31322901 DOI: 10.1021/jacs.9b04864] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Fluorescent molecules and materials that exhibit emission changes in response to analytes are of great interest across multiple disciplines. Herein, we investigate the response of NH-containing fluorophores carbazole and 2-phenylbenzimidazole (Ph-BIM) with two representative isolable singlet carbenes. Specifically, N-heterocyclic carbene 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene (IPr) and cyclic (alkyl)(amino)carbene (2,6-diisopropylphenyl)-4,4-diethyl-2,2-dimethyl-pyrrolidin-5-ylidene (EtCAAC) were discovered to afford three different types of reaction products with carbazole and Ph-BIM. Depending on the reaction pair, hydrogen bonding (1), NH-insertion (2,3), or proton transfer (4) products can be isolated, each displaying variable photophysical responses. These products have been structurally authenticated by single crystal X-ray diffraction and NMR spectrometric methods. Studies of the solution state behavior of 1-4 reveals that these adducts are labile and can reversibly dissociate to free carbenes and fluorophores to varying extents. These equilibria produce concentration dependent solution state behavior as identified and quantified via UV-visible absorption, emission, 1H DOSY, and NMR spectroscopic measurements.
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Affiliation(s)
- Jerod M Kieser
- Department of Chemistry , Case Western Reserve University , 2080 Adelbert Road , Cleveland , Ohio 44106 , United States
| | - Zacharias J Kinney
- Department of Chemistry , Case Western Reserve University , 2080 Adelbert Road , Cleveland , Ohio 44106 , United States
| | - Joshua R Gaffen
- Department of Chemistry , Case Western Reserve University , 2080 Adelbert Road , Cleveland , Ohio 44106 , United States
| | - Sloane Evariste
- Department of Chemistry , Case Western Reserve University , 2080 Adelbert Road , Cleveland , Ohio 44106 , United States
| | - Alexandra M Harrison
- Department of Chemistry , Case Western Reserve University , 2080 Adelbert Road , Cleveland , Ohio 44106 , United States
| | - Arnold L Rheingold
- Department of Chemistry and Biochemistry , University of California, San Diego , La Jolla , California 92093 , United States
| | - John D Protasiewicz
- Department of Chemistry , Case Western Reserve University , 2080 Adelbert Road , Cleveland , Ohio 44106 , United States
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Mandal D, Dolai R, Kumar R, Suhr S, Chrysochos N, Kalita P, Narayanan RS, Rajaraman G, Schulzke C, Sarkar B, Chandrasekhar V, Jana A. Influence of N-Substitution on the Formation and Oxidation of NHC-CAAC-Derived Triazaalkenes. J Org Chem 2019; 84:8899-8909. [PMID: 31187990 DOI: 10.1021/acs.joc.9b00774] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
We have studied the effect of N-substitution on the course of the reaction of imidazolium triflate. The reaction of N-heterocyclic carbene with N-tBu-substituted pyrrolinium triflate afforded 2-(pyrrolidin-2-yl)-imidazolium triflate, 3R. Treatment of 3R with potassium bis(trimethylsilyl)amide (KHMDS) leads to either the dealkylation product 4 or the deprotonation product, triazaalkene 5, depending on the N-substitution at the imidazolium moiety. Density functional studies using the B3LYP/TZVP setup have been employed to explore various pathways for the dealkylation reaction and the calculated energies support the dealkylation by a large energy margin compared to the deprotonatation process. Theoretical calculations revealed that dealkylation reaction is thermodynamically more favorable than deprotonation. The triazaalkene 5 could be oxidized by AgOTf to the corresponding radical cation 6 and dication 7 in-situ. While 6 and 7 could not be isolated, the formation of the former is inferred by electron paramagnetic resonance spectroscopy and its abstraction of a H-atom to afford 3Me. Similarly, the formation of the dication 7 is inferred by its ready elimination of isobutylene affording 8.
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Affiliation(s)
- Debdeep Mandal
- Tata Institute of Fundamental Research Hyderabad , Gopanpally , Hyderabad 500107 , India
| | - Ramapada Dolai
- Tata Institute of Fundamental Research Hyderabad , Gopanpally , Hyderabad 500107 , India
| | - Ravi Kumar
- Department of Chemistry , Indian Institute of Technology Bombay , Powai , Mumbai 400076 , India
| | - Simon Suhr
- Institut für Chemie und Biochemie , Anorganische Chemie, Freie Universität Berlin , Fabeckstraße 34-36 , Berlin 14195 , Germany
| | - Nicolas Chrysochos
- Institut für Biochemie , Universität Greifswald , Felix-Hausdorff-Straße 4 , Greifswald D-17487 , Germany
| | - Pankaj Kalita
- School of Chemical Sciences , National Institute of Science Education and Research , HBNI, Bhimpur-Padanpur, Jatni , Khurda, Bhubaneswar 752050 , Odisha , India
| | | | - Gopalan Rajaraman
- Department of Chemistry , Indian Institute of Technology Bombay , Powai , Mumbai 400076 , India
| | - Carola Schulzke
- Institut für Biochemie , Universität Greifswald , Felix-Hausdorff-Straße 4 , Greifswald D-17487 , Germany
| | - Biprajit Sarkar
- Institut für Chemie und Biochemie , Anorganische Chemie, Freie Universität Berlin , Fabeckstraße 34-36 , Berlin 14195 , Germany
| | - Vadapalli Chandrasekhar
- Tata Institute of Fundamental Research Hyderabad , Gopanpally , Hyderabad 500107 , India.,Department of Chemistry , Indian Institute of Technology Kanpur , Kanpur 208016 , India
| | - Anukul Jana
- Tata Institute of Fundamental Research Hyderabad , Gopanpally , Hyderabad 500107 , India
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Blackaby WJM, Neale SE, Isaac CJ, Sabater S, Macgregor SA, Whittlesey MK. N‐Heterocyclic Carbene Non‐Innocence in the Catalytic Hydrophosphination of Alkynes. ChemCatChem 2019. [DOI: 10.1002/cctc.201900220] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Samuel E. Neale
- Institute of Chemical SciencesHeriot-Watt University Edinburgh EH14 4AS UK
| | - Connie J. Isaac
- Department of ChemistryUniversity of Bath Claverton Down, Bath BA2 7AY UK
| | - Sara Sabater
- Department of ChemistryUniversity of Bath Claverton Down, Bath BA2 7AY UK
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46
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Kuntze-Fechner MW, Kerpen C, Schmidt D, Häring M, Radius U. NHC Nickel Catalyzed Hiyama- and Negishi-Type Cross-Coupling of Aryl Fluorides and Investigations on the Stability of Nickel(II) Fluoroaryl Alkyl Complexes. Eur J Inorg Chem 2019. [DOI: 10.1002/ejic.201801477] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
| | - Christoph Kerpen
- Institut für Anorganische Chemie; Julius-Maximilians-Universität Würzburg; Am Hubland 97074 Würzburg Germany
| | - David Schmidt
- Institut für Anorganische Chemie; Julius-Maximilians-Universität Würzburg; Am Hubland 97074 Würzburg Germany
| | - Mathias Häring
- 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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47
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Mandal D, Sobottka S, Dolai R, Maiti A, Dhara D, Kalita P, Narayanan RS, Chandrasekhar V, Sarkar B, Jana A. Direct access to 2-aryl substituted pyrrolinium salts for carbon centre based radicals without pyrrolidine-2-ylidene alias cyclic(alkyl)(amino)carbene (CAAC) as a precursor. Chem Sci 2019; 10:4077-4081. [PMID: 31049189 PMCID: PMC6470959 DOI: 10.1039/c8sc05477k] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Accepted: 02/27/2019] [Indexed: 12/20/2022] Open
Abstract
A new strategy to synthesise 2-substituted pyrrolinium salts.
The synthesis of organic radicals is challenging due to their inherent instability. In recent years, cyclic(alkyl)(amino)carbene (CAAC)-derived 2-substituted pyrrolinium salts have been used as synthons for the synthesis of isolable carbon-based radicals. Herein, we report a direct, easy and convenient method for the synthesis of 2-aryl substituted pyrrolinium salts without using CAAC as a precursor. These cations can be reduced to the corresponding radicals. The influence of the aryl substituent at the C-2 position on radical stabilization and dimerization has been investigated. Because of the large scope of our strategy (capability to modulate different substituents at all the C- and N-centres of the pyrrolinium salts), it has the merit to be an extremely effective and productive route for generating carbon-based radicals whose stability as well as reactivity can be varied.
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Affiliation(s)
- Debdeep Mandal
- Tata Institute of Fundamental Research Hyderabad , Gopanpally , Hyderabad-500107 , Telangana , India .
| | - Sebastian Sobottka
- Institut für Chemie und Biochemie, Anorganische Chemie , Freie Universität Berlin , Fabeckstraße 34-36 , 14195 , Berlin , Germany .
| | - Ramapada Dolai
- Tata Institute of Fundamental Research Hyderabad , Gopanpally , Hyderabad-500107 , Telangana , India .
| | - Avijit Maiti
- Tata Institute of Fundamental Research Hyderabad , Gopanpally , Hyderabad-500107 , Telangana , India .
| | - Debabrata Dhara
- Tata Institute of Fundamental Research Hyderabad , Gopanpally , Hyderabad-500107 , Telangana , India .
| | - Pankaj Kalita
- School of Chemical Sciences , National Institute of Science Education and Research , HBNI , Bhubaneswar-752050 , India
| | | | - Vadapalli Chandrasekhar
- Tata Institute of Fundamental Research Hyderabad , Gopanpally , Hyderabad-500107 , Telangana , India . .,Department of Chemistry , Indian Institute of Technology Kanpur , Kanpur-208016 , India .
| | - Biprajit Sarkar
- Institut für Chemie und Biochemie, Anorganische Chemie , Freie Universität Berlin , Fabeckstraße 34-36 , 14195 , Berlin , Germany .
| | - Anukul Jana
- Tata Institute of Fundamental Research Hyderabad , Gopanpally , Hyderabad-500107 , Telangana , India .
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48
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Pait M, Kundu G, Tothadi S, Karak S, Jain S, Vanka K, Sen SS. C−F Bond Activation by a Saturated N‐Heterocyclic Carbene: Mesoionic Compound Formation and Adduct Formation with B(C
6
F
5
)
3. Angew Chem Int Ed Engl 2019; 58:2804-2808. [DOI: 10.1002/anie.201814616] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2018] [Indexed: 11/09/2022]
Affiliation(s)
- Moumita Pait
- Inorganic Chemistry and Catalysis DivisionCSIR-National Chemical Laboratory Dr. Homi Bhabha Road Pashan Pune 411008 India
| | - Gargi Kundu
- Inorganic Chemistry and Catalysis DivisionCSIR-National Chemical Laboratory Dr. Homi Bhabha Road Pashan Pune 411008 India
- Academy of Scientific and Innovative Research (AcSIR) Ghaziabad 201002 India
| | - Srinu Tothadi
- Organic Chemistry DivisionCSIR-National Chemical Laboratory Dr. Homi Bhabha Road Pashan Pune 411008 India
| | - Suvendu Karak
- Academy of Scientific and Innovative Research (AcSIR) Ghaziabad 201002 India
- Physical and Material Chemistry DivisionCSIR-National Chemical Laboratory Dr. Homi Bhabha Road Pashan Pune 411008 India
| | - Shailja Jain
- Academy of Scientific and Innovative Research (AcSIR) Ghaziabad 201002 India
- Physical and Material Chemistry DivisionCSIR-National Chemical Laboratory Dr. Homi Bhabha Road Pashan Pune 411008 India
| | - Kumar Vanka
- Academy of Scientific and Innovative Research (AcSIR) Ghaziabad 201002 India
- Physical and Material Chemistry DivisionCSIR-National Chemical Laboratory Dr. Homi Bhabha Road Pashan Pune 411008 India
| | - Sakya S. Sen
- Inorganic Chemistry and Catalysis DivisionCSIR-National Chemical Laboratory Dr. Homi Bhabha Road Pashan Pune 411008 India
- Academy of Scientific and Innovative Research (AcSIR) Ghaziabad 201002 India
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49
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Pait M, Kundu G, Tothadi S, Karak S, Jain S, Vanka K, Sen SS. C−F Bond Activation by a Saturated N‐Heterocyclic Carbene: Mesoionic Compound Formation and Adduct Formation with B(C
6
F
5
)
3. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201814616] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Moumita Pait
- Inorganic Chemistry and Catalysis DivisionCSIR-National Chemical Laboratory Dr. Homi Bhabha Road Pashan Pune 411008 India
| | - Gargi Kundu
- Inorganic Chemistry and Catalysis DivisionCSIR-National Chemical Laboratory Dr. Homi Bhabha Road Pashan Pune 411008 India
- Academy of Scientific and Innovative Research (AcSIR) Ghaziabad 201002 India
| | - Srinu Tothadi
- Organic Chemistry DivisionCSIR-National Chemical Laboratory Dr. Homi Bhabha Road Pashan Pune 411008 India
| | - Suvendu Karak
- Academy of Scientific and Innovative Research (AcSIR) Ghaziabad 201002 India
- Physical and Material Chemistry DivisionCSIR-National Chemical Laboratory Dr. Homi Bhabha Road Pashan Pune 411008 India
| | - Shailja Jain
- Academy of Scientific and Innovative Research (AcSIR) Ghaziabad 201002 India
- Physical and Material Chemistry DivisionCSIR-National Chemical Laboratory Dr. Homi Bhabha Road Pashan Pune 411008 India
| | - Kumar Vanka
- Academy of Scientific and Innovative Research (AcSIR) Ghaziabad 201002 India
- Physical and Material Chemistry DivisionCSIR-National Chemical Laboratory Dr. Homi Bhabha Road Pashan Pune 411008 India
| | - Sakya S. Sen
- Inorganic Chemistry and Catalysis DivisionCSIR-National Chemical Laboratory Dr. Homi Bhabha Road Pashan Pune 411008 India
- Academy of Scientific and Innovative Research (AcSIR) Ghaziabad 201002 India
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50
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Kuehn L, Stang M, Würtemberger-Pietsch S, Friedrich A, Schneider H, Radius U, Marder TB. FBpin and its adducts and their role in catalytic borylations. Faraday Discuss 2019; 220:350-363. [DOI: 10.1039/c9fd00053d] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Fluoride ion plays a dual role in both metal-catalysed and metal-free borylation reactions by activating B2pin2 and trapping Lewis acidic FBpin.
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Affiliation(s)
- Laura Kuehn
- Institut für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with Boron
- Julius-Maximilians-Universität Würzburg
- 97074 Würzburg
- Germany
| | - Martin Stang
- Institut für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with Boron
- Julius-Maximilians-Universität Würzburg
- 97074 Würzburg
- Germany
| | - Sabrina Würtemberger-Pietsch
- Institut für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with Boron
- Julius-Maximilians-Universität Würzburg
- 97074 Würzburg
- Germany
| | - Alexandra Friedrich
- Institut für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with Boron
- Julius-Maximilians-Universität Würzburg
- 97074 Würzburg
- Germany
| | - Heidi Schneider
- Institut für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with Boron
- Julius-Maximilians-Universität Würzburg
- 97074 Würzburg
- Germany
| | - Udo Radius
- Institut für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with Boron
- Julius-Maximilians-Universität Würzburg
- 97074 Würzburg
- Germany
| | - Todd B. Marder
- Institut für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with Boron
- Julius-Maximilians-Universität Würzburg
- 97074 Würzburg
- Germany
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