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).

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.

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.

A tetraanionic OCO pincer ligand metal-oxo-alkylidene complex is prepared from a trianionic pincer ligand supported metal-alkylidyne. The metal can be tungsten or other group 5-7 transition metal. The tetraanionic pincer ligand metal-oxo-alkylidene complex, a trianionic OCO pincer ligand metal complex, or a trianionic ONO pincer ligand metal complex can be used to polymerize cycloalkenes. The poly(cycloalkene)s are predominantly cis-alkene macrocyclics.

Method of making a second olefin using a first olefin, comprising steps (A) and (B): (A) performing a metathesis reaction with the first olefin in the presence of a metal complex configured to catalyse said metathesis reaction; (B) epoxidizing an olefin contained in the reaction mixture obtained in step (A) to form an epoxide; and deoxygenizing said epoxide to form said second olefin.

The disclosure provides Group 6 complexes, which, in some embodiments, are useful for catalyzing olefin metathesis reactions. In some embodiments, the compounds are compounds of the following formula: ##STR00001##
wherein: M is a Group 6 metal atom; X is an oxygen atom, ═N—R.sup.5, ═N—N(R.sup.5)(R.sup.5′) or ═N—O—R.sup.5, R.sup.5 and R.sup.5′ independently being various substituents, such as aryl or heteroaryl, each optionally substituted; n is 0 or 1; R.sup.z is a neutral ligand; R.sup.1 is hydrogen or an organic substituent; R.sup.2 is an aryl or heteroaryl group, each optionally substituted; R.sup.3 is an anionic ligand; and R.sup.4 is an anionic ligand, such as a pyrrolide, a pyrazolide, an imidazolide, an indolide, an azaindolide, or an indazolide, each optionally substituted.

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.

This invention relates generally to the synthesis of E-macrocycles using stereoretentive ruthenium olefin metathesis catalysts supported by dithioiate ligands. Macrocycles were generated with excellent selectivity (>99% E) and in moderate to high/good yields (47% to 80% yield; 58% to 80% yield) from diene starting materials bearing two E-olefins or bearing one E-olefin and one terminal olefin, A variety of rings were constructed, ranging from 12- to 18-membered macrocycles, including the antibiotic recifeiolide. The invention has utility in the fields of organometallics and organic synthesis.

[Problem] To provide a novel artificial protein catalyst that enables the protection of a catalyst from substances in vivo and has potential usefulness in therapeutic in vivo synthetic chemistry.

[Solution] Provided is a complex of a protein and a catalyst selected from a metal catalyst or organic catalyst. In the complex according to the present invention, the protein is a protein having a hydrophobic pocket in the three-dimensional structure thereof, and the catalyst is housed in the hydrophobic pocket so that the catalyst is not or substantially not exposed to a hydrophilic environment.

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.