Regio- and stereoselective cyclization reactions of unsaturated silyl enol ethers by photoinduced electron transfer - Mechanistic aspects and synthetic approach

Hintz S, Mattay J, van Eldik R, Fu WF (1998)
European Journal of Organic Chemistry (8): 1583-1596.

Zeitschriftenaufsatz | Veröffentlicht | Englisch
 
Download
Es wurde kein Volltext hochgeladen. Nur Publikationsnachweis!
Autor/in
; ; ;
Abstract / Bemerkung
Oxidative photoinduced electron transfer (PET) reactions have been performed with various silyl enol ethers and silyloxy-2H-chromones bearing an olefinic or silylacetylenic side chain, The reactions result in regioselective ring closure with the formation of bi- to tetracyclic ring systems with a well-defined ring juncture, e.g. perhydrophenanthrenones 13 or benzo-annellated xanthenones 24. Our investigations have focussed on the optimization of this cyclization method with regard to irradiation time and product yield. The irradiation times could be reduced by using the cosensitized PET method. Modifying the substrate at the silyl group led to enhanced yields. In addition, we found that solvent and pressure dependences are important tools, allowing control of the regiochemistry. Both the synthesis of 6-endo products by radical cationic reaction pathways, as well as 5-exo ring closure by radical intermediates was achieved. Mechanistic details, including findings from deuterium labelling experiments, are discussed.
Stichworte
cyclizations; high-pressure effects; silyl enol ethers; electron transfer; radical cations; solvent effects
Erscheinungsjahr
1998
Zeitschriftentitel
European Journal of Organic Chemistry
Ausgabe
8
Seite(n)
1583-1596
ISSN
1434-193X
Page URI
https://pub.uni-bielefeld.de/record/2402474

Zitieren

Hintz S, Mattay J, van Eldik R, Fu WF. Regio- and stereoselective cyclization reactions of unsaturated silyl enol ethers by photoinduced electron transfer - Mechanistic aspects and synthetic approach. European Journal of Organic Chemistry. 1998;(8):1583-1596.
Hintz, S., Mattay, J., van Eldik, R., & Fu, W. F. (1998). Regio- and stereoselective cyclization reactions of unsaturated silyl enol ethers by photoinduced electron transfer - Mechanistic aspects and synthetic approach. European Journal of Organic Chemistry(8), 1583-1596.
Hintz, S., Mattay, J., van Eldik, R., and Fu, W. F. (1998). Regio- and stereoselective cyclization reactions of unsaturated silyl enol ethers by photoinduced electron transfer - Mechanistic aspects and synthetic approach. European Journal of Organic Chemistry, 1583-1596.
Hintz, S., et al., 1998. Regio- and stereoselective cyclization reactions of unsaturated silyl enol ethers by photoinduced electron transfer - Mechanistic aspects and synthetic approach. European Journal of Organic Chemistry, (8), p 1583-1596.
S. Hintz, et al., “Regio- and stereoselective cyclization reactions of unsaturated silyl enol ethers by photoinduced electron transfer - Mechanistic aspects and synthetic approach”, European Journal of Organic Chemistry, 1998, pp. 1583-1596.
Hintz, S., Mattay, J., van Eldik, R., Fu, W.F.: Regio- and stereoselective cyclization reactions of unsaturated silyl enol ethers by photoinduced electron transfer - Mechanistic aspects and synthetic approach. European Journal of Organic Chemistry. 1583-1596 (1998).
Hintz, S, Mattay, Jochen, van Eldik, R, and Fu, WF. “Regio- and stereoselective cyclization reactions of unsaturated silyl enol ethers by photoinduced electron transfer - Mechanistic aspects and synthetic approach”. European Journal of Organic Chemistry 8 (1998): 1583-1596.