Catalysts for olefin metathesis

Polymer-supported Olefin Metathesis Catalysts for Organic and Combinatorial Synthesis... 

I 11 Polymer-supported Olefin Metathesis Catalysts for Organic and Combinatorial Synthesis Tab. 11.6 Catalytic olefin metathesis with Ru complex (41). ... 

Jordan, J. R Grubbs, R. H. Small-molecule N-heterocychc-carbene-containing olefin-metathesis catalysts for use in water. Angew. Chem. Int. Ed. 2007, 46, 5152-5155. 

Grubbs, R.H. (2006) Olefin-metathesis catalysts for the preparation of molecules and materials (Nobel Lecture). Angew. Chem. Int. Ed., 45, 3760. 

Solid-supported SIMes functionalized complex 181 has been prepared for use as a recoverable olefin metathesis catalyst for use in methanol and water.Using a commercially available amine-functionalized PEG-based support (PEGA-NH2), 181 was prepared in three steps (Scheme 72). It was found to promote relatively efficient ring-closing and cross-metathesis reactions. 

Olefin Metathesis Catalysts for the Synthesis of New Macromolecular Architectures... 

The molybdenum(VI) complex with BIPHEN (Schrock-Hoveyda catalyst) has been widely used as an enantioselective olefin metathesis catalyst for a variety of substrates (145). Recently, the synthesis of a tetrahydrocannabiol derivative in molybdenum-catalyzed asymmetric allylic alkylation by using Trost-ligands is carried out. Enhanced regio-, enantio-, and diastereoselectivities relative to the palladium ones have been observed (146). 

The amount of effort invested in the advancement of latent ruthenium olefin metathesis catalysts for ROMP bodes well for the near future. Certainly, more of these developments will afford ever-more useful macromolecules. The most... 

The selectivity exhibited by an olefin metathesis catalyst for the production of -olefins or Z-olefins is a result of both kinetic and thermodynamic factors. Kinetic selectivity results from preferential formation of either syn- or anri-metallacyclo-butanes following olefin binding iy -metallacycles will undergo a cycloreversion to produce Z-olefins, whereas -olefins are derived from anfi-metallacycles. Thermodynamic selectivity arises as a result of secondary metathesis processes, in which the product olefins continue to react with the propagating catalyst. 

Grubbs, R. H. Olefin-Metathesis Catalysts for the Preparation of Molecules and Materials (Nobel Lecture). Angew Chem IntEd 45, 3760-3765 (2006). 

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