The present disclosure relates to tungsten complexes, catalyst systems including tungsten complexes, and polymerization processes to produce polycycloolefin polymers such as polycyclopentene polymers and polycyclooctene polymers.

Provided herein are trans-cyclic polyacetylenes and methods of preparing the trans-cyclic polyacetylenes.

There is provided a method for producing a catalyst liquid containing a Group 6 to 11 transition metal catalyst in which the transition metal catalyst can be prevented from being blackened during storage, the method including performing addition of an alkenyl compound and addition of a phosphorus ligand, and then performing addition of a Group 6 to 11 transition metal catalyst

An improved catalyst for cyclic olefin polymerization. The catalyst includes a transition metal carbene having the following structure: M.sup.v(OR’).sub.c*mX(.sub.v-c*m-2)=C(R*).sub.2 wherein M.sup.v is a Group 5 transition metal having a valence (v) of 5 or a Group 6 transition metal having a valence (v) of 5 or 6; each R′ is independently a monovalent organic moiety comprising from 8 to 40 atoms selected from Groups 14-17; c is an integer from 1 to 3; m is ⅓, ½, 1, 3/2, 2, 3, or 4 and c*m ≤ v-2; X is a halogen; and each R* is independently H or a C.sub.1 to C.sub.7 alkyl. The catalyst is particularly useful for ring-opening metathesis polymerization (ROMP).

The present invention relates to a method for oxidative cleavage of a substrate consisting of at least one functionalised or non-functionalised linear olefin, in particular a mono- or polyunsaturated aliphatic carboxylic acid, or one of the esters thereof, or at least one non-functionalised cyclic olefin, using hydrogen peroxide, in the presence of a metal catalyst which consists of at least one onium halooxodiperoxometallate. It also relates to a novel catalyst consisting of a specific onium halooxodiperoxometallate which can be used, in particular, in said method.

A process for the dehydrogenation of alkyl-containing compounds comprises reacting an alkyl-containing compound and a Group VI nitrosyl complex characterized as a transition metal complex having the composition Cp′M(NO)(R1)(R2), wherein Cp′ is selected from certain substituted and unsubstituted η.sup.5-cyclopentadienyl groups; M is W or Mo; and R1 and R2 are independently selected from CH.sub.2C(CH.sub.3).sub.3; CH.sub.2Si(CH.sub.3).sub.3; CH.sub.2(C.sub.6H.sub.5); CH.sub.3; hydrogen; and η.sup.3-allyl; provided that if R1 is hydrogen, R2 is η.sup.3-allyl; under conditions such that the alkyl-containing compound is converted to an olefin, and in particular embodiments, a terminal olefin. The dehydrogenation can be carried out using a neat and/or undried alkyl-containing compound and/or may be conducted under air, and does not require a sacrificial olefin to drive the reaction, thereby increasing convenience and decreasing cost in comparison with some other dehydrogenation processes.

The present application provides, among other things, compounds and methods for metathesis reactions. In some embodiments, the present disclosure provides methods for preparing alkenyl halide with regioselectivity and/or stereoselectivity. In some embodiments, the present disclosure provides methods for preparing alkenyl halide with regioselectivity and Z-selectivity. In some embodiments, the present disclosure provides methods for preparing alkenyl halide with regioselectivity and E-selectivity. In some embodiments, provided technologies are particularly useful for preparing alkenyl fluorides. In some embodiments, a provided compound useful for metathesis reactions has the structure of formula II-a. In some embodiments, a provided compound useful for metathesis reactions has the structure of formula II-b.

An organic reductant, in particular an organo silicon reductant suitable for activating supported catalysts of the type MO.sub.nE.sub.m, wherein E is S and/or Se, in particular MO.sub.n, wherein M is W, Mo or Re, is described as well as its use in metathesis reactions. The reduced catalysts are able to metathesize olefins at low temperatures and are therefore also suitable for metathesis of functionalized olefins.

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.

In one aspect, the invention provides a method for synthesizing a fatty olefin derivative. The method includes: a) contacting an olefin according to Formula I

##STR00001##

with a metathesis reaction partner according to Formula IIb

##STR00002##

in the presence of a metathesis catalyst under conditions sufficient to form a metathesis product according to Formula IIIb:

##STR00003##

and
b) converting the metathesis product to the fatty olefin derivative. Each R.sup.1 is independently selected from H, C.sub.1-18 alkyl, and C.sub.2-18 alkenyl; R.sup.2b is C.sub.1-8 alkyl; subscript y is an integer ranging from 0 to 17; and subscript z is an integer ranging from 0 to 17. In certain embodiments, the metathesis catalyst is a tungsten catalyst or a molybdenum catalyst. In various embodiments, the fatty olefin derivative is a pheromone. Pheromone compositions and methods of using them are also described.