Microwave-Assisted Ring-Closing Metathesis Revisited. On the Question of the Nonthermal Microwave Effect

Journal of Organic Chemistry

Volumn 68, Issue 23, 2003, Pages 9136-9139

  Garbacia, Stefania ^a   Desai, Bimbisar ^b   Lavastre, Olivier ^a   Kappe, C Oliver ^b  

^a UNIVERSITÉ DE RENNES 1   (France)

^b UNIVERSITY OF GRAZ   (Austria)

Author keywords

[No Author keywords available]

Indexed keywords

CATALYSIS; DOPING (ADDITIVES); IRRADIATION; MICROWAVES; POSITIVE IONS; SUBSTRATES;

MICROWAVE IRRADIATION;

POLYMERS;

DICHLOROMETHANE; RUTHENIUM;

ARTICLE; CATALYST; HEATING; MICROWAVE RADIATION; RING CLOSING METATHESIS; TEMPERATURE;

EID: 0242491848     PISSN: 00223263     EISSN: None     Source Type: Journal    
DOI: 10.1021/jo035135c     Document Type: Article

References (33)

1. (a) Grubbs, R. H.; Chang, S. Tetrahedron 1998, 54, 4413-4450.
2. (b) Armstrong, S. K. J. Chem. Soc., Perkin Trans. 1 1998, 371-388.
3. (c) Fürstner, A. Angew. Chem., Int. Ed. 2000, 39, 3012-3043.
4. Trnka, T. M.; Grubbs, R. H. Acc. Chem. Res. 2001, 34, 18-29.
5. (a) Fürstner, A. Angew. Chem., Int. Ed. 2000, 39, 3012-3043.
6. (b) Fürstner, A.; Stelzer, F.; Rumbo, A.; Krause, H. Chem. Eur. J. 2002, 8, 1856-1871.
7. (c) Stragies, R.; Blechert, S. Tetrahedron 1999, 55, 8179-8188.
8. (d) Fürstner, A.; Leitner, A. Angew. Chem., Int. Ed. 2003, 42, 308-3011.
9. For general references on microwave synthesis, see: (a) Lidström, P.; Tierney, J.; Wathey, B.; Westman, J. Tetrahedron 2001, 57, 9225-9283.
10. (b) Hayes, B. L. Microwave Synthesis: Chemistry at the Speed of Light; CEM Publishing: Matthews, NC, 2002.
11. (c) Microwaves in Organic Synthesis; Loupy, A., Ed.; Wiley-VCH: Weinheim, 2002.
12. (d) For online resources on microwave-assisted organic synthesis, see: Microwave-Assisted Organic Synthesis (MAOS) Webpages. http://www.maos.net.
13. Mayo, K. G.; Nearhoof, E. H.; Kiddle, J. J. Org. Lett. 2002, 4, 1567-1570.
14. Yang, C.; Murray, W. V.; Wilson, L. J. Tetrahedron Lett. 2003, 44, 1783-1786.
15. Grigg, R.; Martin, W.; Morris, J.; Sridharan, V. Tetrahedron Lett. 2003, 44, 4899-4901.
16. Varray, S.; Gauzy, C.; Lamaty, F.; Lazaro, R.; Martinez, J. J. Org. Chem. 2000, 65, 6787-6790.
17. Efskind, J.; Undheim, K. Tetrahedron Lett. 2003, 44, 2837-2839.
18. For a discussion of nonthermal or specific microwave effects, see: (a) Perreux, L.; Loupy, A. Tetrahedron 2001, 57, 9225-9283.
19. (b) Kuhnert, N. Angew. Chem., Int. Ed. 2002, 41, 1863-1866.
20. (c) Strauss, C. R. Angew. Chem., Int. Ed. 2002, 41, 3589-3590.
21. (d) Langa, F.; de la Cruz, P.; de la Hoz, A.; Díaz-Ortiz, A.; Díez-Barra, E. Contemp. Org. Synth. 1997, 4, 373-386.
22. Fürstner, A.; Liebl, M.; Lehmann, C. W.; Picquet, M.; Kunz, R.; Bruneau, C.; Touchard, D.; Dixneuf, P. H. Chem. Eur. J. 2000, 6, 1847-1857.
23. Semeril, D.; Olivier-Bourbigou, H.; Bruneau, C.; Dixneuf, P. H. Chem. Commun. 2002, 146-147.
24. For microwave dielectric heating mechanisms and loss tangents of solvents, see: Gabriel, C.; Gabriel, S.; Grant, E. H.; Halstead, B. S. J.; Mingos, D. M. P. Chem. Soc. Rev. 1998, 27, 213-223. See also ref 4b.
25. At 140 °C in DCE (microwave irradiation), up to 40% byproducts were formed via different isomerization processes. Employing DCM as a solvent at 100 °C led to formation of less than 5% of the cycloisomerization product. For structural and mechanistic details on this isomer formation, see ref 11. For substrates 1b-f, no byproducts were encountered in the RCM process.
26. Originally reported conditions (ref 11) on the RCM of diene 1a with catalyst 4 (2.5 mol %) in toluene required 19 h (90% conversion) at room temperature or 5 h at 80 °C (99% conversion).
27. For example, for substrate 1a, it was demonstrated that the concentration of catalyst 3 could be further reduced to 0.25 mol % and still lead to complete conversion to 2a (60 °C, 2 min). Further reduction in catalyst concentration to 0.1 mol % showed incomplete conversion.
28. (a) Ley, S. V.; Leach, A. G.; Storer, R. I. J. Chem. Soc., Perkin Trans. 1 2001, 358-361.
29. (b) Leadbeater, N. E.; Torenius, H. M. J. Org. Chem. 2002, 67, 3145-3148.
30. (c) Van der Eycken, E.; Appukkuttan, P.; De Borggraeve, W.; Dehaen, W.; Dallinger, D.; Kappe, C. O. J. Org. Chem. 2002, 67, 7904-7907.
31. For a discussion of the concept of molecular radiators, see for example: (a) Kaiser, N.-F.; Bremberg, U.; Larhed, M.; Moberg, C.; Hallberg, A. Angew. Chem., Int. Ed. 2000, 39, 3595-3598.
32. (b) Steinreiber, A.; Stadler, A.; Mayer, S. F.; Faber, K.; Kappe, C. O. Tetrahedron Lett. 2001, 42, 6283-6286. See also ref 10.
33. Very rapid 15 s conversion 1a - 2a experienced with ionic liquid-doped DCM (Figure 1) could also be reproduced by thermal heating at 80 °C (see Experimental Section for details).