In 2012, bicyclo[1.1.1]pentanes were demonstrated to be bioisosteres of the benzene ring.
View Article and Find Full Text PDFThe chemoselectivity of halo(het)arene sulfonyl halide aminations is studied thoroughly under parallel synthesis conditions, and the scope and limitations of the method are established. It is shown that SAr-reactive sulfonyl halides typically undergo sulfonamide synthesis during the first step; the second amination is also possible provided that the SAr-active center is sufficiently reactive. On the contrary, sulfonyl fluorides bearing an arylating moiety undergo selective transformation at the latter reactive center under proper control.
View Article and Find Full Text PDFChemoselective transformations of functionalized sulfonyl fluorides and chlorides are surveyed comprehensively. It is shown that sulfonyl fluorides provide an excellent selectivity control in their reactions. Thus, numerous conditions are tolerated by the SO F group - from amide and ester formation to directed ortho-lithiation and transition-metal-catalyzed cross-couplings.
View Article and Find Full Text PDFZh Nevrol Psikhiatr Im S S Korsakova
January 2023
Objective: Evaluation of the safety and effectiveness of thrombolytic therapy (TLT) with the drug Revelisa (alteplase) in patients with ischemic stroke (AI) in real clinical practice.
Material And Methods: An open prospective multicenter non-interventional register study was conducted, which included 550 patients with AI - 259 (47.1%) women and 291 (52.
The unprovoked Russian invasion has created considerable challenges for Ukrainian science. In this article, we discuss actions needed to support and rebuild Ukrainian science and educational systems. The proposed actions take into account past Ukrainian scientific achievements including developments in organic chemistry.
View Article and Find Full Text PDFUkrainian companies occupy an important niche in the global drug discovery process; however, before the Russian invasion, the role of Ukraine was not obvious. The biggest Ukrainian fine chemical supplier, Enamine Ltd, had to stop operation for more than a month, which significantly affected various early-stage drug discovery projects. The role of Enamine in drug discovery and the company's past and future in the context of the Russian invasion are described in this Viewpoint.
View Article and Find Full Text PDFA convenient "green" stereoretentive approach to -enriched secondary sulfonamides bearing an asymmetric center at the α position to the sulfur atom is described. The method relies on the electrophilic amination of the corresponding stereochemically pure sulfinates with -alkylhydroxylamine sulfonic acids (in turn easily prepared from -alkylhydroxylamine and HSOCl). It is shown that the efficiency of the approach is governed mainly by steric factors; its tolerance to several functional groups (e.
View Article and Find Full Text PDFA general approach to a new generation of spirocyclic molecules - oxa-spirocycles - was developed. The key synthetic step was iodocyclization. More than 150 oxa-spirocyclic compounds were prepared.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
December 2020
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
View Article and Find Full Text PDFStructural restriction of the sulfonamide bond was used to design sultams with abnormal geometric parameters. Based on analysis of tertiary aliphatic sulfonamides published in the Cambridge crystallographic database, Paquette's sultams (i.e.
View Article and Find Full Text PDFWe present an extensive, large-scale, long-term and multitaxon database on phenological and climatic variation, involving 506,186 observation dates acquired in 471 localities in Russian Federation, Ukraine, Uzbekistan, Belarus and Kyrgyzstan. The data cover the period 1890-2018, with 96% of the data being from 1960 onwards. The database is rich in plants, birds and climatic events, but also includes insects, amphibians, reptiles and fungi.
View Article and Find Full Text PDFDiverse trifluoromethyl-substituted compounds were synthesized by deoxofluorination of cinnamic and (hetero)aromatic carboxylic acids with sulfur tetrafluoride. The obtained products were used as starting materials in the preparation of novel fluorinated amino acids, anilines, and aliphatic amines - valuable building blocks for medicinal chemistry and agrochemistry.
View Article and Find Full Text PDFDerivatives of Brooker's merocyanine (BM) have been investigated, which possess different donors and acceptors and therefore vary their donor-acceptor strength S. The 00 energies have been extracted from the spectra and compared. Under basic conditions, where the neutral (merocyanine) form is present, the absorption energies for all compounds are similar, whereas there is a large difference for acidic conditions where the cationic (cyanine) form is present.
View Article and Find Full Text PDFTwo novel solid reagents-1-sulfonimidoyl- and 1-sulfamimidoyl-3-methylimidazolium derivatives-for the synthesis of sulfonimidamides and imidosulfuric diamides, respectively, were developed. It is shown that these reagents are very effective in substitution reactions with various N- and O-nucleophiles; therefore, they significantly extend the accessibility to the chemical space covered by organosulfur(VI) compounds with S=N bonds. In addition, previously unknown imidosulfuric diamides with free imino nitrogen groups were prepared, and their physical and chemical properties were characterized (including molecular geometry, pK , Log P, microsomal stability, and reactivity towards typical electrophiles).
View Article and Find Full Text PDFDespite intense interest in expanding chemical space, libraries containing hundreds-of-millions to billions of diverse molecules have remained inaccessible. Here we investigate structure-based docking of 170 million make-on-demand compounds from 130 well-characterized reactions. The resulting library is diverse, representing over 10.
View Article and Find Full Text PDFA practical synthesis of 2,4-methanopyrrolidines was elaborated. The key synthetic step was an intramolecular photochemical [2 + 2]-cycloaddition of an acrylic acid derivative in flow. In spite of a higher molecular weight, 2,4-methanopyrrolidines were shown to have higher solubility in water and lower lipophilicity than pyrrolidines, important characteristics of bioactive molecules in drug design.
View Article and Find Full Text PDFThe results of the study on reactions of halogenoximes bearing (protected) functional groups or fluorinated substituents with various phosphorus-containing dipolarophiles are described. To control the regioselectivity of the reaction, vinylphosphonates bearing a leaving group (i.e.
View Article and Find Full Text PDFCyclic saturated aminosulfonyl fluorides were synthesized as their HCl salts. The compounds were found to be stable upon storage and could be used for the protecting-group-free synthesis of sulfonamides. In the presence of the -SO F group, the nitrogen atom could be modified by means of acylation, arylation, or reductive amination to give products that have high potential for the synthesis of bioactive compounds.
View Article and Find Full Text PDFA one-step synthesis of functionalized 3-azabicyclo[3.2.0]heptanes by [2+2]-photochemical intermolecular cycloaddition of N-benzylmaleimide to alkenes was elaborated.
View Article and Find Full Text PDFFacile synthesis of 5-fluoropyrazoles by direct fluorination of pyrazoles with N-fluorobenzenesulfonimide (NFSI) was elaborated. This approach was used to prepare the unsubstituted 5-fluoro-1 H-pyrazole, the known fungicide Penflufen, and many functionalized 5-fluoropyrazoles: building blocks for medicinal chemistry and agrochemistry.
View Article and Find Full Text PDFDifluorocyclopropane-containing building blocks for drug discovery were synthesized from the functionalized alkenes and TMSCF /NaI. Novel fluorinated acids, amines, amino acids, alcohols, ketones and sulfonyl chlorides were obtained.
View Article and Find Full Text PDFThe synthesis of multifunctional spirocycles was achieved from common cyclic carboxylic acids (cyclobutane carboxylate, cyclopentane carboxylate, l-proline, etc.). The whole sequence included only two chemical steps-synthesis of azetidinones, and reduction into azetidines.
View Article and Find Full Text PDFWe provide the initial performance evaluation of a 21 Tesla Fourier transform ion cyclotron resonance mass spectrometer operating at the Environmental Molecular Sciences Laboratory at the Pacific Northwest National Laboratory. The spectrometer constructed for the 21T system employs a commercial dual linear ion trap mass spectrometer coupled to a FTICR spectrometer designed and built in-house. Performance gains from moving to higher magnetic field strength are exemplified by the measurement of peptide isotopic fine structure, complex natural organic matter mixtures, and large proteins.
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