621-37-4Relevant academic research and scientific papers
Palladium-Catalyzed meta-Selective C-H Alkenylation and Acetoxylation of Arylacetic Acid Using a Pyrimidine Template
Jiao, Bo,Peng, Zhen,Dai, Zhen-Hua,Li, Lei,Wang, He,Zhou, Ming-Dong
, p. 3195 - 3202 (2019)
Palladium-catalyzed remote meta-selective C-H functionalization of arylacetic acid has been developed using a pyrimidine template. This transformation is not only tolerated to a diverse range of arylacetic acid and alkene substrates but also applicable to the synthesis of pharmaceutically active ibuprofen derivatives. Moreover, the pyrimidine template was readily removable and recyclable under mild conditions.
Tuning the redox potential of Ag?Ag2O/WO3 and Ag?Ag2S/WO3 photocatalysts toward diclofenac oxidation and nitrophenol reduction
Ismail, Eman H.,Khalil, Mostafa M. H.,Mohamed, Mohamed Mokhtar,Torad, Eman
, (2021/01/05)
WO3 nanoplates modified with either Ag2O or Ag2S nano-architectures were synthesized by a deposition-hydrothermal route (180 °C for 5 h). They were characterized using X-ray powder diffraction, N2 sorptiometry, Transmission electron microscopy, UV–vis diffuse reflectance spectroscopy, Photoluminescence spectroscopy, and X-ray photoelectron spectroscopy. The photo-catalytic (λ > 420 nm, 160 W) degradation of Diclofenac (DCF; 60 mg/l), was achieved using H2O2 (1 × 10?4 M) with either Ag?Ag2O/WO3 (K = 32.0 × 10-3 min-1) or Ag?Ag2S/WO3 (K = 7.3 × 10-3 min-1) catalysts. In the case of DCF degradation using radical scavengers, [rad]O2? played a key role in the degradation process whilst [rad]OH and holes acted moderately minor roles. The possible DCF degradation paths and intermediates were assessed by LC–MS. Both Ag?Ag2O/WO3 and Ag?Ag2S/WO3 catalysts were used in the photo-reduction of 4-nitrophenol (4-NP; 1.8 × 10?4 M) to 4-aminophenol (4-AP) with rate constants equal 8.3 x 10?3 min-1 and 1.6 x 10?3 min?1, respectively.
Copper and L-(?)-quebrachitol catalyzed hydroxylation and amination of aryl halides under air
Bao, Xuefei,Chen, Guoliang,Dong, Jinhua,Du, Fangyu,Li, Hui,Liang, Xinjie,Wu, Ying,Zhang, Yongsheng
supporting information, (2020/08/03)
L-(?)-Quebrachitol, a natural product obtained from waste water of the rubber industry, was utilized as an efficient ligand for the copper-catalyzed hydroxylation and amination of aryl halides to selectively give phenols and aryl amines in water or 95percent ethanol. In addition, the hydroxylation of 2-chloro-4-hydroxybenzoic acid was validated on a 100-g scale under air.
Application of quebrachitol in hydrolysis reaction of copper-catalyzed aryl halide
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Paragraph 0054-0056, (2019/07/16)
The invention belongs to the technical field of drug synthesis, and provides application of quebrachitol in a hydrolysis reaction of a copper-catalyzed aryl halide. According to the hydrolysis reaction, copper serves as a catalyst, quebrachitol serves as a ligand, and the hydrolysis reaction is carried out on the aryl halide. The invention further provides a catalytic system of the hydrolysis reaction of the aryl halide. The reaction system comprises the copper catalyst, the quebrachitol, alkali and water, and the system is environmentally friendly and is suitable for industrial application.
Photogenerated α,n-didehydrotoluenes from chlorophenylacetic acids at physiological pH
Ravelli, Davide,Protti, Stefano,Fagnoni, Maurizio
supporting information, p. 852 - 858 (2015/03/05)
Aromatic diradicals are recognized as promising intermediates for DNA cleavage, but their formation has thus far been limited to the Bergman and Myers-Saito cycloaromatizations. We report here the phototriggered generation of all isomers of the potential DNA-cleaving α,n-didehydrotoluene diradicals at physiological pH, accomplished by the irradiation of chlorophenylacetic acids under mild conditions. The desired diradicals were formed upon photolysis of the chosen aromatic in aqueous phosphate buffer solution (pH = 7.3), with the consecutive elimination of biologically compatible chloride ion and carbon dioxide. Theoretical simulations reveal that the efficient decarboxylation of the primarily generated phenyl cations involves a previously not known diradical structure.
Toward a high added value compound 3, 4-dihydroxyphenylacetic acid by electrochemical conversion of phenylacetic acid
Trabelsi, Souhel Kallel,Dridi Gargouri, Olfa,Gargouri, Boutheina,Abdelhèdi, Ridha,Bouaziz, Mohamed
, p. 370 - 376 (2015/05/27)
Abstract The development of the effective procedure to recover the potentially high-added-value phenolic compound, 3,4-dihydroxyphenylacetic acid (3,4-DHPAA) was investigated using electrochemical conversion of phenylacetic acid (PAA). The proposed mechanism is based on the hypothesis of two-electron oxidation of PAA molecule leading to 3-hydroxyphenyl acetic acid. The latter underwent a second bi-electronic transfer by means of a radical cation, thus leading to the formation of the 2,5 dihydroxyphenylacetic (2,5-DHPAA) acid and 3,4-DHPAA as major products. The 3,4-DHPAA was synthesized by anodic oxidation of PAA at lead dioxide electrode and identified by cyclic voltammetry and spectrophotometry UV-visible. It was also confirmed by mass spectrophotometry using LC-MS/MS apparatus. According to their voltammetric behavior during electrolysis, the oxidation potential of 3,4-DHPAA was lower than that of PAA. The antioxidant activity was measured by DPPH assay, showing that the strongest antiradical activity was detected when the 3,4-DHPAA concentration was higher during electrolysis experiments.
Effect of deuterated solvents toward 2,2,2-trichloroethyl esters with a benzylic methylene moiety
Mineno, Tomoko,Hirayama, Haruyasu,Nakahara, Kazuhide,Yamashita, Mitsuaki,Kansui, Hisao,Moriwaki, Hiroshi
experimental part, p. 6045 - 6048 (2010/11/21)
The indium-promoted chemoselective deprotection of 2,2,2-trichloroethyl esters containing a benzylic methylene was successfully achieved by employing deuterated solvents.
Synthesis of hydroxytyrosol, 2-hydroxyphenylacetic acid, and 3-hydroxyphenylacetic acid by differential conversion of tyrosol isomers using Serratia marcescens strain
Allouche, Noureddine,Sayadi, Sami
, p. 6525 - 6530 (2007/10/03)
We investigated to develop an effective procedure to produce the potentially high-added-value phenolic compounds through bioconversion of tyrosol isomers. A soil bacterium, designated Serratia marcescens strain, was isolated on the basis of its ability to grow on p-tyrosol (4-hydroxyphenylethanol) as a sole source of carbon and energy. During growth on p-tyrosol, Ser. marcescens strain was capable of promoting the formation of hydroxytyrosol. To achieve maximal hydroxytyrosol yield, the growth state of the culture utilized for p-tyrosol conversion as well as the amount of p-tyrosol that was treated were optimized. The optimal yield of hydroxytyrosol (80%) was obtained by Ser. marcescens growing cells after a 7-h incubation using 2 g/L of p-tyrosol added at the end of the exponential phase to a culture pregrown on 1 g/L of p-tyrosol. Furthermore, the substrate specificity of the developed biosynthesis was investigated using m-tyrosol (3-hydroxyphenylethanol) and o-tyrosol (2-hydroxyphenylethanol) as substrates. Ser. marcescens strain transformed completely m-tyrosol and o-tyrosol into 3-hydroxyphenylacetic acid and 2-hydroxyphenylacetic acid, respectively, via the oxidation of the side chain carbon of the treated substrates. This proposed procedure is an alternative approach to obtain hydroxytyrosol, 2-hydroxyphenylacetic acid, and 3-hydroxyphenylacetic acid in an environmentally friendly way which could encourage their use as alternatives in the search for replacement of synthetic food additives.
Reductive deprotection of aryl allyl ethers with Pd(Ph3)4/NaBH4
Beugelmans, Rene,Bourdet, Sebastien,Bigot, Antony,Zhu, Jieping
, p. 4349 - 4350 (2007/10/02)
Treatment of aryl allyl ethers with catalytic amounts of Pd(PPh3)4 and NaBH4 at room temperature afforded the parent phenol in high yield under non-hydrolytic conditions.
Aromatic Hydroxylation with an Iron(III)-Catechol-H2O2 System. Mechanistic Implication of the Role of Catechol
Tamagaki, Seizo,Suzuki, Kenji,Tagaki, Waichiro
, p. 148 - 152 (2007/10/02)
The role of catechol in benzene hydroxylation with Fe3+/catechol/H2O2 system, the so-called Hamilton system, has been mechanistically investigated by using tiron as a substitute for pyrocatechol.The yield of phenol progresses linearly with reaction time.The phenol yield is dependent on the mole ratio of Fe3+ relative to tiron, and the ratio of more than unity is particularly important for the effective functioning of the catalyst system.The o-, m-, and p-product isomer distributions for a few aromatic hydrocarbons are nearly identical with those of the Fenton reaction.These and the separate experimental results are consistent with the mechanism involving the rate-limiting redox reaction between tiron and Fe3+ and then the follow-up radical chain sequence as in the Fenton reaction.
