The invention relates to a method of forming an olefin from a first olefin and a second olefin in a metathesis reaction, comprising step (i): (i) reacting the first olefin with the second olefin in the presence of a compound that catalyzes said metathesis reaction such that the molar ratio of said compound to the first or the second olefin is from 1:500 or less, and the conversion of the first or the second olefin to said olefin is at least 50%, characterized in that as compound that catalyzes said metathesis reaction a compound of the following formula is used:

##STR00001## wherein M is Mo or W; R.sup.1 is aryl, heteroaryl, alkyl, or heteroalkyl; optionally substituted; R.sup.2 and R.sup.3 can be the same or different and are hydrogen, alkyl, alkenyl, heteroalkyl, heteroalkenyl, aryl, or heteroaryl; optionally substituted; R.sup.5 is alkyl, alkoxy, heteroalkyl, aryl, heteroaryl, silylalkyl, silyloxy, optionally substituted; and R.sup.4 is a residue R.sup.6X, wherein X=O and R.sup.6 is aryl, optionally substituted; or X=S and R.sup.6 is aryl, optionally substituted; or X=O and R.sup.6 is (R.sup.7, R.sup.8, R.sup.9)Si; wherein R.sup.7, R.sup.8, R.sup.9 are alkyl or phenyl, optionally substituted; or X=O and R.sup.6 is (R.sup.10, R.sup.11, R.sub.12)C, wherein R.sup.10, R.sup.11, R.sup.12 are independently selected from phenyl, alkyl; optionally substituted; and to the catalysts used in the method.

In a ruthenium complex compound according to the present invention, an NHC ligand has an excellent electron-donating ability to stabilize methylidene species due to the steric interaction between substituents having relatively different sizes. The ruthenium complex compound can improve selectivity when used as a catalyst due to having an asymmetric structure, and the activity of the ruthenium complex compound can be improved by adjusting substituents and additives. Accordingly, the ruthenium complex compound can be used as a catalyst in cross metathesis reactions including ethenolysis to produce desired compounds such as linear ?-olefins at high yield, even under relatively mild conditions.

The present invention relates to an oligomerization catalyst a transition metal or transition metal precursor, a halogen-substituted organic ligand, and a heteroatom ligand, and to a method for selectively preparing 1-hexene or 1-octene from ethylene using the catalyst.

Disclosed herein are mixed catalyst systems including iron-containing catalyst compounds having a carbene ligand and another catalyst compound, as well as at least one activator. The iron-containing catalyst compounds can be asymmetric, while the other catalyst compound can be symmetric. In some embodiments, the other catalyst compound can be an iron-containing catalyst with a bisiminopyridyl ligand, which does not typically incorporate comonomers in copolymer synthesis. Processes for production of an ethylene alpha-olefin copolymers using these mixed catalyst systems are also disclosed. Ethylene-alpha-olefin copolymers so formed can have at least a portion of their alpha-olefin comonomer distribution increasing with increasing molecular weight, indication orthogonal compositional distribution.

Synthetic methods are described herein operable to efficiently produce a wide variety of molecular species through conjugate additions via decarboxylative mechanisms. For example, methods of functionalization of peptide residues are described, including selective functionalization of peptide C-terminal residues. In one aspect, a method of peptide functionalization comprises providing a reaction mixture including a Michael acceptor and a peptide and coupling the Michael acceptor with the peptide via a mechanism including decarboxylation of a peptide reside.

Catalyst systems suitable for tetramerizing ethylene to form 1-octene may include a catalyst having a structure according to Formula (VI) or Formula (VII). In Formulas (VI) and (VII), X is a halogen, a (C.sub.2-C.sub.30) carboxylate, acetylacetonate, or a (C.sub.1-C.sub.30) hydrocarbyl; L.sub.1 is a neutral coordinating ligand; n is an integer from 0 to 6; Y is a (C.sub.6-C.sub.20)fluorine-substituted aryl, a (C.sub.6-C.sub.20)fluorine-substituted aryloxy, or a (C.sub.1-C.sub.20)fluorine-substituted alkoxy; and L?L is a bidentate chelating ligand. The catalyst system may also include an aluminum containing agent which includes a reaction product of an organoaluminum compound and an antifouling compound. The antifouling compound may include one or more quaternary salts.

The invention relates to oligomerization of olefins, such as ethylene, to higher olefins, such as a mixture of 1-hexene and 1-octene, using a catalyst system that comprises a) a source of chromium b) one or more activators and c) a phosphacycle-containing ligating compound. Additionally, the invention relates to a phosphacycle-containing ligating compound and a process for making said compound.

The present disclosure provides tri-orthoalkylphenyl phosphine catalysts of formula I ##STR00001## wherein A is CH2, CO, or NR.sup.A; R.sup.1 is aryl, heteroaryl, isopropyl, tert-butyl, cycloalkyl, or heterocycloalkyl, wherein aryl, heteroaryl, cycloalkyl and heterocycloalkyl are optionally substituted; R.sup.2 is H, (C.sub.1-C.sub.8)alkyl, (C.sub.1-C.sub.8)alkoxy, N(R.sup.A).sub.2, or an electron withdrawing group; and each R.sup.A is independently H or (C.sub.1-C.sub.8)alkyl; that are tuned electrically and sterically.

The invention is directed to a method for preparing a phenolic compound comprising reacting a furanic compound with a dienophile in the presence of a catalyst comprising yttrium.

The invention relates to oligomerization of olefins, such as ethylene, to higher olefins, such as a mixture of 1-hexene and 1-octene, using a catalyst system that comprises a) a source of chromium b) one or more activators and c) a phosphacycle-containing ligating compound. Additionally, the invention relates to a phosphacycle-containing ligating compound and a process for making said compound.