A rapid 1H NMR assay for enantiomeric excess of α-substituted aldehydes

Organic Letters

Volumn 7, Issue 16, 2005, Pages 3469-3472

  Chi, Yonggui ^a   Peelen, Timothy J ^a   Gellman, Samuel H ^a  

^a UNIVERSITY OF WISCONSIN MADISON   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

ALDEHYDE;

ARTICLE; CHEMICAL STRUCTURE; CHEMISTRY; METHODOLOGY; NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY; STEREOISOMERISM;

ALDEHYDES; MAGNETIC RESONANCE SPECTROSCOPY; MOLECULAR STRUCTURE; STEREOISOMERISM;

EID: 23944480330     PISSN: 15237060     EISSN: None     Source Type: Journal    
DOI: 10.1021/ol051174u     Document Type: Article

References (23)

1. For recent reviews on enantiomeric excess measurements, see: (a) Tsukamoto, M.; Kagan, H. B. Adv. Synth. Catal. 2002, 344, 453.
2. (b) Reetz, M. T. Angew. Chem., Int. Ed. 2001, 40, 284.
3. (c) Reetz, M. T. Angew. Chem., Int. Ed. 2002, 41, 1335.
4. Melchiorre, P.; Jørgensen, K. A. J. Org. Chem. 2003, 68, 4151.
5. For examples of substrates epimerization at GC conditions, see: Trapp, O.; Schurig, V. Chem. Eur. J. 2001, 7, 1495.
6. For examples, see: (a) Northrup, A. B.; MacMillan, D. W. C. J. Am. Chem. Soc. 2002, 124, 6798.
7. (b) Pidathala, C.; Hoang, L.; Vignola, N.; List, B. Angew. Chem., Int. Ed. 2003, 42, 2785.
8. (c) Hechavarria Fonseca, M. T.; List, B. Angew. Chem., Ind. Ed. 2004, 43, 3958.
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12. (g) Bolm, C.; Rantanen, I. S.; Zani, L. Angew. Chem., Int. Ed. 2005, 44, 1758.
13. (h) Marigo, M.; Wabnitz, T. C.; Fielenbach, D.; Jørgensen, K. A. Angew. Chem., Int Ed. 2005, 44, 794.
14. For an early review on NMR-based enantiomeric excess measurement, see: Parker, D. Chem. Rev. 1991, 91, 1441.
15. For recent examples, see: (a) Reetz, M. T.; Eipper, A.; Tielmann, P.; Mynott, R. Adv. Synth. Catal 2002, 344, 1008.
16. (b) Bohm, A.; Seebach, D. Helv. Chim. Acta 2000, 83, 3262.
17. (c) Dignam, C. F.; Richards, C. J.; Zopf, J. J.; Wacker, L. S.; Wenzel, T. J. Org. Lett. 2005, 7, 1773.
18. Imines from α-substituted aldehydes and substituted amines were present only as E-isomers. This E presence is well-known, see: (a) Berkessel, A.; Vennemann, M. R.; Lex, J. Eur. J. Org. Chem. 2002, 16, 2800.
19. (b) Boyd, S. L.; Boyd, R. J.; J. Phys. Chem. A. 2001, 105, 7096.
20. (c) Kosmrlj, J.; Weigel, L. O.; Evans, D. A.; Downey, C. W.; Wu, J. J. Am. Chem. Soc. 2003, 125, 3208.
21. No significant reaction between the primary amine and the ketone moiety of the α-substituted δ-keto-aldehyde was observed within 20 min.
22. Rangaishenvi, M. V.; Singaram, B.; Brown, H. C. J. Org. Chem. 1991, 56, 3286.
23. Obtained by using racemic proline as catalyst for the Michael addition.