Poly phenyl copper

Copper compounds are catalysts for the Michael addition reaction (249), olefin dimerizations (245, 248), the polymerization of propylene sulfide (142), and the preparation of straight-chain poly phenol ethers by oxidation of 2,6-dimethylphenol in the presence of ethyl- or phenyl-copper (209a). Pentafluorophenylcopper tetramer is an intriguing catalyst for the rearrangement of highly strained polycyclic molecules (116). The copper compound promotes the cleavage of different bonds in 1,2,2-tri-methylbicyclo[1.1.0]butane compared to ruthenium or rhodium complexes. Methylcopper also catalyzes the decomposition of tetramethyllead in alcohol solution (78, 81). 

Poly(phenylene oxides) are produced by the oxidative coupling of 2,6-disubstituted phenols. The polymers are also known as poly(oxyphenylenes) or poly(phenyl ethers), and, in the case of dimethyl compounds, also as poly(xylenols). Copper (I) salts in the form of their complexes with amines catalyze the reaction. Primary and secondary aliphatic amines must be used at low temperatures, since otherwise they are oxidized. Primary aromatic amines are oxidized to azo compounds, and secondary aromatic compounds probably to hydrazo compounds. Pyridine is very suitable. 

Katsuya et al. [10] reported the oxidative coupling (copper(II) chloride, aluminum chloride) of 2,5-dimethoxybenzene to poly(2,5-dimethoxy-l,4-phenyl-ene) (2). The polymer obtained is only soluble in concentrated sulfuric acid, and is fusible at 320°C. Ueda et al. [11 ] described the coupling of the same monomer with iron(III) chloride/aluminum chloride. However, the polymers obtained were not fully para-linked. 

Brown has reported that poly-1.3-phenylene ether (I) with a molecular weight in the neighborhood of 10,000 can be prepared by heating alkali metal salts of m-bromophenol, in solution, in the presence of copper metal or copper salts. Generally, the reactions were performed between 110° C and 200° C in solvents such as pyridine, nitrobenzene and phenyl ether (9, 10). 

Dimethylphenol is oxidatively polymerized to poly(2,6-dimethyl-1,4-phenyl-ene ether) with a copper-amine complex by a laccaselike reaction. The activated phenols are coupled to form a dimer. The dimer is activated by a mechanism similar to that by which the polymerization proceeds. The effects of the amine ligands are to improve the solubility and the stability of the copper complex as well as the phenol-coordinated complex and to control the redox potential of the copper complex. 

Scheme 8.21 Schematic representation of the synthesis of polyfcyclic poly(tetrahydrofnran)), bottom right, utilizing a bifunctional alkyne-modifled initiator for the living CROP followed by end-capping with -phenyl-pyrrolidine to moderate the end-group reactivity. Subsequent end-group modification with a bifunctional acid modified with an azide moiety yields the cyclic poly(tetrahydrofuran) comprising both aUcyne and azide functionalities, which is subsequently polymerized by cycloaddition in the presence of copper(I).

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