The present invention refers to novel ruthenium-based catalysts for olefin metathesis reactions, particularly to fast initiating catalysts having stereoselective properties. In olefin metathesis reactions, the disclosed catalysts provide a high catalytic activity combined with the capability to generate higher yields of the olefin metathesis product.

A 4,4-divinylazoarylene-bridged diruthenium complex bearing two Ru(CO)(2-mercaptopyridine)(P.sup.iPr.sub.3).sub.2 moieties, its synthesis, and its use as a catalyst.

The present invention relates to the field of polymerisation catalysts, and systems comprising these catalysts for polymerising carbon dioxide and an epoxide, a lactide and/or lactone, and/or an epoxide and an anhydride. The catalyst is of formula (I):

##STR00001##

wherein at least one of M.sub.1 or M.sub.2 is selected from Ni(II) and Ni(III)-X. A process for the reaction of carbon dioxide with an epoxide; an epoxide and an anhydride; and/or a lactide and/or a lactone in the presence of the catalyst is also described.

A catalyst including gold, or a compound thereof, and sulphur, a compound of sulphur, trichloroisocyanuric acid or a metal dichloroisocyanurate on a support, together with a process for manufacturing the catalyst and its use in a chemical process are described.

The present disclosure provides cis-polycycloolefins and methods for forming cis-polycycloolefins typically having 50% or greater cis carbon-carbon double bonds comprising contacting a first cyclic hydrocarbyl monomer with a catalyst represented by Formula (I):

##STR00001##

wherein: M is a group 8 metal; Q.sup.1, Q.sup.2, and Q.sup.3 are independently oxygen or sulfur; each of R.sup.1 and R.sup.4 is a halogen; R.sup.9 is C.sub.1-C.sub.40 hydrocarbyl or C.sub.1-C.sub.40 substituted hydrocarbyl; and each of R.sup.2, R.sup.3, R.sup.5, R.sup.6, R.sup.7, R.sup.8, R.sup.10, R.sup.11, R.sup.12, R.sup.13, R.sup.14, R.sup.15, R.sup.16, R.sup.17, R.sup.18, and R.sup.19 is independently hydrogen, halogen, C.sub.1-C.sub.40 hydrocarbyl or C.sub.1-C.sub.40 substituted hydrocarbyl. In at least one embodiment, a polycyclopentene has 50% or greater cis carbon-carbon double bonds.

Disclosed is an industrial method for efficient production of an ,-difluoroaldehyde compound, which includes reaction of an ,-difluoroacetate with hydrogen gas (H.sub.2) in the presence of a ruthenium catalyst and a base. By the adoption of specific reaction conditions (catalyst, base, pressure etc.), it is possible to produce the target ,-difluoroaldehyde compound with a high conversion rate and high selectivity.

The invention relates to a process for the metathesis of olefins implemented with a catalyst comprising a mesoporous matrix and at least the elements molybdenum and silicon, said elements being incorporated into said matrix by means of at least one precursor comprising molybdenum and silicon and having at least one sequence of SiOMo bonds.

A method for the production of hydrocarbon(s), such as methane, substituted hydrocarbons, such as methanol, or the production of hydrogen, the method comprising the steps of contacting a first catalyst with water in order to photocatalyse the splitting of at least some of the water into hydrogen and oxygen; and contacting a second catalyst with a gas stream comprising carbon dioxide and at least some of the hydrogen produced from step (a) in order to photocatalyse the reaction between the hydrogen and carbon dioxide to produce hydrocarbon(s), such as methane, and/or substituted hydrocarbons, such as methanol. In an embodiment, the catalyst comprises gold and or ruthenium nanoclusters supported on a substrate.

A process for producing alpha-olefin dimers comprises contacting, at a temperature of 80 C. or more, a feedstock comprising at least one C.sub.8+ (linear) alpha-olefin with a catalyst system comprising activator and one or more catalyst compounds represented by the formula:

##STR00001##

where M is a Group 4 metal; n is 1, 2, or 3; R.sup.A is hydrogen or a C.sub.1 to C.sub.10 alkyl; each of R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7, and R.sup.8 is independently selected from hydrogen and C.sub.1 to C.sub.10 alkyl; each X is independently selected from the group consisting of hydrocarbyl radicals having from 1 to 20 carbon atoms, hydrides, amides, alkoxides, sulfides, phosphides, halides, and a combination thereof, (two X's may form a part of a fused ring or a ring system), the contacting being conducted under conditions effective to oligomerize at least part of C.sub.8+ alpha-olefin to produce an oligomerized product containing at least 30 wt % of the alpha-olefin dimer and at least 80 mol % of vinylidene unsaturation, where the conversion of the alpha olefin is at least 10 wt %, based upon the weight of the alpha olefin monomer entering the reactor and the weight of dimer produced.

This invention relates generally to metathesis catalysts and the use of such catalysts in the metathesis of olefins and olefin compounds, more particularly, in the use of such catalysts in Z and E selective olefin metathesis reactions. The invention has utility in the fields of organometallics and organic synthesis.