Oxidative coupling reactions take place during the passage of xylenols through a laboratory-scale helophyte-based constructed wetland system. Typical coupling product groups including tetramethyl-[1,1'-biphenyl] diols and tetramethyl diphenylether monools as stable organic intermediates could be identified by a combination of pre-chromatographic derivatization and GC/MS analysis. Structural assignment of individual analytes was performed by an increment system developed by Zenkevich to pre-calculate retention sequences. The most abundant analyte turned out to be 3,3',5,5'-tetramethyl-[1,1'-biphenyl]-4,4'-diol, which can be formed by a combination of radicals based on 2,6-xylenol or by an attack of a 2,6-xylenol-based radical on 2,6-xylenol. Organic intermediates originating from oxidative coupling could also be identified in anaerobic constructed wetland systems. This finding suggested the presence of (at least partly) oxic conditions in the rhizosphere.
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http://dx.doi.org/10.1016/j.chemosphere.2014.06.004 | DOI Listing |
Anal Chim Acta
May 2025
Department of Chemistry, Texas A&M University, 580 Ross St., College Station, TX, 77843, USA. Electronic address:
Background: Microdroplets have emerged as effective confined-volume reactors due to their remarkable ability to accelerate chemical reactions compared to bulk systems. Recent research highlights the crucial role of air-liquid interfaces in this acceleration. A microdroplet can be viewed as having two kinetically distinct regions: the interface and the interior.
View Article and Find Full Text PDFJ Org Chem
March 2025
Key Lab of Organic Optoelectronics & Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing 100084, P. R. China.
Arylsulfonylindole and arylsulfenylindole motifs stand as privileged scaffolds in drug discovery. Traditional methods for synthesizing these molecules have relied mainly on prefunctionalized precursors, involving multistep processes and generating a large amount of waste. In this study, we present a modular protocol for the preparation of 3-sulfonylindoles and 3-sulfenylindoles using indoles and thiols as starting materials via hexamolybdate/HO-mediated oxidative dehydrogenative C-S coupling.
View Article and Find Full Text PDFNat Chem
March 2025
Department of Chemistry, University of Texas at Austin, Austin, TX, USA.
Transfer hydrogenation is widely practised across all segments of chemical industry, yet its application to aryl halide reductive cross-coupling is undeveloped because of competing hydrogenolysis. Here, exploiting the distinct reactivity of Pd species, an efficient catalytic system for the reductive cross-coupling of activated aryl bromides with aryl iodides via formate-mediated hydrogen transfer is described. These processes display orthogonality with respect to Suzuki and Buchwald-Hartwig couplings, as pinacol boronates and anilines are tolerated and, owing to the intervention of chelated intermediates, are effective for challenging 2-pyridyl systems.
View Article and Find Full Text PDFOrg Biomol Chem
March 2025
Guangxi Colleges and Universities Key Laboratory of Applied Chemistry Technology and Resource Development, School of Chemistry and Chemical Engineering, Guangxi University, Nanning, Guangxi 530004, P. R. China.
The simultaneous introduction of two functional groups into molecules a one-pot process is of great importance for the synthesis of complex molecules. However, this remains a challenging task due to the need for precise control of regio- and chemo-selectivity. In this paper, we present a novel oxidative cross-dehydrogenation coupling (CDC) reaction that selectively introduces two nucleophiles at the C2,3-positions of indoles, thereby constructing the C-N and C-C bonds simultaneously in one pot.
View Article and Find Full Text PDFJ Neurochem
March 2025
Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
Synaptic homeostasis of the principal neurotransmitters glutamate and GABA is tightly regulated by an intricate metabolic coupling between neurons and astrocytes known as the glutamate/GABA-glutamine cycle. In this cycle, astrocytes take up glutamate and GABA from the synapse and convert these neurotransmitters into glutamine. Astrocytic glutamine is subsequently transferred to neurons, serving as the principal precursor for neuronal glutamate and GABA synthesis.
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