Synthesis of new chiral ionic liquids based on (-)-menthol and (-)-borneol

Tetrahedron Letters

Volumn 49, Issue 10, 2008, Pages 1652-1655

  Matos, Ricardo Alexandre F ^a   Andrade, Carlos Kleber Z ^a  

^a UNIVERSITY OF BRASILIA   (Brazil)

Author keywords

[No Author keywords available]

Indexed keywords

BORNEOL; IONIC LIQUID; MENTHOL;

ARTICLE; CHEMICAL REACTION; CHEMICAL STRUCTURE; SYNTHESIS;

EID: 39049155856     PISSN: 00404039     EISSN: None     Source Type: Journal    
DOI: 10.1016/j.tetlet.2008.01.011     Document Type: Article

References (19)

1. Andrade C.Z.K., and Alves L.M. Curr. Org. Chem. 9 (2005) 195-218
2. Dupont J., Souza R.F., and Suarez P.A.Z. Chem. Rev. 102 (2002) 3667-3692
3. Freemantle M. Chem. Eng. News November (2004) 44-49
4. In: Wasserscheid P., and Welton T. (Eds). Ionic Liquids in Synthesis (2003), Wiley-VCH, Weinheim
5. For reviews on CILs, see:. Baudequin C., Baudoux J., Levillain J., Cahard D., Gaumont A.-C., and Plaquevent J.-C. Tetrahedron: Asymmetry 14 (2003) 3081-3093
6. Baudequin C., Brégeon D., Levillain J., Guillen F., Plaquevent J.-C., and Gaumont A.-C. Tetrahedron: Asymmetry 16 (2005) 3921-3945
7. Ding J., and Armstrong D.W. Chirality 17 (2005) 281-292
8. Ni B., Zhang Q., and Headley A.D. Green Chem. 9 (2007) 737-739
9. Luo S., Mi X., Zhang L., Liu S., Xu H., and Cheng J.-P. Angew. Chem., Int. Ed. 45 (2006) 3093-3097
10. Malhotra S.V., and Wang Y. Tetrahedron: Asymmetry 17 (2006) 1032-1035
11. For the synthesis of other ionic liquids based on (-)-menthol, see:. Ding J., Desikan V., Han X., Xiao T.L., Ding R., Jenks W.S., and Armstrong D.W. Org. Lett. 7 (2005) 335-337
12. Pernak J., and Feder-Kubis J. Chem. Eur. J. 11 (2005) 4441-4449
13. Ma H.-Y., Wan X.-H., Chen X.-F., and Zhou Q.-F. Chin. J. Polym. Sci. 21 (2003) 265-270
14. A borneol sulfonamide CIL has been reported:. Gadenne B., Hesemann P., and Moreau J.J.E. Tetrahedron Lett. 45 (2004) 8157-8160
15. 4 and concentrated to give the corresponding chiral ionic liquids, which were further dried under vacuum at 80 °C for several hours. This procedure yielded all compounds in high purity without the need for further purification. Analytical data reported in Ref. 10 were obtained after submitting the samples to simple column chromatography eluting with hexanes/EtOAc (7:3).
16. Two structurally similar CILs based on (-)-menthol have been reported but were solids at room temperature (see Ref. 6c).
17. 3): δ 9.62 (s, 1H), 7.56 (s, 1H), 7.45 (s, 1H)
18. The names of the CILs synthesized herein were proposed based on their constituents and not on the IUPAC rules. In this way, reasonable abbreviations could be proposed for each one (see Ref. 10).
19. This same trend has also been observed for all other CILs based on (-)-menthol reported in Refs. 6a-c.