Methods for making alpha olefin oligomers and polyalphaolefins include a step of contacting a C.sub.4 to C.sub.20 alpha olefin monomer and a catalyst system containing a metallocene, a first activator comprising a solid oxide chemically-treated with an electron withdrawing anion, and a second activator comprising an organoaluminum compound. The alpha olefin oligomers and polyalphaolefins prepared with these catalyst systems can have a high viscosity index combined with a low pour point, making them particularly useful in lubricant compositions and as viscosity modifiers.

Provided is a method of preparing a silylative-reduced N-heterocyclic compound by reducing an N-heteroaromatic compound including a sp.sup.2 hybridized nitrogen atom while simultaneously introducing a silyl group into a beta-position with respect to a nitrogen atom of the N-heteroaromatic compound, using a silane compound, in the presence of an organoboron catalyst.

Provided is a method for industrially producing 2-isopropenyl-5-methyl-4-hexen-1-yl 3-methyl-2-butenoate, which is, for example, a sex pheromone substance of vine mealybug. More specifically, there is provided a method for producing 2-isopropenyl-5-methyl-4-hexen-1-yl 3-methyl-2-butenoate, comprising a step of transesterifying 2-isopropenyl-5-methyl-4-hexen-1-ol represented by Formula (1) with alkyl senecioate represented by General Formula (2) in the presence of a catalyst, while distilling off an alcohol represented by General Formula (4) formed as a by-product, to obtain 2-isopropenyl-5-methyl-4-hexen-1-yl 3-methyl-2-butenoate represented by Formula (3). ##STR00001##

N.sup.2-phosphinyl amidine compounds, N.sup.2-phosphinyl amidinates, N.sup.2-phosphinyl amidine metal salt complexes, N.sup.2-phosphinyl amidinate metal salt complexes are described. Methods for making N.sup.2-phosphinyl amidine compounds, N.sup.2-phosphinyl amidinates, N.sup.2-phosphinyl amidine metal salt complexes, and N.sup.2-phosphinyl amidinate metal salt complexes are also disclosed. Catalyst systems utilizing the N.sup.2-phosphinyl amidine metal salt complexes and N.sup.2-phosphinyl amidinate metal salt complexes are also disclosed along with the use of the N.sup.2-phosphinyl amidine compounds, N.sup.2-phosphinyl amidinates, N.sup.2-phosphinyl amidine metal salt complexes, and N.sup.2-phosphinyl amidinate metal salt complexes for the oligomerization and/or polymerization of olefins.

The present invention relates to a ligand compound, an organic chromium compound, a catalyst system for ethylene oligomerization, a preparation method thereof, and an ethylene oligomerization method using the same. The catalyst system for ethylene oligomerization according to the present invention is used to prepare a low-density polyethylene in one reactor by using a small amount of comonomers such as alpha-olefin or by using only ethylene without comonomers, because it maintains high catalytic activity and high alpha-olefin selectivity even though supported on a support.

A modified solid polyalkylaluminoxane is provided, which is capable of providing α-olefin suppressing adhesion of any polymer produced as a by-product onto the reactor wall and the stirrer, and which is capable of providing a highly active olefin oligomerization reaction catalyst. An olefin oligomerization reaction catalyst containing the modified solid polyalkylaluminoxane is also provided. The modified solid polyalkylaluminoxane for olefin oligomerization reactions contains structural units represented by general formula (a) and structural units represented by general formula (b), whose median diameter is equal to or larger than 0.1 μm and equal to or smaller than 50 μm,

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in which R′ in the general formula (a) represents an alkyl group having 1 to 20 carbon atoms, and R″ in the general formula (b) represents a halogenated alkoxy group having 1 to 20 carbon atoms or a halogenated aryloxy group having 6 to 20 carbon atoms.

Processes for producing an α,β-unsaturated carboxylic acid, such as acrylic acid, or a salt thereof, using treated solid oxides are disclosed. The treated solid oxides can be calcined solid oxides, metal-treated solid oxides, or metal-treated chemically-modified solid oxides, illustrative examples of which can include sodium-treated alumina, calcium-treated alumina, zinc-treated alumina, sodium-treated sulfated alumina, sodium-treated fluorided silica-coated alumina, and similar materials.

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 including 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.

The present specification relates to an olefin oligomerization method and specifically to an olefin oligomerization method comprising the step of subjecting an olefin to a multimerization reaction by controlling a reaction temperature such that the weight ratio of 1-hexene to 1-octene within a product comprising 1-hexene and 1-octene has a predetermined value, in the presence of an oligomerization catalyst system comprising a ligand compound, a transition metal compound, and a cocatalyst, wherein the predetermined value for the weight ratio of 1-hexene to 1-octene within the product is selected in a range of 1:0.5 to 1:7. By the method, 1-hexene and 1-octene can be produced in a desired ratio.