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
Catalytic SNAr Hydroxylation and Alkoxylation of Aryl Fluorides
Kang, Qi-Kai,Li, Ke,Li, Yuntong,Lin, Yunzhi,Shi, Hang,Xu, Lun
supporting information, p. 20391 - 20399 (2021/08/13)
Nucleophilic aromatic substitution (SNAr) is a powerful strategy for incorporating a heteroatom into an aromatic ring by displacement of a leaving group with a nucleophile, but this method is limited to electron-deficient arenes. We have now established a reliable method for accessing phenols and phenyl alkyl ethers via catalytic SNAr reactions. The method is applicable to a broad array of electron-rich and neutral aryl fluorides, which are inert under classical SNAr conditions. Although the mechanism of SNAr reactions involving metal arene complexes is hypothesized to involve a stepwise pathway (addition followed by elimination), experimental data that support this hypothesis is still under exploration. Mechanistic studies and DFT calculations suggest either a stepwise or stepwise-like energy profile. Notably, we isolated a rhodium η5-cyclohexadienyl complex intermediate with an sp3-hybridized carbon bearing both a nucleophile and a leaving group.
Reductive Cleavage of Unactivated Carbon-Cyano Bonds under Ammonia-Free Birch Conditions
An, Jie,Ding, Yuxuan,Luo, Shihui,Ma, Lifu
, (2019/11/29)
A general protocol for the reductive cleavage of unactivated carbon-cyano bonds in aliphatic nitriles has been achieved under single-electron-transfer conditions using Na/15-crown-5/H2O. Electron is supplied by the electride derived from bench-stable sodium dispersions and recoverable 15-crown-5. H2O provides the proton source and suppresses the reduction of aromatic moieties. Compared with the Na/NH3 electride system generated under traditional Birch conditions, this ammonia-free electride system is more practical and features better reactivity and chemoselectivity for the decyanations of a broad range of aliphatic nitriles.