4754-26-1Relevant academic research and scientific papers
Catalytic asymmetric [2+2] cycloaddition between quinones and fulvenes and a subsequent stereoselective isomerization to 2,3-dihydrobenzofurans
Zheng, Haifeng,Xu, Chaoran,Wang, Yan,Kang, Tengfei,Liu, Xiaohua,Lin, Lili,Feng, Xiaoming
supporting information, p. 6585 - 6588 (2017/07/10)
The catalytic enantioselective [2+2] cycloaddition between quinones and fulvenes was achieved, for the first time, by the use of a chiral copper(ii) complex catalyst. The transformation afforded a series of enantiomerically enriched [6,4,5]-tricyclic cyclobutane derivatives in good yields with excellent regio- and stereoselectivities. Furthermore, the [2+2] adducts could be easily converted into formal [3+2] adducts efficiently and stereoselectively.
Chiral cobalt(II) complex catalyzed Friedel-Crafts aromatization for the synthesis of axially chiral biaryldiols
Xu, Chaoran,Zheng, Haifeng,Hu, Bowen,Liu, Xiaohua,Lin, Lili,Feng, Xiaoming
supporting information, p. 9741 - 9744 (2017/09/07)
An efficient atroposelective synthesis of 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 catalyst was identified by X-ray crystal diffraction analysis and a possible catalytic model was suggested.
Substituent effects in the oxidation of 2-alkyl-1,4-dialkoxybenzenes with ceric ammonium nitrate
Love, Brian E.,Simmons, Alexander L.
, p. 5712 - 5715 (2016/11/29)
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.
Effects of reaction conditions on quinone/diquinone product ratios in the oxidation of 1,4-dimethoxybenzene derivatives with ceric ammonium nitrate
Love, Brian E.,Duffy, Brian C.,Simmons, Alexander L.
supporting information, p. 1994 - 1997 (2014/04/03)
Proper choice of reaction conditions allows formation of either the quinone or corresponding diquinone as the major product upon treatment of 2-alkyl-1,4-dimethoxybenzenes with ceric ammonium nitrate.
Chemo- and regioselective direct hydroxylation of arenes with hydrogen peroxide catalyzed by a divanadium-substituted phosphotungstate
Kamata, Keigo,Yamaura, Taiyo,Mizuno, Noritaka
supporting information; scheme or table, p. 7275 - 7278 (2012/08/28)
Peroxide in, phenol out: The catalyst [-PW10O38V 2(μ-OH)2]3- showed high activity in the hydroxylation of various aromatic compounds with aqueous H2O 2. The system was regioselective, producing para-phenols from monosubstituted benzene derivatives. Furthermore, alkylarenes with reactive side-chain Ca spa 3-H bonds could be chemoselectively hydroxylated without significant formation of side-chain oxygenated products. Copyright
Synthesis of 2-substituted quinones, vitamin K3, and vitamin K1 from p-cresol. BF3·OEt2-catalyzed methyl migration of 4-tert-butyldioxycyclohexadienones
Murahashi, Shun-Ichi,Fujii, Akiko,Inubushi, Yasutaka,Komiya, Naruyoshi
scheme or table, p. 2339 - 2341 (2010/05/19)
BF3·OEt2-catalyzed methyl group migration of 4-methyl-4-tert-butyldioxycyclohexadienone, which is obtained by ruthenium-catalyzed 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 vitamin K1 from p-cresol.
Binuclear iron(III) phthalocyanine(μ-oxodimer)/tetrabutylammonium oxone: A powerful catalytic system for oxidation of hydrocarbons in organic solution
Neu, Heather M.,Zhdankin, Viktor V.,Nemykin, Victor N.
scheme or table, p. 6545 - 6548 (2011/02/22)
Binuclear iron(III) phthalocyanine-(μ-oxodimer) complex was tested in catalytic oxygenation reactions of several hydrocarbons using tetrabutylammonium oxone as the oxidant in dichloromethane solution at room temperature. Results of the study demonstrate that this is an extremely powerful catalytic system for oxidative conversion of aromatic hydrocarbons (anthracene, 2-tert- butylanthracene, 2-methylnaphthalene, 9, 10-dihydroanthracene, 1,2,3,4-tetrahydronaphthalene, indane, ethylbenzene, toluene, and benzene) to the respective p-quinones in high yields in 5-30 min. Under these conditions, adamantane is oxidized with 71% conversion after 10 min affording a mixture of 1 -adamantanol, 2-adamantanone, 1-hydroxy-2-adamantanone, and 4-protoadamantanone.
Selective activation of C-H bonds on the ring of ethylbenzene catalyzed by several diperoxovanadate complexes
Liu, Qiuyuan,Zhu, Liangfang,Li, Li,Guo, Bin,Hu, Xiaoke,Hu, Changwei
experimental part, p. 71 - 77 (2011/01/08)
The competitive oxidation of the C-H bonds on the aromatic ring and side-chain of ethylbenzene (EB) with hydrogen peroxide is investigated over four diperoxovanadate catalysts, that is, K3[VO(O2) 2(ox)] (bpV(ox)), K2
Electrophysiological and behavioral activity of secondary metabolites in the confused flour beetle, tribolium confusum
Verheggen,Ryne,Olsson,Arnaud,Lognay,Hoegberg,Persson,Haubruge,Loefstedt
, p. 525 - 539 (2008/09/17)
Several previous studies have addressed pheromone communication in various flour beetles (Coleoptera: Tenebrionidae), including the confused flour beetle, Tribolium confusum (du Val). Different stereoisomers of 4,8-dimethyldecanal (DMD) were reported as the only components of an aggregation pheromone, but the behavioral activity of DMD is low. In the present study, additional previously reported secondary metabolites (benzoquinones and hydrocarbons) were tested for electrophysiological activity (EAG) with both sexes of T. confusum. Two benzoquinones and three monoenic hydrocarbons elicited significant EAG activity from both male and female antennae. There was an elevated male EAG response (vs. the females) to two out of the three hydrocarbons and for both quinones. The EAG-active compounds were subsequently investigated for behavioral activity in a walking bioassay. Benzoquinones are considered toxic and have been assigned a function as alarm substances in flour beetles, but we found that methyl-1, 4-benzoquinone in intermediate concentrations was attractive to both male and female beetles and could therefore act as an aggregation pheromone component. Males were also attracted to ethyl-1,4-benzoquinone. The corresponding hydroquinones, presumed precursors of the benzoquinones, did not elicit any electrophysiological response and were not tested for behavioral activity. The unsaturated hydrocarbons (1-tetradecene, 1-pentadecene, and 1-hexadecene) elicited significant EAG responses from both male and female antennae and were also attractive in the behavioral assay. Our results show that several beetle-produced compounds, in addition to 4,8-dimethyldecanal, may be part of a complex pheromone system in flour beetles and play a role in mediating aggregation in T. confusum.
Acid-induced rearrangement reactions of reduced benzoquinone cyclopentadiene cycloadducts
Eipert, Martin,Maichle-Moessmer, Caecilia,Maier, Martin E.
, p. 8692 - 8695 (2007/10/03)
Several Diels-Alder adducts between benzoquinones and cyclopentadiene were reduced to the corresponding diols 7a-c and 11. Treatment of these diols with strong acid triggered a skeletal rearrangement reaction resulting in compounds 8a-c and 12 that contain a 4,8-methanoazulene substructure. In addition, a dyotropic-like rearrangement of the tetracyclic lactone 13 to the spirolactone 18 was observed. Five of the structures were supported by X-ray analysis.
