Topic
Benzoic acid
About: Benzoic acid is a research topic. Over the lifetime, 11832 publications have been published within this topic receiving 167127 citations. The topic is also known as: Retardex & E210.
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TL;DR: In this article, the acid-catalyzed reactions of heteropoly compounds in the liquid phase were investigated and three typical reaction fields were identified. But the results of these reactions were not analyzed in the presence of solvents.
Abstract: 12-Tungstophosphoric acid and its acidic salts, H3PW12O40, CsxH3−xPW12O40 (abbreviated as Csx; x=1, 2, 2.23, 2.5, 2.7, and 3), BaxH3−2xPW12O40 (abbreviated as Bax; x=0.5, 1.25, and 1.5), and CexH3−3xPW12O40 (abbreviated as Cex; x=0.33, 0.66, 0.87, and 1), were applied as acid catalysts to three organic reactions which are very different in the polarities of substrates and solvents: (1) decomposition of cyclohexyl acetate (in m-xylene), (2) esterification of benzoic acid by 1-butanol (without solvent), and (3) rearrangement of benzopinacol (in toluene). It was demonstrated that these three reactions represent three typical reaction fields in the acid-catalyzed reactions of heteropoly compounds in the liquid phase. Reaction (1) proceeded on the surface of solid catalysts (a surface-type reaction). In this case, the catalytic activities were primarily determined by the surface acidity. Reaction (2) mostly took place in the homogeneous solution and the catalytic activities were correlated with the amount of the heteropolyacids dissolved in the solvents. Catalysis in pseudoliquid phase was observed for reaction (3), where the catalytic activities depended on the amount of substrates absorbed in the solid bulk of the catalysts. Thus, heteropolyacid catalysts provide three different reaction fields, depending on the polarity of substrate and solvent. The orders of the catalytic activity very much differed reflecting the reaction field. These results demonstrate that the recognition of these reaction fields is important for the understanding and the design of heteropolyacid catalysis in the liquid phase.
46 citations
TL;DR: A rhodium-catalyzed regioselective addition of sulfonyl hydrazides to allenes is reported, with Rh(i)/DPEphos/benzoic acid as the catalyst system, and branched allylic sulfones can be obtained, in good to excellent yields and regiOSElectivities.
46 citations
TL;DR: It is suggested that one function of naturally occurring coniferyl and cinnamyl derivatives may be chemical defense in agricultural crops, as an inherent defense against pests and pathogens, may be possible.
Abstract: Phenylpropanoids, a class of common phenolic compounds in plants, may potentially be useful as pest repellents. We investigated the relationship between the chemical structure of coniferyl benzoate and its repellency to birds by comparing coniferyl benzoate to two analogous natural esters, corresponding alcohols, and benzoic acid. The absolute and relative feeding repellency of these compounds were assessed in choice (two-cup) and no-choice (one-cup) tests using European Starlings (Sturnus vulgaris). In addition, benzoin Siam (= gum benzoin Siam) was compared to coniferyl benzoate to ascertain if phenolics that naturally occur with coniferyl benzoate in benzoin Siam enhance its repellency. Two-cup tests suggested that coniferyl alcohol was the most repellent compound followed by 3,4-dimethoxycinnamyl alcohol, 3,4-dimethoxycinnamyl benzoate, cinnamyl alcohol, cinnamyl benzoate, coniferyl benzoate, and benzoic acid. The repellency of most alcohols relative to their corresponding ester reversed in the one-cup tests. One-cup tests suggested that 3,4-dimethoxycinnamyl benzoate was the most repellent substance followed by cinnamyl benzoate, benzoin Siam, 3,4-dimethoxycinnamylalcohol, cinnamyl alcohol, coniferyl alcohol, coniferyl benzoate, and benzoic acid. Three conclusions on structure-activity relationships were inferred from these data. First, benzoate esters are more repellent than their corresponding alcohols.Second, repellency is increased by electron-donating groups. Third, acidic functions decrease repellency. We suggest that one function of naturally occurring coniferyl and cinnamyl derivatives may be chemical defense. Genetically engineering agricultural crops to produce analogs of coniferyl alcohol, as an inherent defense against pests and pathogens, may be possible.
46 citations
45 citations
TL;DR: Subnanocatalysts containing various noble metals with sizes of approximately 1 nm were synthesized using dendritic poly(phenylazomethine)s as a macromolecular template, resulting in the formation of valuable organic products, including benzoic acid as the major product.
Abstract: Subnanocatalysts (SNCs) containing various noble metals (Cu, Ru, Rh, Pd, or Pt) with sizes of approximately 1 nm were synthesized using dendritic poly(phenylazomethine)s as a macromolecular template. These materials exhibit high catalytic performance during toluene oxidation without the use of harmful solvents or explosive oxidants, resulting in the formation of valuable organic products, including benzoic acid as the major product. In particular, Pt19 SNC with a narrow particle size distribution exhibits extraordinary catalytic activity, with a turnover frequency of 3238 atom-1 h-1 , which is 1700 times greater than that obtained by commercial Pt/C catalysts.
45 citations