The invention relates to compounds of formula (I)

##STR00001##

where R.sup.1, R.sup.2, R.sup.3, R.sup.4 are each independently selected from —(C.sub.1-C.sub.12)-alkyl, —(C.sub.3-C.sub.12)-cycloalkyl, —(C.sub.3-C.sub.12)-heterocycloalkyl, —(C.sub.6-C.sub.20)-aryl, —(C.sub.3-C.sub.20)-heteroaryl; at least one of the R.sup.1, R.sup.2, R.sup.3, R.sup.4 radicals is a —(C.sub.3-C.sub.20)-heteroaryl radical; and R.sup.1, R.sup.2, R.sup.3, R.sup.4, if they are —(C.sub.1-C.sub.12)-alkyl, —(C.sub.3-C.sub.12)-cycloalkyl, —(C.sub.3-C.sub.12)-heterocycloalkyl, —(C.sub.6-C.sub.20)-aryl or —(C.sub.3-C.sub.20)-heteroaryl, may each independently be substituted by one or more substituents selected from —(C.sub.1-C.sub.12)-alkyl, —(C.sub.3-C.sub.12)-cycloalkyl, —(C.sub.3-C.sub.12)-heterocycloalkyl, —O—(C.sub.1-C.sub.12)-alkyl, —O—(C.sub.1-C.sub.12)-alkyl-(C.sub.6-C.sub.20)-aryl, —O—(C.sub.3-C.sub.12)-cycloalkyl, —S—(C.sub.1-C.sub.12)-alkyl, —S—(C.sub.3-C.sub.12)-cycloalkyl, —COO—(C.sub.1-C.sub.12)-alkyl, —COO—(C.sub.3-C.sub.12)-cycloalkyl, —CONH—(C.sub.1-C.sub.12)-alkyl, —CONH—(C.sub.3-C.sub.12)-cycloalkyl, —CO—(C.sub.1-C.sub.12)-alkyl, —CO—(C.sub.3-C.sub.12)-cycloalkyl, —N—[(C.sub.1-C.sub.12)-alkyl].sub.2, —(C.sub.6-C.sub.20)-aryl, —(C.sub.6-C.sub.20)-aryl-(C.sub.1-C.sub.12)-alkyl, —(C.sub.6-C.sub.20)-aryl-O—(C.sub.1-C.sub.12)-alkyl, —(C.sub.3-C.sub.20)-heteroaryl, —(C.sub.3-C.sub.20)-heteroaryl-(C.sub.1-C.sub.12)-alkyl, —(C.sub.3-C.sub.20)-heteroaryl-O—(C.sub.1-C.sub.12)-alkyl, —COOH, —OH, —SO.sub.3H, —NH.sub.2, halogen; and to the use thereof as ligands in alkoxycarbonylation.

A catalyst for hydrosilylation is disclosed. The catalyst comprises a complex having a certain formula. A redox-switchable catalyst system for preparing the catalyst is also disclosed. The redox-switchable catalyst system comprises a redox-switchable catalyst and a reducing compound. The reducing compound reduces a formal oxidation state of the redox-switchable catalyst to give the catalyst, where the former is generally inactive in catalyzing hydrosilylation and the latter is catalytically active. A composition comprising the catalyst and/or the redox-switchable catalyst system, and a hydrosilylation reaction product, are also disclosed.

Platinum complexes having benzyl-based diphosphine ligands for the catalysis of the alkoxycarbonylation of ethylenically unsaturated compounds.

A halogen-containing compound represented by a formula I and a use thereof as a ligand of an ethylene oligomerization catalyst composition, an ethylene oligomerization catalyst composition comprising the halogen-containing compound, and an ethylene oligomerization method, ethylene trimerization method and ethylene tetramerization method using the catalyst composition are provided. Serving as the ligand of the ethylene oligomerization catalyst, the halogen-containing polymer may effectively improve the catalytic performance of a catalyst system, especially by displaying a significantly improved catalytic performance in an ethylene oligomerization reaction. The maximum catalyst activity may exceed 4×10.sup.8 g.Math.mol(Cr).sup.−1.Math.h.sup.−1, and the total selectivity of 1-hexene and 1-octene exceeds 92 wt %. In a C6 product, the content of 1-hexene may reach about 97%, and in a C8 product, the content of 1-octene may reach more than 98%.

Processes for preparing aldehydes from olefins under hydroformylation temperature and pressure conditions are disclosed. The processes include a step of contacting at least one olefin with hydrogen and carbon monoxide in the presence of at least one solvent and a transition metal-based catalyst composition comprising a bisphosphine ligand.

Processes for preparing aldehydes from olefins under hydroformylation temperature and pressure conditions are disclosed. The processes include a step of contacting at least one olefin with hydrogen and carbon monoxide in the presence of at least one solvent and a transition metal-based catalyst composition comprising a ferrocene-based biphosphine ligand.

Catalyst systems suitable for tetramerizing ethylene to form 1-octene may include a catalyst including a chromium compound coordinated with a ligand and a co-catalyst including an organoaluminum compound. The ligand may have a chemical structure: (R.sub.1)(R.sub.2)A-X—C(R.sub.3)(R.sub.4). A and C may be phosphorus. X may be B(R.sub.5), Si(R.sub.5).sub.2, N(R.sub.5), wherein R.sub.5 is an aryl group substituted with a halogen, halogenated alkyl or a silyl group, and wherein B, or N, or Si is bound to A and C. R.sub.1, R.sub.2, R.sub.3, and R.sub.4 may be independently chosen hydrocarbyl groups or heterohydrocarbyl groups.

The present disclosure provides a method for efficiently producing and providing compounds having a spirooxindole skeleton, for example compounds having a spirooxindole skeleton and having antitumor activity that inhibit the interaction between Mdm2 protein and p53 protein, or intermediates thereof, using an asymmetric catalyst. Compounds having optically active tricyclic dispiroindole skeletons are obtained through catalytic asymmetric 1,3-dipolar cycloaddition reaction using ketimine as a reaction substrate and using a chiral ligand and a Lewis acid.

Disclosed is a method for preparing an organic carboxylic ester by using a combined catalyst of an aryl bidentate phosphine ligand. The method includes subjecting a terminal olefin, carbon monoxide, and an alcohol to a hydroesterification reaction in the presence of a combined catalyst of a palladium compound, an aryl bidentate phosphine ligand, and an acidic additive, to generate an organic carboxylic ester having one more carbon atom than the terminal olefin.

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-C20)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 chlorinated hydrocarbons, chloro-aluminum alkyls, or combinations of these.