623-05-2Relevant articles and documents
Acute toxicity of benzoic acids to the crustacean Daphnia magna
Kamaya, Yasushi,Fukaya, Yuki,Suzuki, Kyoji
, p. 255 - 261 (2005)
The acute immobilization toxicity of benzoic acids substituted with hydroxyl and/or methoxyl groups on the aromatic ring was determined for the freshwater crustacean Daphnia magna under neutralized condition (initial pH: 7.45 ± 0.05). Toxicity, expressed as EC50 value, varied depending largely on the number and position of phenolic hydroxyl groups. Especially, benzoic acids with ortho-substituted hydroxyl groups were more toxic than benzoic acids with meta- and/or para-substituted hydroxyl groups. Whereas the limited data indicated that methoxyl substitution had relatively small and variable effects on the toxicity. Of the tested compounds, 2,4,6- trihydroxybenzoic acid showed the highest toxicity with the 48 h EC50 of 10 μmol l-1. This was 700 times as toxic as the parent benzoic acid (48 h EC50 = 7.0 mmol l-1) and about two orders of magnitude higher than those previously reported for monohalogenated benzoic acid derivatives in Daphnia. Within the subgroups based on the number of hydroxyl groups (NOH), the toxicity variations due to the position of hydroxyl groups appeared to be correlated with the logarithms of n-octanol/water partition coefficients (log Pow). The toxicity of benzoic acids existing almost entirely as their ionized forms could be expressed as simple structure-toxicity relationships using these two descriptors (NOH and log Pow).
Selective Synthesis of 4-Hydroxymethylphenol catalysed by Cyclodextrins having Hydroxypropyl Residues
Komiyama, Makoto
, p. 651 - 652 (1988)
The selective synthesis of 4-hydroxymethylphenol from phenol and formaldehyde has been achieved using α-, β-, and γ-cyclodextrins having 2-hydroxypropyl residues.
Determining Factors for the Product Para/Ortho Ratio and Reaction Rate in the Formation of (Hydroxymethyl)phenols from Phenol and Formaldehyde
Komiyama, Makoto
, p. 2079 - 2082 (1988)
Formations of 2- and 4-(hydroxymethyl)phenols from phenol and formaldehyde in aqueous alkaline solutions were kinetically investigated by the use of HPLC.The para/ortho ratio for the products sigmoidally increased with increasing concentration of sodium hydroxide, whereas the total yield of the (hydroxymethyl)phenols showed a steep maximum at the charged molar ratio unity of sodium hydroxide to phenol.Use of lithium hydroxide and potassium hydroxide, in place of sodium hydroxide, as alkaline catalysts results in almost the same para/ortho ratios.The addition of potassium chloride and magnesium sulfate decreased both the para/ortho ratio and the yield.These results indicate that the reactions proceed via an electrophilic attack of formaldehyde, which is free from the adduct formation with hydroxide ion, at phenolate ion.Electrostatic interactions between the phenoxide oxygen atom of the phenol and the incoming hydroxymethyl residues in the transition state exhibit a predominant role in the determination of the para/ortho ratio.
Discovery of new and highly effective quadruple FFA1 and PPARα/γ/δ agonists as potential anti-fatty liver agents
Cai, Zongyu,Deng, Liming,Geng, Xinqian,Hu, Lijun,Jiao, Shixuan,Li, Zheng,Ren, Qiang,Wang, Bin,Yang, Ying,Zhang, Luyong,Zhou, Zongtao
supporting information, (2021/12/27)
Non-alcoholic fatty liver disease (NAFLD) has become the most common hepatic disease, while no drug was approved until now. The previous study reported that the quadruple FFA1/PPAR-α/γ/δ agonist RLA8 provided better efficacy than obeticholic acid on NASH. In the present study, two design strategies were introduced to explore better quadruple FFA1/PPAR-α/γ/δ agonists with improved metabolic stability. These efforts ultimately resulted in the identification of ZLY18, a quadruple FFA1/PPAR-α/γ/δ agonist with twice higher metabolic half-life than RLA8 in the liver microsome. In the triton-1339W-induced hyperlipidemic model, ZLY18 reversed hyperlipidemia to an almost normal level, which exhibited far stronger lipid-lowering effects than that of RLA8. Moreover, ZLY18 significantly decreased steatosis, hepatocellular ballooning, inflammation and liver fibrosis in NASH model even better than RLA8. Further mechanism studies suggested that ZLY18 exerts stronger effects than RLA8 on the regulation of the gene related to lipid synthesis, oxidative stress, inflammation and fibrosis. In addition, ZLY18 is more effective than pirfenidone in the prevention of CCl4-induced liver fibrosis. Besides, ZLY18 has an acceptable safety profile in the acute toxicity study at a high dose of 500 mg/kg. Therefore, ZLY18 represents a novel and highly promising quadruple FFA1/PPAR-α/γ/δ agonist worth of further investigation and development.
Ambient-pressure highly active hydrogenation of ketones and aldehydes catalyzed by a metal-ligand bifunctional iridium catalyst under base-free conditions in water
Wang, Rongzhou,Yue, Yuancheng,Qi, Jipeng,Liu, Shiyuan,Song, Ao,Zhuo, Shuping,Xing, Ling-Bao
, p. 1 - 7 (2021/05/17)
A green, efficient, and high active catalytic system for the hydrogenation of ketones and aldehydes to produce corresponding alcohols under atmospheric-pressure H2 gas and ambient temperature conditions was developed by a water-soluble metal–ligand bifunctional catalyst [Cp*Ir(2,2′-bpyO)(OH)][Na] in water without addition of a base. The catalyst exhibited high activity for the hydrogenation of ketones and aldehydes. Furthermore, it was worth noting that many readily reducible or labile functional groups in the same molecule, such as cyan, nitro, and ester groups, remained unchanged. Interestingly, the unsaturated aldehydes can be also selectively hydrogenated to give corresponding unsaturated alcohols with remaining C=C bond in good yields. In addition, this reaction could be extended to gram levels and has a large potential of wide application in future industrial.
Method for synthesizing primary alcohol in water phase
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Paragraph 0034-0035, (2021/07/14)
The invention discloses a method for synthesizing primary alcohol in a water phase. The method comprises the following steps: taking aldehyde as a raw material, selecting water as a solvent, and carrying out catalytic hydrogenation reaction on the aldehyde in the presence of a water-soluble catalyst to obtain the primary alcohol, wherein the catalyst is a metal iridium complex [Cp*Ir(2,2'-bpyO)(OH)][Na]. Water is used as the solvent, so that the use of an organic solvent is avoided, and the method is more environment-friendly; the reaction is carried out at relatively low temperature and normal pressure, and the reaction conditions are mild; alkali is not needed in the reaction, so that generation of byproducts is avoided; and the conversion rate of the raw materials is high, and the yield of the obtained product is high. The method not only has academic research value, but also has a certain industrialization prospect.
Selective aldehyde reductions in neutral water catalysed by encapsulation in a supramolecular cage
Paul, Avishek,Shipman, Michael A.,Onabule, Dolapo Y.,Sproules, Stephen,Symes, Mark D.
, p. 5082 - 5090 (2021/04/21)
The enhancement of reactivity inside supramolecular coordination cages has many analogies to the mode of action of enzymes, and continues to inspire the design of new catalysts for a range of reactions. However, despite being a near-ubiquitous class of reactions in organic chemistry, enhancement of the reduction of carbonyls to their corresponding alcohols remains very much underexplored in supramolecular coordination cages. Herein, we show that encapsulation of small aromatic aldehydes inside a supramolecular coordination cage allows the reduction of these aldehydes with the mild reducing agent sodium cyanoborohydride to proceed with high selectivity (ketones and esters are not reduced) and in good yields. In the absence of the cage, low pH conditions are essential for any appreciable conversion of the aldehydes to the alcohols. In contrast, the specific microenvironment inside the cage allows this reaction to proceed in bulk solution that is pH-neutral, or even basic. We propose that the cage acts to stabilise the protonated oxocarbenium ion reaction intermediates (enhancing aldehyde reactivity) whilst simultaneously favouring the encapsulation and reduction of smaller aldehydes (which fit more easily inside the cage). Such dual action (enhancement of reactivity and size-selectivity) is reminiscent of the mode of operation of natural enzymes and highlights the tremendous promise of cage architectures as selective catalysts.
In situthermosensitive hybrid mesoporous silica: preparation and the catalytic activities for carbonyl compound reduction
Ha, Chang-Sik,Mohan, Anandhu,Nagappan, Saravanan,Parambadath, Surendran,Park, Sung Soo,Peter, Jerome,Rout, Lipeeka,Thomas, Anju Maria,Zhang, Wei-Jin
, p. 11730 - 11741 (2021/09/06)
In this study, free-radical polymerisation inside MCM-41 mesopores was examined to expose a construction route for a temperature-responsive switchable polymer-silica nanohybrid material with well-defined porosity. Herein, we introduced a vinyl monomer (N-isopropyl acrylamide), a cross-linker, and an AIBN initiator into the palladium nanoparticle incorporated MCM-41 pore channels using the wet-impregnation method followed byin situradical polymerisation. The structural properties of the synthesised PNIPAM-PdNP-MCM-41 catalyst were analysed by various sophisticated analytical techniques. The temperature switchable nanohybrid catalyst was used to reduce carbonyl compounds to their corresponding alcohols. The catalyst showed high catalytic efficiency and robustness in an aqueous medium at 25 °C. Moreover, the system's polymer layer remarkably boosted catalytic selectivity and activity for carbonyl compound reduction as compared to other controlled catalysts. The suggested switchable system can be employed as a temperature-controllable heterogeneous catalyst and highlights a substitute technique to counter the methodical insufficiency in switchable supported molecular catalytic system production.
Whole seeds of Bauhinia variegata L. (Fabaceae) as an efficient biocatalyst for benzyl alcohol preparations from benzaldehydes
Aimar, Mario L.,Bordón, Daniela L.,Díaz Panero, Mariángeles,Decarlini, María F.,Demmel, Gabriel I.,Rossi, Laura I.,Vázquez, Ana M.
, (2021/08/03)
Whole seeds of Bauhinia variegata L. (Fabaceae) were utilized as a biological reducer to transform benzaldehyde into benzyl alcohol. The effects of some variables such as temperature, the load of substrate and co-solvent, were established to optimize the reductive process. Utilizing the optimal reaction conditions, a laboratory-scale reaction (final concentration of the substrate: 21.2 mM) was performed to obtain benzyl alcohol (conversion: 95%; isolated yield: 49%; productivity: 1.11 g L?1 or 0.046 g L?1h?1 of benzyl alcohol). In addition, using these optimal conditions, fourteen substituted benzaldehydes were reduced, with a conversion achieved to their corresponding benzyl alcohols ranging from 62% to >99% (isolated yields from 7% to 70%). Moreover, useful building blocks by the synthesis of the drugs and important commercial products were also obtained. The scope, limitations and advantages of this new biocatalytic synthetic method are also discussed.
Efficient single-atom Ni for catalytic transfer hydrogenation of furfural to furfuryl alcohol
Fan, Yafei,Zhuang, Changfu,Li, Shangjing,Wang, Ying,Zou, Xiaoqin,Liu, Xiaoteng,Huang, Weimin,Zhu, Guangshan
, p. 1110 - 1118 (2021/01/25)
The employment of single-atom catalysts in the catalytic transfer hydrogenation (CTH) of furfural (FF) to furfuryl alcohol (FAL) has never been effectively explored. Herein, a catalyst of Ni single-atoms supported on nitrogen doped carbon (Ni-SAs/NC) is synthesized and first ever utilized in the CTH of FF to FAL. Atomically dispersed Ni-N4 sites change the electron density at the metal center and exhibit specific adsorption and desorption to FF and FAL, promoting an outstanding catalytic performance with a turnover frequency (TOF) of 832 h-1 and selectivity as high as 97.1% at 130 °C for 2 h. Such performance is 9-fold higher than that of supported Ni nanocatalysts. The Ni-SAs/NC catalyst also exhibits superior stability for the CTH of FF and excellent catalytic activity for other α,β-unsaturated aldehydes. This work provides a new strategy of producing green chemical compounds using catalytic biomass conversion and suggests the future application of long-lasting single-atom catalysts for emerging sustainable technologies.
