RESUMO
Herein, a microwave promoted tandem reaction of free primary arylamines with diazo compounds in water for clean synthesis of 2,2-disubstituted 3-oxindoles is present. Water plays important roles in the whole cascade process: O-H insertion to diazo, air oxidation, ortho C-H functionalization, cyclization and 1,2-ester migration. In particular, water plays a mediation role in the site selective ortho-C-H addition.
RESUMO
Collaborative treatment of pollutants is a promising approach for wastewater treatment. In this work, a covalent organic framework material (COFs) with an imine structure was synthesised by the Schiff base reaction, and photochemical tests showed good photochemical effects. It was used to explore the photocatalytic treatment of co-existing pollutants (heavy metal ions and antibiotics) and the performance of treating co-existing wastewater was investigated. The degradation performance of levofloxacin (LVX) and Cr(VI) was improved in the coexisting pollutants system, with the LVX degradation being 4.2 times more effective than that of the LVX solitary system. Moreover, this phenomenon was also observed in LVX/Ag(I), LVX/Fe(III), sulfadiazine/Cr(VI), norfloxacin/Cr(VI) and tetracycline/Cr(VI) systems. The analysis of active species suggesting that the synergistic promotion of photocatalytic oxidation-reduction systems was not only promoting from the improvement of simple charge separation, but it was also found that high-valent metal species can act directly in the oxidative decomposition of antibiotics. The interaction of pollutants and intermediates were rationally exploited and confirmed by control experiments and theoretical calculation. This conclusion helps us to re-examine the underlying mechanisms of photocatalytic synchronous oxidation and reduction reactions, simultaneously beneficial for the development of mixed pollutant control processes.
RESUMO
The de novo construction of enantioenriched 3-hydroxyindolenines and 3-oxindoles from easily available starting materials has been highly desired. Herein, an enantioselectively intermolecular direct [3 + 2] annulation of aryl amine with 2,3-diketoesters to construct 3-hydroxyindolenines with a chiral tertiary alcohol has been disclosed. The results of control experiments and DFT calculation revealed that π - π interaction plays a pivotal role in the enantioselectivity-determining process of [3 + 2] annulation. The following unusual concerted [1,2]-ester migration provides a family of chiral 3-oxindoles in good to excellent yields with excellent enantioselectivity.
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A radical cascade cyclization of 2-alkynylaniline derivatives with sulfonyl chlorides was developed to construct C3-sulfone methylene-substituted indolines in yields of 21 to 85% with a broad substrate scope under metal- and base-free conditions. This protocol could simultaneously build three new chemical bonds and employ a solvent-radical relay strategy, providing a rapid and concise approach toward an indoline framework. Scale-up reactions of this method and further transformations to afford useful indolines were also demonstrated.
RESUMO
Objective@#To explore the latent categories and general demographic characteristics of short form video addiction among college students, so as to provide empirical reference for prevention and intervention of short form video addiction among college students.@*Methods@#Convenience sampling method was used to select 1 386 college students from a certain university in Anhui Province in June 2023. A questionnaire survey was conducted among college students by using the Short Video Addiction Scale. The latent profile analysis method of "individual center" was used to explore the categories of college students short form video addiction, and multiple Logistic regression was used to explore the influence of demographic variables on the latent classification of short form video addiction.@*Results@#College students with short form video addiction were divided into three latent categories:non addiction group (22.15%, n =307), low addiction group (63.28%, n =877) and high addiction group (14.57%, n =202). The results of multiple Logistic regression analysis showed that gender, major type and family location were related with short form video addiction among college students:male students (low addiction group: OR =0.47; high addiction group: OR =0.41), cultural and historical majors (low addiction group: OR =0.66), and students from cities (high addiction group: OR =0.51) were less likely to be involved in short form video addiction ( P <0.05).@*Conclusions@#There is significant group heterogeneity in short form video addiction among college students. Families, schools and society should attach importance and pay attention to the phenomenon of short form video addiction among college students, actively take targeted intervention measures to prevent and reduce the occurrence of short form video addiction symptoms among college students.