16 research outputs found
Metal-free C–H functionalization of 2H-imidazole 1-oxides with pyrrolyl fragments in the design of novel azaheterocyclic ensembles
No full textNovel pyrrolyl-2H-imidazoles have been synthesizedviametal-free C–H/C–H coupling reactions under mild conditions and in good to excellent yields.</p
Transition-Metal-Free CH/CLi Coupling of Nonaromatic 2HImidazole 1Oxides with Pentafluorophenyl Lithium in the Design of Novel Fluorophores with Intramolecular Charge Transfer Effect
No full textDirect C-Li/C-H coupling of pentafluorophenyl lithium with azines - An atom- and step-economical strategy for the synthesis of polyfluoroaryl azaaromatics
No full textMetal-Free CH/CH Coupling of 2HImidazole 1Oxides with Polyphenols toward Imidazole-Linked Polyphenolic Compounds
No full textThe methodology of nucleophilic substitution
of hydrogen (SNH) was successfully
applied as a convenient synthetic tool to afford azaheterocyclic derivatives
of phenols of various architectures. A series of 26 novel imidazole-linked
polyphenolic compounds were first prepared in 72–95% yields
through the direct metal-free C–H/C–H coupling of polyphenols
with 2H-imidazole 1-oxides. Comprehensive studies
on the reaction condition optimization, scope, and limitations enabled
the development of a straightforward method toward novel bifunctional
derivatives bearing both phenolic and imidazole scaffolds of particular
interest in the design of challenging molecules for versatile applications
in medicinal chemistry and materials science
Synthesis, Luminescent Properties and Application Opportunities of C-substituted Ortho-carborane π-conjugated Luminophores: a Mini Review
No full textReceived: 28.02.2025. Revised: 25.03.2025. Accepted: 25.03.2025. Available online: 02.04.2025.The synthesis and properties of ortho-carborane-derived luminophores containing a multiple bond conjugated system are considered.The photophysical properties of the С-substituted ortho-carborane π-conjugated compounds and the devices fabricated on them are discussed.The review contains 82 references and covers known data from 2009 to the present.The mini-review summarizes the recent achievements in the synthesis of C-substituted ortho-carborane luminophores bearing an alkenyl- or alkynyl- π-conjugated system. The luminescence properties, such as absorbance, emission peaks, photophysical effects (particularly intramolecular charge transfer), local excitation, dual emission, and structure-property relationships are comprehensively studied. The advantages of the diverse applications for this type of ocarborane cluster compounds as organic light-emitting diodes (OLEDs), semiconductors, chemosensors, and other components of modern organic electronics are extensively discussed. In addition, the existing limitations in the chemical design and application possibilities are also considered.This research was funded by the Russian Science Foundation and the Government of Sverdlovsk region, Project No. 24-13-20023, https://rscf.ru/en/project/24-13-20023/
Copper-Catalyzed Sonogashira-Type Coupling Reaction of Vinylacetylene ortho-Carborane with Boronic Acid in the Synthesis of Luminophores with Phosphorescent Emission
No full textA synthetic approach to prepare boron-enriched π-conjugated photoactive molecular systems based on ortho-carborane using the Cu(I)-catalyzed Sonogashira-type coupling reaction has been developed. The obtained luminophores have been found to possess absorption in the range of 300 to 400 nm, emission of up to 700 nm, and photoluminescence quantum yields of up to 99% in non-polar solvents. TD-DFT calculations have demonstrated that the luminophores are characterized by phosphorescent emission behavior with a lifetime of about 7 μs. In addition, the rigidochromism for the synthesized compounds has been revealed; particularly, the transition electronic state and bathochromic shift have been elucidated in the emission spectra. The exhibited luminescent characteristics indicate that the elaborated vinylcarborane fluorophores could be considered as promising building blocks in the design of advanced photofunctional materials for molecular electronics
Metal-Free Eliminative C-H Arylthiolation of 2<i>H</i>-Imidazole N-Oxides with Thiophenols
No full textA synthetic strategy based on reactions of cyclic imine oxides, namely 2H-imidazole 1-oxides, with thiophenols mediated by acetyl chloride was successfully applied as a convenient tool to obtain a series of novel azaheterocyclic molecules, including water-soluble hydrochloride forms. Optimized reaction conditions found herein for the nucleophilic substitution of hydrogen (SNH) in non-aromatic azaheterocyclic substrates via the “addition-elimination” (SNH AE) scheme enabled 15 arylthiolated 2H-imidazoles to be prepared in yields of up to 90%. The developed methodology discloses an original synthetic way to obtain numerous azaheterocyclic molecules, which are of interest in the field of medicinal chemistry and materials science
Synthesis of Functionalized Pyrazin-2(1<i>H</i>)‑ones via Tele-Nucleophilic Substitution of Hydrogen Involving Grignard Reactants and Electrophiles
No full textThe reaction of 6-chloro-1-methylpyrazin-2(1H)-one
with Grignard reactants followed by quenching with different electrophiles
gave access to a variety of 3,6-difunctionalized 1-methylpyrazin-2(1H)-ones. This regioselective three-component reaction represents
the first example of a tele-nucleophilic substitution of hydrogen
(SNH) in which the anionic σH adduct is quenched by electrophiles (other than a proton) before
elimination takes place. Quenching the reaction with iodine (I2) or bromine (Br2) provides an alternative reaction
pathway, yielding a 3-functionalized 6-chloro-1-methylpyrazin-2(1H)-one or 5-bromo-6-chloro-1-methylpyrazin-2(1H)-one, respectively. The halogens present offer opportunities for
further selective transformations
The Large Enriched Germanium Experiment for Neutrinoless Double Beta Decay (LEGEND)
No full textThe observation of neutrinoless double-beta decay (0νββ) would show that lepton number is violated, reveal that neu-trinos are Majorana particles, and provide information on neutrino mass. A discovery-capable experiment covering the inverted ordering region, with effective Majorana neutrino masses of 15 - 50 meV, will require a tonne-scale experiment with excellent energy resolution and extremely low backgrounds, at the level of ∼0.1 count /(FWHM·t·yr) in the region of the signal. The current generation 76Ge experiments GERDA and the Majorana Demonstrator, utilizing high purity Germanium detectors with an intrinsic energy resolution of 0.12%, have achieved the lowest backgrounds by over an order of magnitude in the 0νββ signal region of all 0νββ experiments. Building on this success, the LEGEND collaboration has been formed to pursue a tonne-scale 76Ge experiment. The collaboration aims to develop a phased 0νββ experimental program with discovery potential at a half-life approaching or at 1028 years, using existing resources as appropriate to expedite physics results
Characterization of correlations of fast-ion H-alpha measurement volumes in Wendelstein 7-X by particle tracking
No full textThis paper characterizes the correlation of simultaneous measurements with different fast-ion H-alpha (FIDA) spectroscopy sightlines on Wendelstein 7-X. Using a collisionless guiding-center code, it is shown that, for two investigated volumes in the bulk of the plasma, some regions of phase space are correlated and the magnetic configuration has little influence on this correlation. For the sightlines of the FIDA system, the correlation between these is explained well by the magnetic configuration. Sightlines with measurement volumes at the same spatial locations have the highest correlation, and sightlines with measurement volumes near the same flux surface but on different sides of the magnetic axis have a high correlation. The correlation between the blueshifted signal in the starting sightline and redshifted signal in the detection sightline is investigated, demonstrating that it is possible to investigate any finite interval of detection wavelengths. Due to the different shapes of the weight functions for the toroidal and oblique sightlines, the blue-redshift correlation is very different from the total-spectrum correlation. The correlation between the toroidal and oblique sightline fans is relatively much larger than the internal correlation in the oblique sightlines, which is however, much larger than the internal correlation in the toroidal sightlines. This is a result of the dependence of the weight functions on the angle between the sightline and magnetic field, illustrating how important it is for the FIDA sightlines to cover different angles with the magnetic field. (c) 2022 Author(s
