7471-31-0Relevant articles and documents
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.
Dual aminoquinolate diarylboron and nickel catalysed metallaphotoredox platform for carbon-oxygen bond construction
Day, Craig,Jia, Xin,Wei, Lanfeng,Xu, Liang,Zu, Weisai
supporting information, p. 8273 - 8276 (2020/08/17)
Herein, aminoquinolate diarylboron complexes are utilized as photocatalysts in dual Ni/photoredox catalyzed carbon-oxygen construction reactions. Via this unified metallaphotoredox platform, diverse (hetero)aryl halides can be conveniently coupled with acids, alcohols and water. This method features operational simplicity, broad substrate scope and good compatibility with functional groups. This journal is
Nucleophilic substitution reactions of Y-Substituted-Phenyl Benzoates with Potassium Ethoxide in Anhydrous Ethanol: Reaction Mechanism and Role of K+ Ion
Kim, Song-I,Cho, Hyo-Jin,Um, Ik-Hwan
, p. 177 - 181 (2014/02/14)
Pseudo-first-order rate constants (kobsd) have been measured spectrophotometrically for the reactions of Ysubstituted-phenyl benzoates (5a-j) with potassium ethoxide (EtOK) in anhydrous ethanol at 25.0 ± 0.1 °C. The plots of kobsd vs. [EtOK] curve upward regardless of the electronic nature of the substituent Y in the leaving group. Dissection of kobsd into the second-order rate constants for the reactions with the dissociated EtOV and ion-paired EtOK (i.e., kEtO-and kEtOK, respectively) has revealed that the ion-paired EtOK is more reactive than the dissociated Et-V. The Bronsted-type plots for the reactions with the dissociated Et-V and ion-paired EtOK exhibit highly scattered points with βlg = -0.5 ± 0.1. The Hammett plots correlated with ao constants result in excellent linear correlations, indicating that no negative charge develops on the O atom of the leaving Ysubstituted-phenoxide ion in transition state. Thus, it has been concluded that the reactions with the dissociated EtOV and ion-paired EtOK proceed through a stepwise mechanism, in which departure of the leaving group occurs after the RDS, and that K+ ion catalyzes the reactions by increasing the electrophilicity of the reaction center through a four-membered cyclic TS structure.
