Dehydrogenation Of N-heterocycles Research Articles

Hydrogenation and dehydrogenation of N-heterocycles under Cp*Co(III)-catalysis.

To realize the goal of a carbon-free energy economy, it is crucial to discover reactions that utilize sustainable resources as alternatives to fossil feedstocks. In this study, a well-defined, air-stable Cp*Co(III)-catalyst for transfer hydrogenation of quinoline derivatives and oxidative dehydrogenation of cyclic amines in water is developed. While the former reaction is promoted by formic acid as a transfer hydrogenation reagent, the latter is mediated by molecular oxygen as the sole oxidant. These processes provide new avenues for the investigation of air-stable cobalt catalysts for environmentally benign hydrogenation and dehydrogenation reactions.

Ce-promoted highly active bifunctional Pd/Al2O3 catalyst for reversible catalytic hydrogenation and dehydrogenation of N-propylcarbazole

In this work, we prepared highly dispersed CeO2 nanoparticle-modified Pd/Al2O3 catalyst and applied it for the reversible hydrogenation and dehydrogenation of N-propylcarbazole. Compared with the commercially available 1 wt% Pd/Al2O3 catalyst, the catalyst Pd/CeAl-20 exhibited better catalytic performance, realizing the full hydrogenation of N-propylcarbazole and the full dehydrogenation of perhydro-N-propylcarbazole within 180 min. Thus, it shows excellent commercial potential in large-scale applications. XRD and CO pulse chemisorption results indicated that CeO2 improved the dispersion of Pd nanoparticles on the support surface. H2-TPR measurements indicated that CeO2 weakened the strong interaction between the Pd particles and the support, inhibiting the formation of stable PdO. HRTEM images and XPS spectroscopic analysis show an apparent electronic transfer between Pd and CeO2 at the Pd–CeO2 interface. The formed Pd–O–Ce structure modulates the electronic state of the Pd particles, which contributes to the excellent catalytic performance of the Pd/CeAl-20 catalyst. This study reveals the crucial role of the combined promotion of the size of the active site and the chemical microenvironment for the reversible hydrogenation and dehydrogenation of N-heterocycles.

Reusable Iron/Iron Oxide-based Nanoparticles Catalyzed Organic Reactions

ABSTRACT:The last decade has witnessed a remarkable progress in the field of nanoscience and nanotechnology. Nanoparticles have been extensively used in diverse areas, including medicine, sensor, and catalysis. The easy accessibility of nanoparticles (NPs) with different shapes, sizes and compositions has inspired researchers to investigate their applications in catalysis. Recently, magnetic nanoparticles, such as iron-based nanoparticles, have attracted much consideration due to their unique properties, such as superparamagnetism, greater surface area, surface-to-volume ratio, and easy separation methodology. They increase the competence of organic reactions in terms of activity, selectivity, yield, simplicity, and sustainability. In this review, we focus on the developments of iron/iron oxide-based nanoparticles-catalyzed organic reactions and some examples of magnetic iron oxide nanoparticles as carriers/support for the main catalyst in organic reactions. Owing to magnetic properties, these nanocatalysts can be easily recovered from the reaction mixture by an external magnet and reused for several runs without loss of catalytic activity. Iron-based nanoparticles are used in a wide range of catalytic processes and applications. Notable focus has been on the hydrogenation of alkenes and alkynes, and also the hydrogenation of nitroarenes to aniline. Other catalyzed organic reactions, such as hydroboration of aldehydes and ketones, oxidative dehydrogenation of N-heterocycles, azide-alkyne cycloaddition reactions, synthesis of various heterocyclic compounds, multicomponent reactions, and crosscoupling reactions for C–C and C–heteroatom bond formation have been covered.

B,F Co-Doped Carbocatalysts with Dual-Active-Sites for Acceptorless Dehydrogenation of N-Heterocycles Under Room Temperature

B,F Co-Doped Carbocatalysts with Dual-Active-Sites for Acceptorless Dehydrogenation of N-Heterocycles Under Room Temperature

State-of-the-art progress for the selective crystallization of actinides, synthesis of actinide compounds and their functionalization

Crystallization and immobilization of actinides to form actinide compounds are of significant importance for the extraction and reutilization of nuclear waste in the nuclear industry. In this paper, the state-of-art progress in the crystallization of actinides are summarized, as well as the main functionalization of the actinide compounds, i.e., as adsorbents for heavy metal ions and organic pollutant in waste management, as (photo)catalysts for organic degradation and conversion, including degradation of organic dyes and antibiotics, dehydrogenation of N-heterocycles, CO2 cycloaddition, selective alcohol oxidation and selective oxidation of sulfides. This review will give a comprehensive summary about the synthesis and application exploration of solid actinide crystalline salts and actinide-based metal organic frameworks in the past decades. Finally, the future perspectives and challenges are proposed in the end to give a promising direction for future investigation.

Iridium-Catalyzed Acceptorless Dehydrogenation of N-Heterocycles and Hydrogenation of N-Hetarenes

Iridium-Catalyzed Acceptorless Dehydrogenation of N-Heterocycles and Hydrogenation of N-Hetarenes

Hydrogenation/dehydrogenation of N-heterocycles catalyzed by ruthenium complexes based on multimodal proton-responsive CNN(H) pincer ligands.

Ru complexes based on lutidine-derived pincer CNN(H) ligands having secondary amine side donors are efficient precatalysts in the hydrogenation and dehydrogenation of N-heterocycles. Reaction of a Ru-CNN(H) complex with an excess of base produces the formation of a Ru(0) derivative, which is observed under catalytic conditions.

Dehydrogenation of N-Heterocycles with Cobalt Nanocrystals on Carbon

Dehydrogenation of N-Heterocycles with Cobalt Nanocrystals on Carbon