The asymmetric reduction of N-aryl imines derived from acetophenones by using Ru complexes bearing both a pybox (2,6-bis(oxazoline)pyridine) and a monodentate phosphite ligand has been described. The catalysts show good activity with a diverse range of substrates, and deliver the amine products in very high levels of enantioselectivity (up to 99 %) under both hydrogenation and transfer hydrogenation conditions in isopropanol. From deuteration studies, a very different labeling is observed under hydrogenation and transfer hydrogenation conditions, which demonstrates the different nature of the hydrogen source in both reactions.
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http://dx.doi.org/10.1002/chem.201405276 | DOI Listing |
J Am Chem Soc
January 2025
Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520, United States.
Hydrogen atom transfer (HAT) reactions and their kinetic barriers Δ are important in organic and inorganic chemistry. This study examines factors that influence Δ, reporting the kinetics and thermodynamics of HAT from various ruthenium bis(acetylacetonate) pyridine-imidazole complexes to nitroxyl radicals. Across these 36 reactions, the Δ and Δ can be independently varied, with different sets of Ru complexes primarily tuning either their ps or their °s.
View Article and Find Full Text PDFWater Res
January 2025
National Engineering Research Center of Industrial Wastewater Detoxication and Resource Recovery, East China University of Science and Technology, Shanghai, 200237, China. Electronic address:
The challenges faced by sludge pyrolysis units, including poor heat transfer efficiency and uneven heating of material groups, significantly hinder the green and low-carbon transformation and sustainable development of sludge treatment. The suspension self-rotation of sludge particles in a cyclone enhances particle heat transfer, thereby improving the pyrolysis process. In this study, we developed a novel method for sludge pyrolysis using Cyclone Suspension Self-Rotation Pyrolysis Reactor (CSSPR).
View Article and Find Full Text PDFSci Rep
January 2025
School of Environmental Science and Engineering, Yancheng Institute of Technology, Yancheng, 224051, People's Republic of China.
MXenes, as a novel two-dimensional lamellar material, has attracted much attention. However, MXenes lamellar are prone to collapse and stacking under hydrogen bonding and interlayer van der Waals forces, which affects their electrochemical and capacitive deionization performance. A three-dimensional Ni-1,3,5-benzenetricarboxylate/TiCT (Ni-BTC/TiCT) composite electrode material was developed to enhance the electrochemical and capacitive deionization performance.
View Article and Find Full Text PDFNature
January 2025
Institute for Extra-Cutting-Edge Science and Technology Avant-Garde Research (X-star), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Japan.
In subsurface methanogenic ecosystems, the ubiquity of methylated-compound-using archaea-methylotrophic methanogens-implies that methylated compounds have an important role in the ecology and carbon cycling of such habitats. However, the origin of these chemicals remains unclear as there are no known energy metabolisms that generate methylated compounds de novo as a major product. Here we identified an energy metabolism in the subsurface-derived thermophilic anaerobe Zhaonella formicivorans that catalyses the conversion of formate to methanol, thereby producing methanol without requiring methylated compounds as an input.
View Article and Find Full Text PDFNat Commun
January 2025
School of Physical Science and Technology, ShanghaiTech University, 393 Middle Huaxia Road, Shanghai, China.
Hydrogen-transfer is the primary process responsible for elevating the degree of unsaturation of intermediates in zeolite-catalyzed methanol-to-hydrocarbon reactions, with olefins serving as the typical receptor and alkanes being produced as the by-product. Intriguingly, the introduction of CO was shown to suppress the selectivity of alkanes and enhance the production of aromatics, yet microscopic understanding of this phenomenon remains elusive. Here, based on ab initio molecular dynamics simulations and free energy sampling methods, we discover a non-olefin-induced hydrogen-transfer reaction in the presence of CO, with ketene/acetyl emerging as a more suitable hydrogen-transfer receptor than olefins.
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