The invention provides a continuous preparation method of 2,3,3,3-tetrafluoropropene, comprising the following steps: carrying out liquid-phase catalytic telomerization reaction on ethylene and carbon tetrachloride serving as initial raw materials in the presence of a composite catalyst to obtain a reaction product; performing two-stage membrane separation and purification on the reaction product, and then sequentially performing a primary high-temperature cracking reaction, a gas-phase chlorination reaction, a secondary high-temperature cracking reaction, a primary gas-phase catalytic fluorination reaction and a secondary gas-phase catalytic fluorination reaction to obtain a reaction product; condensing and rectifying the secondary gas-phase catalytic fluorination reaction product to obtain the 2,3,3,3-tetrafluoropropene product.

Provided herein are enantioselective organocatalytic methods for preparing chiral tetraaryl methanes.

A process for preparing diaryl sulfones, such as 4,4′-dichlorodiphenylsulfone is disclosed. The process comprises contacting an aryl compound with sulfur trioxide to provide a benzene sulfonic acid. The benzene sulfonic acid is coupled to additional aryl compound in the presence of a catalyst. During the coupling step, the additional aryl compound is continuously added while water is removed.

This invention relates to novel hydrogenation catalyst compositions obtainable from reacting metal-based complex hydrogenation catalysts with specific co-catalysts and to a process for selectively hydrogenating nitrile rubbers in the presence of such novel hydrogenation catalyst compositions.

A base polyamide composition comprising a nylon mixture having caprolactam units from 1 wppb to 50 wppm catalyst composition; and greater than 0.75 wt % residual caprolactam, wherein the base polyamide composition has a delta end group level ranging from 30 eq/gram to 90 eq/gram.

A process of preparing a solid catalyst component for the production of polypropylene includes a) dissolving a halide-containing magnesium compound in a mixture, the mixture including an epoxy compound, an organic phosphorus compound, and a hydrocarbon solvent to form a homogenous solution; b) treating the homogenous solution with an organosilicon compound during or after the dissolving step; c) treating the homogenous solution with a first titanium compound in the presence of a first non-phthalate electron donor, and an organosilicon compound, to form a solid precipitate; and d) treating the solid precipitate with a second titanium compound in the presence of a second non-phthalate electron donor to form the solid catalyst component, where the process is free of carboxylic acids and anhydrides.

The present disclosure is generally directed to polyolefin polymers, such as polypropylene homopolymers, and propylene-ethylene copolymers that have improved flow properties. In one embodiment, the polymers can be produced using a solid catalyst component that includes a) dissolving a halide-containing magnesium compound in a mixture, the mixture including an epoxy compound, an organic phosphorus compound, and a hydrocarbon solvent to form a homogenous solution; b) treating the homogenous solution with an organosilicon compound during or after the dissolving step; c) treating the homogenous solution with a first titanium compound in the presence of a first non-phthalate electron donor, and an organosilicon compound, to form a solid precipitate; and d) treating the solid precipitate with a second titanium compound in the presence of a second non-phthalate electron donor to form the solid catalyst component, where the process is free of carboxylic acids and anhydrides.

The disclosed embodiments detail improved methods for the synthesis of diketopiperazines from amino acids. In particular improved methods for the cyclocondensation and purification of N-protected 3,6-(aminoalkyl)-2,5-diketopiperazines from N-protected amino acids. Disclosed embodiments describe methods for the synthesis of 3,6-bis-[N-protected aminoalkyl]-2,5-diketopiperazine comprising heating a mixture of an amino acid in the presence of a catalyst in an organic solvent. The catalyst is selected from the group comprising sulfuric acid, phosphoric acid, p-toluenesulfonic acid, 1-propylphosphonic acid cyclic anhydride, tributyl phosphate, phenyl phosphonic acid and phosphorous pentoxide among others. The solvent is selected from the group comprising: dimethylacetamide, N-methyl-2-pyrrolidone, diglyme, ethyl glyme, proglyme, ethyldiglyme, m-cresol, p-cresol, o-cresol, xylenes, ethylene glycol and phenol among others.

A process for preparing diaryl sulfones, such as 4,4-dichlorodiphenylsulfone is disclosed. The process comprises contacting an aryl compound with sulfur trioxide to provide a benzene sulfonic acid. The benzene sulfonic acid is coupled to additional aryl compound in the presence of a catalyst. During the coupling step, the additional aryl compound is continuously added while water is removed.

The present invention is intended to provide a radical generating catalyst that can generate (produce) radicals under mild conditions. In order to achieve the above object, the first radical generating catalyst of the present invention includes: at least one selected from the group consisting of amino acids, peptides, phospholipids, and salts thereof. The second or third radical generating catalyst of the present invention includes an ammonium salt represented by the following chemical formula (XI) (excluding peroxodisulfate) and having a Lewis acidity of 0.4 eV or more.

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