46 results about "Ring-closing metathesis" patented technology

The invention provides novel organometallic complexes useful as olefin metathesis catalysts. The complexes have an N-heterocyclic carbene ligand and a chelating carbene ligand associated with a Group 8 transition metal center. The molecular structure of the complexes can be altered so as to provide a substantial latency period. The complexes are particularly useful in catalyzing ring closing metathesis of acyclic olefins and ring opening metathesis polymerization of cyclic olefins.

Disclosed is a process for preparing a compound of formula I comprising cyclizing a diene compound of formula III in the presence of a ruthenium catalyst in a suitable organic solvent, wherein the process is performed in a gaseous fluid at supercritical or near-supercritical conditions: The compounds of formula (I) are active agents for the treatment of hepatitis C viral (HCV) infections or are intermediates useful for the preparation of anti-HCV agents.

Disclosed is a process for preparing a compound of formula I comprising cyclizing a diene compound of formula III in the presence of a ruthenium catalyst in a suitable organic solvent, wherein the process is performed in a gaseous fluid at supercritical or near-supercritical conditions:The compounds of formula (I) are active agents for the treatment of hepatitis C viral (HCV) infections or are intermediates useful for the preparation of anti-HCV agents.

The present invention provides inventive polypeptides comprising a C terminal RAB binding domain (RabBD) of RAB family interacting proteins (FIPs) stabilized by peptide stapling, and pharmaceutical compositions thereof. Also provided are methods for modulating RAB function comprising contacting an inventive stapled polypeptide with a RAB protein, and methods of treatment associated with modulation of RAB activity. The present invention also provides methods of making the inventive stapled polypeptides by ring closing metathesis of unstapled polypeptide precursors.

The invention relates to ruthenium alkylidene complexes having an N-heterocyclic carbene ligand comprising a 5-membered heterocyclic ring having a carbenic carbon atom and at least one nitrogen atom contained within the 5-membered heterocyclic ring, wherein the nitrogen atom is directly attached to the carbenic carbon atom and is substituted by a phenyl ring, and wherein the phenyl ring has a hydrogen at either or both ortho positions and is substituted at at least one ortho or meta position. The invention also relates to an olefin metathesis reactions and particularly to the preparation of tetra-substituted cyclic olefins via a ring-closing metathesis.

The present invention provides stapled polypeptides of the Formulae (I) and (VI): (I) (VI) and salts thereof; wherein the groups =====; R1a, R1b, R1c, R2a, R3a, R2b, R3b, R4a, R4b, RA, RZ, L1a, L1b, L2, L3, XAA, v, w, p, m, s, n, t, and q are as defined herein. The present invention further provides methods of preparing the inventive stapled polypeptides from unstapled polypeptide precursors. The present invention further provides pharmaceutical compositions comprising a stapled polypeptide of Formula (I) or (VI), and methods of using the stapled peptides. The present invention also provides modifications of the staples post ring closing metathesis.

The present invention relates to a new process for the preparation of macrocyclic HCV protease inhibitor compounds of the formulawherein R1 is an amino protecting group and X is halogen by way of a ring closing metathesis approach.

The present invention describes the use of cationic vinylidene, allenylidene and higher cumulenylidene complexes of ruthenium or osmium as catalysts or catalyst precursors for olefin metathesis reactions of all types, as well as to new cationic allenylidene complexes of ruthenium and osmium which can be used as metathesis catalysts with preferred embodiment. These catalysts or catalyst precursors are easy to prepare from well accessible, stable and essentially non toxic starting materials, can be isolated and stored, they exhibit a high catalytic activity, a good compatibility with functional groups, solvents, water and additives, and they need not to be activated by any additive. Olefins of all types can be used as the substrates in the present invention in ring closing metathesis (RCM) of acyclic dienes and polyenes, the metathesis of enynes and dienynes, the ring opening metathesis polymerization (ROMP) of cyclic olefins, the acyclic diene metathesis polymerization (ADMET) of acyclic dienes or polyenes, the depolymerization of olefinic polymers, and the cross metathesis of two or more olefins. The present invention also applies to combinations of these types of metathetic reactions and domino processes thereof.

The present invention relates to a new process for the preparation of macrocyclic HCV protease inhibitor compounds of the formulawherein R1 is an amino protecting group and X is halogen by way of a ring closing metathesis approach.

The present invention relates to chiral metal catalysts for stereoselective olefin metathesis reactions, which are recyclable and reusable in such metathesis reactions. The chiral metal-based metathesis catalysts of the invention comprise multidentate optically active or racemic chiral ligands that enable their use in asymmetric synthetic processes, such as for example, in ring-opening and ring-closing metathesis reactions (ROM and RCM, respectively) of alkenes. The catalysts of the invention are organometallic complexes of multivalent metals comprising one or more chiral bidentate ligands that exhibit superior reactivity and stereoselectivity properties. The present invention also provides methods of making such catalysts and methods for utilizing them in catalyzing stereoselective olefin metathesis reactions to provide asymmetric products in relatively high enantiomeric or stereoisomeric excess.

The present invention relates to a process for carrying out olefin ring-closing metathesis (RCM) wherein compressed carbon dioxide (gaseous, liquid or supercritical) acts as solvent for the liquid or solid reactant and the products obtained therefrom, while additionally one or more ionic liquids are introduced as the 2nd phase in which homogeneous olefin metathesis catalysts are immobilised.

Highly active, recoverable and recyclable transition metal-based metathesis catalysts and their organometallic complexes including dendrimeric complexes are disclosed, including a Ru complex bearing a 1,3-dimesityl-4,5-dihydroimidazol-2-ylidene and styrenyl ether ligand. The heterocyclic ligand significantly enhances the catalytic activity, and the styrenyl ether allows for the easy recovery of the Ru complex. Derivatized catalysts capable of being immobilized on substrate surfaces are also disclosed. The present catalysts can be used to catalyze ring-closing metathesis (RCM), ring-opening (ROM) and cross metatheses (CM) reactions, and promote the efficient formation of various trisubstituted olefins at ambient temperature in high yield.

Improved methods for generating a —C—C— bond by cross-coupling of a transferable group with an acceptor group. The transferable group is a substituent of an organosilicon nucleophile and the acceptor group is provided as an organic electrophile. The reaction is catalyzed by a Group 10 transition metal complex (e.g., Ni, Pt or Pd), particularly by a palladium complex. Certain methods of this invention use improved organosilicon nucleophiles which are readily prepared, can give high product yields and exhibit high stereoselectivity. Methods of this invention employ activating ions such as halides, hydroxide, hydride and silyloxides. In specific embodiments, organosilicon nucleophilic reagents of this invention include siloxanes, particularly cyclic siloxanes. The combination of the cross-coupling reactions of this invention with ring-closing metathesis, hydrosilylation and intramolecular hydrosilylation reactions provide useful synthetic strategies that have wide application.

A class of surfactant molecules whose structure includes regularly spaced unsaturation in the tail group and thus, can be readily decomposed by ring-closing metathesis, and particularly by the action of a transition metal catalyst, to form small molecule products. These small molecules are designed to have increased volatility and / or enhanced solubility as compared to the original surfactant molecule and are thus easily removed by solvent extraction or vacuum extraction at low temperature. By producing easily removable decomposition products, the surfactant molecules become particularly desirable as template structures for preparing meso- and microstructural materials with tailored properties.

The present invention relates generally to olefin metathesis. In some embodiments, the present invention provides methods for Z-selective ring-closing metathesis.

The present invention relates to chiral metal catalysts for stereoselective olefin metathesis reactions, which are recyclable and reusable in such metathesis reactions. The chiral metal-based metathesis catalysts of the invention comprise multidentate optically active or racemic chiral ligands that enable their use in asymmetric synthetic processes, such as for example, in ring-opening and ring-closing metathesis reactions (ROM and RCM, respectively) of alkenes. The catalysts of the invention are organometallic complexes of multivalent metals comprising one or more chiral bidentate ligands that exhibit superior reactivity and stereoselectivity properties. The present invention also provides methods of making such catalysts and methods for utilizing them in catalyzing stereoselective olefin metathesis reactions to provide asymmetric products in relatively high enantiomeric or stereoisomeric excess.

The present invention discloses high yielding enantioselective process for synthesis of Oseltamivir from readily available starting material, cis-1,4-butene diol. The process features incorporation of chirality using sharpless asymmetric epoxidation (AE) and diastereoselective Barbier allylation and construction of cyclohexene carboxylic acid ester core through a ring closing metathesis (RCM) reaction. Further also disclosed herein is synthesis of (−)-methyl 3-epi-shikimate.

The invention provides a tripeptide macrocyclic derivative as well as an optical isomer, a pharmaceutically acceptable salt or a solvent compound thereof. A preparation method comprises the followingsteps: by taking a carboxyl protected compound as an initial raw material, condensation with an acid, performing olefin ring closing metathesis, removing carboxyl, condensing Boc protected amino acidwith an epoxy ketone segment, removing an amino protection group, and further condensing with an intermediate of which the carboxyl is removed, so as to obtain a target product. Experiments show thatthe derivative which has a completely novel framework and relatively good proteasome inhibition activity has a very good propagation inhibition function on multiple myeloma such as RPMI 8226, and MM.1S. The compound provided by the invention is easy in raw material obtaining, reasonable in route design, gentle in reaction condition, simple and convenient to operate and applicable to industrial production. The derivative is of a structure of formula (I) as shown in the specification.