Issues related to the use of sulfur based fluorination and fluoroalkylation reagents for the synthesis of organic chemicals are discussed. Topics discussed include using sulfoximines as ...perfluoroalkylation reagents and sulfonium salts as perfluoroalkylation reagents.
•Transduction mechanism of all-solid-state ion-selective electrodes and reference electrodes is discussed.•Approaches to improve the performance (i.e., reproducibility, signal stability and low ...detection limit) of all-solid-state ion-selective electrodes and reference electrodes are critically discussed along with recent examples from the literature.•New directions of the field (e.g., calibration-free sensors and novel sensor designs) are presented.
Potentiometric sensing, which requires the use of ion-selective electrodes (ISEs) and reference electrodes, is used to determine electrochemically the concentration of target ions in a variety of chemical environments. In view of the need for more affordable and portable analytical devices with small sample volumes, all-solid-state ISEs and reference electrodes, in which a solid contact is used as ion-to-electron transducer, are highly desirable. This review describes how all-solid-state ISEs and reference electrodes function and presents important aspects that should be considered when designing such sensors for specific applications. Approaches to improving reproducibility, the stability of the emf response, lowering detection limits, and novel sensor designs are discussed along with specific examples from the recent literature. Emphasis is placed on the ion-to-electron transduction mechanism and the development of new solid contact materials, with a particular view to miniaturized ion-sensing devices with low cost and calibration-free sensing.
The selective incorporation of fluorine atoms or fluorinated moieties into organic molecules has become a “hot” research topic in modern organic chemistry. However, selective and efficient synthesis ...of organofluorine compounds greatly depends on the development of powerful fluorination or fluoroalkylation reagents and reactions. In this context, the past decade has witnessed rapid research progress in the development of α‐fluoro sulfoximines as versatile fluoroalkylation reagents. Many efficient nucleophilic, electrophilic and radical fluoroalkylation reactions based on α‐fluoro sulfoximine reagents have been developed; among these, several chiral sulfoximine reagents were successfully used in the synthesis of enantiomerically enriched organofluorine compounds. It was found that α‐fluoro sulfoximines show unique chemical behaviour characteristics (such as difluorocarbene and fluoroalkyl radical reactivities) significantly different from those of their non‐fluorinated counterparts. In addition to the rapid development of fluorinated sulfoximines in organic synthesis, research into their application in materials science has also attracted increasing attention. Sulfoximines are important bioactive substances, and more recently the synthesis and application of fluorinated sulfoximines has attracted much attention in life sciences and the pharmaceutical industry. In this microreview we summarize the preparation, reactions and applications of fluorinated sulfoximines (mainly α‐fluoro sulfoximines).
During the last forty years, particularly in the past decade, fluorinated sulfoximines have attracted much attention and experienced rapid research progress in organic synthesis and materials‐ and life‐science‐related fields. In this microreview we summarize the preparation, reactions and applications of fluorinated sulfoximines (mainly α‐fluoro sulfoximines).
Summary
Shade affects all aspects of plant growth and development, including seed germination, hypocotyl elongation, petiole growth, leaf hyponasty, and flowering time. Here, we found that mutations ...in the key Arabidopsis karrikins signal perception‐associated KARRIKIN INSENSITIVE 2 (KAI2) gene, encoding an α/β‐fold hydrolase, and the MORE AXILLARY GROWTH 2 (MAX2) gene, encoding an F‐box protein, led to greater hypocotyl elongation under shade avoidance conditions.
We further verified that these phenotypes were caused by perception of the endogenous KAI2‐ligands (KLs), and that this phenotype is independent of strigolactone biosynthetic or signaling pathways. Upon perception of a KL, it is probable that the target protein forms a complex with the KAI2/MAX2 proteins, which are degraded through the action of the 26S proteasome.
We demonstrated that SUPPRESSOR OF MAX2‐1 (SMAX1) is the degradation target for the KAI2/MAX2 complex in the context of shade avoidance. KAI2 and MAX2 require SMAX1 to limit the hypocotyl growth associated with shade avoidance. Treatment with l‐kynurenine, an inhibitor of auxin accumulation, partially restored elongation of kai2 mutant hypocotyls under simulated shade. Furthermore, KAI2 is involved in regulating auxin accumulation and polar auxin transport, which may contribute to the hypocotyl shade response.
In addition, SMAX1 gene overexpression promoted the hypocotyl shade response. RNA‐sequencing analysis revealed that SMAX1‐overexpression affected the expression of many auxin homeostasis genes, especially under simulated shade. Altogether, our data support the conclusion that KL signaling regulates shade avoidance by modulating auxin homeostasis in the hypocotyl.
Fluorinated sulfinate salts RfSO2Na (Rf = CF2H, CF2Ph, and CH2F) have been prepared via NaBH4-mediated reduction of the corresponding benzodthiazol-2-yl sulfones, and their synthetic application as ...di- and monofluoroalkyl radical precursors is demonstrated in the silver-catalyzed cascade fluoroalkylation/aryl migration/SO2 extrusion of conjugated N-arylsulfonylated amides.
Owing to the excellent performance of fluorinated compounds in the areas of pharmaceuticals, agrochemicals, and materials chemistry, organic chemists have made great efforts towards the selective ...incorporation of fluorine or fluorinated moieties into organic molecules through nucleophilic, electrophilic, radical, and metal‐catalyzed pathways. Impressive progress in fluorination and perfluoroalkylation (especially trifluoromethylation) reactions has been made over the past few decades. However, methods for incorporating lightly fluorinated groups (such as −CF2H) are still underdeveloped, in spite of their important applications in pharmaceuticals and agrochemicals. This Focus Review summarizes recent developments in metal‐catalyzed direct difluoromethylation reactions.
Fluoro and fauna: The incorporation of CF2H groups into organic compounds has attracted much recent attention, owing to the broad applications of CF2H‐containing compounds in pharmaceuticals and agrochemicals. Metal‐catalyzed direct difluoromethylation represents one of the most powerful tools for the synthesis of difluoromethylated compounds. This Focus Review describes the recent developments and remaining challenges in this field.
Nitrate can affect many aspects of plant growth and development, such as promoting root growth and inhibiting the synthesis of secondary metabolites. However, the mechanisms underlying such effects ...and how plants can integrate nitrate signals and root growth needs further exploration. Here, we identified a nitrate-inducible NAC family transcription factor (TF) NAC056 which promoted both nitrate assimilation and root growth in Arabidopsis. NAC056 is a nuclear-localized transcription activator, which is predominantly expressed in the root system and hypocotyl. Using the yeast one-hybrid assay, we identified the NAC056-specific binding sequence (NAC56BM), T T/G/A NCTTG. We further showed that the nac056 mutant compromised root growth. NAC056 overexpression promotes LR Initiation and nitrate deficiency tolerance. Using RNA sequencing analysis and in vitro biochemical experiment, we found NAC056 regulated the expression of genes required for NO3- assimilation, directly targeting the key nitrate assimilation gene NIA1. In addition, mutation of NIA1 suppresses LR development and nitrate deficiency tolerance in the 35S::NAC056 transgenic plants. Therefore, NAC056 mediates the response of plants to environmental nitrate signals to promote root growth in Arabidopsis.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Radical fluoroalkylation of alkenes has been developed by electrochemical reduction of fluoroalkyl sulfones. A series of electron-deficient alkenes readily undergo hydrofluoroalkylation in good to ...excellent yields. This chemistry represents the first example of electrochemical generation of fluoroalkyl radicals from sulfones, which are used for practical radical fluoroalkylation of organic compounds.
Radical fluoroalkylation of alkenes has been developed by electrochemical reduction of fluoroalkyl sulfones.
The selective introduction of fluorine atom(s) and fluorinated moieties into organic molecules has become an important and fast-growing research field, since fluorine atoms play crucial roles in life ...science and materials science-related applications. Similar to the trifluoromethyl group, both difluoromethyl and monofluoromethyl groups can often bring about many beneficial effects to the target molecules, and a variety of CF(2)H- and CH(2)F-containing pharmaceuticals and agrochemicals have been developed. Among the synthetic methods for CF(2)H- and CH(2)F-containing compounds, selective di- and monofluoromethylation (i.e., introduction of CF(2)H and CH(2)F groups into organic molecules) represent one of the most straightforward synthetic methods and thus can be conveniently used in the synthetic design. This feature article summarizes the presently known selective difluoromethylation and monofluoromethylation methods, including nucleophilic, electrophilic, and free radical di- and monofluoromethylation reagents and reactions.
Ion‐selective electrodes (ISEs) are widely used tools for fast and accurate ion sensing. Herein their design is simplified by embedding a potentiometric cell into paper, complete with an ISE, a ...reference electrode, and a paper‐based microfluidic sample zone that offer the full function of a conventional ISE setup. The disposable planar paper‐based ion‐sensing platform is suitable for low‐cost point‐of‐care and in‐field testing applications. The design is symmetrical and each interfacial potential within the cell is well defined and reproducible, so that the response of the device can be theoretically predicted. For a demonstration of clinical applications, paper‐based Cl− and K+ sensors are fabricated with highly reproducible and linear responses towards different concentrations of analyte ions in aqueous and biological samples. The single‐use devices can be fabricated by a scalable method, do not need any pretreatment prior to use, and only require a sample volume of 20 μL.
Paper‐based sensors: Embedding a potentiometric cell into paper brings selective ion sensors into the reach of users with limited resources and training. The paper‐based device is simple to use, does not need any pretreatment, and requires only a low sample volume of 20 μL. It can be used to detect clinically relevant ions in biological samples with high sensitivity and reproducibility. ISE=ion‐selective electrode.
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