Water vs. desiccant. Improvement of Yb-BINOL complex catalyzed enantioselective epoxidation of enones

Tetrahedron Letters

Volumn 39, Issue 40, 1998, Pages 7353-7356

  Watanabe, Shizue ^a,b   Kobayashi, Yukari ^a   Arai, Takayoshi ^a   Sasai, Hiroaki ^a   Bougauchi, Masahiro ^b   Shibasaki, Masakatsu ^b  

^a OSAKA UNIVERSITY   (Japan)

^b UNIVERSITY OF TOKYO   (Japan)

Author keywords

Asymmetric reactions; Catalysis; Enones; Epoxidation

Indexed keywords

1,1' BINAPHTHYL DERIVATIVE; 2 NAPHTHOL; CUMENE HYDROPEROXIDE; DESICCANT; KETONE DERIVATIVE; TERT BUTYL HYDROPEROXIDE; TETRAHYDROFURAN; WATER; YTTERBIUM;

ARTICLE; CATALYSIS; CATALYST; CHEMICAL REACTION; ENANTIOMER; EPOXIDATION; STEREOCHEMISTRY;

EID: 0032191537     PISSN: 00404039     EISSN: None     Source Type: Journal    
DOI: 10.1016/S0040-4039(98)01578-0     Document Type: Article

References (27)

1. [1] (a) Bougauchi M, Watanabe S, Arai T, Sasai H, Shibasaki M. J. Am. Chem. Soc. 1997;119:2329-2330.
2. (b) Sasai H, Arai T, Shibasaki M. J. Am. Chem. Soc. 1994;116:1571-1572.
3. [2] For other catalytic asymmetric epoxidation of α,β-unsaturated carbonyl compounds, see: (a) Juliá S, Masana J, Vega JC. Angew. Chem. Int. Ed. Engl. 1980; 19:929-931.
4. (b) Kroutil W, Mayon P, Lasterra-Sánchez ME, Maddrell SJ, Roberts SM, Thornton SR, Todd CJ, Tüter M. Chem. Commun. 1996:845-846 and references cited therein.
5. (c) Helder R, Hummelen JC, Laane RWPM. Wiering JS, Wynberg H. Tetrahedron Lett. 1976; 1831-1834.
6. (d) Colonna S, Gaggero N, Manfredi A, Spadoni M, Casella L, Carrea G, Pasta P. Tetrahedron 1988;44:5169-5178.
7. (e) Colonna S, Manfredi A, Annunziata R, Gaggero N. J. Org. Chem. 1990;55:5862-5866.
8. (f) Baccin C, Gusso A, Pinna F, Strukul G. Organometallics 1995;14:1161-1167.
9. (g) Kumar A, Bhakuni V. Tetrahedron Lett. 1996;37:4751-4754.
10. (h) Jacobsen EN, Deng L, Furukawa Y, Martinez LE. Tetrahedron 1994;50:4323-4334.
11. (i) Lygo B, Wainwright PG. Tetrahedron Lett. 1998;39:1599-1602.
12. [3] Purchased from Kojundo Chemical Co., Ltd., 5-1-28, Chiyoda, Sakato, Saitama 350-0214, Japan (Fax:+81-492-84-1351).
13. 3 with 1 seems to be rather slow.
14. [5] For the multifunctionality of lanthanoid and/or aluminum complex, see: (a) Shibasaki M, Sasai H, Arai T. Angew. Chem. Int. Ed. Engl. 1997;36:1236-1256.
15. (b) Sasai H, Arai T, Satow Y, Houk KN, Shibasaki M. J. Am. Chem. Soc. 1995;117:6194-6198.
16. (c) Arai T, Sasai H, Yamaguchi K, Shibasaki M. J. Am. Chem. Soc. 1998;120:441-442.
17. (d) Gröger H, Saida Y, Sasai H, Yamaguchi K, Martens J, Shibasaki M. J. Am. Chem. Soc. 1998;120:3089-3103.
18. (e) Emori E, Arai T, Sasai H, Shibasaki M. J. Am. Chem. Soc. 1998;120:4043-4044.
19. [6] Catalytic asymmetric Michael reactions utilizing Ln-1 catalyst proceed efficiently without the addition of water. Therefore, activation of enones by a water in the Ln-1 catalysis would not have been a factor. Water may act as a scavenger of free Ln alkoxide moiety.
20. [7] The bimetallic transition state shown below is also feasible. A 2:3 ratio of Yb and 1, and the fragment peak of LDI-TOF MS spectra of Yb-1 complex support the bimetallic structure. (equation presented)
21. [8] Supplier: Aldrich Chemical Co., Inc. Milwaukee, WI53233, USA.
22. [9] Due to the extremely high oxophilicity of lanthanoid element, complete removal of water from the catalyst would be impossible.
23. 13C-NMR spectra were obscure.
24. [11] Performed by KNAUER Vapor Pressure Osmometer.
25. 4, respectively.
26. [13] LDI-TOF MS spectra also support the oligomeric structure of Ln-1 complexes.
27. [14] The general procedure of asymmetric epoxidation of 5 utilizing powder-dried Yb-1 is as follows. After a mixture of MS 4A (48 mg) and powder-dried Yb-1 (7.84 mg, 0.012 mmol based on Yb employed) was dried under reduced pressure for 1 h at room temperature, THF (1.0 mL), a toluene solution of TBHP (3∼4 M, 120 μL, 0.36∼0.48 mmol), and a THF solution of water (1 M, 54 μL, 4.5 equiv to Yb) were added. The resulting suspension was stirred for an additional 10 min at room temperature. To this mixture was added enone 5 (0.24 mmol), followed by stirring for 24 h at room temperature.