84-85-5Relevant articles and documents
Development of a Cross-Conjugated Vinylogous [4+2] Anionic Annulation and Application to the Total Synthesis of Natural Antibiotic (±)-ABX
Huang, Jing-Kai,Shia, Kak-Shan
supporting information, p. 6540 - 6545 (2020/03/03)
The cross-conjugated vinylogous [4+2] anionic annulation has been newly developed, the cascade process of which has a high preference for regiochemical control and chemoselectivity, giving rise to exclusively Michael-type adducts in moderate to high yields (up to 94 %, 35 examples). By making use of this approach as a key operation, the first total synthesis of natural antibiotic ABX, in racemic form, has been successfully achieved in a concise 7-step sequence with an overall yield of about 20 %.
Tuning the Reactivity of Peroxo Anhydrides for Aromatic C-H Bond Oxidation
Pilevar, Afsaneh,Hosseini, Abolfazl,?ekutor, Marina,Hausmann, Heike,Becker, Jonathan,Turke, Kevin,Schreiner, Peter R.
, p. 10070 - 10079 (2018/09/06)
Phenol moieties are key structural motifs in many areas of chemical research from polymers to pharmaceuticals. Herein, we report on the design and use of a structurally demanding cyclic peroxide (spiro[bicyclo[2.2.1]heptane-2,4′-[1,2]dioxolane]-3′,5′-dione, P4) for the direct hydroxylation of aromatic substrates. The new peroxide benefits from high thermal stability and can be synthesized from readily available starting materials. The aromatic C-H oxidation using P4 exhibits generally good yields (up to 96%) and appreciable regioselectivities.
Generation of arynes by selective cleavage of a carbonphosphorus bond of o-(diarylphosphinyl)aryl triflates using a grignard reagent
Nishiyama, Yoshitake,Kamada, Shuhei,Yoshida, Suguru,Hosoya, Takamitsu
, p. 1216 - 1219 (2018/09/11)
A novel method for generating arynes, including disubsti-tuted benzynes and a dehydrophenoxathiin, is reported. The treatment of easily synthesizable o-(diarylphosphinyl)aryl triflates having two electron-deficient aromatic groups on the phosphorus atom with a phenyl Grignard reagent triggered the efficient generation of arynes by selective cleavage of a carbonphosphorus bond.
Ambipolar transistor properties of 2,2′-binaphthosemiquinones
Higashino, Toshiki,Kumeta, Shohei,Tamura, Sumika,Ando, Yoshio,Ohmori, Ken,Suzuki, Keisuke,Mori, Takehiko
supporting information, p. 1588 - 1594 (2015/04/27)
Binaphthosemiquinones are proved to show ambipolar transistor properties. These compounds have characteristic blue colors owing to the small energy gaps, because the quinone part acts as an electron acceptor and the alkoxy group acts as an electron donor. Accordingly, these molecules have an analogous electronic structure to indigo. The crystal structure changes depending on the alkoxy groups, though these compounds generally have stacking structures.
Role of substituents on the reactivity and product selectivity in reactions of naphthalene derivatives catalyzed by the orphan thermostable cytochrome P450, CYP175A1
Banerjee, Shibdas,Goyal, Sandeep,Mazumdar, Shyamalava
, p. 94 - 105 (2015/09/01)
The thermostable nature of CYP175A1 enzyme is of potential interest for the biocatalysis at ambient temperature or at elevated temperature under environmentally benign conditions. Although little is known about the substrate selectivity of this enzyme, the biocatalytic activities of CYP175A1 on different substituted naphthalenes have been studied in oxidative pathway, and the effect of the substituent on the reaction has been determined. The enzyme first acts as a peroxygenase to convert these substituted naphthalenes to the corresponding naphthols, which subsequently undergo in-situ oxidative dimerization to form dyes of different colors possibly by the peroxidase-type activity of CYP175A1. The product analyses and kinetic measurements suggested that the presence of electron releasing substituent (ERS) in the substrate enhanced the substrate conversion, whereas the presence of electron withdrawing substituent (EWS) in the substrate drastically reduced the substrate conversion. The position of the ERS in the substrate was also found to play an important role in the transformation of the substrate. The results further demonstrate that mutation of the Leu80 residue to Phe enhances the reactivity of the enzyme by favoring the substrate association in the active site. The observed rates of the enzymatic oxygenation reaction of the substituted naphthalenes followed the Hammett correlation of substituent effect, supporting aromatic electrophilic substitution mechanism catalyzed by the cytochrome P450 enzyme.
Condensed compound and organic light emitting diode comprising the same
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Paragraph 0382-0385, (2016/10/27)
Disclosed are a condensed ring compound and an organic light emitting diode. The organic light emitting diode has low driving voltage, high efficiency, high brightness, and long life. The organic light emitting diode includes a first electrode; a second electrode facing the first electrode; and an organic layer interposed between the first electrode and the second electrode, and including a light emitting layer, wherein the organic layer includes one or more kind of condensed ring compound of any one claim among a first claim to 15^th claim.COPYRIGHT KIPO 2015
Acceleration of the Dakin reaction by trifluoroacetic acid
Natu, Arun D.,Burde, Ameya S.,Limaye, Rohan A.,Paradkar, Madhusudan V.
, p. 381 - 382 (2014/07/08)
An acceleration of the Dakin reaction caused by addition of trifluoroacetic acid is described. The modified protocol converts aromatic aldehydes to the corresponding phenols within 4 hours at room temperature by means of hydrogen peroxide in acidic medium. This acceleration is attributed to the stability of hydrogen peroxide in an acidic medium. This modified protocol provides alternative and easy access to important phenolic precursors that have been used in the synthesis of various natural products.
Generation of arynes triggered by sulfoxidemetal exchange reaction of ortho-sulfinylaryl triflates
Yoshida, Suguru,Uchida, Keisuke,Hosoya, Takamitsu
, p. 116 - 118 (2014/01/23)
Arynes were efficiently generated from readily available ortho-sulfinylaryl triflates by the treatment with phenylmagnesium bromide in tetrahydrofuran at 78 C. Aryne generation was initiated by a rapid sulfoxidemetal exchange reaction, followed by the immediate elimination of the ortho-OTf group. Various arynophiles efficiently reacted with arynes generated by this method within 10min, providing the corresponding adducts in high yields.
Chemo- and regioselective direct hydroxylation of arenes with hydrogen peroxide catalyzed by a divanadium-substituted phosphotungstate
Kamata, Keigo,Yamaura, Taiyo,Mizuno, Noritaka
supporting information; experimental part, 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
One step hair coloring compositions using salts
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, (2008/06/13)
A hair coloring composition comprising the following two compositions which are mixed just prior to application to the hair: (a) a composition comprising a water-soluble peroxygen oxidizing agent; and (b) a composition comprising one or more oxidative hair coloring agents selected from the group consisting of an aromatic diamine, an amino phenol, a naphthol, a polyhydric phenol, a catechol and mixtures thereof; wherein the composition comprising one or more oxidative hair coloring agents further comprises al least one water soluble carbonate releasing salts; and optionally a water soluble ammonium salt, is described.