Patent classifications
B01J2231/543
Compositions and methods for visible-light-controlled ruthenium-catalyzed olefin metathesis
The present disclosure provides compositions and methods for metathesizing a first alkenyl or alkynyl group with a second alkenyl or alkynyl group, the composition comprising a ruthenium metathesis catalyst and a photoredox catalyst that is activated by visible light.
Two component mass polymerizable compositions containing polycycloolefin monomers and organoruthenium carbide precatalyst
Embodiments in accordance with the present invention encompass a two component composition containing in one component a latent organo-ruthenium carbide catalyst, and in another component a photoactive acid generator or a thermally active acid generator, and either of the components containing a mixture of photoactive compound along with one or more monomers which undergo ring open metathesis polymerization (ROMP) when said components are mixed together and exposed to a suitable radiation (or heat) to form a three-dimensional (3D) object. The three-dimensional objects so formed exhibits improved mechanical properties, particularly, high heat distortion temperature, impact strength, elongation to break, among others. Accordingly, compositions of this invention are useful as 3D inkjet materials for forming high impact strength objects of various sizes with microscale features lower than 100 microns, among various other uses.
Metathesis catalyst system for polymerizing cycloolefins
A supported catalyst system is based on a transition metal carbene including the moiety M1=CR*).sub.2, wherein M.sup.1 is the transition metal and R* is hydrogen or a C.sub.1-C.sub.8 hydrocarbyl. The catalyst system can be supported on a metal oxide support such as silica or the catalyst can be self-supporting. Methods of making the catalyst system can involve precursors based on and/or reacted with aluminum alkyls, halides, and/or alkoxides. Methods of polymerizing cyclic olefins with the catalyst system can obtain polyalkenamers, cyclic olefin polymers, cyclic olefin copolymers, and other metathesis reaction products. The supported catalyst and/or monomer can be recovered and recycled to the polymerization reactor.
Olefin metathesis photopolymers
Described herein are compositions and methods for processing photopolymers based on olefin metathesis. The compositions and methods comprise latent ruthenium complexes and photoacids and/or photoacid generators.
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.
Biofuel and method for preparation by isomerizing metathesis
Subject of the invention is a process for producing a biofuel from fatty acid methyl esters (FAMEs) obtained by transesterification of vegetable oils, comprising the steps of: (a) ethenolysis of the fatty acid methyl esters in the presence of ethylene and an ethenolysis catalyst, and (b) isomerizing metathesis in the presence of an isomerization catalyst and a metathesis catalyst. The invention also relates to biofuels obtainable by the inventive process and to uses of ethylene for adjusting and optimizing biofuels.
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).
METAL-OXO COMPLEX AND METHOD FOR PRODUCTION THEREOF
The present invention provides a metal-oxo complex represented by the following general formula (1),
##STR00001## wherein in the general formula (1) above, “M” represents a molybdenum atom or a tungsten atom; “A” represents a carbon atom, a silicon atom, a germanium atom, a tin atom or a lead atom; X.sup.1 and X.sup.2 each independently represent a halogen atom; R.sup.1 to R.sup.5 each independently represent a hydrogen atom, a straight or branched chain alkyl group that is substituted or unsubstituted and has 1 to 20 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms; each of R.sup.1 to R.sup.3 may be bonded to one another to form a ring.
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.
POLYMERS FOR SPECIALTY APPLICATIONS
The invention relates to ring-opening metathesis polymerization (ROMP) reactions of making polymers suitable for the electronic industry. Particularly, the invention relates to novel polymers with low dielectric constant (D.sub.k) and low dielectric loss (D.sub.f) suited for smaller, lighter, higher speeds and higher frequency transmission electronic products. Such polymers can be used in a variety of materials and composites of the printed circuit board (PCB) industry.