Restricted rotations and stereodynamics of aziridine-2-methanol derivatives

Tetrahedron

Volumn 67, Issue 48, 2011, Pages 9382-9388

  De Ceglie, Maria Carolina ^a   Degennaro, Leonardo ^a   Falcicchio, Aurelia ^b   Luisi, Renzo ^a  

^a UNIVERSITY OF BARI   (Italy)

^b CNR   (Italy)

Author keywords

Aziridines; Molecular dynamics; NMR spectroscopy; Stereochemistry

Indexed keywords

AZIRIDINE 2 METHANOL DERIVATIVE; AZIRIDINE DERIVATIVE; METHANOL DERIVATIVE; UNCLASSIFIED DRUG;

ARTICLE; HYDROGEN BOND; MOLECULAR DYNAMICS; NUCLEAR OVERHAUSER EFFECT; PRIORITY JOURNAL; PROTON NUCLEAR MAGNETIC RESONANCE; STEREOCHEMISTRY;

EID: 80054847382     PISSN: 00404020     EISSN: 14645416     Source Type: Journal    
DOI: 10.1016/j.tet.2011.09.128     Document Type: Article

References (50)

1. Balzani, V.; Venturi, M.; Credi, A. Molecular Devices and Machines; Wiley-VCH: Weinheim, Germany, 2003.
2. Topics in Current Chemistry; Kelly, T. R., Ed.; Springer: Berlin, 2005; Vol. 262.
3. Kottas, G. S.; Clarke, L. I.; Horinek, D.; Michl, J. Chem. Rev. 2005, 105, 1281-1376.
4. Kay, E. R.; Leigh, D. A.; Zerbetto, F. Angew. Chem., Int. Ed. 2007, 46, 72-191.
5. Christie, G. H.; Kenner, J. J. Chem. Soc. 1922, 121, 614-620.
6. Jiménez, M. C.; Dietrich-Buchecker, C.; Sauvage, J.-P. Angew. Chem., Int. Ed. 2000, 39, 3284-3287.
7. Saha, S.; Stoddart, J. F. Chem. Soc. Rev. 2007, 36, 77-92.
8. Fletcher, S. P.; Dumur, F.; Pollard, M. M.; Feringa, B. L. Science 2005, 310, 80-82.
9. Sun, W.-T.; Huang, Y.-T.; Huang, G.-J.; Lu, H.-F.; Chao, I.; Huang, S. L.; Huang, S. J.; Lin, Y. C.; Ho, J. H.; Yang, J. S. Chem. - Eur. J. 2010, 16, 11594-11604.
10. Browne, W. R.; Feringa, B. L. Nature Nanotechnol. 2006, 1, 25-35.
11. For a recent review on the field see: Casarini, D.; Lunazzi, L.; Mazzanti, A. Eur. J. Org. Chem. 2010, 2035-2056.
12. de Ceglie, M. C.; Musio, B.; Affortunato, F.; Moliterni, A.; Altomare, A.; Florio, S.; Luisi, R. Chem. - Eur. J. 2011, 17, 286-296.
13. Johnston, E. R. Magn. Reson. Chem. 1995, 33, 664-668.
14. Kessler, H. Angew. Chem., Int. Ed. Engl. 1970, 9, 219-235.
15. Jennings, W. B. In Cyclic Organonitrogen Stereodynamics; Lambert, J. B., Takeuchi, Y., Eds.; VCH: New York, NY, 1992; p 105.
16. Affortunato, F.; Florio, S.; Luisi, R.; Musio, B. J. Org. Chem. 2008, 73, 9214-9220.
17. Davies, M. W.; Shipman, M.; Tucker, J. H. R.; Walsh, T. R. J. Am. Chem. Soc. 2006, 128, 14260-14261.
18. -1 was observed (Fig. 1, top right).
19. It is expected that, for steric reasons, the invertomers showing a cis relationship between the N-alkyl group and the two phenyl rings should be disfavoured. For other examples aziridine nitrogen dynamics and preferential nitrogen configuration see: Ref. 42.
20. NOESY 2D experiments can be used to highlight exchange phenomena just using a suitable mixing time (750 ms), see Refs. 21,22.
21. Perrin, C. L.; Dwyer, T. J. Chem. Rev. 1990, 90, 935-967.
22. Neuhaus, D.; Williamson, M. In The Nuclear Overhauser Effect in Structural and Conformational Analysis; VCH: New York, NY, 1989.
23. Tietze, L. F.; Schuster, H. J.; Hof, J. M. v.; Hampel, S. M.; Colunga, J. F.; John, M. Chem. - Eur. J. 2010, 16, 12678-12682.
24. HSQC-DEPT experiments were helpful to unequivocally assign the signals of the meta protons and the two ortho methyl groups of the mesityl ring (see Fig. 1 bottom left and Supplementary data)
25. No change in the chemical shifts was observed for Ha and Hb in the range 203-340 K. For other example of correlated rotation see Refs. 26-28.
26. Bragg, R. A.; Clayden, J.; Morris, G. A.; Pink, J. H. Chem. - Eur. J. 2002, 8, 1279-1289.
27. Johnston, E. R.; Fortt, R.; Barborak, J. C. Magn. Reson. Chem. 2000, 38, 932-936.
28. Casarini, D.; Lunazzi, L.; Mazzanti, A. J. Org. Chem. 2008, 73, 2811-2818.
29. a/b (dotted circles in Fig. 1) revealed proximity relationship of the two aryl rings and a polarization transfer process.
30. FT-IR analysis confirmed the presence, in solution, of an intramolecular hydrogen bond in 3a,b (see Fig. 2, bottom right and Supplementary data) and a free OH group in diast-3a,b (see Fig. 3 bottom right and Supplementary data)
31. Kohmoto, S.; Koyano, I.; Kawatsuji, T.; Kasimura, H.; Kishikawa, K.; Yamamoto, M.; Yamada, K. Bull. Chem. Soc. Jpn. 1996, 69, 3261-3265.
32. a/a′ (Fig. 2 and Supplementary data).
33. Recording the spectra at 298 K, a broadening of the signals was observed for the protons of the phenyl ring and the mesityl ring likely due to their hindered rotations.
34. Trapping reaction with tert-butylphenyl ketone occurred with high stereoselectivity in toluene (dr 80/20) but failed to provide the trapping product in THF.
35. It is likely that, in aziridine 4, the steric hindrance of the substituents of the carbinolic carbon (t-Bu and Ph) and the hydrogen bond between the hydroxyl group and the aziridine lone pair, are again responsible of the restricted rotation around the bond between the carbinolic carbon and the aziridine quaternary carbon, giving only one conformer population.
36. Other examples of slow t-Bu group rotation have been reported see Refs. 37,38.
37. Kuno, L.; Biali, S. E. Org. Lett. 2009, 11, 3662-3665.
38. Yamamoto, G.; Oki, M. Tetrahedron Lett. 1986, 27, 49-50.
39. 3).
40. The value calculated for ΔG° (-RTlnK) at 200 K in toluene (A/B ratio=67/33) for the conversion A→B was 0.28 kcal/mol.
41. For examples on the relationship between dynamic phenomena and reactivity see Refs. 42-45.
42. Degennaro, L.; Mansueto, R.; Carenza, E.; Rizzi, R.; Florio, S.; Pratt, L. M.; Luisi, R. Chem. - Eur. J. 2011, 17, 4992-5003.
43. Ohnishi, Y.; Sakai, M.; Nakao, S.; Kitagawa, O. Org. Lett. 2011, 13, 2840-2843.
44. Clark, A. J.; Curran, D. P.; Geden, J. V.; James, N.; Wilson, P. J. Org. Chem. 2011, 76, 4546-4551.
45. Gustafson, J. L.; Lim, D.; Barrett, K.; Miller, S. J. Angew. Chem., Int. Ed. 2011, 50, 5125-5129.
46. Saha, S.; Moorthy, N. J. Org. Chem. 2011, 76, 396-402.
47. Braga, A. L.; Paixao, M. W.; Westermann, B.; Schneider, P. H.; Wessjohann, L. A. J. Org. Chem. 2008, 73, 2879-2882.
48. Chaur, M. N.; Collado, D.; Lehn, J. M. Chem. - Eur. J. 2011, 17, 248-258.
49. Jones, I. M.; Hamilton, A. D. Angew. Chem., Int. Ed. 2011, 50, 4597-4600.
50. Dial, B. E.; Rasberry, R. D.; Bullock, B. N.; Smith, M. D.; Pellecchia, P. J.; Profeta, S.; Shimizu, K. D. Org. Lett. 2011, 13, 244-247.