100-84-5Relevant articles and documents
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Wender et al.
, p. 4079,4082 (1952)
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Reaction of triaryloxonium salts with bases via dehydroarenes
Tolstaya, Tatiana P.,Tsariev, Dmitry A.,Luzikov, Yury N.
, p. 4457 - 4458 (1997)
Tri-p-tolyloxonium tetrafluoroborate reacts with NaOH in water yielding a mixture of m- and p-cresls (1:1) use of MeOH as solvent rsults in a mixture of m- and p-crescols (1:1), use of MeOH as solvent results in a mixture of m- and p-methoxytoluenes (1:5:1). This result proves this reaction to proceed via 3,4-dehydrotoluene.
Design and Synthesis of Natural Product Inspired Libraries Based on the Three-Dimensional (3D) Cedrane Scaffold: Toward the Exploration of 3D Biological Space
Tajabadi, Fatemeh Mazraati,Pouwer, Rebecca H.,Liu, Miaomiao,Dashti, Yousef,Campitelli, Marc R.,Murtaza, Mariyam,Mellick, George D.,Wood, Stephen A.,Jenkins, Ian D.,Quinn, Ronald J.
, p. 6609 - 6628 (2018)
A chemoinformatic method was developed to extract nonflat scaffolds embedded in natural products within the Dictionary of Natural Products (DNP). The cedrane scaffold was then chosen as an example of a nonflat scaffold that directs substituents in three-dimensional (3D) space. A cedrane scaffold that has three orthogonal handles to allow generation of 1D, 2D, and 3D libraries was synthesized on a large scale. These libraries would cover more than 50% of the natural diversity of natural products with an embedded cedrane scaffold. Synthesis of three focused natural product-like libraries based on the 3D cedrane scaffold was achieved. A phenotypic assay was used to test the biological profile of synthesized compounds against normal and Parkinson's patient-derived cells. The cytological profiles of the synthesized analogues based on the cedrane scaffold revealed that this 3D scaffold, prevalidated by nature, can interact with biological systems as it displayed various effects against normal and Parkinson's patient-derived cell lines.
Competitive homolytic and heterolytic dediazoniation mechanisms: Rate constants and product distribution of methoxy-, hydroxy-, and hydro-dediazoniation of 3- and 4-methylbenzenediazonium salts in acidic MeOH/H2O mixtures
Pazo-Llorente, Roman,Gonzalez-Romero, Elisa,Bravo-Diaz, Carlos
, p. 210 - 220 (2000)
The rates and product distribution for methoxy-, hydroxy- and hydro-dediazoniation and the rate constants for disappearance of 3- and 4-methylbenzenediazonium tetrafluoroborate in acidic MeOH/H2O mixtures, in the presence and absence of electrolytes like HCl, NaCl, and CuCl2, are reported. Data were obtained by using a combination of VIS-UV and HPLC techniques. The kinetics and product distributions are completely consistent with competitive homolytic and heterolytic mechanisms, the heterolytic one being predominant at any solvent composition. Heterolytic data are in agreement with the predictions of a DN+AN mechanism; that is, rate determining formation of an aryl cation that reacts immediately with available nucleophiles. Selectivity values, determined from product yields, are low and independent of solvent composition. Product formation is discussed in terms of a preassociation step between aryl cations and the nucleophile, which does not account for much of the trapping, and a nucleophilic attack on a `free' arenediazonium cation. Activation parameters were also determined at 99.5% MeOH: enthalpies of activation are high and entropies of activation are positive, and they are similar to those reported for pure water.
Mechanistic Aspects of Hydrodeoxygenation of p-Methylguaiacol over Rh/Silica and Pt/Silica
Bouxin, Florent P.,Zhang, Xingguang,Kings, Iain N.,Lee, Adam F.,Simmons, Mark J. H.,Wilson, Karen,Jackson, S. David
, p. 1586 - 1589 (2018)
The mechanism of p-methylguaiacol (PMG) hydrodeoxygenation (HDO) has been examined over two Rh/silica catalysts and a Pt/silica catalyst at 300 °C and 4 barg hydrogen. Sequential conversion of PMG to 4-methylcatechol is followed by m- and p-cresol formation and finally toluene production, although direct conversion of PMG to p-cresol is favored over a commercial Rh/silica catalyst. Dehydroxylation and hydrogenation are shown to occur over metal functions, while demethylation and demethoxylation are favored over the fumed silica support. A mechanistic pathway for HDO of PMG is proposed.
The reduction of aromatic aldehydes to hydrocarbons with borohydride exchange resin (BER)-nickel acetate in methanol
Bandgar,Kshirsagar,Wadgaonkar
, p. 941 - 945 (1995)
Aromatic aldehydes were reduced to the corresponding hydrocarbons with borohydride exchange resin (BER)-nickel acetate in methanol in excellent yields.
Study of gas phase m-cresol alkylation with methanol on solid acid catalysts
Acevedo,Bedogni,Okulik,Padr
, p. 1946 - 1954 (2014)
The gas-phase alkylation of m-cresol with methanol was studied at 523 K on Al-MCM-41 and zeolites ZnY, HBEA, HZSM5 and HMCM22. The acidity was determined by ammonia TPD and FTIR of adsorbed pyridine. On acid sites of moderate strength (Al-MCM-41), initially the O-alkylation rate was higher than the C-alkylation rate. In contrast, formation of dimethylphenols by C-alkylation was highly favored on ZnY and HMCM22 which have both strong acidity although different nature; Lewis (ZnY) and Bronsted and Lewis (HMCM22). High selectivity of 2,5-DMP was observed on HZSM5, probably due to diffusional constraint. All catalysts, except Al-MCM-41, showed deactivation by coke formation.
Rate and Mechanism for the Reaction of the Nitrate Radical with Aromatic and Alkylaromatic Compounds in Acetonitrile
Baciocchi, E.,Giacco, T. Del,Murgia, S. M.,Sebastiani, G. V.
, p. 1246 - 1248 (1987)
The results of a laser photolysis study indicate that an electron transfer process occurs in the reaction of the nitrate radical with aromatic and alkylaromatic compounds.
Transition metal mediated asymmetric synthesis. X. Homochiral ?-complexes with planar chirality: synthetic equivalents of chiral cyclohexadiene dications
Howard, Philip, W.,Stephenson, G. Richard,Taylor, Stephen C.
, p. 97 - 110 (1989)
Homochiral 6-methoxy-substituted dienyltricarbonyliron complexes have been obtained from 1-methylcyclohexa-1,3-diene-5,6-diol (available via microbial oxidation of toluene) by complexation and removal of an allylic substituent with acids or with triphenylcarbenium tetrfluoroborate.A variety of optically active tricarbonyliron complexes have been produced from these compounds.The optical purity of the product and the stereochemistry of the complexation reaction have been determined.The high efficiency of chirality transfer during complexation of 5,6-dimethoxy-substituted dienes makes this method suitable as a general route to resolved organoiron complexes.
Phosphoric acid-modified commercial kieselguhr supported palladium nanoparticles as efficient catalysts for low-temperature hydrodeoxygenation of lignin derivatives in water
Cui, Yuntong,Liu, Zhaohui,Ran, Jiansu,Wang, Jianjian,Yangcheng, Ruixue
, p. 1570 - 1577 (2022/03/14)
Efficient production of high value-added chemicals and biofuels via low-temperature chemoselective HDO of lignin derivatives in water is still a challenge. Here, we construct a low-cost, active and stable Pd/PCE catalyst using phosphoric acid-modified commercial Celite (PCE) as the support, and this catalyst exhibits excellent activity in low-temperature HDO of vanillin as well as other lignin derivatives in water. The superior catalytic performance is due to the presence of P species on the surface of Pd/PCE, accelerating the selective conversion of the intermediate into the final product. Detailed experimental and mechanistic studies reveal that the rapid conversion of the intermediate to the final product proceeds via a free-radical process in an interfacial microenvironment created by intimate interacting between the P species and Pd NPs. The insights of this work provide a new low-cost catalytic system for efficient production of valuable chemicals and future biofuels from lignin derivatives. This journal is
Investigation on the stoichiometry of carbon dioxide in isotope-exchange reactions with phenylacetic acids
Audisio, Davide,Goudet, Amelie,Sallustrau, Antoine,Talbot, Alex,Taran, Frederic
supporting information, (2021/08/10)
The functionalization of carbon dioxide (CO 2) as a C1 building block has attracted enormous attention. Carboxylation reactions, in particular, are of major interest for applications in isotope labeling. Due to the inexpensive nature of CO 2, information about its stoichiometric use is generally unavailable in the literature. Because of the rarity and limited availability of CO 2isotopomers, this parameter is of concern for applications in carbon-isotope labeling. We investigated the effects of the stoichiometry of labeled CO 2on carbon isotope exchange of phenyl? acetic acids. Both thermal and photocatalytic procedures were studied, providing insight into product outcome and isotope incorporation. Preliminary results on isotope-dilution effects of carbonate bases in photocatalytic carboxylation reactions have also been obtained.
Synthesis, in vitro cytotoxicity and anti-platelet activity of new 1,3-bentzenedisulfonamides
Xiu-jie, Liu,Zhi-hao, Zhang,Qing-song, Deng,Xin, Chen,Chao-qing, Wang
, p. 1864 - 1872 (2019/08/26)
To obtain more active and selective anti-platelet candidate drugs, we tried to introduce a methyl group at the 5-position and 6-position of the parent benzene ring first time, respectively or simultaneously. The idea could inspect compound with tetra-substituted or penta-substituted characteristics rather than retained classical 1,3,4-position triple substitutions characteristic whether it continues to have anti-platelet activity in vitro. The biological evaluation revealed that most of compounds with this novel structure were more potent than the positive control drug Picotamide. At the concentration of 1.3 μmol/L, using Arachidonic acid as an inducer, it was found that the anti-platelet activity in vitro of five compounds 1a, 1b, 1c, 2f, and 3d was higher than that of Picotamide and the series 1 compounds were generally higher than that of the series 2 and 3. And with ADP as an inducer, the activity in vitro of nine compounds 2a, 2b, 2d, 2f, 2g, 2h, 3a, 3b, and 3c was more elevated than that of Picotamide and the compounds of series 2 and 3 were all evidently even more active than that of series 1. The proportion of newly designed target compounds with active is higher than that of previously developed series of compounds. Based on the in vitro activity results, a preliminary analysis of the structure–activity relationship was deduced. Meanwhile, cytotoxic effects in vitro of 11 target compounds 1b, 1c, 2f, 2a, 2b, 3a, 3b, 3c, 2d, 2g, and 2h on L-929 cells were analyzed, but the data analysis shows that at two concentrations, target compounds have higher effect on L-929 cells than that of control drug Picotamide. The reason or mechanism for obtaining higher in vitro activity and higher cytotoxicity of the target compound under tetra- or penta- substitutions requires further relevant research work before conclusion can be drawn.
