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α-Azido ketones and their vinylogous relatives β-alkoxy-γ-azido enones are versatile building blocks for constructing diverse heterocyclic products, but are prone to azide decomposition. Here, we report their condensation with propargylic amines and investigate the fate of the intermediate azido-enamine condensation products, both experimentally and theoretically. Efficient intramolecular cycloaddition was observed for electron-poor azide substrates, and a range of diversely substituted [1,2,3]triazolo[1,5-]pyrazine products is reported. For electron-rich substrates, azide decomposition predominated. Computational modeling of possible pathways from the azido-enamine intermediates revealed two alternative mechanisms for azide decomposition, which were consistent with observed side products.
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http://dx.doi.org/10.1021/acs.joc.4c01329 | DOI Listing |
Inorg Chem
September 2025
Institute of Inorganic Chemistry of Czech Academy of Sciences, Husinec-Řež 1001, 250 68, Czech Republic.
We report the synthesis and reactivity of phenylpyridine-based boron azides readily accessible via nucleophilic substitution from generated borenium-type precursors. Three azides were obtained: a hydridic species (L)BHN (L = 2-phenylpyridine), a cyclopentyl-substituted analogue (L)B(cyclopentyl)N, and a boron diazide (L)B(N) obtained as a byproduct from the synthesis of (L)BHN. The prepared borane azides exhibit notable thermal and photochemical robustness, with decomposition temperatures around 140 °C in mesitylene solution and above 170 °C in the solid state, as evidenced by DSC/TGA analysis.
View Article and Find Full Text PDFPolymers (Basel)
July 2025
School of Materials Science and Technology, Beijing Institute of Technology, Beijing 100086, China.
As a novel carbon material, multi-walled carbon nanotubes (MWCNTs) have attracted significant research interest in energetic applications due to their high aspect ratio and exceptional physicochemical properties. However, their inherent structural characteristics and poor dispersion severely limit their practical utilization in solid propellant formulations. To address these challenges, this study developed an innovative reverse-engineering strategy that precisely confines MWCNTs within a three-dimensional FeO gel framework through a controllable sol-gel process followed by low-temperature calcination.
View Article and Find Full Text PDFACS Appl Mater Interfaces
August 2025
Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology, Department of Chemical Engineering, Tsinghua University, Beijing 100084, P. R. China.
Metal-azide-based primary explosives are the key charge in ammunition's energy sequence. For the weakness of weak detonation ability or ultrahigh sensitivity of metal azide (Pb(N), LA; AgN, SA; Cu(N), CA) and their composites, novel metal-azide-based primary explosives with characteristics of improved safety and detonation ability are urgently needed to meet ammunition's miniaturization development. In this work, a novel silver-lead-azide core-shell nanoparticle design, with SA as the core and LA as the shell, is realized by the microfluidic method.
View Article and Find Full Text PDFNature
June 2025
Institute of Organic Chemistry, Justus Liebig University Giessen, Giessen, Germany.
Compounds consisting only of the element nitrogen (polynitrogens or nitrogen allotropes) are considered promising clean energy-storage materials owing to their immense energy content that is much higher than hydrogen, ammonia or hydrazine, which are in common use, and because they release only harmless nitrogen on decomposition. However, their extreme instability poses a substantial synthetic challenge and no neutral molecular nitrogen allotrope beyond N has been isolated. Here we present the room-temperature preparation of molecular N (hexanitrogen) through the gas-phase reaction of chlorine or bromine with silver azide, followed by trapping in argon matrices at 10 K.
View Article and Find Full Text PDFEnergetic plasticizers are used to improve the mechanical properties of advanced energetic formulations while increasing the overall energy content. Although nitro-1,2,5-oxadiazoles (nitrofurazans) possess excellent energetic properties such as a favorable oxygen balance and high heat of formation, their use as plasticizers has received little attention in the scientific literature. Four nitrofurazanyl ethers were synthesized by substitution of dinitrofurazan with linear alkoxides.
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