Generation and trapping of isobenzofuran intermediates formed in the coupling of Fischer carbene complexes and o-alkynylbenzoyl derivatives

Organic Letters

Volumn 2, Issue 9, 2000, Pages 1267-1269

  Jiang, Delu ^a   Herndon, James W ^a  

^a NEW MEXICO STATE UNIVERSITY   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 0000690866     PISSN: 15237060     EISSN: None     Source Type: Journal    
DOI: 10.1021/ol005691i     Document Type: Article

References (14)

1. Herndon, J. W.; Wang, H. J. Org. Chem. 1998, 63, 4563-4564.
2. Friedrichsen, W. Adv. Heterocycl. Chem. 1999, 73, 1 -96.
3. This compound was a single isomer; the E-Z configuration for this compound could not be reliably assigned. The depicted configuration has been suggested (see Supporting Information for a discussion).
4. 1H NMR Spectra; Aldrich Chemical: Milwaukee, WI, 1992; Vol. 1, p 334A.
5. For a theoretical discussion of the interconversion of isobenzofurans and alkylidenephthalans, see: Friedrichsen, W. Struct. Chem. 1999, 10, 47-
6. B, which is expected to be nearly 0 Hz in the opposite stereoisomer. Yamaguchi, Y.; Yamada, H.; Hayakawa, H.; Kenematsu, K. J. Org. Chem. 1987, 52, 2040-2046.
7. (b) Chromium carbenealkyne coupling affords E enol ethers. McCallum, J. S.; Kunng, F. A.; Gilberton, S. R.; Wulff, W. D. Organometallics 1988, 7, 2346-2360.
8. Compound 10 (or the corresponding ketone) was observed if the chloroform NMR sample was kept at room temperature for > 12 h or if the silica gel purification was conducted too slowly.
9. Wienand, A.; Reissig, H.-U. Organometallics 1990, 9, 3133-3142.
10. For efficient deoxygenation using chromium(0) species, see: Wulff, W. D.; Kaesler, R. W.; Peterson, G. A.; Tang, P.-C. J. Am. Chem. Soc. 1985, 107, 1060-1062.
11. B at >4 ppm.
12. C (∼3 ppm, see ref 10).
13. 3 complex; however, numerous thiophene and pyrrole complexes have been reported. For a recent example, see: Loft, M. S.; Mowlem, T. J.; Widdowson, D. A. J. Chem. Soc., Perkin Trans. 1 1995, 97-104 and references therein.
14. The stereochemistry can be dramatically affected in metal-mediated processes. Wender, P. A.; Jenkins, T. E.; Suzuki, S. J. Am. Chem. Soc. 1995, 117, 1843-1844.