1
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Tsuji Y, Okazawa K, Yoshizawa K. Hückel Molecular Orbital Analysis for Stability and Instability of Stacked Aromatic and Stacked Antiaromatic Systems. J Org Chem 2023; 88:14887-14898. [PMID: 37846097 DOI: 10.1021/acs.joc.3c01167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2023]
Abstract
Face-to-face stacking of aromatic compounds leads to stacked antiaromaticity, while that of antiaromatic compounds leads to stacked aromaticity. This is a prediction with a long history; in the late 2000s, the prediction was confirmed by high-precision quantum chemical calculations, and finally, in 2016, a π-conjugated system with stacked aromaticity was synthesized. Several variations have since been reported, but essentially, they are all the same molecule. To realize stacked aromaticity in a completely new and different molecular system and to trigger an extension of the concept of stacked aromaticity, it is important to understand the origin of stacked aromaticity. The Hückel method, which has been successful in giving qualitatively correct results for π-conjugated systems despite its bold assumptions, is well suited for the analysis of stacked aromaticity. We use this method to model the face-to-face stacking systems of benzene and cyclobutadiene molecules and discuss their stacked antiaromaticity and stacked aromaticity on the basis of their π-electron energies. By further developing the discussion, we search for clues to realize stacked aromaticity in synthesizable molecular systems.
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Affiliation(s)
- Yuta Tsuji
- Faculty of Engineering Sciences, Kyushu University, Kasuga, Fukuoka 816-8580, Japan
| | - Kazuki Okazawa
- Institute for Materials Chemistry and Engineering and IRCCS, Kyushu University, Nishi-ku, Fukuoka 819-0395, Japan
| | - Kazunari Yoshizawa
- Institute for Materials Chemistry and Engineering and IRCCS, Kyushu University, Nishi-ku, Fukuoka 819-0395, Japan
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2
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Bosse L, Mant BP, Schleier D, Gerlach M, Fischer I, Krueger A, Hemberger P, Worth G. Threshold Photoelectron Spectrum of Cyclobutadiene: Comparison with Time-Dependent Wavepacket Simulations. J Phys Chem Lett 2021; 12:6901-6906. [PMID: 34279954 DOI: 10.1021/acs.jpclett.1c01848] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The C4H4 isomer cyclobutadiene (CBD) is the prime model for antiaromaticity and thus a molecule of considerable interest in chemistry. Because it is highly reactive, it can only be studied under isolated conditions. Its electronic structure is characterized by a pseudo-Jahn-Teller effect in the neutral and a E ⊗ β Jahn-Teller effect in the cation. As a result, recording photoelectron spectra as well as describing them theoretically has been challenging. Here we present the photoion mass-selected threshold photoelectron spectrum of cyclobutadiene together with a simulation based on time-dependent wavepacket dynamics that includes vibronic coupling in the ion, taking into account eight vibrational modes in the cation. Excellent agreement between theory and experiment is found, and the ionization energy is revised to 8.06 ± 0.02 eV.
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Affiliation(s)
- Lea Bosse
- Institute of Physical and Theoretical Chemistry, University of Würzburg, D-97074 Würzburg, Germany
| | - Barry P Mant
- Department of Chemistry, University College London, 20 Gordon St., London WC1H 0AJ, U.K
| | - Domenik Schleier
- Institute of Physical and Theoretical Chemistry, University of Würzburg, D-97074 Würzburg, Germany
| | - Marius Gerlach
- Institute of Physical and Theoretical Chemistry, University of Würzburg, D-97074 Würzburg, Germany
| | - Ingo Fischer
- Institute of Physical and Theoretical Chemistry, University of Würzburg, D-97074 Würzburg, Germany
| | - Anke Krueger
- Institute of Organic Chemistry, University of Würzburg, D-97074 Würzburg, Germany
| | - Patrick Hemberger
- Laboratory for Femtochemistry and Synchrotron Radiation, Paul Scherrer Institut (PSI), CH-5232 Villigen, Switzerland
| | - Graham Worth
- Department of Chemistry, University College London, 20 Gordon St., London WC1H 0AJ, U.K
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3
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Krausbeck F, Sobez JG, Reiher M. Stabilization of activated fragments by shell-wise construction of an embedding environment. J Comput Chem 2017; 38:1023-1038. [DOI: 10.1002/jcc.24749] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2016] [Revised: 01/09/2017] [Accepted: 01/12/2017] [Indexed: 01/30/2023]
Affiliation(s)
- Florian Krausbeck
- ETH Zürich, Laboratorium für Physikalische Chemie; Vladimir-Prelog-Weg 2 Zürich CH-8093 Switzerland
| | - Jan-Grimo Sobez
- ETH Zürich, Laboratorium für Physikalische Chemie; Vladimir-Prelog-Weg 2 Zürich CH-8093 Switzerland
| | - Markus Reiher
- ETH Zürich, Laboratorium für Physikalische Chemie; Vladimir-Prelog-Weg 2 Zürich CH-8093 Switzerland
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Bertermann R, Braunschweig H, Celik MA, Dellermann T, Kelch H. Cyclisation of biscarbenoids – a novel mode of cyclobutadiene stabilisation. Chem Commun (Camb) 2016; 52:13249-13252. [DOI: 10.1039/c6cc07741b] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The reaction of the vicinal biscarbenoid Pip–CC–Pip with dimethyltin dichloride yields a unique tetraamino-substituted cyclobutadienyl system featuring a dative C–Sn interaction.
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Affiliation(s)
- Rüdiger Bertermann
- Institut für Anorganische Chemie
- Julius-Maximilians Universität Würzburg
- 97074 Würzburg
- Germany
| | - Holger Braunschweig
- Institut für Anorganische Chemie
- Julius-Maximilians Universität Würzburg
- 97074 Würzburg
- Germany
| | - Mehmet Ali Celik
- Institut für Anorganische Chemie
- Julius-Maximilians Universität Würzburg
- 97074 Würzburg
- Germany
| | - Theresa Dellermann
- Institut für Anorganische Chemie
- Julius-Maximilians Universität Würzburg
- 97074 Würzburg
- Germany
| | - Hauke Kelch
- Institut für Anorganische Chemie
- Julius-Maximilians Universität Würzburg
- 97074 Würzburg
- Germany
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5
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Mullinax JW, Hollman DS, Schaefer HF. Tetragermacyclobutadiene: energetically disfavored with respect to its structural isomers. Chemistry 2013; 19:7487-95. [PMID: 23576110 DOI: 10.1002/chem.201203481] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Indexed: 11/07/2022]
Abstract
Germanium has been a central feature in the renaissance of main-group inorganic chemistry. Herein, we present the stationary-point geometries of tetragermacyclobutadiene and its related isomers on the singlet potential energy surface at the CCSD(T)/cc-pVTZ level of theory. Three of these 12 structures are reported for the first time and one of them is predicted to lie only 0.4 kcal mol(-1) above the previously reported global minimum. Focal-point analyses has provided electronic energies at the CCSD(T) level of theory, which are extrapolated to the complete basis-set limit and demonstrate the convergence behavior of the electronic energies with improving levels of theory and increasing basis-set size. The lowest-energy structure is the bicyclic structure, which lies 35 kcal mol(-1) below the "all-Ge" cyclobutadiene structure. The reaction energies for the association of known Ge hydrides (e.g., digermene) to form Ge4H4 indicate that Ge4H4 could be observed experimentally. We investigate the bonding patterns by examining the frontier molecular orbitals. Our results demonstrate that: 1) the cyclic isomers of (GeH)4 distort to maximize the mixing of the p orbitals that are involved in the π system of tetragermacyclobutadiene and 2) the lowest-energy isomers exhibit unusual bonding arrangements (e.g., bridging H bonds) that maximize the nonbonding electron density at the Ge centers.
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Affiliation(s)
- J Wayne Mullinax
- Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602, USA
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6
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Legrand YM, Dumitrescu D, Gilles A, Petit E, van der Lee A, Barboiu M. Reply to A computational evaluation of the evidence for the synthesis of 1,3-dimethylcyclobutadiene in solid state and aqueous solution--beyond the experimental reality. Chemistry 2013; 19:4938-41. [PMID: 23504859 DOI: 10.1002/chem.201203235] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Following earlier reports on the photochemical synthesis of 1,3-dimethylcyclobutadiene in a protective host matrix, theoretical calculations for the formation of that adduct have been recently performed by Rzepa. The author formulated criticisms based mainly on density functional theory calculations of (1)H NMR spectra. According to Rzepa the calculated spectra do not correspond with our measured spectra, which leads him to the conclusion that our interpretation is wrong, and that mainly cyclobutadiene has not been stabilized or even synthesized; we believe, however, that the initial model that Rzepa used for his calculations does not correspond to chemical reality or is at the very least a crude simplification of it, which implies that his calculations cannot match, in every point, our experimental spectra. Rzepa's simplified models might be 'reasonable' from the theoretical point of view; however, in the case of assessment in the solid state, the theoretical setup does not force the system to preserve the confined stabilizing space defined by the crystalline matrix for encapsulated hosts in the solid state. Inversely, in the case of solution modeling, the theoretical setup is too rigid to properly assess the complex equilibria occurring in solution and to accurately determine the NMR spectra of exchanging species in solution. The inconsistency between our experimental results and the results of the theoretical models proposed by Rzepa is such that his conclusions are considered to be too far from experimental reality. Accurate modeling taking in account "reasonable" experimental details would be a worthwhile endeavor.
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7
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Legrand YM, Dumitrescu D, Gilles A, Petit E, van der Lee A, Barboiu M. A constrained disorder refinement: "Reinvestigation of "Single-crystal X-ray structure of 1,3-dimethylcyclobutadiene" by M. Shatruk and I. V. Alabugin". Chemistry 2013; 19:4946-50. [PMID: 23504770 DOI: 10.1002/chem.201203234] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Shatruk and Alabugin propose an alternative structural model for the observed electron density that we have attributed to the photochemical formation of 1,3-dimethylcyclobutadiene in a protective solid crystalline matrix. The main criticism from Shatruk and Alabugin concerns the modeling of the disorder in the calixarene cavity and in particular the neglect of a residual electron density close to the O1 atom. We published (Chem. Eur. J. 2011, 17, 10021) our opinion concerning this "ignored peak" in the Supporting Information of the paper. The current response to the Correspondence demonstrates that Shatruk and Alabugin have over-modeled our data by assigning a small electron density peak, which is hardly more than the density corresponding to a hydrogen atom, to an under-occupied oxygen site, using inappropriate refinement contraints.
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Shatruk M, Alabugin IV. Reinvestigation of "Single-crystal X-ray structure of 1,3-dimethylcyclobutadiene". Chemistry 2013; 19:4942-5. [PMID: 23504714 DOI: 10.1002/chem.201103017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2011] [Indexed: 11/07/2022]
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9
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Yang YF, Cheng GJ, Zhu J, Zhang X, Inoue S, Wu YD. Silicon-Containing Formal 4π-Electron Four-Membered Ring Systems: Antiaromatic, Aromatic, or Nonaromatic? Chemistry 2012; 18:7516-24. [DOI: 10.1002/chem.201103443] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2011] [Indexed: 11/08/2022]
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10
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Legrand YM, Gilles A, Petit E, van der Lee A, Barboiu M. Unprecedented Synthesis of 1,3-Dimethylcyclobutadiene in the Solid State and Aqueous Solution. Chemistry 2011; 17:10021-8. [DOI: 10.1002/chem.201100693] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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11
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Wiersum UE. Flash vacuum thermolysis, a versatile method in organic chemistry. Part I, General aspects and techniques. ACTA ACUST UNITED AC 2010. [DOI: 10.1002/recl.19821011001] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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13
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Corminboeuf C, Schleyer PVR, Warner P. Are Antiaromatic Rings Stacked Face-to-Face Aromatic? Org Lett 2007; 9:3263-6. [PMID: 17658752 DOI: 10.1021/ol071183y] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The stacking of 4n pi electron hydrocarbon rings into superphane structures can eliminate their antiaromaticity and result in through-space three-dimensional aromatic character. This is demonstrated by the bond length equalized geometries and diatropic NICS values of the methano-bridged superphane series with interacting three- to nine-membered 4n pi electron rings. Along with triplet and Möbius strategies, stacking is the third way to achieve aromatic ring systems with 4n pi electrons.
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Affiliation(s)
- Clémence Corminboeuf
- Department of Chemistry and Center for Computational Chemistry, University of Georgia, Athens, Georgia 30602, USA
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14
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Fattahi A, Lis L, Tian Z, Kass SR. The Heat of Formation of Cyclobutadiene. Angew Chem Int Ed Engl 2006; 45:4984-8. [PMID: 16819746 DOI: 10.1002/anie.200600839] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Alireza Fattahi
- Department Chemistry, University of Minnesota, Minneapolis, MN 55455, USA
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16
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Byers JH, Sontum SF, Dimitrova TS, Huque S, Zegarelli BM, Zhang Y, Jasinski JP, Butcher RJ. Generation and Trapping of Radicals Derived from Cyclobutadieneiron Tricarbonyl. Organometallics 2006. [DOI: 10.1021/om060263n] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jeffrey H. Byers
- Department of Chemistry and Biochemistry, Middlebury College, Middlebury, Vermont 05753, Department of Chemistry, Keene State College, Keene, New Hampshire 03435, and Department of Chemistry, Howard University, Washington, D.C. 20059
| | - Stephen F. Sontum
- Department of Chemistry and Biochemistry, Middlebury College, Middlebury, Vermont 05753, Department of Chemistry, Keene State College, Keene, New Hampshire 03435, and Department of Chemistry, Howard University, Washington, D.C. 20059
| | - Tina S. Dimitrova
- Department of Chemistry and Biochemistry, Middlebury College, Middlebury, Vermont 05753, Department of Chemistry, Keene State College, Keene, New Hampshire 03435, and Department of Chemistry, Howard University, Washington, D.C. 20059
| | - Sumaya Huque
- Department of Chemistry and Biochemistry, Middlebury College, Middlebury, Vermont 05753, Department of Chemistry, Keene State College, Keene, New Hampshire 03435, and Department of Chemistry, Howard University, Washington, D.C. 20059
| | - Benjamin M. Zegarelli
- Department of Chemistry and Biochemistry, Middlebury College, Middlebury, Vermont 05753, Department of Chemistry, Keene State College, Keene, New Hampshire 03435, and Department of Chemistry, Howard University, Washington, D.C. 20059
| | - Yong Zhang
- Department of Chemistry and Biochemistry, Middlebury College, Middlebury, Vermont 05753, Department of Chemistry, Keene State College, Keene, New Hampshire 03435, and Department of Chemistry, Howard University, Washington, D.C. 20059
| | - Jerry P. Jasinski
- Department of Chemistry and Biochemistry, Middlebury College, Middlebury, Vermont 05753, Department of Chemistry, Keene State College, Keene, New Hampshire 03435, and Department of Chemistry, Howard University, Washington, D.C. 20059
| | - Raymond J. Butcher
- Department of Chemistry and Biochemistry, Middlebury College, Middlebury, Vermont 05753, Department of Chemistry, Keene State College, Keene, New Hampshire 03435, and Department of Chemistry, Howard University, Washington, D.C. 20059
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17
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Harmata M, Zheng P, Schreiner PR, Navarro-Vázquez A. Deantiaromatization as a Driving Force in an Electrocyclic Reaction. Angew Chem Int Ed Engl 2006. [DOI: 10.1002/ange.200503812] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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18
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Harmata M, Zheng P, Schreiner PR, Navarro-Vázquez A. Deantiaromatization as a Driving Force in an Electrocyclic Reaction. Angew Chem Int Ed Engl 2006; 45:1966-71. [PMID: 16496272 DOI: 10.1002/anie.200503812] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Michael Harmata
- Department of Chemistry, University of Missouri--Columbia, MO 65211, USA.
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19
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Affiliation(s)
- Günther Maier
- Institut für Organische Chemie der Universität Heinrich‐Buff‐Ring 58, D‐6300 Lahn‐Gießen 1
| | - Fritz Köhler
- Institut für Organische Chemie der Universität Heinrich‐Buff‐Ring 58, D‐6300 Lahn‐Gießen 1
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20
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Quast H, Herkert T, Witzel A, Peters E, Peters K, von Schnering HG. 2,6‐Dicyano‐1,5‐dimethyl‐4,8‐diphenylsemibullvalene. — Synthesis, Structure and the Reactions with Triplet Oxygen. ACTA ACUST UNITED AC 2006. [DOI: 10.1002/cber.19941270521] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Helmut Quast
- Institut für Organische Chemie der Universität Würzburg, Am Hubland, D‐97074 Würzburg
| | - Thomas Herkert
- Institut für Organische Chemie der Universität Würzburg, Am Hubland, D‐97074 Würzburg
| | - Alexander Witzel
- Institut für Organische Chemie der Universität Würzburg, Am Hubland, D‐97074 Würzburg
| | - Eva‐Maria Peters
- Max‐Planck‐Institut für Festkörperforschung, Heisenbergstraße 1, D‐70506 Stuttgart
| | - Karl Peters
- Max‐Planck‐Institut für Festkörperforschung, Heisenbergstraße 1, D‐70506 Stuttgart
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21
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Maier G, Sayraç T, Reisenauer HP. Kleine Ringe, 42. Versuche zur Darstellung von Oxirenen über photochemische Cycloreversionen. ACTA ACUST UNITED AC 2006. [DOI: 10.1002/cber.19821150616] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Günther Maier
- Institut für Organische Chemie der Universität Gießen, Heinrich‐Buff‐Ring 58, D‐6300 Gießen
| | | | - Hans Peter Reisenauer
- Institut für Organische Chemie der Universität Gießen, Heinrich‐Buff‐Ring 58, D‐6300 Gießen
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22
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Maier G, Born D, Bauer I, Wolf R, Boese R, Cremer D. Kleine Ringe, 78. Tri‐
tert
‐butyl(trimethylsilyl)cyclobutadien und Tri‐
tert
‐butyl(trimethylsilyl)tetrahedran. ACTA ACUST UNITED AC 2006. [DOI: 10.1002/cber.19941270126] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Günther Maier
- Institut für Organische Chemie der Justus‐Liebig‐Universität, Heinrich‐Buff‐Ring 58, D‐35392 Gieβen
| | - Dieter Born
- Institut für Organische Chemie der Justus‐Liebig‐Universität, Heinrich‐Buff‐Ring 58, D‐35392 Gieβen
| | - Ines Bauer
- Institut für Organische Chemie der Justus‐Liebig‐Universität, Heinrich‐Buff‐Ring 58, D‐35392 Gieβen
| | - Reinhard Wolf
- Institut für Organische Chemie der Justus‐Liebig‐Universität, Heinrich‐Buff‐Ring 58, D‐35392 Gieβen
| | - Roland Boese
- Institut für Anorganische Chemie der Universität — GH, Universitätsstraβe 5‐7, D‐45117 Essen
| | - Dieter Cremer
- Department of Theoretical Chemistry, University of Göteborg, Kemigârden 3, S‐41296 Göteborg
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25
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Seigal BA, An MH, Snapper ML. Intramolecular [2+2+1] Cycloadditions with (Cyclobutadiene)tricarbonyliron. Angew Chem Int Ed Engl 2005; 44:4929-32. [PMID: 16007718 DOI: 10.1002/anie.200501100] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Benjamin A Seigal
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, MA 02467, USA
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26
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Seigal BA, An MH, Snapper ML. Intramolecular [2+2+1] Cycloadditions with (Cyclobutadiene)tricarbonyliron. Angew Chem Int Ed Engl 2005. [DOI: 10.1002/ange.200501100] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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27
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Benken R, Finneiser K, Von Puttkamer H, Günther H, Eliasson B, Edlund U. A Comparative1H- and13C-NMR Study of the Dianion and Dication of Biphenylene. Helv Chim Acta 2004. [DOI: 10.1002/hlca.19860690502] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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28
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29
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Hafner K, Diehl H, Süss HU. Cycloadditions of Pentalene and Azulene-A Facile Heptalene Synthesis. ACTA ACUST UNITED AC 2003. [DOI: 10.1002/anie.197601041] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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30
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Affiliation(s)
- Günther Maier
- Institut für Organische Chemie der Universität Heinrich‐Buff‐Ring 58, D‐6300 Lahn‐Giessen 1 (Germany)
| | - Fritz Köhler
- Institut für Organische Chemie der Universität Heinrich‐Buff‐Ring 58, D‐6300 Lahn‐Giessen 1 (Germany)
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31
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Limanto J, Tallarico JA, Porter JR, Khuong KS, Houk KN, Snapper ML. Intramolecular cycloadditions of cyclobutadiene with olefins. J Am Chem Soc 2002; 124:14748-58. [PMID: 12465988 DOI: 10.1021/ja0203162] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Intramolecular cycloadditions between cyclobutadiene and olefins can provide highly functionalized cyclobutene-containing products. The outcome of the reaction depends on the nature of the tether connecting the two reactive partners in the cycloaddition. Electronically unactivated olefins attached to cyclobutadiene through a three-atom, heteroatom-containing tether yield successfully the desired cycloadducts, whereas the corresponding substrates without a heteroatom linkage or with a longer tether are less prone to undergo the intramolecular cycloaddition. Calculations were used to help uncover some of the factors that influence the course of the cycloaddition. Successful intramolecular reactions usually require either electronic activation of the dienophile, conformational restriction of the tether, or a slower oxidation protocol. In general, a facile intermolecular dimerization of cyclobutadiene is the major process that competes with the intramolecular cycloaddition.
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Affiliation(s)
- John Limanto
- Department of Chemistry, Merkert Chemistry Center, Boston College, 2609 Beacon Street, Chestnut Hill, Massachusetts 02467, USA
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Abstract
Low-temperature photolysis of phenyldiazirine, incarcerated inside a hemicarcerand which is built from two cavitands connected by four butane-1,4-dioxy linker groups, yields transient phenylcarbene; this carbene then undergoes ring photochemical expansion to cycloheptatetraene in low yield. Competitively, the transiently formed phenylcarbene reacts with the surrounding hemicarcerand. The yield of the photochemical ring expansion was increased when the photolysis was carried out inside a partially deuterated hemicarcerand. Two insertion products resulting from an intramolecular phenylcarbene insertion into an acetal C-H(D) bond or an alpha-C-H bond of a butane-1,4-dioxy linker group have been isolated and characterized. The measured isotope effect for insertion into an acetal C-H(D) bond at 15.5 K is consistent with a reaction of singlet phenylcarbene. Incarcerated cycloheptatetraene is stable for a limited time at 100 degrees C and almost infinitely stable at room temperature in the absence of oxygen. NOESY experiments provide the distance ratio r21/r23 = 1.134 +/- 0.01 between protons H1-H2 and H2-H3 of cycloheptatetraene which is consistent with its twisted structure. Low-temperature photolysis of phenyldiazirine, incarcerated inside a chiral hemicarcerand which is built from two cavitands connected with three butane-1,4-dioxy and one (S,S)-2,3-O-isopropylidene-2,3-dihydroxybutane-1,4-dioxy linker group yields two diastereomeric cycloheptatetraene hemicarceplexes in a 2:3 ratio (30% total yield). Variable temperature 1H NMR studies provided a lower limit of deltaG++ = 19.6 kcalmol(-1) for the enantiomerization barrier of cycloheptatetraene. Incarcerated cycloheptatetraene reacts rapidly with oxygen to yield benzene and carbon dioxide via the 1,2-dioxaspiro[2,6]nona-4,6,8-triene intermediate. Different mechanisms for the formation of this spirodioxirane intermediate are discussed based on the measured rate of the oxygen addition. The activation parameters for the decarboxylation of the spirodioxirane have been measured in different bulk solvents. The free energy of activation shows very little solvent dependency. However. a strong propensity for enthalpy-entropy compensation due to a solvent reorganization that accompanies the reaction coordinate is observed.
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Affiliation(s)
- R Warmuth
- Department of Chemistry, Kansas State University, Manhattan 66506-3701, USA.
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Notario R, Castaño O, Andrés JL, Elguero J, Maier G, Hermann C. An experimental and theoretical study of the basicity of tetra-tert-butyltetrahedrane. Chemistry 2001; 7:342-6. [PMID: 11271519 DOI: 10.1002/1521-3765(20010119)7:2<342::aid-chem342>3.0.co;2-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The gas-phase basicity (GB) of tetra-tert-butyltetrahedrane (tBu4THD) was determined by FT-ICR mass spectrometry and comparison with reference compounds of known basicity. Its GB, 1035+/-10 kJ x mol(-1), makes tetra-tert-butyltetrahedrane one of the strongest bases reported so far. Ab initio calculations [B3LYP/6-31G(d) and B3LYP/6-311 + G(d,p)//6-31G(d)] have been carried out in order to compare the high experimental basicity of tBu4THD with that estimated theoretically. Both B3LYP/6-31G(d) and QCISD(T) calculations were used to determine the reaction path which connects the initial tetrahedrane-ammonium complex with the final products, protonated cyclobutadiene (CBDH+) and ammonia.
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Affiliation(s)
- R Notario
- Instituto de Química Física Rocasolano, CSIC Serrano, Madrid, Spain
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Carbenes in matrices: Spectroscopy, structure, and photochemical behavior. ACTA ACUST UNITED AC 2001. [DOI: 10.1016/s1079-350x(01)80005-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Kollenz G, Terpetschnig E, Sterk H, Peters K, Peters EM. Regio- and stereoselective photocycloadditions of heterocyclic 2,3-diones — Evidence for an unexpected 1,2-aroyl migration. Tetrahedron 1999. [DOI: 10.1016/s0040-4020(99)00078-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Quast H, Becker C, Peters EM, Peters K, von Schnering HG. A Novel Synthesis and the Autoxidation of 2,4,6,8-Tetraphenylbarbaralane. European J Org Chem 1997. [DOI: 10.1002/jlac.199719970409] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Müller M, Förster WR, Holst A, Kingma AJ, Schaumann E, Adiwidjaja G. Synthesis of 4-Silylcyclobut-2-enethiones and their Use in Cyclobutadiene Generation. Chemistry 1996. [DOI: 10.1002/chem.19960020809] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Heim U, Pritzkow H, Fleischer U, Grützmacher H, Sanchez M, Réau R, Bertrand G. λ5-Phosphetes, Benzo-λ5-Phosphetes, Naphtho-λ5-Phosphetes: Four-π-, Eight-π-, and Twelve-π-Electron Systems. Chemistry 1996. [DOI: 10.1002/chem.19960020113] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Dehmlow EV, Bollmann C. Reactions of 1,3,5-Tri-tert-butylcyclopentadiene formation of a tetracyclo[5.2.1.02,6.03,10]deca-4,8-diene. European J Org Chem 1995. [DOI: 10.1002/jlac.1995199505121] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Streubel R. Phosphaalkin-Cyclooligomere: von Dimeren zu Hexameren – erste Schritte auf dem Weg zu Phosphor-Kohlenstoff-Käfigverbindungen. Angew Chem Int Ed Engl 1995. [DOI: 10.1002/ange.19951070407] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Maier G, Rang H, Emrich R. Kleine Ringe, 87. Suche nach alternativen Wegen zum Tetra-tert-butyltetrahedran; Synthese sterisch überladener Verbindungen. ACTA ACUST UNITED AC 1995. [DOI: 10.1002/jlac.199519950121] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Maier G, Franz LH, Boese R. Kleine Ringe, 86. Versuche zur Darstellung von Alkyltri-tert-butyltetrahedranen auf dem Cyclopentadienon-Weg; photochemisches Verhalten der Cyclopentadienone. ACTA ACUST UNITED AC 1995. [DOI: 10.1002/jlac.199519950120] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Maier G, Wolf R, Kalinowski HO, Boese R. Kleine Ringe, 79. Synthese und Eigenschaften neuer Silyl-substituierter Cyclobutadiene und Tetrahedrane. ACTA ACUST UNITED AC 1994. [DOI: 10.1002/cber.19941270127] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Schoeller WW, Busch T. Stickstoff- versus Phosphorsubstitution in Cyclobutadien: eine theoretische Beschreibung der Bindungseigenschaften. Angew Chem Int Ed Engl 1993. [DOI: 10.1002/ange.19931050441] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Gompper R, Wagner HU. Donor-acceptor-substituierte cyclische π-Elektronensysteme - Prüfsteine für Theorien und Bausteine für neue Materialien. Angew Chem Int Ed Engl 1988. [DOI: 10.1002/ange.19881001105] [Citation(s) in RCA: 62] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Irngartinger H, Nixdorf M, Riegler NH, Krebs A, Kimling H, Pocklington J, Maier G, Malsch KD, Schneider KA. Strukturbestimmungen von Cyclobutadien-Derivaten. ACTA ACUST UNITED AC 1988. [DOI: 10.1002/cber.19881210413] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Maier G, Franz LH, Hartan HG, Lanz K, Reisenauer HP. Kleine Ringe, 54. Cyclopentadienon. ACTA ACUST UNITED AC 1985. [DOI: 10.1002/cber.19851180819] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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