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Sackers E, Osswald T, Weber K, Keller M, Hunkler D, Wörth J, Knothe L, Prinzbach H. Bromination of Unsaturated Dodecahedranes—En Route to C20 Fullerene. Chemistry 2006; 12:6242-54. [PMID: 16927320 DOI: 10.1002/chem.200501609] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
As part of a study to achieve selective oligo(poly)bromination-ultimately perbromination-of the dodecahedral C(20) skeleton, the extent and direction of the ionic bromination of dodecahedrene and 1,16-dodecahedradiene were explored. Along sequences of Br(+) additions/deprotonations and allylic rearrangements, up to ten hydrogen atoms were substituted (traces of C(20)H(x)Br(10)). Tetrabromododecahedrenes obtained under defined conditions in up to 50 % total yield with three and four allylic bromine substituents protecting the extremely bent C==C bonds, proved highly unreactive even towards oxygen but reacted rapidly with CH(2)N(2). Upon electron impact ionization (MS) of the newly secured oligo(poly)bromododecahedra(e)nes, sequential loss of the substituents ended generally in polyunsaturated dodecahedranes (in the extreme C(20)H(4), "tetrahydro-C(20) fullerenes"). Only subsequently did skeletal fragmentations occur. From X-ray crystal-structure analyses, more information was obtained on the structural response of the dodecahedral skeleton to the strain induced by the voluminous substituents. As Appendix, the forcing radical bromination of 1,6-dibromododecahedrane and exploratory cis-beta-HBr/cis-beta-Br(2) eliminations in bromododecahedranes with [Fe(2)(CO)(9)], P(2)F/[FeCp(2)] and [Fe(tmeda)Cp*Cl] (in situ protection) are presented.
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Affiliation(s)
- Emmerich Sackers
- Institut für Organische Chemie und Biochemie, Albert-Ludwigs-Universität, 79104 Freiburg, Germany
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Exner K, Cullmann O, Vögtle M, Prinzbach H, Grossmann B, Heinze J, Liesum L, Bachmann R, Schweiger A, Gescheidt G. Cyclic In-Plane Electron Delocalization (σ-Bishomoaromaticity) in 4N/5e Radical Anions and 4N/6e DianionsGeneration, Structures, Properties, Ion-Pairing, and Calculations. J Am Chem Soc 2000. [DOI: 10.1021/ja0014943] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Kai Exner
- Contribution from the Institute of Organic Chemistry and Biochemistry and the Institute of Physical Chemistry, University of Freiburg, Albertstrasse 21, D-79104 Freiburg, Germany, Institute of Physical Chemistry, ETH Zürich, ETH Zentrum, CH-8000 Zürich, Switzerland, and Institute of Physical Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
| | - Oliver Cullmann
- Contribution from the Institute of Organic Chemistry and Biochemistry and the Institute of Physical Chemistry, University of Freiburg, Albertstrasse 21, D-79104 Freiburg, Germany, Institute of Physical Chemistry, ETH Zürich, ETH Zentrum, CH-8000 Zürich, Switzerland, and Institute of Physical Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
| | - Markus Vögtle
- Contribution from the Institute of Organic Chemistry and Biochemistry and the Institute of Physical Chemistry, University of Freiburg, Albertstrasse 21, D-79104 Freiburg, Germany, Institute of Physical Chemistry, ETH Zürich, ETH Zentrum, CH-8000 Zürich, Switzerland, and Institute of Physical Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
| | - Horst Prinzbach
- Contribution from the Institute of Organic Chemistry and Biochemistry and the Institute of Physical Chemistry, University of Freiburg, Albertstrasse 21, D-79104 Freiburg, Germany, Institute of Physical Chemistry, ETH Zürich, ETH Zentrum, CH-8000 Zürich, Switzerland, and Institute of Physical Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
| | - Birgit Grossmann
- Contribution from the Institute of Organic Chemistry and Biochemistry and the Institute of Physical Chemistry, University of Freiburg, Albertstrasse 21, D-79104 Freiburg, Germany, Institute of Physical Chemistry, ETH Zürich, ETH Zentrum, CH-8000 Zürich, Switzerland, and Institute of Physical Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
| | - Jürgen Heinze
- Contribution from the Institute of Organic Chemistry and Biochemistry and the Institute of Physical Chemistry, University of Freiburg, Albertstrasse 21, D-79104 Freiburg, Germany, Institute of Physical Chemistry, ETH Zürich, ETH Zentrum, CH-8000 Zürich, Switzerland, and Institute of Physical Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
| | - Lorenz Liesum
- Contribution from the Institute of Organic Chemistry and Biochemistry and the Institute of Physical Chemistry, University of Freiburg, Albertstrasse 21, D-79104 Freiburg, Germany, Institute of Physical Chemistry, ETH Zürich, ETH Zentrum, CH-8000 Zürich, Switzerland, and Institute of Physical Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
| | - Rainer Bachmann
- Contribution from the Institute of Organic Chemistry and Biochemistry and the Institute of Physical Chemistry, University of Freiburg, Albertstrasse 21, D-79104 Freiburg, Germany, Institute of Physical Chemistry, ETH Zürich, ETH Zentrum, CH-8000 Zürich, Switzerland, and Institute of Physical Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
| | - Arthur Schweiger
- Contribution from the Institute of Organic Chemistry and Biochemistry and the Institute of Physical Chemistry, University of Freiburg, Albertstrasse 21, D-79104 Freiburg, Germany, Institute of Physical Chemistry, ETH Zürich, ETH Zentrum, CH-8000 Zürich, Switzerland, and Institute of Physical Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
| | - Georg Gescheidt
- Contribution from the Institute of Organic Chemistry and Biochemistry and the Institute of Physical Chemistry, University of Freiburg, Albertstrasse 21, D-79104 Freiburg, Germany, Institute of Physical Chemistry, ETH Zürich, ETH Zentrum, CH-8000 Zürich, Switzerland, and Institute of Physical Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
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