摘要:
The present invention relates to an arylphenoxy catalyst system producing an ethylene homopolymer or copolymers of ethylene and α-olefins, and a method of producing an ethylene homopolymer or copolymers of ethylene and α-olefins having a high molecular weight under a high temperature solution polymerization condition using the same. The catalyst system includes a group IV arylphenoxy-based transition metal catalyst and an aluminoxane cocatalyst or a boron compound cocatalyst. In the transition metal catalyst, a cyclopentadiene derivative and arylphenoxide as fixed ligands are located around the group IV transition metal, arylphenoxide is substituted with at least one aryl derivative and is located at the ortho position thereof, and the ligands are not crosslinked to each other. The catalyst includes an environmentally-friendly raw material, synthesis of the catalyst is economical, and thermal stability of the catalyst is excellent. It is useful for producing an ethylene homopolymer or copolymers of ethylene and α-olefins having various physical properties in commercial polymerization processes.
摘要:
Novel dialkylhydroxybenzoic acid derivatives containing metal chelating groups are disclosed. The novel compounds are used as therapeutics for treating and/or preventing various medical dysfunctions and diseases arising from reactive oxygen species and/or excess Zn ions, in particular stroke, Parkinson's disease, Alzheimer's disease. The compounds have not only low toxicity but also similar or superior LPO inhibition activity to references. They also effectively inhibit the cerebral neuronal cell death by ROS and/or zinc ion, and show neuroprotective effects against ischemic neuronal degeneration.
摘要:
Disclosed is an arylphenoxy catalyst system for producing an ethylene homopolymer or copolymers of ethylene and α-olefins, and a method of producing an ethylene homopolymer or copolymers of ethylene and α-olefins having a high molecular weight under a high temperature solution polymerization condition using the same. The catalyst system includes a group 4 arylphenoxy-based transition metal catalyst and an aluminoxane cocatalyst or a boron compound cocatalyst. In the transition metal catalyst, a cyclopentadienyl derivative and arylphenoxide as fixed ligands are located around the group 4 transition metal, arylphenoxide is substituted with at least one aryl derivative and is located at the ortho position thereof, and the ligands are not crosslinked to each other. The catalyst includes non-toxic raw materials, synthesis of the catalyst is economical, and thermal stability of the catalyst is excellent. It is useful for producing an ethylene homopolymer or copolymers of ethylene and α-olefins having various physical properties in commercial polymerization processes.
摘要:
Novel dialkylhydroxybenzoic acid derivatives containing metal chelating groups are disclosed. The novel compounds are used as therapeutics for treating and/or preventing various medical dysfunctions and diseases arising from reactive oxygen species and/or excess Zn ions, in particular stroke, Parkinson's disease, Alzheimer's disease. The compounds have not only low toxicity but also similar or superior LPO inhibition activity to references. They also effectively inhibit the cerebral neuronal cell death by ROS and/or zinc ion, and show neuroprotective effects against ischemic neuronal degeneration.
摘要:
Disclosed is an arylphenoxy catalyst system for producing an ethylene homopolymer or copolymers of ethylene and α-olefins, and a method of producing an ethylene homopolymer or copolymers of ethylene and α-olefins having a high molecular weight under a high temperature solution polymerization condition using the same. The catalyst system includes a group 4 arylphenoxy-based transition metal catalyst and an aluminoxane cocatalyst or a boron compound cocatalyst. In the transition metal catalyst, a cyclopentadiene derivative and arylphenoxide as fixed ligands are located around the group 4 transition metal, arylphenoxide is substituted with at least one aryl derivative and is located at the ortho position thereof, and the ligands are not crosslinked to each other. The catalyst includes non-toxic raw materials, synthesis of the catalyst is economical, and thermal stability of the catalyst is excellent. It is useful for producing an ethylene homopolymer or copolymers of ethylene and α-olefins having various physical properties in commercial polymerization processes.
摘要:
The present invention relates to an arylphenoxy catalyst system producing an ethylene homopolymer or copolymers of ethylene and α-olefins, and a method of producing an ethylene homopolymer or copolymers of ethylene and α-olefins having a high molecular weight under a high temperature solution polymerization condition using the same. The catalyst system includes a group IV arylphenoxy-based transition metal catalyst and an aluminoxane cocatalyst or a boron compound cocatalyst. In the transition metal catalyst, a cyclopentadiene derivative and arylphenoxide as fixed ligands are located around the group IV transition metal, arylphenoxide is substituted with at least one aryl derivative and is located at the ortho position thereof, and the ligands are not crosslinked to each other. The catalyst includes an environmentally-friendly raw material, synthesis of the catalyst is economical, and thermal stability of the catalyst is excellent. It is useful for producing an ethylene homopolymer or copolymers of ethylene and α-olefins having various physical properties in commercial polymerization processes.
摘要:
The present invention provides a short, convergent total synthesis of camptothecin and related compounds which consists of a novel 4+1 radical annulation. The present invention also provides novel chemical intermediates for such 4+1 radical annulations.
摘要:
A method of synthesizing compounds having the formula via a 4+1 radical annulation/cyclization wherein the precursor is reacted with an aryl isonitrile having the formula wherein X is selected from the group consisting of Br and I, ≡Y is ≡N or ≡C—R3, R1, R2, and R6 are independently hydrogen, a normal alkyl group, a branched alkyl group, an allyl group, a benzyl group, an alkynyl group, a propargyl group, an alkoxyl group, a halogen group, a trialkylsilyl group, an amino group, an alkyl amino group, a dialkylamino group, an aminoalkyl group, a cyano group, or R16CO—, wherein R16 is an alkyl group, an alkoxyl group, or an amino group, R3 is hydrogen, a normal alkyl group, a branched alkyl group, an allyl group, a benzyl group, an alkynyl group, a propargyl group, an alkoxyl group, a halogen group, a trialkylsilyl group, an amino group, an alkyl amino group, a dialkylamino group, an aminoalkyl group, a cyano group, or R16CO—, wherein R16 is an alkyl group, an alkoxyl group, or an amino group, R4 is an alkyl group, an allyl group, a propargyl group or a benzyl group and R15 is hydrogen.
摘要:
The present invention provides novel N-alkyl-N-phenylhydroxylamine derivatives containing metal chelating groups, a process for preparing the same, the use of the novel compounds as therapeutics for treating and/or preventing various medical dysfunctions and diseases arising from reactive oxygen species (ROS) and/or excess Zn ions, in particular stroke, Parkinson's disease and Alzheimer's disease. The compounds of the invention possess similar or superior LPO inhibition activity to the reference compounds of Trolox and Ebselen. While showing lower toxicity, they also effectively inhibit the cerebral neuronal cell death caused by ROS and/or zinc ion, and show neuroprotective effects against ischemic neuronal degeneration.
摘要:
The present invention provides a short, convergent total synthesis of camptothecin and related compounds which consists of a novel 4+1 radical annulation. The present invention also provides novel chemical intermediates for such 4+1 radical annulations.