18803-19-5Relevant academic research and scientific papers
Substituent and Surfactant Effects on the Photochemical Reaction of Some Aryl Benzoates in Micellar Green Environment?
Siano, Gastón,Crespi, Stefano,Bonesi, Sergio M.
, p. 1298 - 1309 (2021/05/07)
In this study, we carried out preparative and mechanistic studies on the photochemical reaction of a series of p-substituted phenyl benzoates in confined and sustainable micellar environment. The aim of this work is mainly focused to show whether the nature of the surfactant (ionic or nonionic) leads to noticeable selectivity in the photoproduct formation and whether the electronic effects of the substituents affect the chemical yields and the rate of formation of the 5-substituted-2-hydroxybenzophenone derivatives. Application of the Hammett linear free energy relationship (LFER) on the rate of formation of benzophenone derivatives, on the lower energy band of the UV-visible absorption spectra of the aryl benzoates and 5-substituted-2-hydroxybenzophenone derivatives allows a satisfactory quantification of the substituent effects. Furthermore, UV-visible and 2D-NMR (NOESY) spectroscopies have been employed to measure the binding constant Kb and the location of the aryl benzoates within the hydrophobic core of the micelle. Finally, TD-DFT calculations have been carried out to estimate the energies of the absorption bands of p-substituted phenyl benzoates and 5-substituted-2-hydroxybenzophenone derivatives providing good linear correlation with those values measured experimentally.
Selectivity in the photo-fries rearrangement of some aryl benzoates in green and sustainable media. Preparative and mechanistic studies
Siano, Gastón,Bonesi, Sergio M.,Crespi, Stefano,Mella, Mariella
, p. 4338 - 4352 (2019/05/01)
Irradiation of a series of p-substituted aryl benzoates under N2 atmosphere in homogeneous and micellar media was investigated by means of steady-state condition and of time-resolved spectroscopy. A notable selectivity in favor of the 2-hydroxybenzophenone derivatives was observed in micellar media. The benzophenone derivatives were the main photoproduct. On the other hand, in homogeneous media (cyclohexane, acetonitrile, and methanol) the observed product distribution was entirely different, viz. substituted 2-hydroxybenzophenones, p-substituted phenols, benzyl and benzoic acid were found. The binding constants in the surfactant were also measured and NOESY experiments showed that the aryl benzoates were located in the hydrophobic core of the micelle. Laser flash photolysis experiments led to the characterization of both p-substituted phenoxy radical and substituted 2-benzoylcyclohexadienone transients in homogeneous and micellar environment.
Nusbiarylins, a new class of antimicrobial agents: Rational design of bacterial transcription inhibitors targeting the interaction between the NusB and NusE proteins
Qiu, Yangyi,Chan, Shu Ting,Lin, Lin,Shek, Tsun Lam,Tsang, Tsz Fung,Zhang, Yufeng,Ip, Margaret,Chan, Paul Kay-sheung,Blanchard, Nicolas,Hanquet, Gilles,Zuo, Zhong,Yang, Xiao,Ma, Cong
, (2019/08/26)
Discovery of antibiotics of a novel mode of action is highly required in the fierce battlefield with multi-drug resistant bacterial infections. Previously we have validated the protein-protein interaction between bacterial NusB and NusE proteins as an unp
[4 + 2]-Cycloaddition and 1,4-Addition of ortho-Quinone Methides by a Chiral Crotyl Silane
Wong, Christopher R.,Hummel, Gerald,Cai, Yongqi,Schaus, Scott E.,Panek, James S.
supporting information, p. 32 - 35 (2019/01/04)
Anhydrous FeCl3 in the presence of 2,6-lutidine promotes the substrate-controlled enantioselective [4 + 2]-cycloaddition and crotylation reaction between an enantioenriched (S,E)-crotyl silane and in situ generated ortho-quinone methides (oQMs)
Copper catalyzed oxidative deamination of Betti bases: An efficient approach for benzoylation/formylation of naphthols and phenols
Deb, Mohit L.,Pegu, Choitanya Dev,Borpatra, Paran J.,Baruah, Pranjal K.
, p. 40552 - 40559 (2016/05/24)
An efficient route for benzoylation or formylation of naphthols/phenols is developed via oxidative deamination of Betti bases. A copper salt catalyst with TBHP as an oxidant is used. Water is used as a reagent as well as solvent. The reaction proceeds through a regioselective radical pathway. Most importantly, the position of acylation is unambiguous. The method is also applicable to non-hydroxy substrates.
Direct C-H bond arylation of 2-hydroxybenzaldehydes with arylboronic acids via ligand-free palladium catalysis
Weng, Fei,Wang, Chengming,Xu, Bin
supporting information; experimental part, p. 2593 - 2596 (2010/07/04)
A mild and efficient ligand-free palladium-catalyzed direct C-H bond arylation reaction was developed to afford 2-hydroxybenzophenones in good to excellent yields from easily available 2-hydroxybenzaldehydes and arylboronic acids. The given reaction provided one of the easiest pathways for accessing 2-hydroxybenzophenones, and a variety of functional groups could be tolerated in this process.
One-step reaction of friedel-crafts acylation and demethylation of aryl-methyl ethers catalyzed by ytterbium(III) triflate
Su, Weike,Jin, Can
, p. 4199 - 4205 (2007/10/03)
Catalytic amount of ytterbium(III) inflate [Yb(OTf)3] has been used to catalyze Friedel-Crafts acylation and demethylation of aryl-methyl ethers in one-step reaction to produce hydroxyacylphenones with moderate yields under mild conditions.
Preparation of hydroxybenzophenones using silica-gel supported ferric chloride
Bendale, Pravin M.,Khadilkar, Bhushan M.
, p. 1738 - 1739 (2007/10/03)
The synthesis of commercially important hydroxybenzophenones by condensing phenols with benzotrichloride has been reported. Benzoylation is catalyzed by silica supported ferric chloride under solvent-free conditions. Hydroxybenzophenones are isolated in low to moderate yields.
Fries rearrangement at atmospheric pressure using microwave irradiation
Khadilkar, Bhushan M.,Madyar, Virendra R.
, p. 1195 - 1200 (2007/10/03)
A very safe, fast and practical Fries rearrangement with conventional AlCl3 catalyst, carried out in a modified domestic microwave oven at atmospheric pressure is reported.
Hydroxylation of Nitroarenes with Alkyl Hydroperoxide Anions via Vicarious Nucleophilic Substitution of Hydrogen
Makosza, Mieczyslaw,Sienkiewicz, Krzysztof
, p. 4199 - 4208 (2007/10/03)
Rhone-Poulenc Polska Ltd., ul. Grzybowska 80/82, 00-844 Warszawa, Poland Garbo- and heterocyclic nitroarenes react with anions of tert-butyl and cumyl hydroperoxides in the presence of strong bases to form substituted o- and p-nitrophenols. The reaction usually proceeds in high yields and is of practical value as a method of synthesis and manufacturing of nitrophenols. Orientation of the hydroxylation can be controlled to a substantial extent by selection of the proper conditions. Basic mechanistic features of this process were clarified.
