Thermodynamic stability and reactivity of silylated bis(oxy)iminium ions

Journal of Organic Chemistry

Volumn 72, Issue 24, 2007, Pages 9134-9140

  Khomutova, Yulia A ^a   Smirnov, Vladimir O ^a   Mayr, Herbert ^b   Ioffe, Sema L ^a  

^a N D ZELINSKY INSTITUTE OF ORGANIC CHEMISTRY   (Russian Federation)

^b UNIVERSITY OF MUNICH   (Germany)

Author keywords

[No Author keywords available]

Indexed keywords

ACTIVATION ENERGY; DILUTION; NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY; REACTION KINETICS; THERMODYNAMIC STABILITY;

ACTIVATION PARAMETERS; BIS(OXY)IMINIUM IONS; TRIALKYLSILYL TRIFLATES;

IONS;

SILANE DERIVATIVE; TRIFLUOROMETHANESULFONIC ACID;

ARTICLE; CHEMICAL ANALYSIS; CHEMICAL REACTION; CHEMICAL STRUCTURE; DILUTION; NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY; SILYLATION; TEMPERATURE; THERMODYNAMICS;

EID: 36649038327     PISSN: 00223263     EISSN: None     Source Type: Journal    
DOI: 10.1021/jo070633x     Document Type: Article

References (16)

1. Ono, N. The Nitro Group in Organic Synthesis; Wiley-VCH: New York, 2001.
2. Smirnov, V. O.; Ioffe, S. L.; Tishkov, A. A.; Khomutova, Yu. A.; Nesterov, I. D.; Antipin, M. Yu.; Smit, W. A.; Tartakovsky, V. A. J. Org. Chem. 2004, 69, 8485-8488.
3. N,N-Bis(hydroxy)iminium ions are discussed as evident intermediates of the Nef reaction (see ref 1 and: Kornblum, N.; Brown, R. A. J. Am. Chem. Soc. 1965, 87, 1742-1747).
4. For activity of these cations in C,C-coupling reactions, see: Prakash, S.; Schleyer, P. v. R. Stable Carbocation Chemistry; John Wiley & Sons: New York, 1997; pp 525-539 and references therein. However, the procedures cited in these papers are very harsh for use in directed organic synthesis.
5. Similar NMR spectra were fixed recently for cations generated by silylation of some nitrones (Chalaye-Mauger, H.; Denis, J.-N.; Averbuch-Pouchot, M.-T.; Vallee, Y. Tetrahedron 2000, 56, 791-804).
6. See Karplus curves for cyclohexanes (Hesse, M.; Meier, H.; Zeeh, B. Spektroskopische Methoden in der organischen Chemie; Thieme: Stuttgart, 1995; p 108)
7. and N-containing heterocycles (Lambert, J. B.; Takeuchi, Y., Cyclic Organonitrogen Stereodynamics; VCH: New York, 1992; p 170).
8. R barrier of cyclohexene: Clayden, J.; Greeves, N.; Warren, S.; Wothers, P. Organic Chemistry; Oxford University Press: Oxford, 2001; p 471.
9. The half-chair conformation of six-membered nitronates in the solid state was established according to X-ray data. (For example, see: Tishkov, A. A.; Lesiv, A. V.; Khomutova, Yu. A.; Strelenko, Yu. A.; Nesterov, I. D.; Antipin, M. Yu.; Ioffe, S. L.; Denmark, S. E. J. Org. Chem. 2003, 68, 9477-9480). The same conclusion on dominant conformation of cyclic nitronates could be made according to the NMR spectra of their solution.
10. 2
11. For possible explanation of this fenomena see below.
12. Within this discussion, we can't distinguish tight ion pair and loose ion pair.
13. Mayr, H.; Kempf, B.; Ofial, A. R. Acc. Chem. Res. 2003, 36, 66-77.
14. Mayr, H.; Bug, T.; Gotta, M. F.; Hering, N.; Irrgang, B.; Janker, B.; Kempf, B.; Loos, R.; Ofial, A. R.; Remennikov, G.; Schimmel, H. J. Am. Chem. Soc. 2001, 123, 9500-9512.
15. Denmark, S. E.; Seierstad, M.; Herbert, B. J. Org. Chem. 1999, 64, 884-901.
16. Nesterov, I. D.; Lesiv, A. V.; Ioffe, S. L.; Antipin, M. Yu. Mendeleev Commun. 2004, 281-282.