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The rerouting of the nitrilium ion formed in the Schmidt reaction of ketones and TMSN to encompass C-C bond formation with an electron-rich aromatic group is reported. Thus, when the reaction is carried out in HFIP using AlCl or AlBr as the promoter, imines, iminium ions, or enamide derivatives are obtained through one-pot procedures. The scope and possible mechanisms of these new transformations are considered.
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http://dx.doi.org/10.1021/acs.orglett.8b02531 | DOI Listing |
Nature
September 2025
Los Alamos National Laboratory, Los Alamos, NM, USA.
The Perseverance rover has explored and sampled igneous and sedimentary rocks within Jezero Crater to characterize early Martian geological processes and habitability and search for potential biosignatures. Upon entering Neretva Vallis, on Jezero Crater's western edge, Perseverance investigated distinctive mudstone and conglomerate outcrops of the Bright Angel formation. Here we report a detailed geological, petrographic and geochemical survey of these rocks and show that organic-carbon-bearing mudstones in the Bright Angel formation contain submillimetre-scale nodules and millimetre-scale reaction fronts enriched in ferrous iron phosphate and sulfide minerals, likely vivianite and greigite, respectively.
View Article and Find Full Text PDFJ Org Chem
September 2025
A.E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, 1 Favorsky St, Irkutsk 664033, Russian Federation.
In this work, the superbase-mediated self-organization of tetrasubstituted pyrroles from three molecules of acetylenes and one molecule of nitriles was theoretically investigated. On the example of interaction of phenylacetylene with benzonitrile in the KOBu/DMSO medium, three possible pathways of the assembly of 2-benzyl-3,5-diphenyl-4-phenylethynyl-1-pyrrole have been studied using a combined B2PLYP-D3/6-311+G**//B3LYP-D3/6-31+G* quantum chemical approach. The calculated activation barriers correspond to mild reaction conditions (room temperature for 15 min).
View Article and Find Full Text PDFDalton Trans
September 2025
Section for Solid State and Theoretical Inorganic Chemistry, Institute of Inorganic Chemistry, Auf der Morgenstelle 18, 72076 Tübingen, Germany.
A series of niobium oxyiodide compounds has recently been identified using a non-conventional reduction method. The continuation of these studies of heterogeneous solid-state reactions in a closed system has led to the crystallization and structural analysis of two novel compounds LiNbOI and NbOI(NbI). Both crystal structures are derived from the pentanuclear [NbO] cluster core and are expanded through the incorporation of additional niobium atoms, forming new [NbO] and [NbO] cluster cores.
View Article and Find Full Text PDFAstrobiology
September 2025
Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, USA.
Concentrated magnesium chloride brines are extreme environments that are inhospitable to life on Earth. The ionic strength of these brines significantly depresses water activity and concomitantly exerts significant chaotropic stress. Although these brines are largely considered sterile, the well-known preservative effects of magnesium chloride on certain biomolecules, such as DNA, confound life detection approaches and efforts to constrain precisely the habitable window of life on Earth.
View Article and Find Full Text PDFBiochemistry
August 2025
Department of Chemical and Pharmaceutical Biology, Groningen Research Institute of Pharmacy, University of Groningen, Antonius Deusinglaan 1, Groningen 9713AV, Netherlands.
Rieske oxygenases (ROs) are a diverse family of nonheme iron enzymes that catalyze a wide array of oxidative transformations in both catabolic and biosynthetic pathways. Their catalytic repertoire spans dioxygenation, monooxygenation, oxidative - and -dealkylation, desaturation, sulfoxidation, C-C bond formation, -oxygenation, and C-N bond cleavage─reactions that are often challenging to achieve selectively through synthetic methods. These diverse functions highlight the increasing importance of ROs in natural product biosynthesis and establish them as promising candidates for biocatalytic applications.
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