33440-68-5Relevant academic research and scientific papers
Metal-free oxidative cross-dehydrogenative coupling of quinones with benzylic C(sp3)-H bonds
Dong, Yu,Yang, Jian,He, Shuai,Shi, Zhi-Chuan,Wang, Yu,Zhang, Xiao-Mei,Wang, Ji-Yu
, p. 27588 - 27592 (2019/09/12)
A metal-free cross-dehydrogenative coupling of quinones with toluene derivatives has been established. A series of quinones were subjected to reaction with toluene derivatives in the presence of di-tertbutyl peroxide (DTBP) for direct synthesis of benzylq
Radical Benzylation of Quinones via C-H Abstraction
Galloway, Jordan D.,Mai, Duy N.,Baxter, Ryan D.
, p. 12131 - 12137 (2019/10/02)
Herein we report the development of radical benzylation reactions of quinones using Selectfluor and catalytic Ag(I) initiators. The reaction is believed to proceed via a C-H abstraction mechanism after Ag(I)-mediated reduction of Selectfluor. This reaction occurs under mild conditions and is effective for a variety of quinones and radical precursors bearing primary benzylic carbons. The use of preformed Ag(4-OMePy)2NO3 as a catalyst proved effective in improving the reaction efficiency by reducing unwanted degradation pathways available to Selectfluor.
The Application of 2-Benzyl-1,4-naphthoquinones as Pronucleophiles in Aminocatalytic Synthesis of Tricyclic Derivatives
Skrzyńska, Anna,Romaniszyn, Marta,Pomiklo, Dominika,Albrecht, Lukasz
, p. 5019 - 5026 (2018/05/17)
This study demonstrates an unprecedented reactivity of 2-substituted-1,4-naphthoquinones. By applying the principle of vinylogy, they have been employed as vinylogous pronucleophiles in the organocatalytic cascade reaction for the first time. This novel catalytic activation of 1,4-naphthoquinones enables access to carboannulated naphthalen-1(4H)-one derivatives of biological importance. The site-selectivity and stereoselectivity of a process proved possible to control by the proper choice of reaction conditions.
Cytotoxicity of lapachol, β-lapachone and related synthetic 1,4-naphthoquinones against oesophageal cancer cells
Sunassee, Suthananda N.,Veale, Clinton G.L.,Shunmoogam-Gounden, Nelusha,Osoniyi, Omalaja,Hendricks, Denver T.,Caira, Mino R.,De La Mare, Jo-Anne,Edkins, Adrienne L.,Pinto, Antonio V.,Da Silva Junior, Eufranio N.,Davies-Coleman, Michael T.
, p. 98 - 110 (2013/05/09)
Naphthoquinones have been found to have a wide range of biological activities, including cytotoxicity to cancer cells. The secondary metabolites lapachol, α- and β-lapachone and a series of 25 related synthetic 1,4-naphthoquinones were screened against the oesophageal cancer cell line (WHCO1). Most of the compounds exhibited enhanced cytotoxicity (IC50 1.6-11.7 μM) compared to the current drug of choice cisplatin (IC 50 = 16.5 μM). This study also established that the two new synthetic halogenated compounds 12a and 16a (IC50 = 3.0 and 7.3 μM) and the previously reported compound 11a (IC50 = 3.9 μM), were non-toxic to NIH3T3 normal fibroblast cells. Cell death of oesophageal cancer cells by processes involving PARP cleavage caused by 11a was shown to be associated with elevated c-Jun levels, suggesting a role for this pathway in the mechanism of action of this cohort of naphthoquinone compounds.
Enantioselective epoxidation of 2-substituted 1,4-naphthoquinones using gem-dihydroperoxides
Bunge, Alexander,Hamann, Hans-Jürgen,McCalmont, Eve,Liebscher, Jürgen
supporting information; experimental part, p. 4629 - 4632 (2009/10/26)
New gem-dihydroperoxides were successfully used for DBU-promoted enantioselective epoxidation of 2-substituted 1,4-naphthoquinones. The corresponding 1,4-naphthoquinone epoxides were obtained in yields up to 97% and ee's up to 82%.
A new synthetic route to substituted quinones by radical-mediated coupling of organotellurium compounds with quinones
Yamago, Shigeru,Hashidume, Masahiro,Yoshida, Jun-Ichi
, p. 6805 - 6813 (2007/10/03)
Carbon-centered radicals generated from the corresponding organotellurium compounds react with a variety of quinones under photo-thermal conditions to give the monoaddition product in moderate to excellent yield. The reaction can be used for the synthesis of polyprenyl quinoid natural products and C-glycosides.
Electroorganic reactions. Part 56: Anodic oxidation of 2-methyl- and 2-benzylnaphthalenes: Factors influencing competing pathways
Utley, James H.P,Rozenberg, Gregor G
, p. 5251 - 5265 (2007/10/03)
A systematic investigation of the anodic oxidation in nucleophilic media of 2-methyl and 2-benzylnaphthalenes, substituted at the 6-position in the naphthalene nucleus and at the 4-phenyl position of the benzylic side chain, has been carried out to identify factors favouring side-chain substitution. Cyclic voltammetry confirms that 6-substitution has a profound effect on the oxidation potentials of the naphthalene nucleus and 13C chemical shifts indicate polar effects at the benzylic carbon. However, little side-chain anodic oxidation is observed under any conditions tried; the radical-cations of electron-rich substrates preferentially dimerise and a strongly electron-withdrawing substituent at the 6-position (EtOSO2) promotes nuclear substitution. In contrast, oxidation with DDQ in aqueous acetic acid gives efficient side-chain oxidation for electron rich substrates, consistent with hydride transfer, possibly intramolecularly via a charge transfer complex.
Synthetic Studies on the Kinamycin Family of Antibiotics: Synthesis of 2-(Diazobenzyl)-p-naphthoquinone, 1,7-Dideoxy-3-demethylprekinamycin, and 1-Deoxy-3-demethylprekinamycin
Williams, William,Sun, Xin,Jebaratnam, David
, p. 4364 - 4369 (2007/10/03)
2-(Diazobenzyl)-p-naphthoquinone was synthesized from 2-benzyl-1,4-dimethoxynaphthalene by cerric ammonium nitrate oxidation to 2-benzyl-p-naphthoquinone followed by diazo transfer with tosyl azide. 1,7-Dideoxy-3-demethylprekinamycin was prepared from 1,4-dimethoxynaphthalene by bromination, lithiation, and condensation with acetanthranil to give 2-(2′-N-acetaminobenzoyl)-1,4-dimethoxynaphthalene, which, following deacylation, was subjected to Pschorr cyclization to give 1,3,7-trihydro-O,O-dimethylkinafluorenone. This was then demethylated, subjected to hydrazinolysis, and then oxidized with Fetizon's reagent to complete the synthesis. 1-Deoxy-3-demethylprekinamycin was synthesized from 3-bromo-1,5-dimethoxy-4-naphthol by an identical route.
ELECTRON-TRANSFER PROCESSES: MECHANISMS OF OXIDATION OF ETHERS AND ESTERS BY SILVER-CATALYZED PEROXYDISULPHATE
Minisci, Francesco,Coppa, Fausta,Fontana, Francesca,Zhao, Lihua
, p. 613 - 616 (2007/10/02)
Nucleophilic carbon-centred radicals, generated from the oxidation of diethyl ether, ethyl acetate, propyl acetate, ethyl propionate, diethyl oxalate and 2-phenylethyl acetate by silver-catalyzed decomposition of peroxydisulphate, have been trapped, mostly by naphthoquinone and in a few cases by protonated quinoline. Characterization of the intermediate radicals allows the rationalization of the mechanism of these oxidations, which are likely to occur through an initial electron-transfer step by Ag(II).
PHOTOCHEMICAL REACTION OF EPOXYNAPHTOQUINONE WITH AMINE. ITS DEPENDENCY ON SOLVENT STUDIED BY CIDNP TECHNIQUE
Maruyama, Kazuhiro,Otsuki, Tetsuo,Osuka, Atsuhiro,Suzuki, Hitomi
, p. 1 - 4 (2007/10/02)
The oxirane ring of epoxynaphthoquinones was reductively opened upon irradiation in the presence of triethylamine and, in addition, a cross adduct was obtained in the reaction with N,N-dimethylaniline in benzene.CIDNP signals observed in the reaction with N,N-dimethylaniline were interpreted as evidence for hydrogen atom abstraction in benzene and for electron transfer in acetone and acetonitrile.
