Hemiaminal generated by hydration of ketone-based nitrone as an N,O-centered nucleophile in organic synthesis

Tetrahedron

Volumn 54, Issue 11, 1998, Pages 2433-2448

  Ishikawa, Teruhiko ^a   Nagai, Keita ^a   Senzaki, Mami ^a   Tatsukawa, Akiko ^a   Saito, Seiki ^a  

^a OKAYAMA UNIVERSITY   (Japan)

Author keywords

[No Author keywords available]

Indexed keywords

HYDROXYLAMINE; ISOXAZOLIDINE DERIVATIVE; KETONE;

ARTICLE; HYDRATION; ORGANIC CHEMISTRY; PRIORITY JOURNAL; SYNTHESIS;

EID: 0032510258     PISSN: 00404020     EISSN: None     Source Type: Journal    
DOI: 10.1016/S0040-4020(98)00008-8     Document Type: Article

References (34)

1. (1) Ishikawa, T.; Nagai, K.; Kudoh, T.; Saito, S. Synlett 1995, 1171-1173.
2. (2) For a recent review, see Cole, D. C. Tetrahedron 1994, 50, 9517-9582 and Juaristi, E.; Quintana, D.; Escalante, J. Aldrichimica Acta, 1994, 27, 3-11.
3. (2) For a recent review, see Cole, D. C. Tetrahedron 1994, 50, 9517-9582 and Juaristi, E.; Quintana, D.; Escalante, J. Aldrichimica Acta, 1994, 27, 3-11.
4. N2 pathway.
5. N2 pathway.
6. (4) For the intramolecular [3+2] cycloaddition reactions of ketone-based nitrones, see Confalone, P. N.; Huie, E. M. Org. React. 1988, 36, 1-173. We have only limited reports, however, with regard to the intermolecular versions of such cycloaddition reactions because the reactions become extremely sluggish as compared with the intramolecular cases. In general the intermolecular [3+2] cycloaddition reactions of the ketone-based nitrones require a large excess (25 eq) of dipolarophiles such as methyl methacrylate, for instance, in order to gain a practical reaction rate: for intermolecular examples, see Vasella, A. Helv, Chim. Acta 1977, 60, 426-446 and 1273-1295.
7. (4) For the intramolecular [3+2] cycloaddition reactions of ketone-based nitrones, see Confalone, P. N.; Huie, E. M. Org. React. 1988, 36, 1-173. We have only limited reports, however, with regard to the intermolecular versions of such cycloaddition reactions because the reactions become extremely sluggish as compared with the intramolecular cases. In general the intermolecular [3+2] cycloaddition reactions of the ketone-based nitrones require a large excess (25 eq) of dipolarophiles such as methyl methacrylate, for instance, in order to gain a practical reaction rate: for intermolecular examples, see Vasella, A. Helv, Chim. Acta 1977, 60, 426-446 and 1273-1295.
8. (5) The nucleophilic character of a negative end of nitrone has been delineated in the reaction of the nitrones with acid halides (acyl substitution reaction): see, for instance, Cummins, C. H.; Coates, R. M. J. Org. Chem. 1983, 48, 2070-2076 and references cited therein.
9. (6) For intramolecular Michael addition reactions with nitrogen nucleophiles which are successful in terms of diastereo differentiation, see Hirama, M.; Shigemoto, T.; Yamazaki, Y.; Ito, S. J. Am. Chem. Soc. 1985, 107, 1797-1798 and Tetrahedron Lett. 1985, 26, 4133-4136.
10. (6) For intramolecular Michael addition reactions with nitrogen nucleophiles which are successful in terms of diastereo differentiation, see Hirama, M.; Shigemoto, T.; Yamazaki, Y.; Ito, S. J. Am. Chem. Soc. 1985, 107, 1797-1798 and Tetrahedron Lett. 1985, 26, 4133-4136.
11. 2OH to acetone and the rate controlling dehydration of the carbinolamine: see Cocivera, M.; Effio, A. J. Am. Chem. Soc. 1976, 98, 7371-7374.
12. 2), 4.42-4.52 (br, 1H, CHOH), 7.2-7.4 (m, 5H, ArH).
13. (9) To the best of our knowledge the diastereoselectivity for reactions of this class ranges from 1:1 to 4:1 in general: see Arrowsmith, R. J.; Carter, K.; Dann, J. G.; Davies, D. E.; Harris, C. J.; Morton, J. A.; Lister, P.; Robinson, J. A.; Williams, D. J. J. Chem. Soc. Chem. Commun. 1986, 755-757; see also
14. (b) Cha, J. K.; Christ, W. J.; Kishi Y. Tetrahedron Lett. 1983, 24, 3943-3946.
15. (c) Saito, S.; Hirohara, Y.; Narahara, O.; Moriwake, T. J. Am. Chem. Soc. 1989, 111, 4533-4535.
16. (d) Saito, S.; Morikawa, Y.; Moriwake, T. J. Org. Chem. 1990, 55, 5424-5426.
17. 3) δ 21.3, 23.5, 23.9, 53.5, 53.8, 56.4, 63.8, 95,7, 126.7, 127.3, 128.1, 128.3, 128.7, 128.9, 138.1, 138.8 ppm. For nitrone tautomerization and adducts, see Foster, R.; Iball, J.; Nash, R. J. Chem. Soc. Perkin Trans. 2, 1974, 1210-1214. (equation presented)
18. (11) The [3+2] cycloaddition reaction of 6 (3 eq) with 10 did not take place at all when a solution of these compounds in benzene was heated under reflux for 3 hr. Also the trace of any other reactions has been detected but 10 was recovered unchanged quantitatively.
19. 2O (benzene, 80 °C)]. In any event the fact that 33 actually reacted with 10 is highly suggestive that the proposed mechanism involving 9 (Scheme II) is reasonable and tertiary hydroxylamines such as 9 or 33 have enhanced nucleophilicity.
20. 3): δ 19.8, 20.4, 63.5, 127.4, 127.8, 128.5, 133.3, 144.7. These data indicated that no hydration of 6 took place at rt. The same mixture, however, gave the following signals after heating at 60 °C for 20 min; δ 19.7, 20.3, 22.6, 58.0, 63.6, 95.7, 127.4, 127.5, 127.7., 127.8, 128.4, 128.5, 133.5, 144.5 (underlined for 9) together with those for the nitrone adduct 33 (see ref. 9), the amount of which increased after such a thermal treatment as judged from the signal intensity.
21. 2O [see ref (9)]. This is pointing out the absence of BHA under the conditions examined.
22. (15) On the basis of the relative intensity of NMR signals appeared at 144 and 96 ppm, it can be estimated that the equilibrium at rt shifts on the nitrone side with a 4:1 ratio, which becomes a 1:1 ratio at 60 °C.
23. (16) Although definite conclusion on this issue must await future study, the hydrogen bonding between the acetone-based hydroxy group and the oxygen atom attached to the nitrogen atom would probably enhance the polarization of the O-H bond attached to the nitrogen atom.
24. (17) The mechanism of Michael addition reaction of amines to α,β-unsaturated ester has been the question under debate: see Bernasconi, C. F. Tetrahedron 1989, 45, 4017-4090 and Pardo, L.; Osman, R.; Weinstein, H.; Rabinowitz, J. R. J. Am. Chem. Soc. 1993, 115, 8263-8269.
25. (17) The mechanism of Michael addition reaction of amines to α,β-unsaturated ester has been the question under debate: see Bernasconi, C. F. Tetrahedron 1989, 45, 4017-4090 and Pardo, L.; Osman, R.; Weinstein, H.; Rabinowitz, J. R. J. Am. Chem. Soc. 1993, 115, 8263-8269.
26. (18) The hydrogen at C(3) of 21 appeared at 3.17 ppm as a broad doublet (J = 6.4 Hz for the doublet). This signal became broad singlet with shoulders on irradiating the hydrogen at C(4) probably because of geminal spin-spin couplings of this hydrogen with the deuterium, which, in this case, must be very small (< 1 Hz). Since the geminal coupling constant of hydrogens at C(3) has been known to be, in general, around 14 Hz (see Wang and Roskamp, J. Am. Chem. Soc., 1993, 115, 9417-9420), the geminal spin coupling constant between the hydrogen and deuterium at C(3) in this case is expected to be around 2 Hz on the theoretical basis.
27. (19) For alkylation of ester enolates derived from β-aminoesters, see (a) McGarvey, G. J.; Williams, J. M.; Hiner, R. N.; Matsubara, Y.; Oh, T. J. Am. Chem. Soc., 1986, 108, 4943-4952;
28. (b) Seebach, D.; Estermann, H. Tetrahedron Lett. 1987, 28, 3103-3106;
29. (c) Estermann, H.; Seebach, D. Helv. Chim. Acta 1988, 71, 1824-1839;
30. (d) Davies, S. D.; Walters, I. A. S. J. Chem. Soc. Perkin Trans, 1 1994, 1129-1139;
31. (e) Collis, M. P.; Perlmutter, P. Tetrahedron: Asymmetry 1966, 7, 2117-2134.
32. (20) Tanner, D.; Somfai, P. Tetrahedron 1988, 44, 619-624.
33. (21) Kawase, M.; Kikugawa, Y. J. Chem. Soc. Perkin Trans, 1 1979, 643-645.
34. (22) Takano, S.; Kurotaki, A.; Takahashi, M.; Ogasawara, K. Synthesis 1986, 403-406.