Synfacts 2009(1): 0109-0109  
DOI: 10.1055/s-0028-1087250
Polymer-Supported Synthesis
© Georg Thieme Verlag Stuttgart ˙ New York

Silica-Immobilized Second-Generation Hoveyda-Grubbs Catalyst

Contributor(s): Yasuhiro Uozumi, Toshimasa Suzuka
B. Van Berlo, K. Houthoofd, B. F. Sels*, P. A. Jacobs*
Katholieke Universiteit Leuven, Heverlee, Belgium
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Publikationsverlauf

Publikationsdatum:
18. Dezember 2008 (online)

Significance

Silica-immobilized second-generation Hoveyda-Grubbs catalysts were prepared and found to promote metathesis reactions. Thus, Hoveyda-Grubbs catalyst 1 reacted with silica powder (Fluka silica gel) in toluene at 20 ˚C for 2 h to afford the bright greenish power 2a. The silica pellets catalyst 2b was prepared via a similar protocol using silica pellets instead of silica powder. Ring-opening metathesis polymerization (ROMP) of cyclooctene was carried out with 1 mol% Ru of the silica catalysts 2a and 2b in hexane at 20 ˚C to give polymer 4 in 95 and 98% yield, respectively. Catalyst 2b was separated from the polymer by decantation under air conditions and reused four times without any loss of activity.