Chemo- and Regioselective Direct Hydroxylation of Arenes with Hydrogen Peroxide Catalyzed by a Divanadium-Substituted Phosphotungstate
作者:Keigo Kamata、Taiyo Yamaura、Noritaka Mizuno
DOI:10.1002/anie.201201605
日期:2012.7.16
Peroxide in, phenol out: The catalyst [γ‐PW10O38V2(μ‐OH)2]3− showed high activity in the hydroxylation of various aromatic compounds with aqueous H2O2. The system was regioselective, producing para‐phenols from monosubstituted benzene derivatives. Furthermore, alkylarenes with reactive side‐chain CH bonds could be chemoselectively hydroxylated without significant formation of side‐chain oxygenated
过氧化物,酚出:将催化剂[γ-PW 10 ö 38 V 2(μ-OH)2 ] 3-表明在各种芳族化合物与水性小时羟化活性高2 Ò 2。该系统具有区域选择性,可从单取代的苯衍生物生产对酚。此外,反应性侧链的C烷基芳烃 H键可以化学选择性羟基化而不显著形成的侧链氧化产物。
Chiral cobalt(<scp>ii</scp>) complex catalyzed Friedel–Crafts aromatization for the synthesis of axially chiral biaryldiols
axially chiral biaryldiols via asymmetric Friedel–Crafts aromatization between p-quinones and 2-naphthols was developed. A chiral cobalt(II) complex of N,N′-dioxide enabled the process to generate axially chiral biaryldiols in up to 98% yield and 95% ee. A large range of substituents at different positions of p-quinones and 2-naphthols was tolerable. The configuration of the product and the chiral N,N′-dioxide-Co(ClO4)2
Oxidation of C<sub>2</sub>, C<sub>3</sub>and higher alkanes by a ruthenium–oxo system
作者:Tai-Chu Lau、Chi-Keung Mak
DOI:10.1039/c39950000943
日期:——
Barium ruthenate, BaRuO3(OH)2, when dissolved in TFAâCH2Cl2 containing a few equivalents of 2,2â²-bipyridine, generates a highly reactive rutheniumâoxo system that is capable of oxidizing ethane and propane at room temperature with good yields.
Substituent effects in the oxidation of 2-alkyl-1,4-dialkoxybenzenes with ceric ammonium nitrate
作者:Brian E. Love、Alexander L. Simmons
DOI:10.1016/j.tetlet.2016.11.042
日期:2016.12
Increased steric size of alkyl groups and the presence of coordinating atoms on alkoxy groups have both been found to contribute to decreasing yields of diquinones upon reaction of 2-alkyl-1,4-dialkoxybenzenes with CAN. The overall hydrophilicity of the substrates does not appear to be a significant factor in determining the diquinone yield for these reactions.
Synthesis of 2-substituted quinones, vitamin K3, and vitamin K1 from p-cresol. BF3·OEt2-catalyzed methyl migration of 4-tert-butyldioxycyclohexadienones
oxidation of p-cresol with tert-butyl hydroperoxide, in hexafluoro-2-propanol/toluene gave toluquinone efficiently. The reaction can be applied to the regio-selective short-step syntheses of vitamin K3 and vitaminK1 from p-cresol.