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 LL 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 organic acids, organic acid salts, esters, anhydrides, or combinations of these.

The present invention relates to a photocatalyst composition having visible light activity for hydrogen production through water splitting. More particularly, the present invention discloses a photocatalyst composition comprising a zinc oxide nanoparticles and a conjugated organic moiety selected from the group consisting of oligothiophenes, azo dyes, and perylenes.

The present invention relates to a photocatalyst composition having visible light activity for hydrogen production through water splitting. More particularly, the present invention discloses a photocatalyst composition comprising a zinc oxide nanoparticles and a conjugated organic moiety selected from the group consisting of oligothiophenes, azo dyes, and perylenes.

An o-aminoheteroaryl alkynyl-containing compound has a structure represented by formula (I), and the compound of formula (I) has advantages of a high FGFR and RET double target inhibitory activity and a relatively low KDR activity, and the compound of formula (I) exhibits a strong inhibitory activity in a human lung cancer cell line NCI-H1581 and a gastric cancer cell line SNU16 as well as an RET-dependent sensitive cell line BaF3-CCDC6-Ret and a mutant thereof. Pharmacokinetic data shows that the o-aminoheteroaryl alkynyl-containing compound has druggability, and exhibits significant relevant inhibition of the growth of related tumors in a long-term animal model of drug efficacy and results in favorable animal condition at effective doses.

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Provided are a method for preparing chiral nitro derivatives using organic chiral catalyst compounds and water as an eco-friendly solvent, and the like. The catalyst is an organic catalyst based on (R,R)-1,2-diphenylethylenediamine (DPEN), and can prepare nitro derivatives having enantioselectivity and diastereoselectivity in excellent yield through a hydrophobic hydration effect. In particular, the preparation method of the present disclosure can stabilize a transition state through an interfacial reaction between the catalyst and water. In addition, indole derivatives can be synthesized using the chiral nitro derivatives prepared according to the present disclosure to be usefully used for the prevention or treatment of brain-nervous system diseases including depression and muscular diseases including cachexia.

Provided is a catalyst composition comprising (a) a collection of resin beads having sulfonic acid functional groups, (b) a promoter having a thiol group and an amine group, and (c) an antioxidant having the structure (I)

##STR00001## wherein each of R.sup.1 and R.sup.2, and R.sup.3 is hydrogen or a substituted or unsubstituted alkyl or alkenyl group wherein n is 0 to 10, with the proviso that when R.sup.3 contains one or more nitrogen atoms, n is not 1 or 2.

The present invention relates to a ligand compound, a catalyst system for oligomerization of olefins, and a method for oligomerization of olefins using the catalyst system. The catalyst system for oligomerization of olefins according to the present invention not only has excellent catalytic activity, but also exhibits high selectivity to 1-hexene or 1-octene, thus enabling more efficient preparation of alpha-olefin.

Provided is a method for oligomerization of ethylene, and more particularly, a method for producing 1-hexene and 1-octene at a high selectivity under an ethylene atmosphere by inducing a remarkably improved catalytic activity while effectively reducing a production amount of polyethylene by introducing the oligomerization catalyst and a cocatalyst mixture containing at least two aluminums together and adjusting the kind of oligomerization catalyst and injection conditions thereof.

Disclosed are a novel catalyst system which is a catalyst system for selectively oligomerizing olefin including ethylene and may trimerize and tetramerize olefin, different from the catalyst system for olefin oligomerization reported until now, and a method for preparing an olefin oligomer using same. The present invention provides a catalyst system for olefin oligomerization, including a ligand compound represented by Formula 1; a chromium compound; and a metal alkyl compound, and a method for preparing an olefin oligomer using same.

The invention has as its object a catalyst that comprises a substrate based on alumina or silica or silica-alumina, at least one element from group VIII, at least one element from group VIB, and at least one additive that is selected from among 2-acetylbutyrolactone and/or its hydrolysis products, 2-(2-hydroxyethyl)-3-oxobutanoic acid, and 3-hydroxy-2-(2-hydroxyethyl)-2-butenoic acid. The invention also relates to the method for preparation of said catalyst and its use in a method for hydrotreatment and/or hydrocracking.