62224-34-4Relevant academic research and scientific papers
Enzymatic oxidative polymerization of p-t-butylphenol and characterization of the product polymer
Mita, Naruyoshi,Maruichi, Naoyuki,Tonami, Hiroyuki,Nagahata, Ritsuko,Tawaki, Shin-ichiro,Uyama, Hiroshi,Kobayashi, Shiro
, p. 375 - 379 (2003)
For structural control and analysis of an enzymatically synthesized polyphenol, peroxidase-catalyzed polymerization of p-t-butylphenol in a mixture of polar organic solvent and phosphate buffer has been examined in detail. The resulting products were subjected to preparative HPLC. Two dimers and one trimer were isolated and their structures were determined by 1H and 13C NMR. ESI-TOF mass analysis showed the formation of two kinds of dimer and of at least four kinds of trimer. These data clearly showed that the polymer was composed of a mixture of phenylene and oxyphenylene units. The ratio of phenylene and oxyphenylene units in the product could be controlled by changing the solvent composition. The phenylene unit linearly increased as a function of the water content in the mixed solvent.
Autoxidation of Phenols Catalyzed by Copper(II)-Ethylenediamine Complexes: The Reaction Mechanism
Kushioka, Keiko
, p. 4456 - 4459 (2007/10/02)
The mechanism of the autoxidation of phenols with molecular oxygen catalyzed by Cu(II)-ethylenediamine complexes is elucidated.The kinetics are of first order in both and and of one-half order in .Those results imply the formation of a oxygen-bridged complex in the course of the reaction.The C-C coupling of two phenoxy radicals is facilitated within the coordination sphere of Cu(II) and affords the primary oxidation products, i. e. 2,2'-biphenyldiols.The bulkiness of substituents determines the type of the secondary products and either benzofuran or dioxepin is produced.Taking into account the results of oxidation of 2,2'-biphenyldiols, the mechanism of the production of benzofuran and dioxepin is also clarified.In the Cu(II) complex with sterically crowded biphenyldiolate, the oxidation activity of Cu(II) has been enhanced and the coordinating biphenyldiolate is immediately oxidized to benzofuran.On the contrary, the biphenyldiolate-Cu(II) complex with square-planar geometry could not produce benzofuran.After the complex is forced into the active tetrahedral configuration by the access of phenoxy radical-Cu(II) complex, the biphenyldiolate is oxidized to biphenyloxy radical and suffers C-O coupling with the phenoxy radical to afford dioxepin.
