Bulky Aryloxide Ligand Stabilizes a Heterogeneous Metathesis Catalyst |
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Authors: | Dr Matthew P Conley Dr William P Forrest Dr Victor Mougel Prof Dr Christophe Copéret Prof Dr Richard R Schrock |
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Institution: | 1. Department of Chemistry and Applied Biosciences, ETH‐Zürich, Vladimir Prelog Weg 2, CH‐8093, Zürich (Switzerland);2. Department of Chemistry 6‐331, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, Massachusetts, 02139 (USA) |
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Abstract: | The reaction of W(?O)(?CHCMe2Ph)(dAdPO)2], containing bulky 2,6‐diadamantyl aryloxide ligands, with partially dehydroxylated silica selectively yields a well‐defined silica‐supported alkylidene complex, (?SiO)W(?O)(?CHCMe2Ph)(dAdPO)]. This fully characterized material is a very active and stable alkene metathesis catalyst, thus allowing loadings as low as 50 ppm in the metathesis of internal alkenes. (?SiO)W(?O)(?CHCMe2Ph)(dAdPO)] also efficiently catalyzes the homocoupling of terminal alkenes, with turnover numbers exceeding 75 000 when ethylene is constantly removed to avoid the formation of the less reactive square‐based pyramidal metallacycle resting state. |
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Keywords: | alkenes metathesis metallacycles NMR spectroscopy tungsten |
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