Browse > Article
http://dx.doi.org/10.5012/bkcs.2005.26.7.1017

Base-Promoted, Ketene-Forming Elimination Reactions. Mechanistic Borderline between E2 and E1cb Mechanisms  

Pyun, Sang-Yong (Department of Chemistry, Pukyong National University)
Cho, Bong-Rae (Department of Chemistry, Korea University)
Publication Information
Bulletin of the Korean Chemical Society / v.26, no.7, 2005 , pp. 1017-1024 More about this Journal
Abstract
Elimination reactions of $XC_6H_4CH_2CO_2C_6H_3-2-Y-4-NO_2$ have been studied under various conditions. When X was moderately electron-withdrawing, Y = H, and base-solvent was $R_2$NH-MeCN, the reaction proceeded by the E2 mechanism via an E1cb-like transition state. Concave downward curve was noted in the Hammett plots. When X = 4-$NO_2$, Y = Cl, $CF_3,\;NO_2$, and the base-solvent was ${R_2NH/R_2NH_2}^+$ in 70 mol % MeCN(aq), the reaction proceeded by the E2 mechanism. The mechanism changed to a competing E2 and E1cb when X = 4-$NO_2$ and Y = H, MeO, and to the E1cb when X = 2,4-($NO_2)_2$, and Y = $NO_2$. From these results, a plausible pathway of the change of the mechanism from E2 to the E1cb extreme is proposed.
Keywords
Elimination reactions; Mechanistic borderline; E2 and E1cb mechanisms;
Citations & Related Records
Times Cited By KSCI : 4  (Citation Analysis)
Times Cited By Web Of Science : 1  (Related Records In Web of Science)
Times Cited By SCOPUS : 0
연도 인용수 순위
1 Cho, B. R.; Cho, N. S.; Chung, H. S.; Son, K. N.; Han, M. S.; Pyun, S. Y. Bull. Korean Chem. Soc. 1997, 18, 1301
2 Saunders, W. H., Jr.; Cockerill, A. F. Mechanism of Elimination Reactions; Wiley: NewYork, 1973
3 Bartsch, R. A.; Zavada, J. Chem. Rev. 1980, 80, 453   DOI
4 Lowry, T. H.; Richardson, K. S. Mechanism and Theory in Organic Chemistry; Harper and Row: New York, 1987; (a) pp 214-218, (b) pp 591-560, (c) pp 640-644
5 Hoffamn, R. V.; Bartsch, R. A.; Cho, B. R. Acc. Chem. Res. 1989, 22, 211   DOI
6 Cho, B. R.; Suh, Y. W.; Pyun, S. Y. Bull. Korean Chem. Soc. 1990, 11, 79
7 Cho, B. R.; Jung, J. H.; Ahn, E. K. J. Am. Chem. Soc. 1992, 114, 3425   DOI
8 Cho, B. R.; Pyun, S. Y. J. Am. Chem. Soc. 1991, 91, 3920
9 Meng, Q.; Thibblin, A. J. Am. Chem. Soc. 1995, 117, 9399   DOI   ScienceOn
10 Carey, F. A.; Sundberg, R. J. Advanced Organic Chemistry; Plenum Press: New York, 1984
11 Oh, H. K.; Lee, J. M.; Sung, D. D.; Lee, I. C. Bull. Korean Chem. Soc. 2004, 25, 557   DOI   ScienceOn
12 Lee, H. W.; Lee, H. W.; Koh, H. H.; Lee, I. C. Bull. Korean Chem. Soc. 1998, 19, 642
13 Thibblin, A. J. Am. Chem. Soc. 1988, 110, 4582   DOI
14 Gandler, J. R.; Jencks, W. P. J. Am. Chem. Soc. 1982, 104, 1937   DOI
15 Thibblin, A. J. Am. Chem. Soc. 1989, 111, 5412   DOI
16 Holmquist, B.; Bruice, T. C. J. Am. Chem. Soc. 1969, 91, 3003   DOI
17 Tagaki, W.; Kobayashi, S.; Kurihara, K.; Kurashima, K.; Yoshida, Y.; Yano, J. J. Chem. Soc., Chem. Commum. 1976, 843
18 Chandrasekar, R.; Venkatasubramanian, N. J. Chem. Soc., Perkin Trans. 2 1982, 1625
19 Broxton, T. J.; Duddy, N. W. J. Org. Chem. 1981, 46, 1186   DOI
20 Chung, S. Y.; Yoh, S. D.; Choi, J. H.; Shim, K. T. J. Korean Chem. Soc. 1992, 36, 446
21 Inoue, M.; Bruice, T. C. J. Org. Soc. 1982, 51, 959
22 Holmquist, B.; Bruice, T. C. J. Am. Chem. Soc. 1969, 91, 2993   DOI
23 Pratt, R. F.; Bruice, T. C. J. Am. Chem. Soc. 1970, 92, 5956   DOI
24 Inoue, M.; Bruice, T. C. J. Am. Chem. Soc. 1982, 104, 1644   DOI
25 Young, P. R.; Jencks, W. P. J. Am. Chem. Soc. 1979, 101, 3288   DOI
26 Drago, R. S.; Zoltewiez, J. A. J. Org. Chem. 1994, 59, 2824   DOI   ScienceOn
27 Yoshida, T.; Yano, Y.; Oae, S. Tetrahedron 1971, 27, 5343   DOI   ScienceOn
28 Um, I. H.; Chun, S. M.; Bae, S. K. Bull. Korean Chem. Soc. 2005, 26, 457   DOI   ScienceOn
29 Um, I. H.; Lee, E. J.; Lee, J. P. Bull. Korean Chem. Soc. 2002, 23, 381   DOI   ScienceOn
30 Bunnett, J. F.; Sridharan, S.; Cavin, W. P. J. Org. Chem. 1979, 44, 1458   DOI
31 Hasan, T.; Sim, B.; Fry, A. J. Am. Chem. Soc. 1983, 105, 3967   DOI   ScienceOn
32 Cabaleiro, M. C.; Montani, R. S. J. Chem. Res. (S) 1986, 220
33 Jencks, W. P. Chem. Rev. 1985, 85, 511   DOI
34 Williams, A.; Douglas, K. T. Chem. Rev. 1975, 627
35 Cho, B. R.; Jeong, H. C.; Seung, Y. J.; Pyun, S. Y. J. Org. Chem. 2002, 67, 5232   DOI   ScienceOn
36 Gandler, J. R. In The Chemistry Double Bonded Functional Groups; Patai, S., Ed.; Chichester, New York, 1989; Vol. 2, Part 1, pp 734-797
37 Gandler, J. R.; Yokohama, T. J. Am. Chem. Soc. 1984, 106, 130   DOI   ScienceOn
38 Gandler, J. R.; Storer, J. W.; Ohlberg, D. A. A. J. Am. Chem. Soc. 1990, 112, 7756   DOI
39 Cho, B. R.; Kim, Y. K.; Seong, Y. J.; Kim, J. C.; Pyun, S. Y. J. Org. Chem. 2000, 65, 1239   DOI   ScienceOn
40 Pyun, S. Y.; Lee, D. C.; Kim, J. C.; Cho, B. R. Org. Biomol. Chem. 2003, 1, 2734   DOI   ScienceOn
41 Cho, B. R.; Kim, Y. K.; Maing Yoon, C. O. J. Am. Chem. Soc. 1997, 119, 691   DOI   ScienceOn
42 Um, I. H.; Chun, S. M.; Bae, S. K. Bull. Korean Chem. Soc. 2005, 26, 457   DOI   ScienceOn
43 Cho, B. R.; Kim, N. S.; Kim, Y. K.; Son, K. H. J. Chem. Soc., Perkin Trans. 2 2000, 1419
44 Isaac, N. S.; Najem, T. S. J. Chem. Soc., Perkin Trans. 2 1988, 557
45 Douglas, K. T.; Alborz, M.; Rullo, G. R.; Yaggi, N. F. J. Chem. Soc., Chem. Commum. 1982, 242
46 William, A. J. Chem. Soc., Perkin Trans. 2 1972, 808
47 MicroCal Origin Version 3.5; MicroCal Software, Inc.: Northampton, MA, 1991
48 Cho, B. R.; Lee, S. J.; Kim, Y. K. J. Org. Chem. 1995, 60, 2072   DOI   ScienceOn