Bulletin of the Korean Chemical Society

Korean Chemical Society (대한화학회)
권호 표지
DOI QR코드

DOI QR Code

Elimination Reactions of (E)-2,4,6-Trinitrobenzaldehyde O-Aryloximes Promoted by R3N/R3NH+ in 70 mol% MeCN(aq). Effect of β-Aryl Group the Nitrile-Forming Transition-State

  • Received : 2011.03.16
  • Accepted : 2011.04.19
  • Published : 2011.06.20
Download PDF
⟨ Previous Next ⟩

Abstract

Nitrile-forming eliminations from $(E)-2,4,6-(NO_2)_3C_6H_2CH=NOC_6H_4-2-X-4-NO_2$ (1) promoted by $R_3NH/R_3NH^+$ in 70 mol % MeCN(aq) have been studied kinetically. When X = $NO_2$, the reactions exhibited second-order kinetics as well as Br$\"{o}$nsted ${\beta}$ = 0.63 and ${\mid}{\beta}_{lg}{\mid}$ = 0.34-0.46, and an E2 mechanism is evident. As the leaving group was made poorer (X = H, Cl, and $CF_3$), Br$\"{o}$nsted ${\beta}$ value increased from 0.63 to 0.85-0.89 without much change in the ${\mid}{\beta}_{lg}{\mid}$ value E2, indicating that structure of the transition state changed to an E1cb-like with extensive $C_{\beta}-H$ bond cleavage, significant negative charge development at the ${\beta}$-carbon, and limited $C_{\alpha}$-OAr bond cleavage.

Keywords

References

  1. Cho, B. R.; Kim, K. D.; Lee, J. C.; Cho, N. S. J. Am. Chem. Soc. 1988, 110, 6145-6148. https://doi.org/10.1021/ja00226a032
  2. Cho, B. R.; Lee, J. C.; Cho, N. S.; Kim, K. D. J. Chem. Soc. Perkin Trans II 1989, 489-492.
  3. Cho, B. R.; Min, B. K.; Lee, C. W.; Je, J. T. J. Org. Chem. 1991, 56, 5513-5517. https://doi.org/10.1021/jo00019a008
  4. Cho, B. R.; Jung, J.; Ahn, E. K. J. Am. Chem. Soc. 1992, 114, 3425-3429. https://doi.org/10.1021/ja00035a040
  5. Cho, B. R.; Je, J. T. J. Org. Chem. 1993, 58, 6190-6193. https://doi.org/10.1021/jo00075a009
  6. Cho, B. R.; Cho, N. S.; Song, K. S.; Son, K. N.; Kim, Y. K. J. Org. Chem. 1998, 63, 3006-3009. https://doi.org/10.1021/jo972192v
  7. Cho, B. R.; Pyun, S. Y. Bull. Korean Chem. Soc. 2010, 31, 1043- 1046. https://doi.org/10.5012/bkcs.2010.31.04.1043
  8. Coetzee, J. F. Prog. Phys. Org. Chem. 1965, 4, 45-92.
  9. Hegarty, A. F.; Tuohey, P. J. J. Chem. Soc., Perkin Trans. 2 1980, 1313-1317.
  10. Tamura, Y.; Minamikawa, J.; Sumoto, K.; Fujii, S.; Ikeda, M. Synthesis 1977, 1-17.
  11. Bumgardner, C. L.; Lilly, R. L. Chem. Ind.(London) 1962, 24, 599-560.
  12. Gandler, J. R. The Chemistry of Double Bonded Functional Groups; Patai, S., Ed.; John Wiley and Sons: Chichester, 1989; vol. 2, part 1, pp 734-797.
  13. Lowry, T. H.; Richardson, K. S. Mechanism and Theory in Organic Chemistry; Harper and Row: New York, 1987. pp 214-218. pp 591-616. pp 640-644.
  14. Hoffman, R. V.; Shankweiler, J. M J. Am. Chem. Soc. 1986, 108, 5536-5539. https://doi.org/10.1021/ja00278a028
  15. Tagaki, W.; Kobayashi, S.; Kurihara, K.; Kurashima, K.; Yoshida, Y.; Yano, J. J. Chem. Soc., Chem. Commun. 1976, 843-845.
  16. Cho, B. R.; Kim, Y. K.; Maing Yoon, C. O. J. Am. Chem. Soc. 1997, 119, 691-697. https://doi.org/10.1021/ja961294k
  17. Jencks, W. P. Chem. Rev. 1985, 85, 511-527. https://doi.org/10.1021/cr00070a001
  18. Gandler, J. R.; Jencks, W. P. J. Am. Chem. Soc. 1982, 104, 1937-1951. https://doi.org/10.1021/ja00371a024
  19. Cho, B. R.; Chung, H. S.; Pyun, S. Y. J. Org. Soc. 1999, 64, 8375- 8378. https://doi.org/10.1021/jo990752f
  20. Sitzmann, M. E.; Dacons, J. C. J. Org. Soc. 1973, 38, 4363-4365. https://doi.org/10.1021/jo00965a002

Cited by

  1. in 70 mol% MeCN (aq). Effects of the β-Aryl Group and Leaving Group on Nitrile-Forming Transition States vol.37, pp.6, 2016, https://doi.org/10.1002/bkcs.10791