Equilibration Studies: Amide-Imidate and Thioamide-Thioimidate Functions

Journal of Organic Chemistry

Volumn 43, Issue 8, 1978, Pages 1536-1538

  Beak, Peter ^a   Lee, Jae keun ^a   Zeigler, John M ^a  

^a UNIVERSITY OF ILLINOIS AT URBANA CHAMPAIGN   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 0010851829     PISSN: 00223263     EISSN: 15206904     Source Type: Journal    
DOI: 10.1021/jo00402a010     Document Type: Article

References (20)

1. P. Beak, Acc. Chem. Res., 10, 186 (1977)., and references cited therein.
2. P. Beak, D. S. Mueller, and J. Lee, J. Am. Chem. Soc., 96, 3867 (1974).
3. P. Beak, F. S. Fry, J. Lee, and F. Steele, J. Am. Chem. Soc., 98, 171 (1976).
4. P. Beak, J. Covington, and S. G. Smith, J. Am. Chem. Soc., 98, 8284 (1976).
5. P. Beak, J. Bonham, and J. T. Lee, J. Am. Chem. Soc., 90, 1569 (1968).
6. C. O. Meese, W. Walter, and M. Berger, J. Am. Chem. Soc., 96, 2259 (1974).
7. For a case in which both isomers are detected, see A. C. Satterthwait and W. P. Jencks, J. Am. Chem. Soc., 96, 7045 (1974).
8. W. Walter and C. O. Meese, Chem. Ber., 109, 922 (1976).
9. For examples, see L. E. Overman and L. A. Clizbe, J. Am. Chem. Soc., 98, 2353 (1976).
10. L. E. Overman, J. Am. Chem. Soc., 98, 2901 (1976).
11. R. G. Glushkov and V. B. Granik, Adv. Heterocycl. Chem., 12, 185 (1970).; and ref 2, footnotes 35 and 36.
12. For another example, note that the enthalpy differences of a 2-and 4-pyrone system and a 2-and 4-pyridone system are 9.7 ± 2.3 kcal/mol: P. Beak, T. S. Woods, and D. S. Mueller, Tetrahedron, 28, 5507 (1972)., and ref 2.
13. It is possible to perturb the amide-imidate enthalpy difference by intramolecular effects. For example, as earlier noted,6 the enthalpy difference is reduced by 6 kcal/mol when the functions are part of an aromatic ring, a result which allows a thermodynamic estimate of the relative aromaticity of the pyridine and pyridone rings. For discussion, see A. K. Burnham, J. Lee, T. G. Schmalz, P. Beak, and W. H. Flygare, J. Am. Chem. Soc., 99, 1836(1977).
14. L. Radom, W. J. Hehre, and J. A. Pople, J, Am. Chem. Soc., 93, 289 (1971).
15. W-Methyl-O-methylbenzimidate
16. H. Paul, A. Weise, and R. Settmer, Chem. Ber., 98, 1450 (1965).
17. N-Methyl-O-methylacetimidate: H. Bredereck, F. Effenberger, and E. Henseleit, Chem. Ber., 98, 2754 (1965).
18. W-Methyl-S-methylthiobenzimidate
19. B. Böttcher and F. Bauer, Justus Liebigs Ann. Chem., 568, 218 (1950).
20. D. M. W. Van den Ham and D. Van der Meer, Chem. Eng. News, 54, 5 (1976).