On the counterion dependence of the rhodium(I)-catalysed [4+2] cycloaddition - A remarkable accelerating effect of the hexafluoroantimonate anion

Synlett

Volumn , Issue 4, 1998, Pages 443-445

  O'Mahony, Donogh J R ^a   Belanger, David B ^a   Livinghouse, Tom ^a  

^a MONTANA STATE UNIVERSITY   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 0000186697     PISSN: 09365214     EISSN: None     Source Type: Journal    
DOI: 10.1055/s-1998-1664     Document Type: Article

References (18)

1. Wender, P. A.; Jenkins, T. E.; J. Am. Chem. Soc. 1989, 111, 6432.
2. For subsequent reports on this catalyst system see: a) Wender, P. A.; Smith, T. E.; J. Org. Chem. 1995, 60, 2962.
3. b) Wender, P. A.; Smith, T. E. J. Org. Chem. 1996, 61, 824.
4. Jolly, R. S.; Luedtke, G. R.; Sheehan, D.; Livinghouse, T. J. Am. Chem. Soc. 1990, 112, 4965.
5. An asymmetric version has also been reported: McKinstry, L; Livinghouse. T. Tetrahedron 1994, 50, 6145.
6. Cycloaddition precursors were prepared from the secondary sulfonamide by Mitsunobu coupling with the readily available dienols. A slight modification of the standard reaction conditions involving the use of the more basic tri-n-butyl phosphine in THF gave good yields of the triene with excellent retention of initial diene stereochemistry (>50/1 by 500 MHz NMR).
7. 4 complex is 6 times that of the OTf analog: Svetlanova-Larsen, A.; Hubbard, J. L. Inorg. Chem. 1996, 35, 3073.
8. See also Lawrence, G. A. Chem. Rev. 1986, 86, 17.
9. For a report of similar differences in cationicity in copper-based catalysis see: Evans, D. A.; Murry, J. A.; von Matt, P.; Norcross, R. D.; Miller, S. J. Angew. Chem. Int. Ed. Engl. 1995, 34, 798.
10. a) Honeychuck, R. V.; Hersh, W. A. Inorg. Chem. 1989, 28, 2869, and refs therein.
11. 4B: see b) Beck, W. A.; Sünkel, K. Chem. Rev. 1988, 88, 1405.
12. a) RajanBabu, T. V.; Ayers, T. A.; Halliday, G. A.; You, K. K.; Calabrese, J. C. J. Org. Chem. 1997, 62, 6012.
13. b) Burk, M. J.; Feaster, J. E.; Nugent, W. A.; Harlow, R. L. J. Am. Chem. Soc. 1993, 115, 10125.
14. The thermodynamic preference for trans [3.3.0] bicyclooctane species in zirconocene mediated cyclisations of 1,6-dienes is presumably a result of the very long Zr-C bonds (2.28 Å), and non-bonded interactions between the carbocyclic ring and an endo Cp ring in the cis metallacycle: see Taber, D. F.; Louey, J. P.; Wang, Y.; Nugent, W. A.; Dixon, D. A.; Harlow, R. L. J. Am. Chem. Soc. 1994, 116, 9457.
15. A trigonal bipyramidal rhodacyclopentadiene has a Rh-C bond length of 2.00 Å: Müller, E.; Langer, E.; Jälke, H.; Muhm, H.; Hoppe, W.; Graziani, R.; Gieren, A.; Brandl, F. Z. Naturforsch. 1971, 26B, 305.
16. 3)] has a 2.08 Å Rh-C bond: Troughton, P. G. H.; Skapski, A. C. J. Chem. Soc. Chem. Commun. 1968, 575.
17. 2S: 291.1293, found 291.1289.
18. 1H NMR of the Mosher ester.