612-69-1Relevant articles and documents
Facile and Selective Cross-Coupling of Phenols Using Selenium Dioxide
Quell, Thomas,Beiser, Nicole,Dyballa, Katrin M.,Franke, Robert,Waldvogel, Siegfried R.
, p. 4307 - 4310 (2016)
Nonsymmetric biphenols are important structural motifs in organic chemistry. Therefore, an easy and versatile protocol for oxidative cross-coupling is essential to generate these so-called “privileged ligands”. We developed an efficient and selective oxidative pathway to synthesize 2,2′-biphenols as well as 2,4′- and 4,4′-biphenols. The use of selenium dioxide, a stable, powerful, and commercially available oxidizer, in 1,1,1,3,3,3-hexafluoroisopropanol allowed the oxidative coupling of alkyl-, alkoxy-, and halogen-substituted phenols.
Selective oxidation of phenols to hydroxybenzaldehydes and benzoquinones with dioxygen catalyzed by polymer-supported copper
Takaki, Ken,Shimasaki, Yohei,Shishido, Tetsuya,Takehira, Katsuomi
, p. 311 - 317 (2007/10/03)
Oxidation of 2,6-disubstituted 4-methylphenols with dioxygen by using a CuCl2-poly(4-methyl-4′-vinyl-2,2′-bipyridine) catalyst gave the corresponding 4-hydroxybenzaldehydes in high yields. The activity of the catalyst and the selectivity of the products significantly depended on the reaction conditions and the composition of the catalyst. When the molar ratio of the bipyridine unit of the polymer ligand to Cu was unity, i.e., N/Cu = 2, the best results were obtained. Moreover, the reaction is likely to be promoted by coordination of the products to the catalyst. Similarly, 2,3,6-trimethylphenol and related compounds were converted to p-benzoquinones selectively with a CuCl2-poly(4-vinylpyridine) catalyst. These polymer-supported catalysts were readily recovered and are reusable without noticeable decrease of their activity.
