Patent classifications
B01J31/2278
Synthesis and characterization of Ru alkylidene complexes
This invention relates generally to olefin metathesis catalyst compounds, to the preparation of such compounds, compositions comprising such compounds, methods of using such compounds, articles of manufacture comprising such compounds, and the use of such compounds in the metathesis of olefins and olefin compounds. The invention has utility in the fields of catalysts, organic synthesis, polymer chemistry, and industrial and fine chemicals industry.
Novel ruthenium complexes, methods of their preparation and application thereof in olefin cross metathesis
Novel ruthenium complexes of general formula 4
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in which the substituents are defined herein. The present disclosure relates also to methods for preparing such compounds and use thereof as catalysts and/or (pre)catalysts in olefin cross metathesis.
Reactions of olefin derivatives in the presence of methathesis catalysts
The invention provides a method for synthesizing musk macrocycles comprising contacting an easily accessible diene starting materials bearing a Z-olefin moiety and performing a ring closing metathesis reaction in the presence of a Group 8 olefin metathesis catalyst. ##STR00001##
RUTHENIUM-BASED METATHESIS CATALYSTS, PRECURSORS FOR THEIR PREPARATION AND THEIR USE
The invention is directed to ruthenium-based metathesis catalysts of the Grubbs-Hoveyda type. The new 2-aryloxy-substituted ruthenium catalysts described herein reveal rapid initiation behavior. Further, the corresponding styrene-based precursor compounds are disclosed. The catalysts are prepared in a cross-metathesis reaction starting from styrene-based precursors which can be prepared in a cost-effective manner.
The new Grubbs-Hoveyda type catalysts are suitable to catalyze ring-closing metathesis (RCM), cross metathesis (CM) and ring-opening metathesis polymerization (ROMP). Low catalyst loadings are necessary to convert a wide range of substrates including more complex and critical substrates via metathesis reactions at low to moderate temperatures in high yields within short reaction times.
Synthesis and characterization of metathesis catalysts
This invention relates generally to olefin metathesis catalysts, to the preparation of such compounds, compositions comprising such compounds, methods of using such compounds, and the use of such compounds in the metathesis of olefins and in the synthesis of related olefin metathesis catalysts. The invention has utility in the fields of catalysis, organic synthesis, polymer chemistry, and in industrial applications such as oil and gas, fine chemicals and pharmaceuticals.
Highly efficient synthesis of Z-macrocycles using stereoretentive, ruthenium-based metathesis catalysts
A highly efficient, Z-selective ring-closing metathesis system for the formation of macrocycles using a stereoretentive, ruthenium-based catalyst supported by a dithiolate ligand is reported. This catalyst is demonstrated to be remarkably active as observed in initiation experiments showing complete catalyst initiation at −20° C. within 10 min. Using easily accessible diene starting materials bearing a Z-olefin moiety, macrocyclization reactions generated products with significantly higher Z-selectivity in appreciably shorter reaction times, in higher yield, and with much lower catalyst loadings than in previously reported systems. Macrocyclic lactones ranging in size from twelve-membered to seventeen-membered rings are synthesized in moderate to high yields (68-79% yield) with excellent Z-selectivity (95%-99% Z).
LIQUID HYDROGENATED NITRILE-BUTADIENE RUBBER, PREPARATION METHOD THEREOF AND USE THEREOF
Disclosed are a liquid hydrogenated nitrile-butadiene rubber, a preparation method therefor and the use thereof. In the liquid hydrogenated nitrile-butadiene rubber: the content of acrylonitrile is 15-50%; the hydrogenation saturation is 75-99.5%; the weight-average molecular weight (Mw) is 3,000-60,000; the molecular weight polydispersity index (PDI) is 2.0-8.0; and the glass transition temperature (Tg) is lower than −28° C. The liquid hydrogenated nitrile-butadiene rubber is low in molecular weight and wide in molecular weight polydispersity, simultaneously has an excellent fluidity during processing and excellent mechanical properties after curing and has a unique application value in the field of special rubbers; and the preparation method therefor is simple and feasible in terms of the process.
Hydrogenation catalyst compositions and their use for hydrogenation of nitrile rubber
This invention relates to novel hydrogenation catalyst compositions obtainable from reacting metal-based complex hydrogenation catalysts with specific co-catalysts and to a process for selectively hydrogenating nitrile rubbers in the presence of such novel hydrogenation catalyst compositions.
Long shelf life stable photoactive mass polymerizable polycycloolefin compositions as optical materials
Embodiments in accordance with the present invention encompass compositions encompassing a latent organo-ruthenium compound, a photosensitizer and one or more monomers which undergo ring open metathesis polymerization (ROMP) when said composition is exposed to suitable actinic radiation to form a substantially transparent film or a three dimensional object. Surprisingly, the compositions are very stable at ambient conditions to temperatures up to 80° C. for several weeks and undergo mass polymerization only when subjected to actinic radiation under inert atmosphere such as for example a blanket of nitrogen. Accordingly, compositions of this invention are useful in various opto-electronic applications, including as 3D printing materials, coatings, encapsulants, fillers, leveling agents, among others.
Process for producing nitrile rubbers using ruthenium complex catalysts
The present invention relates to a process for preparing nitrile rubbers having reduced molecular weight by metathesis of a first nitrile rubber in the presence of specific ruthenium complex catalysts that have particular N-heterocyclic carbene ligands.