Gold nanoparticles were prepared by sol immobilization (Au) or deposition precipitation (Au), then deposited on NiO and commercial TiO₂ (P25). The Au/NiO catalysts showed higher activity and yield to the secondary amine, compared to Au/TiO₂ catalysts, when tested for the reductive amination of benzyl alcohol with isopropylamine. We attribute this result to a synergistic effect between Au and NiO. Moreover, as a result of the protective effect of the polyvinyl alcohol used in the sol immobilization synthesis, the gold nanoparticles on NiO demonstrate an increased resistance to structural changes during the reaction. This effect results in enhanced catalytic efficiency in terms of activity, and better stability against deactivation.
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http://dx.doi.org/10.3390/ma10121435 | DOI Listing |
Org Process Res Dev
January 2025
School of Chemistry, The University of Nottingham, University Park, Nottingham NG7 2RD, U.K.
We report the development and optimization of a scalable flow process for metallaphotoredox (Ir/Ni) C-O coupling, a mild and efficient approach for forming alkyl-aryl ethers, a common motif in medicinal and process chemistry settings. Time-resolved infrared spectroscopy (TRIR) highlighted the amine as the major quencher of the photocatalyst triplet excited state, along with the formation of an Ir(II) species that, in the presence of the Ni cocatalyst, has its lifetime shortened, suggesting reductive quenching of Ir(III)*, followed by reoxidation facilitated by the Ni cocatalyst. TRIR and batch reaction screening was used to develop conditions transferrable to flow, and many processing benefits of performing the reaction in flow were then demonstrated using a simple to construct/operate, small-footprint FEP coil flow reactor, including short (<10 min) space times and reduced catalyst loadings (down to 0.
View Article and Find Full Text PDFDalton Trans
January 2025
Department of Chemistry, Panjab University, Sector 14, Chandigarh-160014, India.
This work reports the step-wise fabrication of a core-shell plasmonic nanocomposite Pd@BTL-Cd consisting of a BTL-Cd shell and a palladium nanoparticle core. BTL-Cd is the [Cd(BTL)·CdCl] complex where the heptadentate framework of the bis-compartmental ligand encapsulated two Cd(II) centres in separate pockets. Pd@BTL-Cd has been found to be highly efficient for the photocatalytic conversion of furfural (a biomass-derived aldehyde) to furfuryl amine reductive amination in aqueous ammonia at room temperature.
View Article and Find Full Text PDFACS Catal
October 2024
Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States.
A class of generated Lewis acid (LA) activated acridine complexes is reported, which act as potent photochemical catalysts for the oxidation of a variety of protected secondary amines. Acridine/LA complexes exhibit tunable excited state reduction potentials ranging from +2.07 to 2.
View Article and Find Full Text PDFJ Biotechnol
January 2025
Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu 214122, China; The Research Center of Chiral Drugs, Shanghai Frontiers Science Center for TCM Chemical Biology, Innovation Research Institute of Traditional Chinese Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China. Electronic address:
Chiral azacyclic amine derivatives occupy a vital role of nitrogen-containing compounds, due to serve as foundational motifs in numerous pharmaceuticals and bioactive substances. Novel complementary enantioselective reductive aminases IRED9 and IRED11 were unveiled through comprehensive gene mining from Streptomyces viridochromogenes and Micromonospora echinaurantiaca, respectively, which both demonstrated enantiomeric excess (ee) values and conversion ratios of up to 99 % towards N-Boc-3-pyridinone (NBPO) and cyclopropylamine. IRED9 exhibited the highest activity at pH 8.
View Article and Find Full Text PDFEnviron Sci Technol
January 2025
Key Laboratory of Jiangxi Province for Persistent Pollutants Prevention Control and Resource Reuse, Nanchang Hangkong University, Nanchang 330063, China.
The traditional treatment of toxic and refractory copper(II)-ethylenediaminetetraacetic acid chelate (Cu(II)-EDTA) in electroless effluents often generates hazardous waste and secondary nitrogen-containing pollutants without maximizing the resource recovery. This study demonstrates a facile strategy to simultaneously recover Cu and EDTA ligands from Cu(II)-EDTA electroless effluent with commercially available metallic Cu and formaldehyde. In this strategy, metallic Cu is used to activate formaldehyde, a prevalent yet often overlooked cocontaminant in Cu(II)-EDTA effluents, to produce highly reductive hydrogen radical (H), which in situ decomplex Cu(II)-EDTA, reduces the central Cu(II) into metallic Cu, and release EDTA ligand.
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