A system for transfer hydrogenation of alkenes, composed of a ruthenium metathesis catalyst and HCOOH, is presented. This operationally simple system can be formed directly after a metathesis reaction to effect hydrogenation of the metathesis product in a single-pot. These hydrogenation conditions are applicable to a wide range of alkenes and offer remarkable selectivity.

The cross metathesis of 1,2-epoxy-5-hexene (1) with methyl acrylate and acrylonitrile was investigated as an entry to the synthesis of polyfunctional compounds. The resulting cross metathesis products were hydrogenated in a tandem fashion employing the residual ruthenium from the metathesis step as the hydrogenation catalyst. Interestingly, the epoxide ring remained unreactive toward this hydro...

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...

The first continuous flow Z-selective olefin metathesis process is reported. Key to realizing this was the adequate choice of stereoselective catalysts combined with design an appropriate reactor setup. designed permits various self-, cross- and macro-ring-closing-metathesis reactions, delivering products in high selectivity short residence times. This technique exemplified by direct applicatio...

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.

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...

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...

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...

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.

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.