Surgical reduction: N‐Heterocyclic carbene–borane complexes such as depicted are neutral, organic soluble analogues of borohydride anions with a weak hydridic character, compatible with organometallic catalysis. They are applicable for surgical reductions in complex, multifunctional molecules.
Disclosed is a selective ester production process of an alcoholic hydroxyl group, which proceeds under chemically mild conditions, while having adequate environmental suitability, operability and economical efficiency. Specifically disclosed is a process for producing an ester compound, which is characterized in that an alcohol and a carboxylic acid ester compound are reacted in the presence of a compound containing zinc element, thereby selectively acylating a hydroxyl group of the alcohol.
Catalyst component, its preparation and use in polymerization of alpha-olefins
申请人:TOA NENRYO KOGYO KABUSHIKI KAISHA
公开号:EP0050498A1
公开(公告)日:1982-04-28
A supported titanium containing catalyst component for use in propylene polymerization is prepared by co-pulverizing a magnesium haiide, an aromatic carboxylic acid ester and an aromatic carboxylic acid or a derivative thereof such the halide or anhydride and contacting the magnesium-containing solid with a titanium compound. The polymerization of propylene in the presence of a catalyst comprising this component and an organoaluminum compound produces polypropylene of high bulk density.
Catalyst components for polymerization of alpha-olefins and processes for their preparation and use
申请人:TOA NENRYO KOGYO KABUSHIKI KAISHA
公开号:EP0050497A1
公开(公告)日:1982-04-28
A supported titanium-containing catalyt component for .alpha-olefin polymerization is prepared by contacting a magnesium halide such as magnesium dichloride, an electron donor compound such as ethylbenzoate, an aromatic carboxylic acid or its derivative such as benzoyl chloride, an organic aluminum chloride compound such as ethylaluminum dichloride and a titanium compound such as titanium tetrachloride. The supported titanium-containing catalyst component in combination with an aluminum alkyl cocatalyst is useful for obtaining polypropylene having good bulk density.
A process for preparing a polyolefin by polymerizing at least one olefin in the presence of a catalyst comprising a solid catalyst component and an organometallic compound, said solid catalyst component being a product obtained by intercontacting the following components (i)-(iv):
(i) a silicon oxide and/or an aluminium oxide,
(II) a reaction product obtained by the reaction of a magnesium halide and a compound represented by the general formula Me(OR)nXz-n wherein Me is an element of Groups I-IV in the Periodic Table, z is the valence of the element Me, n is 0 < n ≦ z, X is a halogen atom and R is a hydrocarbon radical having 1 to 20 carbon atoms,
(iii) a halogenated silicon compound, and
(iv) a titanium compound and/or a vanadium compound.
一种制备聚烯烃的工艺,其方法是在由固体催化剂组分和有机金属化合物组成的催化剂存在下聚合至少一种烯烃,所述固体催化剂组分是由以下组分(i)-(iv)相互接触得到的产物:
(i) 氧化硅和/或氧化铝、
(II) 由卤化镁和通式 Me(OR)nXz-n 所代表的化合物反应得到的反应产物,其中 Me 是元素周期表中 I-IV 族的元素,z 是 Me 元素的化合价,n 是 0 < n ≦ z,X 是卤素原子,R 是具有 1 至 20 个碳原子的烃基、
(iii) 卤化硅化合物,和
(iv) 钛化合物和/或钒化合物。