KOt-Bu/DMF promoted intramolecular cyclization of 1,1′-biphenyl aldehydes and ketones: an efficient synthesis of phenanthrenes
作者:Yan-yan Chen、Niu-niu Zhang、Lin-miao Ye、Jia-hua Chen、Xiang Sun、Xue-jing Zhang、Ming Yan
DOI:10.1039/c5ra07188g
日期:——
A new synthesis of phenanthrene derivatives has been achieved through intramolecular cyclization of 1,1′-biphenyl aldehydes and ketones promoted by KOt-Bu/DMF. A free radical reaction pathway is proposed.
通过KO t -Bu / DMF促进的1,1'-联苯醛和酮的分子内环化,实现了菲衍生物的新合成。提出了自由基反应途径。
The one-electron oxidation of biphenyl-2-ylethylenes. Subsequent chemical reactivity controlled by electron return or proton transfer
Biphenyl-2-ylethylenes react with (4-BrC6H4)3N˙+SbCl6– to give the radical cation of the electrocyclization product which initiates a protic catalysis to the related fluorenes or, in presence of 2,6-di-t-butylpyridine or water, lead stoicheiometrically to phenanthrenes; with photochemical oxidants only phenanthrenes or 9,10-dihydrophenanthrenes are obtained, with an efficiency related to the polarity
[EN] METHOD FOR PREPARING ELASTOMERIC COPOLYMERS OF ETHYLENE AND a-OLEFINS<br/>[FR] PROCÉDÉ DE FABRICATION DE COPOLYMÈRES ÉLASTOMÈRES DE L'ÉTHYLÈNE ET D'?-OLÉFINES
申请人:SK ENERGY CO LTD
公开号:WO2010053264A2
公开(公告)日:2010-05-14
Provided is a process for preparing copolymers of ethylene with α-olefin. More specifically, provided are transition metal compound being useful as catalyst for preparing those copolymers, a catalyst composition comprising the same, and a process for preparing elastic copolymers of ethylene with α-olefin, having the density of not more than 0.910, which can be adopted to a wide variety of applications including film,, electric wires, and hot-melt adhesives. The catalyst composition is a catalytic system which comprises transition metal catalyst comprising a cyclopentadiene derivative and at least one anionic ligand(s) of aryloxy group with an aryl derivative at ortho-position, and boron or aluminum compound as an activator. Provided is a process for copolymerizing ethylene with α-olefin to produce copolymer having narrow molecular weight distribution and uniform density distribution with the density of not more than 0.910, with high activity and excellent reactivity on higher α-olefin.