As a widely existing functional group in organic molecules, the carboxyl group has numerous advantageous characteristics such as great convenience for further transformation, relatively low toxicity ...and cost, and weak coordination to transition metal catalysts, which render it an attractive directing group in transition metal‐catalyzed CH bond functionalization reactions. This review surveys transition metal‐catalyzed CH bond functionalization reactions directed by carboxylates, including carbon‐carbon, carbon‐oxygen, and other carbon‐heteroatom bond formation reactions. Reactions directed by the acidic N‐arylamides, which are derived from carboxylic acids and have a directing mode similar to that of carboxylates, are also presented here.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
A highly efficient palladium‐catalyzed disilylation reaction of aryl halides through C−H activation has been developed for the first time. The reaction has broad substrate scope. A variety of aryl ...halides can be disilylated by three types of C−H activation, including C(sp2)−H, C(sp3)−H, and remote C−H activation. In particular, the reactions are also unusually efficient. The yields are essentially quantitative in many cases, even in the presence of less than 1 mol % catalyst and 1 equivalent of the silylating reagent under relatively mild conditions. The disilylated biphenyls can be converted into disiloxane‐bridged biphenyls.
Choice of three: A palladium‐catalyzed disilylation reaction of aryl halides has been developed through C−H activation. The reaction has broad substrate scope and is unusually efficient. A variety of aryl halides can be disilylated by three types of C−H activation, including C(sp2)−H, C(sp3)−H, and remote C−H activation, in excellent yields. The method is scalable and features high atom economy.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
3,4-Fused tricyclic indole scaffolds are ubiquitous in bioactive natural products and pharmaceuticals. A new protocol for the synthesis of 3,4-fused tricyclic indoles has been developed through ...cascade carbopalladation and C–H amination with N,N-di-tert-butyldiaziridinone. The protocol allows access to a range of 3,4-fused tricyclic indoles, including those containing various linkers and fused with medium-sized rings. Rucaparib can be synthesized via this reaction, providing an advantageous synthetic method for the FDA-approved cancer medicine.
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IJS, KILJ, NUK, PNG, UL, UM
The mining industry production is an important pillar industry in China, while its extensive production activities have led to several ecological and environmental problems. Earth observation ...technology using high-resolution satellite imagery can help us efficiently obtain information on surface elements, surveying and monitoring various land occupation issues arising from open-pit mining production activities. Conventional pixel-based interpretation methods for high-resolution remote sensing images are restricted by "salt and pepper" noise caused by environmental factors, making it difficult to meet increasing requirements for monitoring accuracy. With the Jingxiang phosphorus mining area in Jingmen Hubei Province as the studied area, this paper uses a multi-scale segmentation algorithm to extract large-scale main characteristic information using a layered mask method based on the hierarchical structure of the image object. The remaining characteristic elements were classified and extracted in combination with the random forest model and characteristic factors to obtain land occupation information related mining industry production, which was compared with the results of the Classification and Regression Tree model. 23 characteristic factors in three aspects were selected, including spectral, geometric and texture characteristics. The methods employed in this study achieved 86% and 0.78 respectively in overall extraction accuracy analysis and the Kappa coefficient analysis, compared to 79% and 0.68 using the conventional method.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
A facile and efficient approach is developed for the synthesis of fluorene and its derivatives starting from 2-iodobiphenyls and CH2Br2. A range of fluorene derivatives can be synthesized under ...relatively mild conditions. The reaction proceeds via a tandem palladium-catalyzed dual C–C bond formation sequence through the key dibenzopalladacyclopentadiene intermediates, which are obtained from 2-iodobiphenyls through palladium-catalyzed C–H activation.
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An expeditious approach to the construction of spiroindenyl-2-oxindoles was developed via a palladium-catalyzed spirocyclization reaction of 2-bromoarylamides with vinyl bromides. The reaction formed ...spiropalladacycles as the intermediates via carbopalladation and the C-H functionalization of 2-bromoarylamides. The spiropalladacycles reacted with vinyl bromides to form spiroindenyl-2-oxindoles. A Heck process rather than vinylic C-H functionalization was involved in the reaction.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Direct trifluoromethylation of arenes using TFA as the trifluoromethylating reagent was achieved with Ag as the catalyst. This reaction not only provides a new protocol for aryl C–H ...trifluoromethylation, but the generation of CF3· from TFA may prove useful in other contexts and could potentially be extended to other trifluoromethylation reactions.
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A novel and facile approach for the synthesis of triphenylenes has been developed via palladium-catalyzed coupling of 2-iodobiphenyls and iodobenzenes. The reaction involves dual palladium-catalyzed ...C–H activations and double palladium-catalyzed C–C bond formations. A range of unsymmetrically functionalized triphenylenes can be synthesized with the reaction. The approach features readily available starting materials, high atom- and step-economy, and access to various unsymmetrically functionalized triphenylenes.
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The three-component reaction of aryl iodides, alkynes, and diaziridinone is described. The reaction provides an innovative synthetic approach for indoles. The approach features high efficiency, broad ...substrate scope, and excellent regioselectivity. C,C-Palladacycles should act as the intermediates. The C,C-palladacycles are obtained from simple aryl halides and alkynes and then reacted with diaziridinone to afford indoles.
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Tetraphenylenes not only are theoretically and experimentally interesting but also have potential applications in a variety of fields such as materials science, supramolecular chemistry, and ...asymmetric catalysis. A facile and efficient approach is reported for the syntheis of tetraphenylene and its derivatives from 2-iodobiphenyls via Pd-catalyzed C–H activation. A range of substituted tetraphenylenes can be synthesized using this method, and the reaction can be performed on gram scale with relatively high efficiency, demonstrating its practical utility. This novel approach provides easy access to tetraphenylenes and should facilitate research on the application of this type of fascinating molecules.
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