The discovery of highly active catalysts and the success of ionic liquid immobilized systems have accelerated attention to a new class of cationic metathesis catalysts. We herein report the facile syntheses of cationic ruthenium catalysts bearing bulky phosphine ligands. Simple ligand exchange using silver(I) salts of non-coordinating or weakly coordinating anions provided either PPh3 or chelat...

gem-Difluoro-1,7-enyne amides are suitable building blocks for the synthesis of difluorodihydropyridinones via a ring-closing metathesis reaction, and of 4,4-difluoro-3-oxoisoquinolines through a ring-closing metathesis-enyne metathesis tandem reaction. These products, in turn, undergo a Diels-Alder reaction to yield heterotricyclic systems in moderate to good yields.

A fluorous-tagged "safety catch" linker is described for the synthesis of heterocycles with use of ring-closing metathesis. The linker facilitates the purification of metathesis substrates, the removal of the catalyst, the functionalization of the products, and the release of only metathesis products. The synthesis of a range of heterocycles is described.

We report the development of ruthenium-based metathesis catalysts with chelating N-heterocyclic carbene (NHC) ligands that catalyze highly Z-selective olefin metathesis. A very simple and convenient procedure for the synthesis of such catalysts has been developed. Intramolecular C-H bond activation of the NHC ligand, promoted by anion ligand substitution, forms the appropriate chelate for stere...

Allyl sulfides undergo efficient cross-metathesis in aqueous media with Hoveyda-Grubbs second generation catalyst 1. The high reactivity of allyl sulfides in cross-metathesis was exploited in the first examples of cross-metathesis on a protein surface. S-Allylcysteine was incorporated chemically into the protein, providing the requisite allyl sulfide handle. Preliminary efforts to genetically i...

metathesis of proteins under aqueous conditions, which makes a powerful reaction in organic and polymer chemistry potentially available for the elaboration of biopolymers. The work by Davis and colleagues raises two follow-up questions regarding the versatility of the metathesis approach and its implementation under physiological conditions. The present study tests metathesis of proteins on a r...

In situ modification of Grubbs' first-generation metathesis catalyst allows for a tandem enyne metathesis/hydrovinylation that is complementary to the regioselectivity of known ruthenium-catalyzed hydrovinylations.

Ring-opening metathesis catalysis has received little attention as a means to functionalize or crosslink biopolymers in water since the required catalysts are not usually stable under these conditions. However, biopolymer solubility suggests such a procedure. We show that Grubbs 1 and 2 generation catalysts (in emulsion) as well as a water-soluble Hoveyda-Grubbs catalyst can be applied to cross...