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Bartholomus Pieber Jamal A. Malik Cristian Cavedon Sebastian Gisbertz Aleksandr Savateev Daniel Cruz Tobias Heil Guigang Zhang Peter H. Seeberger 《Angewandte Chemie (International ed. in English)》2019,58(28):9575-9580
Cross‐coupling reactions mediated by dual nickel/photocatalysis are synthetically attractive but rely mainly on expensive, non‐recyclable noble‐metal complexes as photocatalysts. Heterogeneous semiconductors, which are commonly used for artificial photosynthesis and wastewater treatment, are a sustainable alternative. Graphitic carbon nitrides, a class of metal‐free polymers that can be easily prepared from bulk chemicals, are heterogeneous semiconductors with high potential for photocatalytic organic transformations. Here, we demonstrate that graphitic carbon nitrides in combination with nickel catalysis can induce selective C?O cross‐couplings of carboxylic acids with aryl halides, yielding the respective aryl esters in excellent yield and selectivity. The heterogeneous organic photocatalyst exhibits a broad substrate scope, is able to harvest green light, and can be recycled multiple times. In situ FTIR was used to track the reaction progress to study this transformation at different irradiation wavelengths and reaction scales. 相似文献
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P.K.A. De Witt Huberts L. Lapikás H. De Vries J.B. Bellicard J.M. Cavedon B. Frois M. Huet Ph. Leconte A. Nakada Phan Xuan Ho S.K. Platchkov I. Sick 《Physics letters. [Part B]》1977,71(2):317-320
Cross sections for magnetic elastic electron scattering of high multipolarity from 51V and 59Co have been measured. They are interpreted in terms of the rms radius of the proton orbit. The results for 51V and 59Co 1f rms radii are smaller by 3% and 9%, respectively, than predicted by the Hartree-Fock-Bogoliubov theory. 相似文献
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Enrico Lepre Dr. Sylvain Rat Dr. Cristian Cavedon Prof. Peter H. Seeberger Dr. Bartholomäus Pieber Prof. Markus Antonietti Dr. Nieves López-Salas 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2023,135(2):e202211663
The influence of structural modifications on the catalytic activity of carbon materials is poorly understood. A collection of carbonaceous materials with different pore networks and high nitrogen content was characterized and used to catalyze four reactions to deduce structure–activity relationships. The CO2 cycloaddition and Knoevenagel reaction depend on Lewis basic sites (electron-rich nitrogen species). The absence of large conjugated carbon domains resulting from the introduction of large amounts of nitrogen in the carbon network is responsible for poor redox activity, as observed through the catalytic reduction of nitrobenzene with hydrazine and the catalytic oxidation of 3,3′,5,5′-tetramethylbenzidine using hydroperoxide. The material with the highest activity towards Lewis acid catalysis (in the hydrolysis of (dimethoxymethyl)benzene to benzaldehyde) is the most effective for small molecule activation and presents the highest concentration of electron-poor nitrogen species. 相似文献
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