A Novel Resolution Procedure for the Preparation of P-Stereogenic Phosphine Oxides

Organic Letters

Volumn 1, Issue 12, 1999, Pages 2009-2011

  Andersen, Neil G ^a   Ramsden, Philip D ^a   Che, Daqing ^a   Parvez, Masood ^a   Keay, Brian A ^a  

^a UNIVERSITY OF CALGARY   (Canada)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 0001345592     PISSN: 15237060     EISSN: None     Source Type: Journal    
DOI: 10.1021/ol991174s     Document Type: Article

References (32)

1. Stephenson, G. R. Advanced Asymmetric Synthesis; Chapman & Hall: New York, 1996 and references therein.
2. For reviews, see: (a) Noyori, R. Asymmetric Catalysis in Organic Synthesis; Wiley & Sons: New York, 1994; Chapter 2.
3. (b) Ojima, I. Catalytic Asymmetric Synthesis; VCH Publishers: Weinheim, 1993; Chapter 1.
4. (c) Morrison, J. D. Asymmetric Synthesis; Academic Press: New York, 1985; Vol. 5, Chapter 1.
5. Pietrusiewicz, K. M.; Zablocka M. Chem. Rev. 1994, 94, 1375.
6. Kolodiazhnyi, O. I. Tetrahedron: Asymmetry 1998, 9, 1279.
7. The calculated P=N rotational barrier is ca. 2.54 kcal/mol. See: Koketsu, J.; Ninomiya, Y.; Suzuki, Y.; Koga, N. Inorg. Chem. 1997, 36, 694 and references therein.
8. Cremlyn, R.; Burrell, K.; Fish, K.; Hough, I.; Mason, D. Phosphorus Sulfur 1982, 12, 197.
9. Alkyl azides such as (+)-neomenthyl azide, 3α-azido-5α-cholestane, and 6-azido-6-deoxy-1,2,3,4-di-O-isopropyliden-α-D-galactopyranose were found to be unsuitable resolving agents since the resulting phosphinimine mixtures were generally less stable toward storage or flash chromatography.
10. Dimmel, D. R.; Fu, W. Y., J. Org. Chem. 1973, 38, 3782.
11. 9 316.1151, found 316.1120.
12. Racemic phosphines were prepared via known general methods, see: (a) Payne, N. C.; Stephan, D. W. Can. J. Chem. 1980, 58, 15.
13. (b) Bestman, H. J.; Lienert, J.; Heid, E. Chem. Ber. 1982, 115, 3875.
14. (c) Wittig, G.; Braun, H.; Cristau, H. Liebigs Ann. Chem. 1971, 751, 17.
15. 31P NMR, IR, and MS) characteristics including suitable combustion analysis (C, H) and/or high-resolution mass spectral analysis.
16. Entries 1a-1c of Table 1 were separated by fractional crystallization.
17. Entries 1d-1f of Table 1 were separated by flash chromatography.
18. Typical Procedure. Azide 3 (0.410 g, 1.10 mmol) in THF (2.5 mL) was added dropwise to the starting phosphine (1.00 mmol) in THF (2.5 mL). The resulting mixture was then heated (60 °C, 12 h) and subsequently concentrated in vacuo. The crude phosphinimines thus obtained were separated by crystallization or flash chromatography. The yield reported in Table 1 is the combined isolated yield of 6 and 7. In each case, compound 6 was assigned as the first isomer to crystallize or elute from the column.
19. 31P NMR analysis. Compound 7c was obtained as a ca. 7:1 mixture with isomer 6c.
20. Optical rotation data for the phosphine oxides closely matched the reported values. See Table 3.
21. At present, we have not found a suitable method for recycling the resolving agent.
22. 3; Z = 4; R = 0.0459; wR = 0.1208; Flack parameter [Flack, H. D. Acta Crystallogr. 1983, A39, 876] = -0.03(2). Bijvoet analysis was performed. A refinement of the inverted structure was carried out and converged with R = 0.0543, wR = 0.1427 with Flack parameter = 1.03(3) and was therefore rejected as the absolute configuration present in the crystal.
23. Farnham, W. B.; Lewis R. A.; Murray, R. K.; Mislow, K. J. Am. Chem. Soc. 1970, 92, 5809.
24. See: (a) Horner, L.; Balzer W.-D., Tetrahedron Lett. 1965, 1157.
25. (b) Naumann, K.; Zon, G.; Mislow, K. J. Am. Chem. Soc. 1969, 91, 7012.
26. (c) Marsi, K. L. J. Org. Chem. 1974, 39, 265.
27. (d) Naumann, K.; Zon, G.; Mislow, K. J. Am. Chem. Soc. 1969, 91, 2788.
28. 20D +19.0° in MeOH; (+)-R. Korpium, O.; Lewis, R. A.; Chickos, J.; Mislow, K. J. Am. Chem. Soc. 1968, 90, 4842.
29. 20D -21.2° in MeOH; (+)-R. Byrne, L. T.; Engelhardt, L. M.; Jacobsen, G. E.; Leung, W.-P.; Papasergio, R. I.; Raston, C. L.; Skelton, B. W.; Twiss, P.; White, A. H. J. Chem. Soc., Dalton Trans. 1989, 105.
30. 20D -19.8° in MeOH; (+)-S. Luckenbach, R. Phosphorus 1972, 5, 223.
31. Although methyl-9-phenanthrylphenylphosphine oxide has appeared numerous times in the literature, to our knowledge no optical rotation data has been reported for this compound.
32. 32D -27.0° in MeOH. Tani, K.; Brown, L. D.; Ahmed, J.; Ibers, J. A.; Yokota. M.; Nakamura, A.; Otsuka, S. J. Am. Chem. Soc. 1977, 99, 7876.