A facile synthesis of N-[2-(trifluoromethyl)allyl]amides and their transformation into angularly trifluoromethylated bicyclic cyclopentenones

Chemistry Letters

Volumn 36, Issue 1, 2007, Pages 22-23

  Nadano, Ryo ^a   Ichikawa, Junji ^a  

^a UNIVERSITY OF TOKYO   (Japan)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 34247272526     PISSN: 03667022     EISSN: None     Source Type: Journal    
DOI: 10.1246/cl.2007.22     Document Type: Article

References (23)

1. M. Shimizu, T. Hiyama, Angew. Chem., Int. Ed. 2005, 44, 214, and references therein.
2. For a review on the synthesis of trifluoromethylated cyclic compounds, see: P. Lin, J. Jiang, Tetrahedron 2000, 3635.
3. a) H. Lebel, V. Paquet, Org. Lett. 2002, 4, 1671, and references therein,
4. b) V. De Matteis, F. L. van Delft, H. Jakobi, S. Lindell, J. Tiebes, F. P. J. T. Rutjes, J. Org. Chem. 2006, 71, 7527.
5. J. Ichikawa, H. Fukui, Y. Ishibashi, J. Org. Chem. 2003, 68, 7800.
6. a) J. Ichikawa, T. Mod, Y. Iwai, Chem. Lett. 2004, 33, 1354, and references therein,
7. b) T. Mori, Y. Iwai, J. Ichikawa, Chem. Lett. 2005, 34, 778.
8. J. Ichikawa, M. Fujiwara, T. Okauchi, T. Minami, Synlett 1998, 927.
9. a) F. G. Drakesmith, O. J. Stewart, P. Tarrant, J. Org. Chem. 1968, 33, 280.
10. b) K. Iseki, Y. Kuroki, T. Nagai, Y. Kobayashi, J. Fluorine Chem. 1994, 69, 5.
11. R. Nadano, J. Ichikawa, Synthesis 2006, 128.
12. For 1-(trifluoromethyl)vinylmetal species, see references in Ref. 8.
13. n-BuLi seemed less reactive than vinyllithium 1 under the reaction conditions, presumably due to aggregation. See, Organolithiums: Selectivity for Synthesis, ed. by J. Clayden, Elsevier, Oxford, 2002.
14. When a 1:1 mixture of 2 and n-BuLi was kept at - 100°C for 15 min and then treated with benzaldehyde, two alcohols, derived from vinyllithium 1 and n-BuLi, were obtained in 25 and 64% yield, respectively.
15. 2O (10mL) was added over 20min. The reaction mixture was allowed to warm to -50°C over 2h, and the reaction was quenched with phosphate buffer (pH 7, 10 mL). Organic materials were extracted with EtOAc three times, and the combined extracts were washed with brine, and dried over MgSO4. After removal of the solvent under reduced pressure, the residue was purified by silica-gel column chromatography (hex-ane-EtOAc, 10:1) to give 7c (180mg, 90%) as colorless crystals.
16. For a recent example, see: T. Barhoumi-Slimi, B. Crousse, M. Ourevitch, M. El Gaied, J.-P. Bégué, D. Bonnet-Delpon, J. Fluorine Chem. 2002, 117, 137.
17. For reviews on the Pauson-Khand reaction, see: S. E. Gibson, N. Mainolfi, Angew. Chem., Int. Ed. 2005, 44, 3022, and references therein.
18. For the Pauson-Khand reaction in (-)-dendrobin synthesis, see: J. Cassayre, S. Z. Zard, J. Orgcmomet. Chem. 2001, 624, 316.
19. For reviews on the Pauson-Khand reaction of electron-deficient alkenes, see: a) M. R. Rivero, J. Adrio, J. C. Carretero, Synlett 2005, 26.
20. b) M. R. Rivero, J. Adrio, J. C. Carretero, Eur. J. Org. Chem. 2002, 2881.
21. See also: c) L. V. R. Boñaga, M. E. Krafft, Tetrahedron 2004, 9795.
22. The configuration of the major isomer was determined to be anti by X-ray crystallography of the cyclopentanone, derived via reduction of 9a.
23. 3 group at C-1 was reported to be unsuccessful. M. Ishizaki, D. Suzuki, O. Hoshino, J. Fluorine Chem. 2001, 111, 81.