Iron-catalyzed selective oxidative arylation of phenols and biphenols
作者:Vlada Vershinin、Alina Dyadyuk、Doron Pappo
DOI:10.1016/j.tet.2017.03.094
日期:2017.6
and unnatural polyaryls by biomimetic oxidative cross-coupling between phenolic components and 1,3,5-trimethoxybenzene catalyzed by FeCl3 in fluorinated solvents is reported. The regioselectivity (ortho, meta or para) and the chemoselectivity (CC vs CO) in this highly efficient transformation are controlled by the phenolic ortho-groups of the growing phenolic oligomer. The reaction scope was examined
据报道,在氟化溶剂中,FeCl 3催化酚类成分与1,3,5-三甲氧基苯的仿生氧化交叉偶联,一步合成了被保护的酚和非天然聚芳基。在这种高效转化中,区域选择性(邻位,间位或对位)和化学选择性(C C vs C O)受酚邻位键的控制-不断增长的酚类低聚物。通过将双酚衍生物与亲核芳烃偶合,以提供大的聚芳基化合物,而该聚芳基化合物不易通过其他方式获得,从而检查了反应范围。通过进行顺序氧化苯酚-苯酚和苯酚-芳烃的偶联反应,可以高效地提供单一的聚芳基产物,从而证明了催化系统在设计聚芳基骨架中的多功能性。
Solvent-controlled selective synthesis of biphenols and quinones via oxidative coupling of phenols
作者:Nagnath Yadav More、Masilamani Jeganmohan
DOI:10.1039/c7cc04829g
日期:——
A regioselective synthesis of unsymmetrical and symmetrical biphenols and binaphthols via oxidativecoupling of phenols or naphthols in the presence of K2S2O8 in CF3COOH at ambient conditions is described. Interestingly, 1:1 ratio of H2O and CH3CN solvent mixtures at 80 °C instead of CF3COOH provided substituted unsymmetrical quinones. A gram scale synthesis of biphenols and binaphthols was demonstrated
描述了在环境条件下在CF 3 COOH中在K 2 S 2 O 8存在下通过酚或萘酚的氧化偶联的不对称和对称的双酚和联萘酚的区域选择性合成。有趣的是,在80°C的H2O和CH3CN溶剂混合物以1:1的比例代替CF3COOH提供了取代的不对称醌。证明了双酚和联萘酚的克级合成。
Process for preparing biphenyl compounds
申请人:UNIVERSITÉ DE BORDEAUX
公开号:US10155969B2
公开(公告)日:2018-12-18
The present invention relates to a process for preparing a compound having the formula (I), said process comprising the following steps: a) the addition of an oxygen source into a solution of a compound of formula (II), in a water-miscible solvent, b) the addition of a laccase in the solution obtained after step a); and c) the possible recovering of the compound of formula (I) thus obtained.
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.
Facile and Selective Cross-Coupling of Phenols Using Selenium Dioxide
作者:Thomas Quell、Nicole Beiser、Katrin M. Dyballa、Robert Franke、Siegfried R. Waldvogel
DOI:10.1002/ejoc.201600886
日期:2016.9
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