Direct ortho arylation of phenols with aryl bromides catalyzed by a rhodium complex and hexamethylphosphorous triamide (HMPT) have been developed. A plausible reaction mechanism involving in situ generation of arylphosphites from phenols and HMPT, phosphorus-directed ortho metalation, and transesterification of the arylated arylphosphites with the substrate phenols is proposed.
The Effect of Aromatic Ethers on the Trimerisation of Ethylene using a Chromium Catalyst and Aryloxy Ligands
作者:David H. Morgan、Sianne L. Schwikkard、John T. Dixon、Jerald J. Nair、Roger Hunter
DOI:10.1002/adsc.200303070
日期:2003.8
A catalyst system consisting of a chromium source, a 2,6-disubstituted phenol and an aromaticether solvent, on activation with triethylaluminium, is active and selective for the trimerisation of ethylene to form 1-hexene. The aromaticether appears to play a role as both solvent and reagent and is pivotal in ensuring both the good activity of the system as well as selectivity to the desired product
established that the acidity of phenol can be fine-tuned with substituents on its aromatic ring via through-bond effects, the role of through-space effects on the acidity of phenols is presently poorly understood. Here, we present integrated experimental and computational studies on substituted 2,6-diarylphenols that demonstrate the essential contribution from through-space OH−π interactions and O––π interactions
A process for producing polyphenylene oxide which comprises contacting a phenolic monomer with oxygen in the presence of a catalyst composed of a manganese (II) salt and an ortho-hydroxyazo compound represented by the following formula:
where A and B represent identical or different arylene ring having a valency of at least 2 and having an oxy group and an azo group directly linked to the ortho carbon atoms of the arylene ring and R represents hydrogen or lower alkyl group, or in the presence of said catalyst and an amine, in a polymerization solvent containing a base and thereby subjecting said phenolic monomer to an oxidative polymerization.
一种生产聚苯醚的工艺,它包括在由锰(II)盐和下式代表的邻羟基偶氮化合物组成的催化剂存在下,使酚类单体与氧气接触:
式中 A 和 B 代表相同或不同的芳烯环,其价数至少为 2,并有一个氧基和一个偶氮基直接连接到芳烯环的正碳原子上,R 代表氢或低级烷基,或在所述催化剂和胺的存在下,在含有碱的聚合溶剂中,使所述酚类单体进行氧化聚合。
Process for producing polyphenylene ethers
申请人:MITSUBISHI PETROCHEMICAL CO., LTD.
公开号:EP0255230A1
公开(公告)日:1988-02-03
A process for producing a polyphenylene ether comprises oxidatively polymerizing a phenol in an organic solvent in the presence of an oxidative polymerization catalyst, finely dispersing the resulting polyphenylene ether contained in the organic solvent in an aqueous dispersion medium containing an acid compound, and heating the aqueous dispersion to remove the solvent from the polyphenylene ether. The resulting polyphenylene ether has excellent powder properties and contains a reduced amount of catalyst residue.