45 results about "Ring-closing metathesis" patented technology

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 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 =====; R^1a, R^1b, R^1c, R^2a, R^3a, R^2b, R^3b, R^4a, R^4b, R_A, R_Z, L_1a, L_1b, L₂, L₃, X^AA, 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 formula

wherein 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 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.

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.

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

A simple process for producing v-coelenterazine compounds has been desired. Described is a process for producing a v-coelenterazine compound represented by general formula (II) comprising (1) the step of reacting a compound of general formula (VIII) with a methyltriphenylphosphonium salt in the presence of a base to give a compound represented by general formula (IX), (2) the step of performing a ring-closing metathesis reaction on any one selected from the group consisting of the compound represented by general formula (IX) and a compound of general formula (X) which is the compound of general formula (IX) wherein the amino is protected with R⁵, and then deprotecting R⁴ and, if any, R⁵ to give a v-coelenteramine compound represented by general formula (XIV), and (3) the step of reacting the compound of general formula (XIV) with a compound represented by general formula (XV) to give the compound of general formula (II).

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.

Compounds and processes for catalytic ring-opening cyclooligomerization metathesis and ring-closing metathesis of olefins are described. The compound is a molybdenum or tungsten metal (M) complex which comprises an imido ligand (N—R) bound to the M to provide an M=N—R site, an M=C reaction site wherein the C of the M=C reaction site is tethered to the R of the imido ligand via a carbon or carbon and heteroatom (NOS) chain containing 1 to 12 carbon atoms to form a ring structure, and two to four ligands (R′) bound to the M to provide two to four M-R′ sites. In particular embodiments, the M-R′ sites include each of the oxygens of a dialkoxide ligand or each of the nitrogens of an η¹-pyrrolyl ligand bound to the M.

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.