An Extraordinarily Twisted Polycyclic Aromatic Hydrocarbon

Angewandte Chemie (International Edition in English)

Volumn 36, Issue 13-14, 1997, Pages 1531-1532

  Qiao, Xiaoxin ^a   Ho, Douglas M ^a   Pascal Jr , Robert A ^a  

^a PRINCETON UNIVERSITY   (United States)

Author keywords

Arenes; Aromaticity; Chirality; Hydrocarbons; Polycycles

Indexed keywords

EID: 0030750823     PISSN: 05700833     EISSN: None     Source Type: Journal    
DOI: 10.1002/anie.199715311     Document Type: Article

References (16)

1. K. P. Meurer, F. Vögtle, Top. Curr. Chem. 1985, 127, 1-76.
2. a) R. A. Pascal, Jr., W. D. McMillan, D. Van Engen, J. Am. Chem. Soc. 1986, 108, 5652-5653;
3. b) R. A. Pascal, Jr., W. D. McMillan, D. Van Engen, R. G. Eason, ibid. 1987, 109, 4660-4665;
4. c) P. J. Fagan, M. D. Ward, J. V. Caspar, J. C. Calabrese, P. J. Krusic, ibid. 1988, 110, 2981-2983;
5. d) N. Smyth, D. Van Engen, R. A. Pascal, Jr., J. Org. Chem. 1990, 55, 1937-1940.
6. X. Qiao, M. A. Padula, D. M. Ho, N. J. Vogelaar, C. E. Schutt, R. A. Pascal, Jr., J. Am. Chem. Soc. 1996, 118, 741-745.
7. 5-pentamethylcyclopentadienyl)-ruthenium] complex of rubrene (67.3°) [2c].
8. W. Ried, K. H. Bonnighausen, Liebigs Ann. Chem. 1961, 639, 61-67.
9. -3. Crystallographic data (excluding structure factors) for the structure reported in this paper have been deposited with the Cambridge Crystallographic Data Centre as supplementary publication no. CCDC-100115. Copies of the data can be obtained free of charge on application to The Director, CCDC, 12 Union Road, Cambridge CB2 1EZ, UK (fax: int. code +(1223) 336-033; e-mail: deposit@chemcrys.cam.ac.uk).
10. G. M. Sheldrick, SHELXTL, Version 4.2. Siemens Analytical X-ray Instruments, Madison, Wisconsin, USA, 1991.
11. G. M. Sheldrick, SHELXL-93. Program for the Refinement of Crystal Structures. University of Gottingen, Germany. 1993.
12. a) E. Clar, Chem. Ber. 1948, 81, 253-269.
13. b) E. Clar, Polycyclic Hydrocarbons, Vol. 1, Academic Press, London, 1964, p 407.
14. 1H NMR spectrum of 1 in the chiral solvent mixture d-trifluoromethylbenzyl alcohol/deuterochloroform (1/2) is broadened, but not cleanly split into enantiomeric subspectra, suggesting that it may have a significant barrier to racemization. Previously prepared longitudinally twisted aromatic polycycles show evidence of great conformational flexibility, possess only modest barriers to racemization, and none has been successfully resolved [2 b, 3, 11].
15. K. Shibata, A. A. Kulkarni, D. M. Ho, R. A. Pascal, Jr., J. Org. Chem. 1995, 60, 428-434.
16. M. J. S. Dewar, E. G. Zoebisch, E. F. Healy, J. J. P. Stewart, J. Am. Chem. Soc. 1985, 107, 3902-3909.