121-92-6Relevant academic research and scientific papers
A green, reusable and highly efficient solid acid catalyst for the oxidation of aldehydes to the corresponding carboxylic acids using H 2O2 and KMnO4:H5PV 2Mo10O40 (10-molybdo-2-vanadophosphoric heteropolyacid)
Shojaei, Abdollah Fallah,Rezvani, Mohamad Ali,Heravi, Majid
, p. 1513 - 1522 (2011)
H5PV2Mo10O40-catalyzed oxidation of aromatic aldehydes to the corresponding carboxylic acids using hydrogen peroxide and KMnO4 as oxidants under mild conditions is reported. This system provides an efficient, convenient and practical method for the oxidation of aromatic aldehydes. In this work, differences between Keggin and Well-Dawson type polyoxometalates are addressed in term of relative stability, hardness and acidity.
Screening of various procedures for the oxidation of a 1,3-diol with a 2-benzylic position; how to obtain the 1,3-diketone?
Provent,Chautemps,Pierre
, p. 1907 - 1912 (1995)
Various oxidizing procedures (Swern, Collins, Dess-Martin, Corey (PCC), MnO2, TEMPO, Jones) have been screened with the aim of oxidizing a 1,3-diol with a 2-benzylic position, into the corresponding β-diketone. Surprisingly, this functional group interconversion has been successfully achieved only by a special version of the Jones procedure.
Intensification of Nitrobenzaldehydes Synthesis from Benzyl Alcohol in a Microreactor
Russo, Danilo,Di Somma, Ilaria,Marotta, Raffaele,Tomaiuolo, Giovanna,Andreozzi, Roberto,Guido, Stefano,Lapkin, Alexei A.
, p. 357 - 364 (2017)
A one-step process to produce 2- and 3-nitrobenzaldehyde isomers starting from benzyl alcohol in aqueous mixed nitric and sulfuric acid was developed as an inherently safe continuous flow process in a microreactor. The previously published kinetic model was validated in a microreactor and used to optimize operating conditions in silico to attain the desired product distribution. The molar fractions of nitric and sulfuric acids were increased up to 0.35, 0.45, and temperature to 68 °C, which was impossible to do under batch conditions. Experiments under continuous flow conditions have shown that yields of about 42% and 96% for the ortho- and the meta- isomers, respectively, can be achieved.
Facile and selective deprotection of allyl esters catalyzed by H-β zeolite
Pandey, Rajesh K.,Kadam, Vijay S.,Upadhyay, Rajesh K.,Dongare, Mohan K.,Kumar, Pradeep
, p. 3017 - 3024 (2003)
Carboxylic acids are regenerated from their corresponding allyl or cinnamyl esters by H-β zeolite under environmentally safe, heterogeneous reaction conditions in excellent yields.
Ag-nanoparticle embedded p(AA) hydrogel as an efficient green heterogeneous Nano-catalyst for oxidation and reduction of organic compounds
Ghorbanloo, Massomeh,Heydari, Ali,Yahiro, Hidenori
, (2018)
P(AA)-Ag heterogeneous catalyst system comprised of Ag nanoparticles embedded within hydrogel matrices has been described for the selective aerobic oxidation of alcohols and reduction of nitro phenols in water. P(AA)-Ag nanocomposite was characterized by Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermal gravimetric analysis (TGA), X-Ray photoelectron spectroscopy (XPS) and inductively coupled plasma atomic emission spectrometer (ICP). Catalytic activity of p(AA)-Ag catalyst was investigated in the aerobic oxidation of primary alcohols and reduction of nitro compounds by emphasizing the effect of different parameters such as temperature, catalyst amount, substituent effect, etc. The catalyst was easily recovered from the reaction medium and it could be re-used for other three runs without significant loss of activity.
Solvolysis of substituted benzoyl chlorides in nonionic and mixed micellar solutions
Campos-Rey,Cabaleiro-Lago,Hervés
, p. 14004 - 14011 (2010)
The solvolysis of substituted benzoyl chlorides is sensitive both to substituent electronic effects and to medium effects. The solvolysis reactions of substituted benzoyl chlorides have been analyzed in the presence of nonionic micelles. The reaction is inhibited or catalyzed depending on the reaction mechanism, dissociative or associative, respectively. The micellar effects observed can be related to the low water content and low polarity of the interface as well as an increase of the nucleophilic character of the interfacial water. Moreover, the effect of the micellar surface charge on the solvolysis mechanism with high associative character was systematically studied. Mixed micelles of nonionic-ionic surfactants with a variable ionic content were prepared and characterized regarding charge and polarity. A correlation between the net charge of the micelles and the rate constants at the micellar interface was observed. The results suggest that the transient state for this mechanism is highly stabilized in a positively charged environment while the negative surface given by anionic micelles strongly inhibit the solvolysis reaction.
Oxidative cleavage of aryl oxazolines using Methyl(trifluoromethyI)dioxirane generated in situ
Yang, Dan,Yip, Yiu-Chung,Wang, Xue-Chao
, p. 7083 - 7086 (1997)
Oxidative cleavage of aryl oxazoline 2 using methyl(trifluoromethyl)dioxirane la generated in situ provides the intermediate nitro-ester 8, which undergoes a basic hydrolysis to furnish benzoic acid 11. Even the hindered oxazoline 7 can be cleaved smoothly to afford 3,3'-dimethyl-2,2'-diphenic acid 16. All substituted benzoic acids 11-16 can be isolated in excellent yields (80-95 %).
Synthesis of stilbene, 1,4-distyrylbenzene and 4,4′-distyrylbiphenyl via Horner-Wadsworth-Emmons reaction in phase-transfer catalysis system
Zhao, Qiangqiang,Sun, Jie,Liu, Baojiang,He, Jinxin
, p. 339 - 347 (2013)
Stilbenes, 1,4-distyrylbenzenes and 4,4′-distyrylbiphenyls were synthesized via Horner-Wadsworth-Emmons (HWE) reaction in liquid-liquid (LL) and solid-liquid (SL) phase transfer catalysis (PTC) systems. The effect of the side reaction, reactants and the third phase on the activity of HWE reaction were investigated. For aldehydes bearing electron-donating substitute, the yields were more than 90% and the products were all (E)-isomers in both PTC systems. The SL-PTC system was milder than LL-PTC system for HWE reaction due to the different mechanisms. The side reaction of aldehyde was similar to Cannizzaro reaction, whereas the molar ratio of benzoic acid to benzyl alcohol as the products was not 1:1. The limited third phase was discovered to exist in LL-PTC system. In SL-PTC system, the third phase could increase substantially the reaction rate. Moreover, the aqueous phase in LL-PTC system could be reused four times without sacrifice of the yield and reaction rate.
Kinetics of Oxidation of Benzaldehydes by Quinolinium Dichromate
Medien, Hesham A. A.
, p. 1201 - 1205 (2003)
Quinolinium dichromate (QDC) in sulfuric acid oxidizes benzaldehydes to the corresponding acids in a 50% (v/v) acetic acid-water medium. The reaction is first order each in [QDC], [substrate] and [H+]. The reaction rates have been determined at different temperatures and the activation parameters calculated. The rate decreases with an increase in the water content of the medium. The effects of substituents have been studied. A suitable mechanism is proposed.
Kinetics and Mechanism of the Oxidation of Substituted Benzaldehydes by N-Bromobenzamide
Banerji, Kalyan K.
, p. 4764 - 4767 (1986)
The oxidation of eighteen meta- and para-substituted benzaldehydes by N-bromobenzamide (NBB), to the corresponding benzoic acid, is first order with respect to the aldehyde, NBB, and hydrogen ion.The oxidation of benzaldehyde exhibited a substantial primary kinetic isotope effect(kH/kD = 5.3 +/- 0.1).Addition of benzamide has no effect on the reaction rate. (PhCONH2Br)+ has been postulated as the reactive oxidizing species.The rates of the oxidation of meta- and para-substituted benzaldehydes were separately correlated in Taft's and Swain's dual substituent parameter equations.For para-substituted aldehydes, the best correlation was obtained with ?1 and ?R+ values, while meta-substituted compounds correlate with ?1 and ?R0 values.The reaction constants have negative values.A mechanism involving transfer of a hydride ion from the aldehyde to the oxidant, in the rate-determining step, has been proposed.
