H. Heaney, J. H. Hallinsheed, S. M. F. Lai and P. Singh,
F2
F2
F2
F2
F2
F2
F2
F2
F
F
F
F
F
F
F
F
Tetrahedron, 1995, 51, 7777; (h) J. M. Khurana and A. Sehgal,
Synth. Commun., 1996, 26, 3791; (i) F. A. J. Kerdesky and L. S. Seif,
Synth. Commun., 1995, 25, 4081; (j) S. Sayama and Y. Inamura,
Chem. Lett., 1996, 8, 633; (k) T. Nozoe, H. Wakabayashi, K. Shindo
and M. Yasunami, Chem. Lett., 1995, 6, 439; (l) Y. Zhang, Y. Yu and
W. Bao, Synth. Commun., 1995, 25, 1825; (m) R. Yanada, K. Bessho
and K. Yanada, Chem. Lett., 1994, 7, 1279.
∆E = – 0.3 kcal mol–1
F2
F2 + F
O
F
F
F
3
6
F
F
F
F
F
F
F
F
O
3 D. R. Lide and H. P. R. Frederikse, CRC Handbook of Chemistry
and Physics, 74th edn., CRC press: Ann Arbor, MI, 1993, p. 9124.
4 (a) A. R. Ravishankara, S. Solomon, A. A. Turnipseed and R. F.
Warren, Science, 1993, 259, 194; (b) Organofluorine Chemistry,
Principles and Commercial Applications, eds. R. E. Banks,
B. E. Smart and J. C. Tatlow, Plenum Press: New York, 1994, pp.
70–74; (c) S. Tasker, R. D. Chambers and J. P. S. Badyal, J. Phys.
Chem., 1994, 98, 12 442; (d) M. Hudlicky, Chemistry of Organic
Fluorine Compounds, 2nd edn., Ellis Horwood, 1992, p. 608.
5 (a) S. T. Belt, M. Helliwell, W. D. Jones, M. G. Partridge and
R. N. Perutz, J. Am. Chem. Soc., 1993, 115, 1429; (b) A. H. Klahn,
M. H. Moore and R. N. Perutz, J. Chem. Soc., Chem. Commun.,
1992, 1699; (c) P. Hoffmann and G. Unfried, Chem. Ber., 1992, 125,
659; (d) C. M. Anderson, M. Crespo, G. Ferguson, A. J. Lough and
R. J. Puddephatt, Organometallics, 1992, 11, 1177; (e) M. Crespo,
M. Martinez and J. Sales, J. Chem. Soc., Chem. Commun., 1992, 822;
( f ) B. L. Lucht, M. J. Poss, M. A. King and T. G. Richmond,
J. Chem. Soc., Chem. Commun., 1991, 400; (g) O. Blum, F. Frolow
and D. Milstein, J. Chem. Soc., Chem. Commun., 1991, 258; (h)
W. D. Jones, M. G. Partridge and R. N. Perutz, J. Chem. Soc., Chem.
Commun., 1991, 264; (i) T. G. Richmond, Coord. Chem. Rev., 1990,
105, 221; (j) C. E. Osterberg, M. A. King, A. M. Arif and
T. G. Richmond, Angew. Chem., Int. Ed. Engl., 1990, 29, 888; (k)
S. Park, M Pontier-Johnson and D. M. Roundhill, Inorg. Chem.,
1990, 29, 2689; (l) P. L. Watson, T. H. Tulip and I. Williams,
Organometallics, 1990, 9, 1999.
F
F
F
(eqn. 1)
F
F
+ 2
F
2
F
F
F
F
F
F
F
F
F
F
F
∆E = 56.7 kcal mol–1
+
F
F
F
F
F
F
F
F
F
6
6
F
F
F
F
F
F
F
F
F
F
F
(eqn. 2)
+
2
F
F
F
5
6 (a) W. A. Sheppard and C. M. Sharts, Organic Fluorine Chemistry,
W. A. Benjamin: New York, 1969, p. 450; (b) A. Oku, J. Nishimura,
S. Nakagawa and K. Yamada, Nippon Kagaku Kaishi, 1985, 1963
(Chem Abstr., 1985, 105, 97 047z); (c) L. Kavan and F. P. Dousek,
J. Fluorine Chem., 1988, 41, 383.
7 (a) B. Gething, C. R. Patrick, M. Stacey and J. C. Tatlow, Nature,
1959, 183, 588; (b) J. Bailey, R. G. Plevey and J. C. Tatlow,
J. Fluorine Chem., 1987, 32, 1; (c) J. Burdeniuc and R. H. Crabtree,
Science, 1996, 271, 340.
8 (a) J. A. Marsella, A. G. Gilicinski, A. M. Coughlin and G. P. Pez,
J. Org. Chem., 1992, 57, 2856; (b) J. A. Marsella, G. P. Pez and
A. M. Coughlin, U. S. Patent 5 026 929 (1991); (c) R. G. Harrison
and T. G. Richmond, J. Am. Chem. Soc., 1993, 115, 5303.
Fig. 1 Optimized structures of perfluoro(dibenzofuran) 2, perfluoro-
(diphenyl ether) 3, perfluoro(biphenylene) 5, and perfluoro(diphenyl)
6 at the level of AM1
bonds on both sides of the reaction. The reaction is exothermic
with ∆E = Ϫ0.3 kcal molϪ1 and this implies that the ring-
closure does give a small amount of aromatic stability. The same
method was applied to ring-closure of 5 to 6. As expected, the
isodesmic reaction (eqn. 2) is endothermic with ∆E = 56.7 kcal
molϪ1. The ring-closure of 5 to 6 would bring antiaromatic
character in the central ring of 6 or along the periphery of the
whole fused molecule, which is the source of instability.
In addition to aromatic stabilization, flexibility of the ether
linkage and a suitable reducing potential of 1 are possible driv-
ing forces for the reductive defluorination of 1 to 2 with a
special ring closure.
9 (a) D. D. MacNicol and C. D. Robertson, Nature, 1988, 332, 59; (b)
J. Burdeniuc and R. H. Crabtree, J. Am. Chem. Soc., 1996, 118,
2525; (c) J. Burdeniuc, W. Chupka and R. H. Crabtree, J. Am. Chem.
Soc., 1995, 117, 10 119; (d) N. A. Kaprinidis and N. J. Turro,
Tetrahedron Lett., 1996, 37, 2373.
10 (a) M. Weydert, R. A. Anderson and R. G. Bergman, J. Am. Chem.
Soc., 1993, 115, 8837; (b) J. L. Kiplinger and T. G. Richmond, J. Am.
Chem. Soc., 1996, 118, 1805; (c) B. K. Bennett, R. G. Harrison and
T. G. Richmond, J. Am. Chem. Soc., 1994, 116, 11 165.
11 Perfluoro(dicyclohexyl ether) 1 and perfluoro(dicyclohexyl) 4 were
prepared by liquid-phase direct fluorination of corresponding
hydrocarbons and purified by preparative GC.
12 (a) R. D. Chambers, J. A. Cunningham and D. J. Spring, J. Chem.
Soc. C, 1968, 1560; (b) P. Sartori and A. Golloch, Chem. Ber., 1970,
103, 313; (c) P. Sartori and A. Golloch, Chem. Ber., 1969, 102, 1765;
(d) D. V. Gardner, J. F. W. McOmie, P. Albriktsen and R. K. Harris,
J. Chem. Soc. C, 1969, 1994; (e) R. J. De Pasquale and
C. Tamborski, J. Org. Chem., 1969, 34, 1736.
We are grateful for support for this work at the University of
Texas from the US National Science Foundation, the Office of
Naval Research and the Robert A. Welch Foundation.
13 R. J. De Pasquale and C. Tamborski, J. Org. Chem., 1967, 32, 3163.
14 Gaussian 94, Revision D.2: M. J. Frisch, G. W. Trucks,
H. B. Schlegel, P. M. W. Gill, B. G. Johnson, M. A. Robb,
J. R. Cheeseman, T. A. Keith, G. A. Peterson, J. A. Montgomery,
K. Raghavachari, M. A. Al-Laham, V. G. Zakrzewski, J. V. Ortiz,
J. B. Foresman, J. Cioslowski, B. B. Stefanov, A. Nanayakkara,
M. Challacombe, C. Y. Peng, P. Y. Ayala, W. Chen, M. W. Wong,
J. L. Andres, E. S. Replogle, R. Gomperts, R. L. Martin, D. J. Fox,
J. S. Binkley, D. J. Defrees, J. Baker, J. P. Stewart, M. Head-Gordon,
C. Gonzales and J. A. Pople, Gaussian Inc., Pittsburgh, PA, 1995.
15 M. W. Wong, A. Pross and L. Radom, J. Am. Chem. Soc., 1994, 116,
6284.
References
1 (a) Principles and Applications of Organotransition Metal Chemistry,
eds., J. P. Collman, L. S. Hegedus, J. R. Norton and R. G. Finke,
University Science Books: Mill Valley, CA, 1987, ch. 5; (b) H. M.
A. Walborsky, Acc. Chem. Rev., 1990, 23, 286.
2 (a) B. M. Branan, L. A. Paquette, J. Org. Chem., 1994, 59, 7709;
(b) G. W. Ebert, D. R. Pfennig, S. D. Suchan, T. A. Donovan, Jr.,
E. Aouad, S. S. Tehrani, J. N. Gunnersen and L. Dong, J. Org.
Chem., 1995, 60, 2361; (c) P. Haberfield, J. Am. Chem. Soc., 1995,
117, 3314; (d) A. Arnone, P. Bravo, M. Frigerio, F. Viani,
G. Cavicchio and M. Crucianelli, J. Org. Chem., 1994, 59, 6448;
(e) A. Bomben, C. A. Marques, M. Selva and P. Tundo, Synthesis,
1996, 1109; ( f ) B.-C. Chen, S. L. Quinlan, D. R. Stark, J. G. Reid,
V. H. Audia, J. G. George, E. Eisenreich, S. P. Brundidge, S. Racha
and R. H. Spector, Tetrahedron Lett., 1995, 36, 7957; (g) N. J. Hales,
Paper 7/08781K
Received 5th December 1997
Accepted 5th December 1997
638
J. Chem. Soc., Perkin Trans. 1, 1998