A practical protocol for the preparation of quinoxaline‐2,3(1H,4H)‐diones through direct C(sp2)−H hydroxylation of quinoxalin‐2(1H)‐ones in recyclable DL‐α‐Tocopherol methoxypolyethylene glycol ...succinate solution (2 wt% in water) (TPGS‐750‐M/H2O) was developed. The target products were exclusively generated and could be collected through extraction and recrystallization.
Direct olefinic C-H functionalization represents the ideal way of introducing an alkenyl group into organic molecules. A well-known process is the Heck reaction, which involves alkene insertion and ...β-hydride elimination in the presence of a transition metal. However, the traditional Heck reaction mainly deals with the alkenylation of aryl or vinyl electrophiles. Recent developments have revealed that alkenylation can also be achieved through radical addition to alkenes and following single-electron-transfer (SET) oxidation/elimination. The radical alkenylation pathway allows alkenylation with a variety of carbon-centered radicals and even heteroatom-centered radicals. This tutorial review gives an overview of recent advances in this emerging field.
Intermolecular 3 + 2 annulation is one of the most straightforward approaches to construct five membered heterocycles. However, it generally requires the use of functionalized substrates. An ideal ...reaction approach is to achieve dehydrogenative 3 + 2 annulation under oxidant-free conditions. Here we show an electrooxidative 3 + 2 annulation between phenols and N-acetylindoles under undivided electrolytic conditions. Neither external chemical oxidants nor metal catalysts are required to facilitate the dehydrogenation processes. This reaction protocol provides an environmentally friendly way for the selective synthesis of benzofuroindolines. Various N-acetylindoles bearing different C-3 and C-2 substituents are suitable in this electrochemical transformation, furnishing corresponding benzofuroindolines in up to 99% yield.Electrochemical oxidation provides a green alternative to the use of hazardous chemical oxidants and forcing conditions. Here, the authors show the electrocatalytic cross-coupling of phenols and indoles to generate biologically relevant benzofuroindolines in high yields.
Ethylene and ethyne are among the simplest two-carbon building blocks. However, quite limited methods can be applied to incorporate ethylene or ethyne into fine chemicals. Here we demonstrate a ...cobalt-catalyzed dehydrogenative C-H/N-H 4+2 annulation of aryl/vinyl amides with ethylene or ethyne by using an electrochemical reaction protocol. Significantly, this work shows an example of electrochemical recycling of cobalt catalyst in oxidative C-H functionalization reactions, avoiding the use of external chemical oxidants and co-oxidants. The electrochemical method provides a reliable and safe way for incorporating gas-phase ethylene or ethyne into fine chemicals. High reaction efficiency and good functional group tolerance are observed under divided electrolytic conditions.
Plasma miRNAs can characterize several diseases, including acute ischemic stroke (AIS), which is noninvasive and currently affordable in most laboratories worldwide. We aimed to demonstrate plasma ...miR-140-3p, miR-130a-3p, and miR-320b as diagnostic biomarkers in AIS.GSE110993 and GSE86291 datasets were analyzed to obtain plasma differentially expressed miRNAs between AIS and healthy control subjects (HCs). We further applied RT-qPCR for the validation in 85 AIS patients and 85 HCs. Receiver operating characteristic (ROC) curve were conducted to evaluate their diagnostic utility in AIS. Correlation was analyzed between DEmiRNAs and clinical and laboratory parameters, as well as inflammatory markers. The plasma levels of miR-140-3p, miR-130a-3p, and miR-320b were found to be consistently altered in both GSE110993 and GSE86291 datasets. In comparison to HCs, AIS patients at admission exhibited lower levels of miR-140-3p and miR-320b and higher level of miR-130a-3p in their plasma. The ROC analysis revealed that plasma miR-140-3p, miR-130a-3p, and miR-320b had area under the curve values of 0.790, 0.831, and 0.907, respectively. When combined, these miRNAs showed superior discriminatory power with a sensitivity of 91.76% and specificity of 95.29%. Plasma miR-140-3p and miR-320b negatively correlated glucose levels and inflammatory markers (IL-6, MMP-2, MMP-9, and VEGF) in AIS patients. Conversely, plasma miR-130a-3p levels were positively associated with glucose levels and these markers. Plasma miR-140-3p, miR-130a-3p, and miR-320b levels varied significantly among AIS patients with different NIHSS scores. Plasma miR-140-3p, miR-130a-3p, and miR-320b had high diagnostic value in AIS patients, which were correlated with inflammation and severity in stroke.
Dehydrogenative C−H/N−H cross‐coupling serves as one of the most straightforward and atom‐economical approaches for C−N bond formation. In this work, an electrochemical reaction protocol has been ...developed for the oxidative C−H amination of unprotected phenols under undivided electrolytic conditions. Neither metal catalysts nor chemical oxidants are needed to facilitate the dehydrogenation process. A series of triarylamine derivatives could be obtained with good functional‐group tolerance. The electrolysis is scalable and can be performed at ambient conditions.
Undivided attention: An atom‐economical oxidative C−H amination of unprotected phenols was achieved by an external oxidant‐free electrochemical reaction. Under undivided electrolytic conditions, triarylamine derivatives were produced with high functional‐group tolerance along with H2 generation.
An eco-friendly protocol for the synthesis of various 2-sulfonyl quinolines/pyridines through sulfonylation of heteroaromatic N-oxides with sodium sulfinates in water under metal- and oxidant-free ...conditions has been developed. The high reaction efficiency, operational simplicity, short reaction time, air- and moisture-insensitive conditions and remarkable functional group compatibility make the developed protocol very attractive for the preparation of 2-sulfonyl N-heteroaromatic compounds.
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An eco-friendly protocol for the synthesis of various 2-sulfonyl quinolines/pyridines through sulfonylation of heteroaromatic N-oxides with sodium sulfinates in water at ambient temperature under metal- and oxidant-free conditions has been developed. The mild reaction conditions, high reaction efficiency, operational simplicity, short reaction time and remarkable functional-group compatibility make the developed protocol very attractive for the preparation of 2-sulfonyl N-heteroaromatic compounds.
The catalytic performance towards methanol synthesis from CO2 hydrogenation is enhanced by incorporating Ga into ZnZrOx solid solution catalyst. The results from chemisorption and H2-D2 exchange as ...well as in situ DRIFTS show the promoting role of incorporating Ga mainly reflects in improving the adsorption and activation of H2 and CO2 and in boosting the hydrogenation of HCOO* to CH3O*.
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•The methanol synthesis activity is enhanced by incorporated Ga.•The adsorption and activation of H2 and CO2 are greatly promoted by incorporated Ga.•The hydrogenation of HCOO* to CH3O* is boosted by incorporated Ga.
Catalytic conversion of CO2 into methanol utilizing green hydrogen produced from renewable energy is a promising route to realize carbon neutrality. Although ZnZrOx solid solution catalyst displays excellent catalytic performance, it is still highly desired to make any further improvement. Herein, we found the promoting effect of incorporating Ga into ZnZrOx solid solution catalyst in CO2 hydrogenation to methanol. Ga promoted ZnZrOx (GaZnZrOx) solid solution catalyst exhibits CO2 conversion of 8.8% and methanol space time yield of 630 mg gcat−1 h−1 that are higher than those of ZnZrOx solid solution catalyst (7.7%, 556 mg gcat−1 h−1) at 320 °C, while the highly selectivity toward methanol remains unchanged. Chemisorption and H2-D2 exchange results show that GaZnZrOx solid solution catalyst displays higher capacity for the adsorption and activation of H2 than ZnZrOx solid solution catalyst. Electron paramagnetic resonance result suggests that more oxygen vacancies are derived after incorporating Ga into ZnZrOx solid solution catalyst. In situ diffuse reflectance infrared Fourier transform spectra indicate that the HCOO* and CH3O* species are the main intermediate species. The higher IR intensity of intermediate species and lower CH3O*/HCOO* ratio on GaZnZrOx solid solution catalyst suggest that the hydrogenation of HCOO* to CH3O* is boosted. These results reveal the promoting effect of incorporated Ga into ZnZrOx solid solution catalyst that improves the adsorption and activation of H2 and CO2, thus enhancing catalytic performance of methanol synthesis from CO2 hydrogenation.
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