Ligand-Modified Catalysts for the McMurry Pinacol Reaction

Journal of Organic Chemistry

Volumn 62, Issue 14, 1997, Pages 4566-4567

  Lipski, Timothy A ^a   Hilfiker, Mark A ^a   Nelson, Scott G ^a  

^a UNIVERSITY OF PITTSBURGH   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 0000067275     PISSN: 00223263     EISSN: None     Source Type: Journal    
DOI: 10.1021/jo970792o     Document Type: Article

References (27)

1. (a) McMurry, J. E. Chem. Rev. 1989, 89, 1513-1524 and references cited therein.
2. Robertson, G. M. In Comprehensive Organic Synthesis: Carbon-Carbon σ-Bond Formation; Trost, B. M., Fleming, I., Heathcock, C. H., Eds.; Pergamon Press: New York, 1991; Vol. 3, Chapter 2.6, pp 563-611.
3. A number of highly diastereoselective intramolecular pinacol couplings have been reported; see: (a) Reference 1.
4. (b) Raw, A. S.; Pedersen, S. F. J. Org. Chem. 1991, 56, 830-833.
5. (c) Guidot, J. P.; Le Gall, T.; Mioskowski, C. Tetrahedron Lett. 1994, 35, 6671-6672.
6. (d) Hays, D. S.; Fu, G. C. J. Am. Chem. Soc. 1995, 117, 7283-7284.
7. (e) Kang, M.; Park, J.; Konradi, A. W.; Pedersen, S. F. J. Org. Chem. 1996, 61, 5528-5531.
8. (a) Fürstner, A.; Hupperts, A. J. Am. Chem. Soc. 1995, 117, 4468-4475.
9. (b) Gansäuer, A. J. Chem. Soc., Chem. Commun. 1997, 457-458.
10. Hirao, T.; Hasegawa, T.; Muguruma, Y.; Ikeda, I. J. Org. Chem. 1996, 61, 366-367.
11. (a) Léonard, E.; Duñach, E.; Périchon, J. J. Chem. Soc., Chem. Commun. 1989, 276-277.
12. (b) Nomura, R.; Matsuno, T.; Endo, T. J. Am. Chem. Soc. 1996, 118, 11666-11667.
13. (a) Raubenheimer, H. G.; Seebach, D. Chimia 1986, 40, 12-13.
14. (b) Handa, Y; Inanaga, J. Tetrahedron Lett. 1987, 28, 5717-5718.
15. (c) Barden, M. C.; Schwartz, J. J. Am. Chem. Soc. 1996, 118, 5484-5485.
16. Konradi, A. W.; Kemp, S. J.; Pedersen, S. F. J. Am. Chem. Soc. 1994, 116, 1316-1323 and references cited therein.
17. Manzer, L. E. Inorg. Synth. 1982, 21, 135-140.
18. So, J.-H.; Park, M.-K.; Boudjouk, P. J. Org. Chem. 1988, 53, 5871-5875.
19. The structure of the Ti(III) catalyst proved to be a determining factor in the success of the catalyzed pinacol reactions. Titanium(III) chloride that had not been precomplexed with THF was inactive as a catalyst under the indicated reaction conditions.
20. For a discussion of possible mechanisms of low-valent metal-catalyzed pinacol reactions in the presence of TMSCl, see refs 4, 5, and 6b.
21. The magnitude of the rate acceleration is substrate dependent; less reactive substrates (e.g., aliphatic aldehydes) exhibit the largest rate accelerations relative to the parent catalyst system.
22. 4 and concentrated in vacuo. Flash chromatography (hexanes/ethyl acetate) afforded the desired diol in the indicated yield and diastereoselectivity (Table 2). Results reported in Table 1 were for reactions employing this same experimental procedure but excluding the 1,3-diethyl-1,3-diphenylurea.
23. Use of magnesium as the stoichiometric reductant, in place of zinc, provided substantially improved chemical yields in the annulative pinacol coupling of glutaraldehyde (1) and adipaldehyde (2).
24. Girolami, G. S.; Wilkinson, G.; Galas, A. M. R.; Thorton-Pett, M.; Hursthouse, M. B. J. Chem. Soc., Dalton Trans. 1985, 1339-1348.
25. Ligand effects in stoichiometric McMurry pinacol reactions have been examined, see: Balu, N.; Nayak, S. K.; Banerji, A. J. Am. Chem. Soc. 1996, 118, 5932-5937.
26. 3-DEPU catalyst system was deduced by optimizing both of these reaction variables.
27. Stoichiometric quantities of other urea additives (e.g., DMPU) do not afford improved stereoselectivity, suggesting that enhanced diastereoselection due to the DEPU ligand is not simply an artifact of a modified catalyst aggregation state.