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.

A method of forming dialkyl carbonate is provided, which includes introducing carbon dioxide into a catalyst to form dialkyl carbonate, wherein the catalyst is formed by activating a catalyst precursor using alcohol, wherein alcohol is R.sup.3—OH, and R.sup.3 is C.sub.1-12 alkyl group or C.sub.5-12 aryl or heteroaryl group. The catalyst precursor is formed by reacting Sn(R.sub.1).sub.2(L).sub.2 and Ti(OR.sup.2).sub.4, and Sn(R.sup.1).sub.2(L).sub.2 and Ti(OR.sup.2).sub.4 have a molar ratio of 1:2 to 2:1. R.sup.1 is C.sub.1-10 alkyl group, R.sup.2 is H or C.sub.1-12 alkyl group, and L is O—(C═O)—R.sup.5, and R.sup.5 is C.sub.1-12 alkyl group. The dialkyl carbonate is

##STR00001##

Methods of selectively synthesizing n-tetrasilane are disclosed. N-tetrasilane is prepared by catalysis of silane (SiH.sub.4), disilane (Si.sub.2H.sub.6), trisilane (Si.sub.3H.sub.8), or mixtures thereof. More particularly, the disclosed synthesis methods tune and optimize the n-tetrasilane:i-tetrasilane isomer ratio. The isomer ratio may be optimized by selection of process parameters, such as temperature and the relative amount of starting compounds, as well as selection of proper catalyst. The disclosed synthesis methods allow facile preparation of n-tetrasilane.

A method of forming dialkyl carbonate is provided, which includes introducing carbon dioxide into a catalyst to form dialkyl carbonate, wherein the catalyst is formed by activating a catalyst precursor using alcohol, wherein alcohol is R.sup.3—OH, and R.sup.3 is C.sub.1-12 alkyl group or C.sub.5-12 aryl or heteroaryl group. The catalyst precursor is formed by reacting Sn(R.sub.1).sub.2(L).sub.2 and Ti(OR.sup.2).sub.4, and Sn(R.sup.1).sub.2(L).sub.2 and Ti(OR.sup.2).sub.4 have a molar ratio of 1:2 to 2:1. R.sup.1 is C.sub.1-10 alkyl group, R.sup.2 is H or C.sub.1-12 alkyl group, and L is O—(C═O)—R.sup.5, and R.sup.5 is C.sub.1-12 alkyl group. The dialkyl carbonate is ##STR00001##

Methods for synthesizing a water-soluble titanium-silicon complex are disclosed herein. The titanium-silicon complex can be utilized to produce titanated solid oxide supports and titanated chromium supported catalysts. The titanated chromium supported catalysts subsequently can be used to polymerize olefins to produce, for example, ethylene based homopolymer and copolymers.

Methods for synthesizing a water-soluble titanium-silicon complex are disclosed herein. The titanium-silicon complex can be utilized to produce titanated solid oxide supports and titanated chromium supported catalysts. The titanated chromium supported catalysts subsequently can be used to polymerize olefins to produce, for example, ethylene based homopolymer and copolymers.

According to one embodiment, a catalyst system that reduces polymeric fouling may include at least one chromium compound, at least one aluminum compound, and at least one antifouling agent or a derivative thereof. The antifouling agent may have a structure including a central aluminum molecule bound to an R1 group, bound to an R2 group, and bound to an R3 group. One or more of the chemical groups R1, R2, and R3 may be antifouling groups having the structure —O((CH.sub.2).sub.nO).sub.mR4, a phosphonium or phosphonium salt, a sulfonate or sulfonate salt, a sulfonium or sulfonium salt, an ester, an anhydride, a polyether, or a long-chained amine-capped compound, where n is an integer from 1 to 20, m is an integer from 1 to 100, and R4 is a hydrocarbyl group. The chemical groups R1, R2, or R3 that do not include an antifouling group, if any, may be hydrocarbyl groups.

Method for Synthesizing Pitavastatin t-Butyl Ester A method for synthesizing pitavastatin tert-butyl ester includes obtaining a substance B through reacting (4R-CIS)-6-chloromethyl-2,2-dimethyl-1,3-dioxolane-4-acetic acid tert-butyl ester with a substance A under the action of a first base catalyst, 5 oxidizing with an oxidizing agent to obtain a substance C, then reacting with 2-cyclopropyl-4-(4-fluorophenyl)-quinoline-3-formaldehyde under the action of a second base catalyst to obtain a substance D, and finally, carrying out an acid deprotection to obtain pitavastatin t-butyl ester. The reaction conditions of the present invention are mild and controllable, and the reaction conditions of the synthesis of the Julia olefination do 10 not require an ultra-low temperature reaction. The operation is convenient and simple, the stereoselectivity is good, the yield is high, and the synthesized pitavastatin t-butyl ester is a completely non-cis isomer, and its purity is high.

According to one embodiment, a catalyst system that reduces polymeric fouling may comprise at least one titanate compound, at least one aluminum compound, and at least one antifouling agent or a derivative thereof. The antifouling agent may comprise a structure comprising a central aluminum molecule bound to an R1 group, bound to an R2 group, and bound to an R3 group. One or more of the chemical groups R1, R2, and R3 may be antifouling groups comprising the structure —O((CH.sub.2).sub.nO).sub.mR4, where n is an integer from 1 to 20, m is an integer from 1 to 100, and R4 is a hydrocarbyl group. The chemical groups R1, R2, or R3 that do not comprise the antifouling group, if any, may be hydrocarbyl groups.

According to one embodiment, a catalyst system that reduces polymeric fouling may comprise at least one titanate compound, at least one aluminum compound, and at least one antifouling agent or a derivative thereof. The antifouling agent may comprise a structure comprising a central aluminum molecule bound to an R1 group, bound to an R2 group, and bound to an R3 group. One or more of the chemical groups R1, R2, and R3 may be antifouling groups comprising the structure —O((CH.sub.2).sub.nO).sub.mR4, where n is an integer from 1 to 20, m is an integer from 1 to 100, and R4 is a hydrocarbyl group. The chemical groups R1, R2, or R3 that do not comprise the antifouling group, if any, may be hydrocarbyl groups.