A visible-light-induced cascade radical trifluoromethylation/cyclization/dearomatization reaction between isocyanide-containing indoles and CFBr has been developed to afford trifluoromethylated spiro[indole-3,3-quinoline] and spiro [indole-3,3-pyrrole] derivatives in good yields. The utility of the process is demonstrated by a scale-up experiment. The mechanism was proposed based on the control experiments.
View Article and Find Full Text PDFAn efficient [3 + 2] cycloaddition reaction of difluoromethyl or trifluoromethyl hydrazonoyl bromides with trifluoromethyl-substituted alkenes was investigated to produce a variety of 3,5-bis(fluoroalkyl)pyrazoles/pyrazolines in moderate to good yields. This protocol features obvious advantages such as easily available and stable substrates, step economy, gram-scalability and simple operation, providing a novel and practical method for the preparation of 3,5-bis(fluoroalkyl)pyrazoles/pyrazolines.
View Article and Find Full Text PDFA concise and efficient method for the construction of fully substituted difluoromethylpyrazoles is achieved by a cyclization reaction between difluoroacetohydrazonoyl bromides and 2-acylacetonitrile or malononitrile. The method features advantages such as mild reaction conditions, broad substrate scope, good product yields, and high regioselectivity.
View Article and Find Full Text PDFAn efficient [3 + 2] cycloaddition reaction between generated nitrile imines from hydrazonoyl halides and vinylsulfonium salts is developed. The nitrile imines are demonstrated to be a new class of reaction partner for vinylsulfonium salts to conduct the [3 + 2] cycloaddition reaction. The process provides a concise and efficient method for the construction of pyrazole derivatives under mild reaction conditions with broad substrate scope, good product yields, and high regioselectivity.
View Article and Find Full Text PDFUV can serve as an effective light spectrum for regulating plant secondary metabolites, while relevant studies on UV-A are much less extensive than those on UV-B. A comprehensive understanding of the selective effects of UV-A on different secondary metabolites and the specific features of primary metabolism that drive these effects is still lacking. To address this knowledge gap, we conducted a study to analyze the dynamic changes in the metabolome and transcriptome of lettuce leaves irradiated with red plus UV-A light (monochromatic red light as control).
View Article and Find Full Text PDFAn effective [3 + 2] cycloaddition reaction of difluoromethyl or trifluoromethyl hydrazonoyl bromides with alkylidene pyrazolones was disclosed. This method provides an efficient approach for accessing a variety of highly functionalized fluoroalkyl spiropyrazolones in good yields. This protocol also features some advantages such as easily available and stable substrates, simple operation procedures, and atom and step economy.
View Article and Find Full Text PDFA highly efficient and metal-free [3+2] cyclization/rearrangement reaction toward the synthesis of multisubstituted trifluoromethyloxazolines from α-hydroxyketones and trifluoromethyl -acylhydrazones has been developed. The unprecedented rearrangement of the amide fragment under acidic conditions after cleavage of the N-N bond of acylhydrazones has opened up new avenues for the development of reactions involving trifluoromethyl -acylhydrazones. DFT calculations show that the mechanism involves multiple proton transfer processes.
View Article and Find Full Text PDFA visible-light-induced four-component Ritter-type reaction was developed for the synthesis of β-trifluoromethyl imides from CFBr, alkenes, carboxylic acids, and nitriles. This protocol features mild reaction conditions, a broad substrate scope, and excellent functional group compatibility. Furthermore, this method has been proven to be suitable for the late-stage diversification of drug molecules.
View Article and Find Full Text PDFIntroduction: In precision agriculture, the diagnosis of the nitrogen (N) nutrition status based on the plant phenotype, combined effects of soil types, various agricultural practices, and environmental factors which are essential for plant N accumulation. It helps to assess the N supply for plants at the right time and optimal amount to ensure high N use efficiency thereby reducing the N fertilizer applications to minimize environmental pollution. For this purpose, three different experiments were performed.
View Article and Find Full Text PDFEfficient visible-light-induced radical cascade trifluoromethylation/cyclization of inactivated alkenes with CFBr, which is a nonhygroscopic, noncorrosive, cheap and industrially abundant chemical, was developed in this work, producing trifluoromethyl polycyclic quinazolinones, benzimidazoles and indoles under mild reaction conditions. The method features wide functional group compatibility and a broad substrate scope, offering a facile strategy to pharmaceutically produce valuable CF-containing polycyclic -heterocycles.
View Article and Find Full Text PDFHouttuynia cordata is a medicinal and edible plant with a wide biological interest. Many parts were discarded due to various modes of consumption, resulting in resource waste. In this study, a comprehensive study was conducted on various edible indicators and medicinal components of Houttuynia cordata to understand its edible and medicinal value.
View Article and Find Full Text PDFNitrogen (N) is an essential element for plant growth and development. The application of a balanced and optimal amount of N is required for sustainable plant yield. For this, different N sources and forms are used, that including ammonium (NH) and nitrate (NO).
View Article and Find Full Text PDFAn efficient and novel photoinduced trifluoromethylation employing CFBr as a trifluoromethyl source is described. With commercially accessible -Ir(ppy) as the catalyst, radical trifluoromethylation between -silyl enol ether and CFBr occurs successfully. This method provides various α-CF-substituted ketones with a broad substrate scope in good yields under mild reaction conditions.
View Article and Find Full Text PDFA tandem addition/cyclization reaction between trifluoromethyl -acylhydrazones and cyanamide is described, which provides a novel and efficient process for the synthesis of polysubstituted 3-trifluoromethyl-1,2,4-triazolines and their derivatives. The method has the advantages of mild reaction conditions, a broad substrate scope, good product yields, and atom economy.
View Article and Find Full Text PDFAsynchronized and non-uniform seed germination is causing obstacles to the large-scale cultivation of carrot ( L.). In the present study, the combination of high voltage electrostatic field treatment (EF) with hydropriming (HYD), namely hydro-electro hybrid priming (HEHP), significantly improved all germination indicators of carrot seeds, and the promoting effect was superior to that of the HYD treatment.
View Article and Find Full Text PDFAs novel and efficient difluoromethyl building blocks, difluoroacetohydrazonoyl bromides have been synthesized for the first time. The synthetic utility of this reagent for the construction of difluoromethyl organic compounds is demonstrated by their effective regioselective [3 + 2] cycloaddition reactions with ynones, alkynoates, and ynamides. The reactions provide a novel and efficient protocol to access difluoromethyl-substituted pyrazoles in good to excellent yields.
View Article and Find Full Text PDFCarrot ( L.) is widely cultivated as one of the most important root crops, and developing an effective presowing treatment method can promote the development of modern mechanized precision sowing. In the present study, a novel seed priming technology, named hydro-electro hybrid priming (HEHP), was used to promote the germination of carrot seeds.
View Article and Find Full Text PDFPurpose: China was affected by an outbreak of coronavirus disease 2019 (COVID-19) in 2019-2020. Research data are needed to develop evidence-driven strategies to reduce the adverse psychological and occupational impacts on healthcare workers (HCWs).
Methods: From March 1, 2020, to March 8, 2020, 946 HCWs in China completed a survey consist of sociodemographic data, precautionary measures against COVID-19, and concerns about COVID-19.
In plants, alternative splicing (AS) is markedly induced in response to environmental stresses, but it is unclear why plants generate multiple transcripts under stress conditions. In this study, RNA-seq was performed to identify AS events in cucumber seedlings grown under different light intensities. We identified a novel transcript of the gibberellin (GA)-deactivating enzyme Gibberellin 2-beta-dioxygenase 8 (CsGA2ox8).
View Article and Find Full Text PDFA highly efficient strategy for the construction of CF-substituted 1,6-dihydropyridazines has been developed by cascade oxidation/cyclization of trifluoromethylated -acylhydrazines. The produced 1,6-dihydropyridazines could be easily transformed to 3-trifluoromethyl pyridazine derivatives. Some of the 1,6-dihydropyridazines exhibited aggregation-induced emission (AIE).
View Article and Find Full Text PDFIntroduction: Data analysis during UPLC-MS non-targeted metabolomics introduces variation as different manufacturers use specific algorithms for data treatment and this makes untargeted metabolomics an application for the discovery of new biomarkers with low confidence in the reproducibility of the results under the use of different metabolomics platforms.
Objectives: This study compared the ability of two platforms (Agilent UPLC-ESI-QTOF-MS and Waters UPLC-IMS-QTOF-MS) to identify biomarkers in butterhead and romaine lettuce cultivars.
Methods: Two case studies by different metabolomics platforms: (1) Waters and Agilent datasets processed by the same data pre-processing software (Progenesis QI), and (2) Datasets processed by different data pre-processing software.
An efficient sulfide-catalyzed [2 + 1] annulation of para-quinone methides (p-QMs) with diverse bromides has been achieved. This catalytic strategy provides an efficient and straightforward protocol for accessing a variety of spiro-cyclopropanyl-cyclohexadienone compounds in good to excellent yields (64% to 96% yields) with outstanding diastereoselectivities (>20 : 1 dr), displaying good functional group tolerance as well as gram-scale capacity.
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