In this article, we describe the development of a new aerobic C-H oxidation methodology catalyzed by a precious metal-free LaMnO perovskite catalyst. Molecular oxygen is used as the sole oxidant in this approach, obviating the need for other expensive and/or environmentally hazardous stoichiometric oxidants. The electronic and structural properties of the LaMnO catalysts were systematically optimized, and a reductive pretreatment protocol was proved to be essential for acquiring the observed high catalytic activities. It is demonstrated that this newly developed method was extremely effective for the oxidation of alkylarenes to ketones as well as for the oxidative dimerization of 2-naphthol to 1,1-binaphthyl-2,2-diol (BINOL), a particularly important scaffold for asymmetric catalysis. Detailed spectroscopic and mechanistic studies provided valuable insights into the structural aspects of the active catalyst and the reaction mechanism.
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http://dx.doi.org/10.1021/acsami.0c20490 | DOI Listing |
Adv Sci (Weinh)
December 2024
Key Lab of Fluorine and Silicon for Energy Materials and Chemistry of Ministry of Education, College of Chemistry and Materials, Jiangxi Normal University, Nanchang, 330022, China.
Oxygen evolution reaction (OER) is an indispensable anode reaction for sustainable hydrogen production from water electrolysis, yet overreliance on metal-based catalysts featured with vibrant d-electrons. It still has notable gap between metal-free and metal-based electrocatalysts, due to lacking accurate and efficient p-band regulation methods on non-metal atoms. Herein, a molecular modularization strategy is proposed for fine-tuning the p-orbital states of series metal-free covalent organic frameworks (COFs) for realizing OER performance beyond benchmark precious metal catalysts.
View Article and Find Full Text PDFOrg Biomol Chem
December 2024
Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361001, Fujian, People's Republic of China.
A novel and transition-metal-free hydrophosphinylation of allenes with secondary phosphine oxides was developed. In the presence of the cheap and commercially available cesium carbonate, various hydrophosphinylation products were synthesized with exclusive regio- and stereoselectivity under mild conditions. This methodology provides simple and efficient access to ()-alkenylphosphine oxides in moderate to excellent yields with a relatively broad substrate scope.
View Article and Find Full Text PDFJ Colloid Interface Sci
December 2024
Chongqing Key Laboratory of Green Catalysis Materials and Technology, College of Chemistry, Chongqing Normal University, Chongqing 401331, China. Electronic address:
The chlor-alkali process is crucial in the modern chemical industry, yet it is highly energy-intensive, consuming about 4 % of global electricity due to the significant overpotential and low selectivity of existing chlorine evolution reaction (CER) electrocatalysts. Although advanced electrocatalysts have reduced the energy demands of the chlor-alkali process, they typically incorporate precious metals. Here, we introduce a novel precious metal-free electrocatalyst, (CoZn)VO@C, with a hollow nanocube structure that exhibits outstanding CER performance.
View Article and Find Full Text PDFJ Am Chem Soc
December 2024
Engineering Research Center of Advanced Rare Earth Materials, Department of Chemistry, Tsinghua University, Beijing 100084, China.
Developing precious metal-free catalysts for organic reactions under mild conditions is urgent. Herein, we report a three-dimensional covalent organic framework (3D-COF) with high crystallinity and permanent pores, termed 3D-TABPA-COF, for the oxidation of tetrahydroquinoline to quinoline. The 3D-TABPA-COF assembled based on ,-bis(4'-amino-[1,1'-biphenyl]-4-yl)-[1,1'-biphenyl]-4,4'-diamine (TABPA) is the catalytic active center for the conversion of tetrahydroquinoline.
View Article and Find Full Text PDFLangmuir
December 2024
National Engineering Laboratory for Modern Silk, College of Textile and Clothing Engineering, Soochow University, Suzhou 215123, China.
Handling tons of waste textiles is a big challenge in the textile and apparel industry. The recycling of waste textiles, especially expensive silk fabrics, is of great significance for resource conservation and green, low-carbon cycle development. In addition, the development of precious metal-free electrocatalysts for the hydrogen evolution reaction (HER) remains a major challenge.
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