Observation of pseudorotamers of two unconstrained Wittig intermediates, (3RS,4SR)- and (3RS,4RS)-4-cyclohexyl-2-ethyl-3,4-dimethyl-2,2-diphenyl- 1,2λ5-oxaphosphetane, by dynamic 31P NMR spectroscopy: Line-shape analyses, conformations, and decomposition kinetics

Journal of the American Chemical Society

Volumn 120, Issue 41, 1998, Pages 10653-10659

  Bangerter, Felix ^a   Karpf, Martin ^b   Meier, Lukas A ^b   Rys, Paul ^a   Skrabal, Peter ^a  

^a ETH ZURICH   (Switzerland)

^b F HOFFMANN LA ROCHE LTD   (Switzerland)

Author keywords

[No Author keywords available]

Indexed keywords

4 CYCLOHEXYL 2 ETHYL 3,4 DIMETHYL 2,2 DIPHENYL 1,2 OXAPHOSPHATENE; ALKENE; UNCLASSIFIED DRUG;

ARTICLE; CHEMICAL STRUCTURE; CONFORMATION; KINETICS; NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY; STEREOISOMERISM; STRUCTURE ANALYSIS; X RAY ANALYSIS;

EID: 0032556211     PISSN: 00027863     EISSN: None     Source Type: Journal    
DOI: 10.1021/ja974332o     Document Type: Article

References (68)

1. (a) Vedejs, E.; Peterson, M. J. In Advances in Carbanion Chemistry, Vol. 2; Snieckus, V., Ed.; JAI Press Inc.: Greenwich, 1996; pp 1-85.
2. (b) Vedejs, E.; Peterson, M. J. Top. Stereochem. 1994, 21, 1-157.
3. (c) The reader is also referred to the comprehensive review article with more than 550 references by Maryanoff and Reitz: Maryanoff, B. E.; Reitz, A. B. Chem. Rev. 1989, 89, 863-927.
4. Vedejs, E.; Marth, C. F. In Phosphorus-31 NMR Spectral Properties in Compound Characterization and Structural Analysis; Quin, L. D., Verkade, J. G., Eds.; VCH Publishers: New York, 1994; pp 297-313.
5. (a) Vedejs, E.; Snoble, K. A. J.; Fuchs, P. L. J. Org. Chem. 1973, 38, 1178-1183.
6. (b) Vedejs, E.; Snoble, K. A. J. J. Am. Chem. Soc. 1973, 95, 5778-5780. For the first oxaphosphetane detected from an unusual ylide, see: Birum, G. H.; Matthews, C. N. J. Chem. Soc., Chem. Commun. 1967, 137-138.
7. (b) Vedejs, E.; Snoble, K. A. J. J. Am. Chem. Soc. 1973, 95, 5778-5780. For the first oxaphosphetane detected from an unusual ylide, see: Birum, G. H.; Matthews, C. N. J. Chem. Soc., Chem. Commun. 1967, 137-138.
8. Recent examples: (a) Geletneky, C.; Försterling, F.-H.; Bock, W.; Berger, S. Chem. Ber. 1993, 126, 2397-2401. (b) Neumann, R. A.; Berger, S. Book of Abstracts: International Symposium: The Research of Georg Wittig - Relevance to Chemistry Today, Heidelberg, July 15-18, 1997; p 42.
9. Recent examples: (a) Geletneky, C.; Försterling, F.-H.; Bock, W.; Berger, S. Chem. Ber. 1993, 126, 2397-2401. (b) Neumann, R. A.; Berger, S. Book of Abstracts: International Symposium: The Research of Georg Wittig - Relevance to Chemistry Today, Heidelberg, July 15-18, 1997; p 42.
10. (a) Kawashima, T.; Kato, K.; Okazaki, R. J. Am. Chem. Soc. 1992, 114, 4008-4010.
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12. (b) Kawashima, T.; Kato, K.; Okazaki, R. Angew. Chem., Int. Ed. Engl. 1993, 32, 869-870. Review: Kawashima, T.; Okazaki, R. Synlett 1996, 600-608.
13. Isolable 1,2-oxaphosphetanes have been reported much earlier. See refs 39 and 41 in ref 1a and ref 4 in ref 5a.
14. For example: (a) Ramirez, F.; Smith, C. P.; Pilot, J. F. J. Am. Chem. Soc. 1968, 90, 6726-6732. (b) Ramirez, F.; Pfohl, S.; Tsolis, E. A.; Pilot, J. F.; Smith, C. P.; Ugi, I.; Marquarding, D.; Gillespie, P.; Hoffmann, P. Phosphorus 1971, 1, 1-16.
15. For example: (a) Ramirez, F.; Smith, C. P.; Pilot, J. F. J. Am. Chem. Soc. 1968, 90, 6726-6732. (b) Ramirez, F.; Pfohl, S.; Tsolis, E. A.; Pilot, J. F.; Smith, C. P.; Ugi, I.; Marquarding, D.; Gillespie, P.; Hoffmann, P. Phosphorus 1971, 1, 1-16.
16. (a) Vedejs, E.; Marth, C. F. J. Am. Chem. Soc. 1989, 111, 1519-1520.
17. (b) Vedejs, E.; Marth, C. F. J. Am. Chem. Soc. 1990, 112, 3905-3909.
18. (c) Marth, C. F. Ph.D. Dissertation (Order No. 8826058), University of Wisconsin, Madison, WI, 1988.
19. For reviews, see refs 1 and 2.
20. For the elaboration of this stereoselective method starting from oxiranes, see: Vedejs, E.; Fuchs, P. L. J. Am. Chem. Soc. 1973, 95, 822-825.
21. Meier, L. A. Ph.D. Thesis No. 12315, ETH, 1997.
22. 4-cyclohexyl. The diastereomeric ratio 2:4 (at -75 °C) is 95:5 and that for 3:5 (at -73 °C) is 4:96 (in THF, with potassium hexamethyldisilazide). For the first resolutions of diastereomeric 1,2-oxaphosphetanes, see: Reitz, A. B.; Mutter, M. S.; Maryanoff, B. E. J. Am. Chem. Soc. 1984, 106, 1873-1875. See also: ref 1a, pp 34-36.
23. 4-cyclohexyl. The diastereomeric ratio 2:4 (at -75 °C) is 95:5 and that for 3:5 (at -73 °C) is 4:96 (in THF, with potassium hexamethyldisilazide). For the first resolutions of diastereomeric 1,2-oxaphosphetanes, see: Reitz, A. B.; Mutter, M. S.; Maryanoff, B. E. J. Am. Chem. Soc. 1984, 106, 1873-1875. See also: ref 1a, pp 34-36.
24. With WIN-KUBO, Version 951208, Bruker-Franzen Analytik GmbH, Bremen, BRD (Kubo, R.; Tomita, K. J. Phys. Soc. Jpn. 1954, 9, 888-919. Kubo, R. J. Phys. Soc. Jpn. 1954, 9, 935-944. Sack, R. A. Mol. Phys. 1958, 1, 163-167. Johnson, C. S., Jr.; Moreland, C. G. J. Chem. Educ. 1973, 50, 477-483).
25. With WIN-KUBO, Version 951208, Bruker-Franzen Analytik GmbH, Bremen, BRD (Kubo, R.; Tomita, K. J. Phys. Soc. Jpn. 1954, 9, 888-919. Kubo, R. J. Phys. Soc. Jpn. 1954, 9, 935-944. Sack, R. A. Mol. Phys. 1958, 1, 163-167. Johnson, C. S., Jr.; Moreland, C. G. J. Chem. Educ. 1973, 50, 477-483).
26. With WIN-KUBO, Version 951208, Bruker-Franzen Analytik GmbH, Bremen, BRD (Kubo, R.; Tomita, K. J. Phys. Soc. Jpn. 1954, 9, 888-919. Kubo, R. J. Phys. Soc. Jpn. 1954, 9, 935-944. Sack, R. A. Mol. Phys. 1958, 1, 163-167. Johnson, C. S., Jr.; Moreland, C. G. J. Chem. Educ. 1973, 50, 477-483).
27. With WIN-KUBO, Version 951208, Bruker-Franzen Analytik GmbH, Bremen, BRD (Kubo, R.; Tomita, K. J. Phys. Soc. Jpn. 1954, 9, 888-919. Kubo, R. J. Phys. Soc. Jpn. 1954, 9, 935-944. Sack, R. A. Mol. Phys. 1958, 1, 163-167. Johnson, C. S., Jr.; Moreland, C. G. J. Chem. Educ. 1973, 50, 477-483).
28. 3.
29. Linear regression analyses of the Eyring equation gave squared correlation coefficients of 0.9999 for 3 and 0.9993 for 5. To avoid potential problems due to the viscosity of the solutions or to the lower solubility of 3 and 5, spectra obtained below -95 °C have been excluded from line-shape analyses.
30. 1H coupling patterns have been analyzed by iteration with the program WIN-DAISY, Version 3.0, Bruker-Franzen Analytik GmbH, Bremen, BRD, 1995.
31. 2-labeled 3 (20 mM) at -110 °C.
32. 13C-labeled 3) is impossible. Since the third rotamer is not detectable at low temperature, a three-site exchange analysis is not possible. Nevertheless, this uncertainty does not call into question the principal results presented herein.
33. Shanan-Atidi, H.; Bar-Eli, K. H. J. Phys. Chem. 1970, 74, 961-963. Martin, M. L.; Delpuech, J.-J.; Martin, G. J. Practical NMR Spectroscopy; Heyden & Son, Ltd.: London, 1980; pp 295-297.
34. Shanan-Atidi, H.; Bar-Eli, K. H. J. Phys. Chem. 1970, 74, 961-963. Martin, M. L.; Delpuech, J.-J.; Martin, G. J. Practical NMR Spectroscopy; Heyden & Son, Ltd.: London, 1980; pp 295-297.
35. 2-labeled 3.
36. 22,23), this upfield shift is likely to reflect the higher population of the rotamer 5B compared to 3B (Table 1).
37. For MM+ force fields in the program HyperChem 5.0 (Hypercube Inc., Waterloo, Canada) the MM2 parameters and atom types (Allinger, N. L., 1991) with the 1977 functional form (Allinger, N. L. J. Am. Chem. Soc. 1977, 99, 8127-8134. Burkert, U.; Allinger, N. L. Molecular Mechanics; ACS Monograph 177; American Chemical Society: Washington, DC, 1982) are used.
38. For MM+ force fields in the program HyperChem 5.0 (Hypercube Inc., Waterloo, Canada) the MM2 parameters and atom types (Allinger, N. L., 1991) with the 1977 functional form (Allinger, N. L. J. Am. Chem. Soc. 1977, 99, 8127-8134. Burkert, U.; Allinger, N. L. Molecular Mechanics; ACS Monograph 177; American Chemical Society: Washington, DC, 1982) are used.
39. 22
40. Ramirez, F.; Ugi, I. Adv. Phys. Org. Chem. 1971, 9, 25-126.
41. Berry, R. S. J. Chem. Phys. 1960, 32, 933-938.
42. 5b slightly polar transition states have been postulated.
43. Fraser, R. R.; Mansour, T. S.; Savard, S. J. Org. Chem. 1985, 50, 3232-3234.
44. 1a
45. Kojima, S.; Doi, J.; Okuda, M.; Akiba, K.-y. Organometallics 1995, 14, 1928-1937.
46. 5-azaphosphetidine, see: Kawashima, T.; Soda, T.; Okazaki R. Angew. Chem., Int. Ed. Engl. 1996, 35, 1096-1098.
47. 5-azaphosphetidine, see: Kawashima, T.; Soda, T.; Okazaki R. Angew. Chem., Int. Ed. Engl. 1996, 35, 1096-1098.
48. 5-azaphosphetidine, see: Kawashima, T.; Soda, T.; Okazaki R. Angew. Chem., Int. Ed. Engl. 1996, 35, 1096-1098.
49. 5-azaphosphetidine, see: Kawashima, T.; Soda, T.; Okazaki R. Angew. Chem., Int. Ed. Engl. 1996, 35, 1096-1098.
50. Footnote 18 in ref 29: Kojima, S.; Nakamoto, M.; Kajiyama, K.; Akiba, K.-y. Unpublished results.
51. Ogawa, S.; Sato, S.; Erata, T.; Furukawa, N. Tetrahedron Lett. 1992, 33, 1915-1918.
52. Assuming the turnstile mechanism, in 1,2-oxaphosphetanes this less stable rotamer has the P-O bond in the unfavorable equatorial position. Originally it had been postulated as a necessary intermediate in the alkene formation step: Bestmann, H. J. Pure Appl. Chem. 1979, 51, 515-533. See, however, the discussions in refs 1a and 8a.
53. Reference 1a, pp 46-48.
54. 31P spectra. Reference 8c, pp 155-157.
55. Both isomers are known compounds. (a) E isomer: Danheiser, R. L.; Nowick, J. S. J. Org. Chem. 1991, 56, 1176-1185.
56. (b) Z and E isomers: Vedejs, E.; Cabaj, J.; Peterson, M. J. J Org. Chem. 1993, 58, 6509-6512.
57. 36b
58. 31P peak integrals have been assumed to be normally distributed with a variance independent of time and temperature. In addition to the enthalpies and entropies of activation, the initial integral value at each temperature has been treated as adjustable parameter (allowing 45 - 5 degrees of freedom for 3, 58 - 5 for 5). The confidence intervals for the adjusted parameters have been obtained according to a scheme extending the classical linear approach to an iterative nonlinear approach. For one of the first applications to NMR spectroscopic data, see: Leipert, T. K.; Marquardt, D. W. J. Magn. Reson. 1976, 24, 181-199 and references therein. Supporting Information is available.
59. Maryanoff, B. E.; Reitz, A. B.; Mutter, M. S.; Inners, R. R.; Almond, H. R., Jr.; Whittle, R. R.; Olofson, R. A. J. Am. Chem. Soc. 1986, 108, 7664-7678. See also: ref 1a, pp 37-39. Recent examples: Yamataka, H.; Takatsuka, T.; Hanafusa, T. J. Org. Chem. 1996, 61, 722-726.
60. Maryanoff, B. E.; Reitz, A. B.; Mutter, M. S.; Inners, R. R.; Almond, H. R., Jr.; Whittle, R. R.; Olofson, R. A. J. Am. Chem. Soc. 1986, 108, 7664-7678. See also: ref 1a, pp 37-39. Recent examples: Yamataka, H.; Takatsuka, T.; Hanafusa, T. J. Org. Chem. 1996, 61, 722-726.
61. Maryanoff, B. E.; Reitz, A. B.; Mutter, M. S.; Inners, R. R.; Almond, H. R., Jr.; Whittle, R. R.; Olofson, R. A. J. Am. Chem. Soc. 1986, 108, 7664-7678. See also: ref 1a, pp 37-39. Recent examples: Yamataka, H.; Takatsuka, T.; Hanafusa, T. J. Org. Chem. 1996, 61, 722-726.
62. Vedejs, E.; Fleck, T. J. J. Am. Chem. Soc. 1989, 111, 5861-5871.
63. Reference 5b, footnote 11.
64. 2CHO group has been observed since one of the three P-O bonds is always in an apical position: Gibson, J. A.; Röschenthaler, G.-V.; Schmutzler, R. Z. Naturforsch. B 1977, 32, 599-600.
65. 2CHO group has been observed since one of the three P-O bonds is always in an apical position: Gibson, J. A.; Röschenthaler, G.-V.; Schmutzler, R. Z. Naturforsch. B 1977, 32, 599-600.
66. 2CHO group has been observed since one of the three P-O bonds is always in an apical position: Gibson, J. A.; Röschenthaler, G.-V.; Schmutzler, R. Z. Naturforsch. B 1977, 32, 599-600.
67. Vedejs, E.; Marth, C. Tetrahedron Lett. 1987, 28, 3445-3448.
68. C. F. Marth has discussed ring and steric effects on the pseudorotation of a large number of pentacoordinate phosphorus compounds, but experimental data of 1,2-oxaphosphetanes are still scarce. See ref 8c, pp 171-179.