5859-41-6Relevant academic research and scientific papers
MnO2?Fe3O4 Magnetic Nanoparticles as Efficient and Recyclable Heterogeneous Catalyst for Benzylic sp3 C?H Oxidation
Pandey, Akanksha M.,Agalave, Sandip G.,Vinod, Chathakudath P.,Gnanaprakasam, Boopathy
supporting information, p. 3414 - 3423 (2019/10/19)
Herein, we report a highly chemoselective and efficient heterogeneous MnO2?Fe3O4 MNP catalyst for the oxidation of benzylic sp3 C?H group of ethers using TBHP as a green oxidant to afford ester derivatives in high yield under batch/continuous flow module. This catalyst was also effective for the benzylic sp3 C?H group of methylene derivatives to furnish the ketone in high yield which can be easily integrated into continuous flow condition for scale up. The catalyst is fully characterized by spectroscopic techniques and it was found that 0.424 % MnO2?Fe3O4 catalyzes the reaction; the magnetic nanoparticles of this catalyst could be easily recovered from the reaction mixture. The recovered catalyst was recycled for twelve cycles without any loss of the catalytic activity. The advantages of MnO2?Fe3O4 MNP are its catalytic activity, easy preparation, recovery, and recyclability, gram scale synthesis with a TOF of up to 14.93 h?1 and low metal leaching during the reaction.
Iron-doped single-walled carbon nanotubes as new heterogeneous and highly efficient catalyst for acylation of alcohols, phenols, carboxylic acids and amines under solvent-free conditions
Sharghi, Hashem,Jokar, Mahboubeh,Doroodmand, Mohammad Mahdi
experimental part, p. 426 - 442 (2011/04/15)
Iron-doped single-walled carbon nanotubes (Fe/SWCNTs) represent an efficient and new heterogeneous reusable catalyst for the acylation of a variety of alcohols, phenols, carboxylic acids and amines with acid chlorides or acid anhydrides under solvent-free conditions. The reactions of various primary, secondary, tertiary, and benzylic alcohols, diols, phenols, as well as aromatic and aliphatic amines give acylated adducts in good to excellent yields.
A convenient procedure for the esterification of benzoic acids with phenols: a new application for the Mitsunobu reaction
Fitzjarrald, Victor P.,Pongdee, Rongson
, p. 3553 - 3557 (2008/02/06)
The Mitsunobu reaction was found to be a convenient and effective method for the esterification of various benzoic acids with differentially functionalized phenols producing the corresponding phenyl esters in good to excellent yields.
Evidence of substituent-induced electronic interplay. Effect of the remote aromatic ring substituent of phenyl benzoates on the sensitivity of the carbonyl unit to electronic effects of phenyl or benzoyl ring substituents
Neuvonen, Helmi,Neuvonen, Kari,Pasanen, Paavo
, p. 3794 - 3800 (2007/10/03)
Carbonyl carbon 13C NMR chemical shifts δC(C=O) measured in this work for a wide set of substituted phenyl benzoates p-Y-C 6H4CO2C6H4-p-X (X = NO2, CN, Cl, Br, H, Me, or MeO; Y = NO2, Cl, H, Me, MeO, or NMe2) have been used as a tool to study substituent effects on the carbonyl unit. The goal of the work was to study the cross-interaction between X and Y in that respect. Both the phenyl substituents X and the benzoyl substituents Y have a reverse effect on δC(C=O). Electron-withdrawing substituents cause shielding while electron-donating ones have an opposite influence, with both inductive and resonance effects being significant. The presence of cross-interaction between X and Y could be clearly verified. Electronic effects of the remote aromatic ring substituents systematically modify the sensitivity of the C=O group to the electronic effects of the phenyl or benzoyl ring substituents. Electron-withdrawing substituents in one ring decrease the sensitivity of δC(C=O) to the substitution of another ring, while electron-donating substituents inversely affect the sensitivity. It is suggested that the results can be explained by substituent-sensitive balance of the contributions of different resonance structures (electron delocalization, Scheme 1).
Electrochemical generation and reactions of acyloxytriphenylphosphonium ions
Ohmori, Hidenobu,Maeda, Hatsuo,Kikuoka, Masayuki,Maki, Toshihide,Masui, Masaichiro
, p. 767 - 776 (2007/10/02)
Constant-current electrolysis, in an undivided cell, of Ph3P in the presence of a carboxylic acid in CH2Cl2 containing 2,6-lutidinium perchlorate as the supporting electrolyte was shown to generate the corresponding acyloxyphosphonium ion, Ph3P+-OCOR, which was converted in situ to esters, amides, and β-lactams under mild conditions.
EFFECT OF NEIGHBORING PYRIDINIUM GROUPS ON THE BASIC HYDROLYSIS OF ARYLBENZOATE ESTERS
Engbersen, J. F. J.,Geurtsen, G.,Bie, D. A. De,Plas, H. C. Van Der
, p. 1795 - 1802 (2007/10/02)
Arylbenzoate esters with a quaternary pyridinium group ortho to the ester function exhibit enhanced reactivity towards basic hydrolysis relative to their para analogs in the order pyridinium 4-aminocarbonylpyridinium 3-aminocarbonylpyridinium 3-aminocarbonylquinolium.In contrast, a trimethylammonium group in the ortho position shows a decelerating effect relative to the para analog.It is concluded that the catalytic effect of a neighboring pyridinium group is based upon interaction of the negatively charged transition state of ester hydrolysis with the electron deficient ?-system of the pyridinium ring.For the p-methoxyphenolate ester containing the 3-aminocarbonylpyridinium group in the ortho position this interaction leads to a change in mechanism from rate limiting hydroxide ion attack to hydroxide ion catalyzed expulsion of the leaving group as became apparent from deviation of the Hammett plot and second-order dependence on OH(1-) concentration.For the p-nitrophenolate ester it was observed that decrease of the solvent polarity by addition of dioxane results in an increase of the rate of hydrolysis and a marked increase of the neighboring group effect.
