Improved catalysis of nitrone 1,3-dipolar cycloadditions by solving the aggregation issue of the DBFOX/Ph-transition metal complexes

Tetrahedron Letters

Volumn 45, Issue 21, 2004, Pages 4061-4063

  Shirahase, Moto ^a   Kanemasa, Shuji ^a   Hasegawa, Masayuki ^a  

^a KYUSHU UNIVERSITY   (Japan)

Author keywords

1,3 Dipolar cycloaddition; Aldehyde dipolarophile; Catalyzed enantioselective reaction; Nitrone

Indexed keywords

ALDEHYDE DERIVATIVE; LIGAND; METAL COMPLEX; NITRONE DERIVATIVE;

ARTICLE; CATALYSIS; CATALYST; CHEMICAL MODIFICATION; CHEMICAL REACTION; CHEMICAL STRUCTURE; CHIRALITY; CYCLOADDITION; ENANTIOSELECTIVITY; PROTECTION; REACTION ANALYSIS; ROOM TEMPERATURE; STRUCTURE ANALYSIS; TECHNIQUE;

EID: 2342652407     PISSN: 00404039     EISSN: None     Source Type: Journal    
DOI: 10.1016/j.tetlet.2004.03.151     Document Type: Article

References (15)

1. Shirahase M., Kanemasa S. Org. Lett. 6:2004;675-678
2. Viton F., Bernardinelli G., Kündig E.P. J. Am. Chem. Soc. 124:2002;4968-4969
3. Mita T., Ohtsuki N., Ikeno T., Yamada T. Org. Lett. 4:2002;2457-2460
4. Ohtsuki N., Kezuka S., Kogami Y., Mita T., Ashizawa T., Ikeno T., Yamada T. Synthesis. 9:2003;1462-1466
5. Carmona D., Lamata M.P., Viguri F., Rodríguez R., Oro L.A., Balana A.I., Lahoz F.J., Tejero T., Merino P., Franco S., Montesa I. J. Am. Chem. Soc. 126:2004;2716-2717
6. The colorless suspension remained all the time until the reaction mixture was quenched with saturated ammonium chloride after the completion of reaction
7. General procedure for the preparation of DBFOX/Ph complexes is as follows: Equimolar amounts of DBFOX/Ph and a metal salt are stirred in dichloromethane for a few hours at room temperature, and a clear solution including the resulting complex is evaporated in vacuo to give a solid of the complex
8. We have confirmed, on the basis of the experiment by use of a reference compound, that the DBFOX/Ph ligand used for the complex preparation experiment was recovered almost quantitatively without formation of complex
9. 1H NMR spectra
10. Kanemasa S., Oderaotoshi Y., Sakaguchi S., Yamamoto H., Tanaka J., Wada E., Curran D.P. J. Am. Chem. Soc. 120:1998;3074-3088
11. Iserloh U., Curran D.P., Kanemasa S. Tetrahedron: Asymmetry. 10:1999;2417-2428
12. 2) were isolable and could be stored in open air for months without loss of catalytic activity
13. 1H NMR analysis showing quantitative formation of the complex
14. See the footnote "a" in the table included in Scheme 2
15. Complexes derived from D show much smaller solubility in dichloromethane than the complexes of other ligands A-C