95-71-6Relevant academic research and scientific papers
A chemical oscillator based on the photoreduction of 2-methyl-1,4- benzoquinone
Amemiya, Takashi,Wang, Jichang
, p. 13347 - 13352 (2010)
This study investigated bromate-2-methyl-1,4-benzoquinone photoreaction in a batch reactor, in which the photoreduction of 2-methyl-1,4-benzoquinone plays a vital role in initiating and sustaining the reaction process. Transient oscillatory phenomena are observed over broad reaction conditions, but a phase diagram in the bromate and sulfuric acid concentration plane shows that the nonlinear behavior is more sensitive to the ratio of bromate and acid than their absolute concentrations. Light intensity and the photosensitive substance 2-methyl-1,4-benzoquinone exhibited opposite effects on the induction time of these oscillations, implying that illumination does more than just reduce 2-methyl-benzoquinone. The oscillatory behavior has been qualitatively reproduced with a generic model developed for bromate-aromatic compounds systems.
Can Donor Ligands Make Pd(OAc)2a Stronger Oxidant? Access to Elusive Palladium(II) Reduction Potentials and Effects of Ancillary Ligands via Palladium(II)/Hydroquinone Redox Equilibria
Bruns, David L.,Musaev, Djamaladdin G.,Stahl, Shannon S.
supporting information, p. 19678 - 19688 (2020/12/18)
Palladium(II)-catalyzed oxidation reactions represent an important class of methods for selective modification and functionalization of organic molecules. This field has benefitted greatly from the discovery of ancillary ligands that expand the scope, reactivity, and selectivity in these reactions; however, ancillary ligands also commonly poison these reactions. The different influences of ligands in these reactions remain poorly understood. For example, over the 60-year history of this field, the PdII/0 redox potentials for catalytically relevant Pd complexes have never been determined. Here, we report the unexpected discovery of (L)PdII(OAc)2-mediated oxidation of hydroquinones, the microscopic reverse of quinone-mediated oxidation of Pd0 commonly employed in PdII-catalyzed oxidation reactions. Analysis of redox equilibria arising from the reaction of (L)Pd(OAc)2 and hydroquinones (L = bathocuproine, 4,5-diazafluoren-9-one), generating reduced (L)Pd species and benzoquinones, provides the basis for determination of (L)PdII(OAc)2 reduction potentials. Experimental results are complemented by density functional theory calculations to show how a series of nitrogen-based ligands modulate the (L)PdII(OAc)2 reduction potential, thereby tuning the ability of PdII to serve as an effective oxidant of organic molecules in catalytic reactions.
1-Methyl-1,4-cyclohexadiene as a Traceless Reducing Agent for the Synthesis of Catechols and Hydroquinones
Baschieri, Andrea,Amorati, Riccardo,Valgimigli, Luca,Sambri, Letizia
, p. 13655 - 13664 (2019/10/28)
Pro-aromatic and volatile 1-methyl-1,4-cyclohexadiene (MeCHD) was used for the first time as a valid H-atom source in an innovative method to reduce ortho or para quinones to obtain the corresponding catechols and hydroquinones in good to excellent yields. Notably, the excess of MeCHD and the toluene formed as the oxidation product can be easily removed by evaporation. In some cases, trifluoroacetic acid as a catalyst was added to obtain the desired products. The reaction proceeds in air and under mild conditions, without metal catalysts and sulfur derivatives, resulting in an excellent and competitive method to reduce quinones. The mechanism is attributed to a radical reaction triggered by a hydrogen atom transfer from MeCHD to quinones, or, in the presence of trifluoroacetic acid, to a hydride transfer process.
Regioselective synthesis of gentisyl alcohol-type marine natural products
Wang, Hong-Shuang,Li, Hui-Jing,Wang, Long-Fei,Shen, Zhi-Lun,Wu, Yan-Chao
supporting information, p. 1891 - 1896 (2018/05/29)
Gentisyl alcohol-type natural products, possessing various important biological properties, have been synthesized from 4-methoxyphenol by using a selective phenol monohydroxymethylation/monochlorination, a CAN oxidation and a sodium dithionite reduction as the key steps. The natural product synthesis is efficient, atom- and step-economical, and requires no protecting groups.
METHOD AND AGENT FOR TRANSPORTING HYDROGEN
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Paragraph 0038; 0039; 0040; 0041; 0048; 0049; 0050; 0051, (2019/05/22)
To provide techniques for transporting hydrogen in which problems of energy loss and biological safety are mitigated.SOLUTION: Provided is an agent which is used when transporting hydrogen from location A to location B. This agent is a compound represented by general formula [I] in the figure.SELECTED DRAWING: Figure 1
Direct Synthesis of Hydroquinones from Quinones through Sequential and Continuous-Flow Hydrogenation-Derivatization Using Heterogeneous Au–Pt Nanoparticles as Catalysts
Miyamura, Hiroyuki,Tobita, Fumiya,Suzuki, Aya,Kobayashi, Shū
supporting information, p. 9220 - 9224 (2019/06/13)
Pt–Au bimetallic nanoparticle catalysts immobilized on dimethyl polysilane (Pt–Au/(DMPSi-Al2O3)) have been developed for selective hydrogenation of quinones to hydroquinones. High reactivity, selectivity, and robustness of the catalysts were confirmed under continuous-flow conditions. Various direct derivatizations of quinones, such as methylation, acetylation, trifluoromethanesulfonylation, methacrylation, and benzoylation were successfully performed under sequential and continuous-flow conditions to afford the desired products in good to excellent yields. Especially, air-sensitive hydroquinones, such as anthrahydroquinones and naphthohydroquinones, could be successfully generated and derivatized under closed sequential and continuous-flow conditions without decomposition.
The synthesis and evaluation of thymoquinone analogues as anti-ovarian cancer and antimalarial agents
Johnson-Ajinwo, Okiemute Rosa,Ullah, Imran,Mbye, Haddijatou,Richardson, Alan,Horrocks, Paul,Li, Wen-Wu
supporting information, p. 1219 - 1222 (2018/03/12)
Thymoquinone (TQ), 2-isopropyl-5-methyl-1,4-benzoquinone, a natural product isolated from Nigella sativa L., has previously been demonstrated to exhibit antiproliferative activity in vitro against a range of cancers as well as the human malarial parasite Plasmodium falciparum. We describe here the synthesis of a series of analogues of TQ that explore the potential for nitrogen-substitution to this scaffold, or reduction to a hydroquinone scaffold, in increasing the potency of this antiproliferative activity against ovarian cancer cell lines and P. falciparum. In addition, alkyl or halogen-substituted analogues were commercially sourced and tested in parallel. Several TQ analogues with improved potency against ovarian cancer cells and P. falciparum were found, although this increase is suggested to be moderate. Key aspects of the structure activity relationship that could be further explored are highlighted.
Pyroline derivative, and preparation method and application thereof
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Paragraph 0055; 0056; 0059-0060, (2018/06/15)
The invention discloses a pyroline derivative. The pyroline derivative has a chemical structural formula which is described in the specification. According to the invention, the pyroline derivative isobtained through an esterification reaction of pyroline and ibuprofen by using dicyclohexylcarbodiimide as a dehydrating agent and 4-dimethylaminopyridine as a catalyst in an alkaline environment provided by triethylamine. Acute toxicity test results show that the pyroline derivative provided by the invention is non-toxic, while pharmacodynamic test results show that the pyroline derivative provided by the invention has better anti-inflammatory and analgesic effects compared with pyroline, ibuprofen technical and a physical mixture of the pyroline and the ibuprofen technical with equivalent amounts, and has potential application in preparation of anti-inflammatory and analgesic drugs.
Pd0-PyPPh2@porous organic polymer: Efficient heterogeneous nanoparticle catalyst for dehydrogenation of 3-methyl-2-cyclohexen-1-one without extra oxidants and hydrogen acceptors
Chen, Xingkun,Wang, Wenlong,Zhu, Hejun,Yang, Wenshao,Ding, Yunjie
, p. 49 - 56 (2018/07/24)
In this contribution, we have developed an efficient and recyclable porous organic polymer (POP) supported Pd nanoparticle catalyst (Pd°-PyPPh2@POP) for dehydrogenation of 3-methyl-2-cyclohexen-1-one. This heterogeneous catalytic system represents a totally clean process without using any extra oxidant and hydrogen acceptors. The SEM-EDS mapping images of the Pd°-PyPPh2@POP catalyst reveal the highly uniformly dispersed character of C, Pd, P and N elements. The coordination bonds between Pd nanoparticle and exposed P atom as well as N atom on the surface of PyPPh2@POP polymer are confirmed by means of solid-state 31P NMR and XPS. Importantly, both P atom and pyridyl ring on the PyPPh2@POP polymer are themselves used as solid base over the Pd°-PyPPh2@POP catalyst, leading to a catalytic conversion of 88.2% even without the employment of inorganic base additives (K2CO3). Our results have provided a strategy for designing highly active bifunctional POP supported nanoparticle catalysts.
Glycyrrhetinate and preparation method thereof and application thereof to preparation of antiviral medicine
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Paragraph 0050; 0053; 0054; 0055, (2018/07/30)
The invention discloses glycyrrhetinate. The glycyrrhetinate adopts a chemical structural formula as follows: FORMULA, and can be obtained by performing a reaction on pyroline and glycyrrhetinic acidin an oil-water two-phase system consisting of a water-insoluble organic solvent and an alkaline aqueous solution. The compound is almost non-toxic, has a relatively good therapeutic effect, which issuperior to that of the glycyrrhetinic acid, on chicken bursal disease, and can be used as a novel medicine for treating the chicken bursal disease.
