Oxygen chemistry plays a pivotal role in numerous chemical reactions. In particular, selective cleavage of C-H bonds by metal oxo species is highly desirable in dehydrogenation of light alkanes. However, high selectivity of alkene is usually hampered through consecutive oxygenation reactions in a conventional oxidative dehydrogenation (ODH) scheme. Herein, we show that dual-functional Mo-V-O mixed oxides selectively convert propane to propylene via an alternative chemical looping oxidative dehydrogenation (CL-ODH) approach. At 500 °C, we obtain 89% propylene selectivity at 36% propane conversion over 100 dehydrogenation-regeneration cycles. We attribute such high propylene yield-which exceeds that of previously reported ODH catalysts-to the involvement and precise modulation of bulk lattice oxygen via atomic-scale doping of Mo and show that increasing the binding energy of V-O bonds is critical to enhance the selectivity of propylene. This work provides the fundamental understanding of metal-oxygen chemistry and a promising strategy for alkane dehydrogenation.
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http://dx.doi.org/10.1021/jacs.9b09235 | DOI Listing |
Herein, we present a sustainable and atom-economical approach for the synthesis of quinazolinones via acceptorless dehydrogenative coupling (ADC) using earth-abundant Co-salt, (CoCl2) as the catalyst under neat condition. This method is distinguished by its green credentials, like, solvent-free, microwave-assisted heating, cost-effective, use of renewable alcohols, and generating only H2 and water as byproducts. Remarkably, this protocol achieves quinazolinone synthesis without the need for external ligands, oxidants, or additional additives.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Tianjin University, Department of Chemistry, #92, Weijin Road, Nankai District, Department of Chemistry, School of Science, Tianjin University, 300072, Tianjin, CHINA.
Electrocatalytic oxidation of cyclohexanol/cyclohexanonein water provides a promising strategy for obtaining adipic acid (AA), which is an essential feedstock in the polymer industry. However, this process is impeded by slow kinetics and limited Faradaic efficiency (FE) due to a poor understanding of the reaction mechanism. Herein, NiCo2O4/CeO2 is developed to enable the electrooxidation of cyclohexanol to AA with a 0.
View Article and Find Full Text PDFOrg Lett
January 2025
Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, Hubei Key Laboratory of Bioinorganic Chemistry and Materia Medica, Hubei Engineering Research Center for Biomaterials and Medical Protective Materials, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan 430074, China.
Herein, we report an approach for the synthesis of 2-sulfonyl carbazoles from the oxidative C-H sulfonylation of tetrahydrocarbazoles. The mechanistic study reveals that this special selectivity is realized by the addition of a sulfonyl radical to the 3,4-dihydrocabazole intermediate via dehydrogenative desaturation of tetrahydrocarbazoles. This approach features readily available starting materials, high regioselectivity, broad substrate scope, and attractive synthetic utility.
View Article and Find Full Text PDFOrg Lett
January 2025
China Guangxi Key Laboratory of Pharmaceutical Precision Detection and Screening, Guangxi Key Laboratory of Bioactive Molecules Research and Evaluation, and Key Laboratory of Micro-Nanoscale Bioanalysis and Drug Screening of Guangxi Education Department, Pharmaceutical College, Guangxi Medical University, Nanning 530021, China.
Herein, a one-pot domino catalyzed three-component process is described, which is initiated by a palladium/zinc cooperatively catalyzed cycloaddition between trimethylenemethane (TMM) and unactivated alkyl/aryl imines, followed by one-pot isomerization and Zn(OTf)-catalyzed DDQ oxidation, furnishing valuable substituted pyrroles. We disclose that the palladium/zinc cooperative catalysis affords a dual-Zn(OTf)-stabilized azapalladacycle, wherein the Pd-N bond is polarized by Zn(OTf), facilitating a unique outer-sphere allylic amination. Moreover, subsequent DDQ dehydrogenation can be feasibly promoted by zinc catalysis.
View Article and Find Full Text PDFChemistry
January 2025
Shihezi University, School of Chemistry and Chemical Engineering/State Key Laboratory Incubation Base for Green Processing of Chemical Engineering, North 4th Road, 832003, Shihezi, CHINA.
An N,N,N-type Cu(Ⅱ) complex-catalyzed desaturation method for converting alcohols, ketones, lactones, and lactams to their α,β-unsaturated carbonyl compounds is reported. The dehydrogenation reaction can be conducted with a green terminal oxidant O2 without requiring strong acid/base or stoichiometric oxidants. The Cu(Ⅱ) complex/TEMPO/O2 system uses a non-noble catalyst, and a green terminal oxidant as well as demonstrates high activity and functional group tolerance.
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