Reactions of SmI2 with olefins: Mechanism and complexation effect on chemoselectivity

Journal of the American Chemical Society

Volumn 118, Issue 1, 1996, Pages 261-262

  Yacovan, Avihai ^a   Hoz, Shmaryahu ^a   Bilkis, Itzhak ^b  

^a BAR ILAN UNIVERSITY   (Israel)

^b HEBREW UNIVERSITY OF JERUSALEM   (Israel)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 0003242186     PISSN: 00027863     EISSN: None     Source Type: Journal    
DOI: 10.1021/ja950937d     Document Type: Article

References (25)

1. Hoz, S. Acc. Chem. Res. 1993, 26, 69.
2. Gross, Z.; Hoz, S. J. Am. Chem. Soc. 1994, 116, 7489.
3. 4, electrochemistry (see also: Avaca, L. A.; Utely, J. H. P. J. Chem. Soc., Perkin Trans. I 1975, 971; J. Chem. Soc., Perkin Trans. 2 1975, 161); all gave reduction of the double bond but were less amenable for detailed studies.
4. 4, electrochemistry (see also: Avaca, L. A.; Utely, J. H. P. J. Chem. Soc., Perkin Trans. I 1975, 971; J. Chem. Soc., Perkin Trans. 2 1975, 161); all gave reduction of the double bond but were less amenable for detailed studies.
5. Namy, J. L.; Girard, P.; Kagan, H. B. New J. Chem. 1977, 1, 5.
6. (a) Molander, G A Chem. Rev 1992, 92, 26.
7. (b) Molander, G. A. In Comprehensive Organic Synthesis: Trost, B. M., Fleming, I., Eds.; Pergamon: Oxford, 1991: Vol 4, pp 251.
8. (c) Soderquist, J. A. Aldrichimica Acta 1991, 24, 15.
9. (d) Kagan, H. B. New J. Chem. 1990, 14, 453.
10. (e) Molander, G. A In Chemistry of the Carbon-Metal Bond; Hartley, F. R., Patai, S., Eds.; Wiley New York, 1989; Vol. 5, p 319.
11. (f) Kagan, H. B.; Sasaki, M.; Collin, J. Pure Appl Chem. 1988, 60, 1725.
12. (g) Kagan, H. B.; Namy, J. L. Tetrahedron 1986, 42, 6573.
13. (h) Hasegawa, E.; Curran, D. P. J. Org. Chem. 1993, 58, 5008 and references cited therein.
14. 2 chemistry is ref 14 below.
15. 2 is needed to fully reduce 1 equiv of the olefin.
16. 2-water, and analyzed (reactants and products) by NMR and/or by HPLC. The agreement between the two methods was better than 5%. Products were stable with time.
17. 1/2 -1.08 and -1.16 V vs SCE for DP and MA respectively, unpublished results.
18. 2 in acetonitrile is -1.62 V vs SCE (Kolthoff, I. M.; Coetzee, J. F. J. Am Chem. Soc. 1957, 79, 1852). According to this value there is a thermodynamic driving force of ca. 13 kcal/mol for the electron transfer reaction. This value is sufficient for a diffusion-controlled reaction. However, the intrinsic barrier due to the internal reorganization of the ligation sphere may be too high to enable such a fast process (Eberson, L. Electron Transfer in Organic Chemistry; Springer-Verlag: Berlin, 1987; Chapter 4).
19. 2 in acetonitrile is -1.62 V vs SCE (Kolthoff, I. M.; Coetzee, J. F. J. Am Chem. Soc. 1957, 79, 1852). According to this value there is a thermodynamic driving force of ca. 13 kcal/mol for the electron transfer reaction. This value is sufficient for a diffusion-controlled reaction. However, the intrinsic barrier due to the internal reorganization of the ligation sphere may be too high to enable such a fast process (Eberson, L. Electron Transfer in Organic Chemistry; Springer-Verlag: Berlin, 1987; Chapter 4).
20. (a) Throughout this paper we use the term radical anion although other intermediates such as charge transfer complex or Grignard samarium may be the actual chemical species involved.
21. (b) On the basis of other results it seems to us that, unlike the alcohols, TFA does not form complexes with samarium.
22. Calculations were based on a 1:1 complex composition. Correlation coefficients are higher than 0.994.
23. 2 usually for about a minute, the time necessary to complete the operations in the glovebox.
24. Kagan, H. B. Tetrahedron 1981, 37, Suppl. 1, 175.
25. A referee had sugggested that the samarium may insert into the O-H bond to give a hydride which does not easily exchange the proton. We have tried to computationally explore this avenue. However, although pseudopotentials are available for Sm, we found that, with programs such as Gaussian and Gamess, polyatomic gradient optimization is not possible with f-functions.