The present disclosure provides compounds, compositions, and methods for preparing alkenyl halides and/or haloalkyl-substituted olefins with Z-selectivity. The methods are particularly useful for preparing alkenyl fluorides such as CF.sub.3-substituted olefins by means of cross-metathesis reactions using halogen-containing molybdenum and tungsten complexes.

Chiral acetyl-protected aminoethyl quinoline (APAQ), pyridine and imazoline ligands are disclosed that enable Pd (II)-catalyzed enantioselective arylation or heteroarylation of ubiquitous prochiral -methylene CH bonds of aliphatic amides offers an alternative disconnection for constructing -chiral centers. Systematic tuning of the ligand structure reveals that a six-membered instead of a five-membered chelation of these types of ligands with the Pd(II) is important for accelerating the C(sp.sup.3)-H activation thereby achieving enantioselectivity for quinoline and pyridine ligands.

Disclosed herein are a chromium compound represented by Formula 1a or 1b and a catalyst system including the same, exhibiting superior catalytic activity in an olefin trimerization reaction:
[{CH.sub.3(CH.sub.2).sub.3CH(CH.sub.2CH.sub.3)CO.sub.2}.sub.2Cr(OH)][Formula 1a]
[{CH.sub.3CH.sub.2CH(CH.sub.2CH.sub.3)CO.sub.2}.sub.2Cr(OH)].[Formula 1b]

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.

Method of making an immobilized tungsten catalyst comprising or consisting of (SiO).sub.X W(O)(CR.sup.1R.sup.2)(R.sup.3 or R.sup.4).sub.2-x(L).sub.z, comprising at least the following step (i): (i) reacting silica (Si02) with a tungsten oxo alkylidene complex comprising or consisting of (R.sup.3)(R.sup.4)W(O)(CR.sup.1R.sup.2)(L).sub.y, preferably wherein CR.sup.1R.sup.2 is selected from CHC(CH.sub.3).sub.3 or CH(C(CH.sub.3).sub.2)C.sub.6H.sub.5 and R.sup.3 and R.sup.4 are independently selected from pyrrol-1-yl, 2,5-dimethylpyrrol-1-yl, or 2,5-diphenylpyrrol-1-yl, or OR, wherein R is a six membered or 10 membered aryl ring, optionally substituted.

This application is in the field of technologies for desulfurization and demercaptanization of gaseous hydrocarbons. The device includes a catalytic reactor loaded with a catalyst solution in an organic solvent, a means of withdrawal sulfur solution from the reactor into the sulfur-separating unit, and a sulfur-separating unit. The said device has at least means of supplying gaseous hydrocarbon medium to be purified and oxygen-containing gas into the reactor, and a means of outletting the purified gas from the reactor. The sulfur-separation unit includes a means of sulfur extraction. The reactor design and the catalyst composition provide conversion of at least 99.99% of hydrogen sulfide and mercaptans into sulfur and disulfides. The catalyst is composed of mixed-ligand complexes of transition metals. The technical result achieved by use of claimed invention is single-stage purification of gaseous hydrocarbons from hydrogen sulfide and mercaptans with remaining concentration of SH down up to 0.001 ppm.

The invention relates to the use of ruthenium complexes, which are homogeneous catalysts and/or precatalysts of the olefin metathesis reaction, which lead to the production of alkenes containing an internal (non-terminal) double CC bond.

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This application is in the field of technologies for desulfurization and demercaptanization of raw gaseous hydrocarbons (including natural gas, tail gas, technological gas, etc, including gaseous media). It can be used for simultaneous dehydration and desulfurization/demercaptanization of any kind of raw gaseous hydrocarbons.

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.