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。
Synthesis of axially chiral C10-BridgePHOS oxides and their use as organocatalysts in enantioselective allylations of aldehydes
of C10-BridgePHOS oxides possessing different substituted groups on the diphenyl phosphine system were synthesized and tested as organocatalysts in the allylation of aldehydes with allyltrichlorosilane, providing chiral homoallylic alcohols. These types of organocatalysts showed high catalytic activity and only 2 mol% catalyst loading was required to induce short reaction times. Under optimal reaction
Branch-Selective and Enantioselective Iridium-Catalyzed Alkene Hydroarylation via Anilide-Directed C–H Oxidative Addition
作者:Simon Grélaud、Phillippa Cooper、Lyman J. Feron、John F. Bower
DOI:10.1021/jacs.8b04627
日期:2018.8.1
Tertiary benzylic stereocenters are accessed in high enantioselectivity by Ir-catalyzed branch selective addition of anilide ortho-C-H bonds across styrenes and α-olefins. Mechanistic studies indicate that the stereocenter generating step is reversible.
通过 Ir 催化的苯胺邻位-CH 键在苯乙烯和 α-烯烃上的分支选择性加成,可以高对映选择性地获得叔苄基立构中心。机理研究表明,立体中心生成步骤是可逆的。
Homogeneous Palladium-Catalyzed Selective Reduction of 2,2′-Biphenols Using HCO2H as Hydrogen Source
作者:Wen Yang、Wanxiang Zhao、Ruoling Li、Chenchen Li
DOI:10.1055/a-1337-5153
日期:2021.5
efficient homogeneous palladium-catalyzed selective deoxygenation of 2,2′-biphenols by reduction of aryl triflates with HCO2H as the hydrogensource is reported. This protocol complements the current method based on heterogeneous Pd/C-catalyzed hydrogenation with hydrogen gas. This process provided the reduction products in good to excellent yields, which could be readily converted to various synthetically
The reactions of free radicals, formed by thermal decomposition of t-butyi peroxide, with phenols has been studied Although the major products were 2,2′-dihydroxy-derivatives of biphenyl the isomeric 2-hydoxydiphenyl ethers were also formed. Pummerer's ketone was not formed, and the isolation of 4,4′-dihydroxy-3,3′-dimethylbibenzyl from the reaction with 2,4-dimethylphenol has shown that coupling via