Ureas, carbamoyl derivatives, amides, and sulfonamides can be easily prepared from the strained (R,R)-cylohexanediamine urea (1) in high yield, leaving a free amino group that shows good catalytic activity in intramolecular aldol condensations. The preparation of Wieland-Miescher ketone has been studied with these catalysts.
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http://dx.doi.org/10.1021/jo101723v | DOI Listing |
Biochemistry
January 2025
Laboratory of Clinical Biochemistry and Metabolism, Department of General Pediatrics, Adolescent Medicine and Neonatology, Faculty of Medicine, Medical Center, University of Freiburg, Freiburg im Breisgau 79106, Germany.
Human CblC catalyzes the indispensable processing of dietary vitamin B by the removal of its β-axial ligand and an either one- or two-electron reduction of its cobalt center to yield cob(II)alamin and cob(I)alamin, respectively. Human CblC possesses five cysteine residues of an unknown function. We hypothesized that Cys149, conserved in mammals, tunes the CblC reactivity.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
State Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai 200433, China.
Frustrated Lewis pair chemistry (FLP) occupy a crucial position in nonmetal-mediated catalysis, especially toward activation of inert gas molecules. Yet, one formidable issue of homogeneous FLP catalysts is their instability on preservation and recycling. Here we contribute a general solution that marries the polyhedral oligomeric silsesquioxane (POSS) with a structurally specific frustrated Lewis acid to fabricate porous polymer networks, which can form water-insensitive heterogeneous FLP catalysts upon employing Lewis base substrates.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Department of Chemical Engineering, University of Patras, Patras 26504, Greece.
Energy-efficient separation of light alkanes from alkenes is considered as one of the most important separations of the chemical industry today due to the high energy penalty associated with the applied conventional cryogenic technologies. This study introduces fluorine-doped activated carbon adsorbents, where elemental fluorine incorporation into the carbon matrix plays a unique role in achieving high ethane selectivity. This enhanced selectivity arises from specific interactions between surface-doped fluorine atoms and ethane molecules, coupled with porosity modulation.
View Article and Find Full Text PDFNat Commun
January 2025
School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, 637371, Singapore.
Designing efficient Ruthenium-based catalysts as practical anodes is of critical importance in proton exchange membrane water electrolysis. Here, we develop a self-assembly technique to synthesize 1 nm-thick rutile-structured high-entropy oxides (RuIrFeCoCrO) from naked metal ions assembly and oxidation at air-molten salt interface. The RuIrFeCoCrO requires an overpotential of 185 mV at 10 m A cm and maintains the high activity for over 1000 h in an acidic electrolyte via the adsorption evolution mechanism.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
Jiangsu Key Laboratory for Biomass-based Energy and Enzyme Technology, Jiangsu Collaborative Innovation Center of Regional Modern Agriculture & Environmental Protection, School of Chemistry and Chemical Engineering, Huaiyin Normal University, Huai'an 223300, China. Electronic address:
Catalytic depolymerization is a favorable option for the valorization of industrial lignin. In this study, a new strategy was demonstrated for the efficient reductive depolymerization of industrial lignin based on a complex solvent of choline chloride-lactic acid (ChCl-LA) DES integrated with ethanol and a C-supported N-doped niobium-based catalyst with industrial lignin as carbon source (NBC@N-LC). It was found that the introduction of ethanol significantly improved the conversion of industrial lignin in ChCl-LA.
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