Search results

Search for "preparation" in Full Text gives 1890 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.

Regioselective quinazoline C2 modifications through the azide–tetrazole tautomeric equilibrium

  • Dāgs Dāvis Līpiņš,
  • Andris Jeminejs,
  • Una Ušacka,
  • Anatoly Mishnev,
  • Māris Turks and
  • Irina Novosjolova

Beilstein J. Org. Chem. 2024, 20, 675–683, doi:10.3762/bjoc.20.61

Graphical Abstract
  • preparation of 2-chloro-4-sulfonylquinazolines 8 (Scheme 3). The starting material 7 underwent SNAr reactions with sodium sulfinates and the C4-substituted products 8a,b were isolated [24]. The complete conversion was achieved in DMF or DMSO. In the case of sodium dodecylsulfinate, the reaction stopped at 70
PDF
Album
Supp Info
Full Research Paper
Published 28 Mar 2024

A laterally-fused N-heterocyclic carbene framework from polysubstituted aminoimidazo[5,1-b]oxazol-6-ium salts

  • Andrew D. Gillie,
  • Matthew G. Wakeling,
  • Bethan L. Greene,
  • Louise Male and
  • Paul W. Davies

Beilstein J. Org. Chem. 2024, 20, 621–627, doi:10.3762/bjoc.20.54

Graphical Abstract
  • particularly underinvestigated [2][18][19]. In this work we report the preparation of a new L-shaped NHC motif, the 3-aminoimidazo[5,1-b]oxazol-5-ylidene A (shortened hereafter to AImOx), which fuses two π-rich rings and positions a sulfonamide group alongside the metal centre (Figure 1b). We envisaged that
  • aminide 7 in good yield on a gram scale (Scheme 1b). With the novel 3-aminoimidazo[5,1-b]oxazol-6-ium salt in hand, we examined its use as an NHC precursor for the preparation of late transition metal complexes. Treating compound 9a with triethylamine and either dimethyl sulfide gold(I) chloride or copper
  • support from the Centre for Chemical and Materials Analysis in the School of Chemistry (UoB). We thank the EPSRC UK National Crystallography Service at the University of Southampton for the collection of the crystallographic data for compound 14. [40] We thank Dr Richard Mudd (UoB) for the preparation of
PDF
Album
Supp Info
Letter
Published 18 Mar 2024

Synthesis and biological profile of 2,3-dihydro[1,3]thiazolo[4,5-b]pyridines, a novel class of acyl-ACP thioesterase inhibitors

  • Jens Frackenpohl,
  • David M. Barber,
  • Guido Bojack,
  • Birgit Bollenbach-Wahl,
  • Ralf Braun,
  • Rahel Getachew,
  • Sabine Hohmann,
  • Kwang-Yoon Ko,
  • Karoline Kurowski,
  • Bernd Laber,
  • Rebecca L. Mattison,
  • Thomas Müller,
  • Anna M. Reingruber,
  • Dirk Schmutzler and
  • Andrea Svejda

Beilstein J. Org. Chem. 2024, 20, 540–551, doi:10.3762/bjoc.20.46

Graphical Abstract
  • introducing a nonaromatic motif via preparation of the novel 2,3-dihydro[1,3]thiazolo[4,5-b]pyridines 7. Results and Discussion Although the 2,3-dihydro[1,3]thiazolo[4,5-b]pyridine scaffold looks relatively simple at a first glance, it displays a very different reactivity compared to the parent naphthyridine
  • prepare the thiazolo[4,5-b]pyridines using the Friedländer synthesis often being met with failure or disappointingly low product yield [12]. We thus particularly emphasized on upscaling, facile workup, and a robust yield for each step. This was due to the potential need for the preparation of multigram
  • conditions to prepare 2,3-dihydro[1,3]thiazolo[4,5-b]pyridines 7a–c and 13a–c via a late-stage reduction (Scheme 2 and Table 1). Whilst several synthetic approaches towards 2,3-dihydro-1,3-benzothiazoles involving the hydrogenation of 1,3-benzothiazoles have been described [20], the corresponding preparation
PDF
Album
Supp Info
Full Research Paper
Published 01 Mar 2024

Synthesis of 2,2-difluoro-1,3-diketone and 2,2-difluoro-1,3-ketoester derivatives using fluorine gas

  • Alexander S. Hampton,
  • David R. W. Hodgson,
  • Graham McDougald,
  • Linhua Wang and
  • Graham Sandford

Beilstein J. Org. Chem. 2024, 20, 460–469, doi:10.3762/bjoc.20.41

Graphical Abstract
  • lithium hexamethyldisilazane following a literature procedure reported by Liu and co-workers (see Supporting Information File 1) [44]. Subsequently, difluorinations of DBM substrates 1b–n were performed under conditions similar to those optimized for the preparation of 3a. The desired difluorinated
PDF
Album
Supp Info
Full Research Paper
Published 28 Feb 2024

(E,Z)-1,1,1,4,4,4-Hexafluorobut-2-enes: hydrofluoroolefins halogenation/dehydrohalogenation cascade to reach new fluorinated allene

  • Nataliia V. Kirij,
  • Andrey A. Filatov,
  • Yurii L. Yagupolskii,
  • Sheng Peng and
  • Lee Sprague

Beilstein J. Org. Chem. 2024, 20, 452–459, doi:10.3762/bjoc.20.40

Graphical Abstract
  • -1,1,1,4,4,4-hexafluorobut-2-enes have been investigated. A simple, one-pot procedure for the preparation of a new allene (1,1,4,4,4-pentafluorobuta-1,2-diene) and some of its transformations is presented. Keywords: allenes; dehydrohalogenation; halogenation; 1,1,1,4,4,4-hexafluorobut-2-enes; isomerization
  • demonstrated that 1,1,1,4,4,4-hexafluorobut-2-ene reacts with dithietane, sulfur and KF with the formation of the corresponding 1,3-dithiole [16]. Also, a recent patent presents a method for the preparation of 5,6-bis(trifluoromethyl)-1,2,4-triazine-3-carboxylic acid ethyl ester starting from 1,1,1,4,4,4
PDF
Album
Supp Info
Full Research Paper
Published 27 Feb 2024

Mono or double Pd-catalyzed C–H bond functionalization for the annulative π-extension of 1,8-dibromonaphthalene: a one pot access to fluoranthene derivatives

  • Nahed Ketata,
  • Linhao Liu,
  • Ridha Ben Salem and
  • Henri Doucet

Beilstein J. Org. Chem. 2024, 20, 427–435, doi:10.3762/bjoc.20.37

Graphical Abstract
  • -catalyzed annulative π-extension of 1,8-dibromonaphthalene for the preparation of fluoranthenes in a single operation has been investigated. With specific arenes such as fluorobenzenes, the Pd-catalyzed double functionalization of C–H bonds yields the desired fluoranthenes. The reaction proceeds via a
  • palladium-catalyzed direct intermolecular arylation, followed by a direct intramolecular arylation step. As the C–H bond activation of several benzene derivatives remains very challenging, the preparation of fluoranthenes from 1,8-dibromonaphthalene via Suzuki coupling followed by intramolecular C–H
  • contrast, only a few examples of fluoranthene backbone preparation by Pd-catalyzed C–H arylation have been reported. Some examples of the preparation of this skeleton by Suzuki coupling followed by intramolecular C–H coupling have been described [18][19][20][21][22][23][24]. In 2017, Metin, Türkmen and co
PDF
Album
Supp Info
Full Research Paper
Published 23 Feb 2024

Green and sustainable approaches for the Friedel–Crafts reaction between aldehydes and indoles

  • Periklis X. Kolagkis,
  • Eirini M. Galathri and
  • Christoforos G. Kokotos

Beilstein J. Org. Chem. 2024, 20, 379–426, doi:10.3762/bjoc.20.36

Graphical Abstract
PDF
Album
Review
Published 22 Feb 2024

Mechanisms for radical reactions initiating from N-hydroxyphthalimide esters

  • Carlos R. Azpilcueta-Nicolas and
  • Jean-Philip Lumb

Beilstein J. Org. Chem. 2024, 20, 346–378, doi:10.3762/bjoc.20.35

Graphical Abstract
  • Carlos R. Azpilcueta-Nicolas Jean-Philip Lumb Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, Quebec H3A 0B8, Canada 10.3762/bjoc.20.35 Abstract Due to their ease of preparation, stability, and diverse reactivity, N-hydroxyphthalimide (NHPI) esters have found
  • -rich (hetero)aryl halides was equally effective (Scheme 36). In addition, the preparation of unnatural amino acids in multigram scale [115], along with the syntheses of complex terpenes [116] and (+)-calcipotriol [117] have showcased the vast synthetic potential and broad applicability of NHPI esters
PDF
Album
Perspective
Published 21 Feb 2024

Facile approach to N,O,S-heteropentacycles via condensation of sterically crowded 3H-phenoxazin-3-one with ortho-substituted anilines

  • Eugeny Ivakhnenko,
  • Vasily Malay,
  • Pavel Knyazev,
  • Nikita Merezhko,
  • Nadezhda Makarova,
  • Oleg Demidov,
  • Gennady Borodkin,
  • Andrey Starikov and
  • Vladimir Minkin

Beilstein J. Org. Chem. 2024, 20, 336–345, doi:10.3762/bjoc.20.34

Graphical Abstract
  • probes, organic light-emitting diodes, and organic solar cells [2][7][8][9]. The principal way for the preparation of these heterocycles involves the coupling of 3H-phenoxazin-3-ones with variously functionalized aromatic amines. This is followed by the cyclization of the initially formed adducts [10][11
  • ) possible. By using a similar procedure to that applied to the synthesis of compounds 4, we succeeded in the preparation of 14Н-quinoxaline[2,3-b]phenoxazine derivatives 5 (Scheme 3). The nitrogen atoms in the oxazine and pyrazine rings of 5, N(7), N(12), and N(14), offer three possible positions for the N
  • successfully under the conditions applied to the preparation of 14H-quinoxaline[2,3-b]phenoxazines 5. The reaction proceeds readily with o-mercaptoaniline to produce the benzo[5,6][1,4]oxazino[2,3-b]phenothiazine derivative 10c (Scheme 6). Electronic absorption spectra of the prepared 14Н-quinoxaline[2,3-b
PDF
Album
Supp Info
Full Research Paper
Published 21 Feb 2024

Synthesis of π-conjugated polycyclic compounds by late-stage extrusion of chalcogen fragments

  • Aissam Okba,
  • Pablo Simón Marqués,
  • Kyohei Matsuo,
  • Naoki Aratani,
  • Hiroko Yamada,
  • Gwénaël Rapenne and
  • Claire Kammerer

Beilstein J. Org. Chem. 2024, 20, 287–305, doi:10.3762/bjoc.20.30

Graphical Abstract
  • , Nara 630-0192, Japan Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan 10.3762/bjoc.20.30 Abstract The “precursor approach” has proved particularly valuable for the preparation of insoluble and unstable π-conjugated polycyclic compounds (π-CPCs), which cannot be
  • investigations at the single molecule scale of π-CPCs, which could otherwise not be synthesized and/or deposited on surface. As seen above, the “precursor approach” has proved particularly valuable i) for the preparation of insoluble and unstable π-CPCs which cannot be synthesized (and purified) via conventional
  • thiepines were progressively isolated as a result of very diverse synthetic strategies [46][47][48][49], which were further applied to the preparation of stable selenepines and tellurepines [50][51][52][53]. Extrusion reactions from sulfur-, selenium- and tellurium-containing compounds have long been
PDF
Album
Review
Published 15 Feb 2024

Synthesis of spiropyridazine-benzosultams by the [4 + 2] annulation reaction of 3-substituted benzoisothiazole 1,1-dioxides with 1,2-diaza-1,3-dienes

  • Wenqing Hao,
  • Long Wang,
  • Jinlei Zhang,
  • Dawei Teng and
  • Guorui Cao

Beilstein J. Org. Chem. 2024, 20, 280–286, doi:10.3762/bjoc.20.29

Graphical Abstract
  • developed by means of [4 + 2] annulation reaction of 3-substituted benzoisothiazole 1,1-dioxides with 1,2-diaza-1,3-dienes. This approach displays advantages such as mild reaction conditions, wide substrate range tolerance, simple operation, compatibility with gram-scale preparation. Keywords: [4 + 2
  • bond under basic conditions. Finally, the ring expansion led to intermediate C which was then hydrolyzed to 4aa. Conclusion In conclusion, we have developed a [4 + 2] annulation reaction of 3-substituted benzo[d]isothiazole 1,1-dioxides with 1,2-diaza-1,3-dienes for the efficient preparation of
PDF
Album
Supp Info
Full Research Paper
Published 14 Feb 2024

Optimizations of lipid II synthesis: an essential glycolipid precursor in bacterial cell wall synthesis and a validated antibiotic target

  • Milandip Karak,
  • Cian R. Cloonan,
  • Brad R. Baker,
  • Rachel V. K. Cochrane and
  • Stephen A. Cochrane

Beilstein J. Org. Chem. 2024, 20, 220–227, doi:10.3762/bjoc.20.22

Graphical Abstract
  • -(phenylsulfonyl)ethyl ester, as previously reported by Saha and co-workers [44]. This modification prevents a deleterious side reaction occurring, wherein during glycosylation, muramic acid esters undergo a 6-exo-trig cyclization with the 4-OH group. Comprehensive experimental protocols detailing the preparation
  • . Eventually, we found that the utilization of extra equivalents of 1a and activators, following conditions akin to those employed by Kurosu, resulted in a significant boost in the yield of the target product to 68% (Table 1, entry 11). Next, a comprehensive synthetic strategy for the preparation of α
PDF
Album
Supp Info
Full Research Paper
Published 06 Feb 2024

Copper-catalyzed multicomponent reaction of β-trifluoromethyl β-diazo esters enabling the synthesis of β-trifluoromethyl N,N-diacyl-β-amino esters

  • Youlong Du,
  • Haibo Mei,
  • Ata Makarem,
  • Ramin Javahershenas,
  • Vadim A. Soloshonok and
  • Jianlin Han

Beilstein J. Org. Chem. 2024, 20, 212–219, doi:10.3762/bjoc.20.21

Graphical Abstract
  • diacyl β-amino esters can be easily constructed with good chemical yields. The reaction is conducted under mild conditions and shows good applicability to different series of substrates, which provides an efficient way for the preparation of unsymmetric trifluoromethyl diacyl β-amino esters. Experimental
PDF
Album
Supp Info
Letter
Published 02 Feb 2024

Comparison of glycosyl donors: a supramer approach

  • Anna V. Orlova,
  • Nelly N. Malysheva,
  • Maria V. Panova,
  • Nikita M. Podvalnyy,
  • Michael G. Medvedev and
  • Leonid O. Kononov

Beilstein J. Org. Chem. 2024, 20, 181–192, doi:10.3762/bjoc.20.18

Graphical Abstract
  • spectrum of phenomena including virus and bacterial recognition and cellular adhesion [1][2][3][4][5][6][7][8][9][10][11]. The development of effective means for the preparation of α-sialosides through chemical glycosylation (sialylation) received considerable attention since sialo-containing saccharides
PDF
Album
Supp Info
Full Research Paper
Published 31 Jan 2024

Synthesis of the 3’-O-sulfated TF antigen with a TEG-N3 linker for glycodendrimersomes preparation to study lectin binding

  • Mark Reihill,
  • Hanyue Ma,
  • Dennis Bengtsson and
  • Stefan Oscarson

Beilstein J. Org. Chem. 2024, 20, 173–180, doi:10.3762/bjoc.20.17

Graphical Abstract
PDF
Album
Supp Info
Full Research Paper
Published 30 Jan 2024

Copper-promoted C5-selective bromination of 8-aminoquinoline amides with alkyl bromides

  • Changdong Shao,
  • Chen Ma,
  • Li Li,
  • Jingyi Liu,
  • Yanan Shen,
  • Chen Chen,
  • Qionglin Yang,
  • Tianyi Xu,
  • Zhengsong Hu,
  • Yuhe Kan and
  • Tingting Zhang

Beilstein J. Org. Chem. 2024, 20, 155–161, doi:10.3762/bjoc.20.14

Graphical Abstract
  • gram-scale preparation was carried out using 1a, that afforded the desired product in 96% yield (Scheme 4, reaction 4). To gain more insight into the reaction mechanism, several control experiments were carried out (Scheme 5). On one hand, the failure of substrates 10–15 to participate in the reaction
PDF
Album
Supp Info
Full Research Paper
Published 23 Jan 2024
Graphical Abstract
  • landscape of [2 + 2] CA–RE reactions for the preparation of push–pull chromophores is rapidly evolving and expanding. This evolution necessitates an update on the latest insights for materials science researchers. Furthermore, the diverse research advancements related to the distinctive physicochemical
PDF
Album
Review
Published 22 Jan 2024

Preparing a liquid crystalline dispersion of carbon nanotubes with high aspect ratio

  • Keiko Kojima,
  • Nodoka Kosugi,
  • Hirokuni Jintoku,
  • Kazufumi Kobashi and
  • Toshiya Okazaki

Beilstein J. Org. Chem. 2024, 20, 52–58, doi:10.3762/bjoc.20.7

Graphical Abstract
  • ) absorption measurements were carried out using a Fourier-transform infrared spectroscopy (Bruker, VERTEX 80v) and a THz time domain spectroscopy (THz-TDS) system (Otsuka Electronics, TR-1000). Preparation of the DWCNT dispersion The dispersion of DWCNTs was prepared using a two-step process in accordance
  • were sealed by UV resin. After the samples were left for one week, the liquid phases were observed using an OLYMPUS BX51 polarized optical microscope (POM). Preparation and characterization of DWCNT film The DWCNT film was prepared from the dispersion with nematic phase by bar-coating method. Initially
PDF
Album
Supp Info
Full Research Paper
Published 11 Jan 2024

NMRium: Teaching nuclear magnetic resonance spectra interpretation in an online platform

  • Luc Patiny,
  • Hamed Musallam,
  • Alejandro Bolaños,
  • Michaël Zasso,
  • Julien Wist,
  • Metin Karayilan,
  • Eva Ziegler,
  • Johannes C. Liermann and
  • Nils E. Schlörer

Beilstein J. Org. Chem. 2024, 20, 25–31, doi:10.3762/bjoc.20.4

Graphical Abstract
  • ]. Thus, the first part of data handling, i.e., processing and preparation of an interpretation-ready state of spectra, is insufficiently treated in education. In the same way, the export format of evaluated/assigned experiments remains vague [36], and adequate recent developments for electronic
PDF
Album
Perspective
Published 05 Jan 2024

Cycloaddition reactions of heterocyclic azides with 2-cyanoacetamidines as a new route to C,N-diheteroarylcarbamidines

  • Pavel S. Silaichev,
  • Tetyana V. Beryozkina,
  • Vsevolod V. Melekhin,
  • Valeriy O. Filimonov,
  • Andrey N. Maslivets,
  • Vladimir G. Ilkin,
  • Wim Dehaen and
  • Vasiliy A. Bakulev

Beilstein J. Org. Chem. 2024, 20, 17–24, doi:10.3762/bjoc.20.3

Graphical Abstract
  • formal cycloaddition reaction of readily available heterocyclic azides with 3,3-diaminoacrylonitriles. The reaction represents a novel method for the preparation of 1,2,3-triazoles bearing an N-hetaryl amidine moiety and thus this reaction offers a novel method for the preparation of new types of 1
  • ethyl 2-cyanoacetimidate and corresponding amines according to the literature procedure [17] and compounds 1a,c–e,h–j are commercially available. Azides 2a–d,f,g were synthesized according to the literature procedures [18][19][20][21][22][23], and azide 2e is commercially available. Preparation of
PDF
Album
Supp Info
Full Research Paper
Published 05 Jan 2024

1-Butyl-3-methylimidazolium tetrafluoroborate as suitable solvent for BF3: the case of alkyne hydration. Chemistry vs electrochemistry

  • Marta David,
  • Elisa Galli,
  • Richard C. D. Brown,
  • Marta Feroci,
  • Fabrizio Vetica and
  • Martina Bortolami

Beilstein J. Org. Chem. 2023, 19, 1966–1981, doi:10.3762/bjoc.19.147

Graphical Abstract
  • complex organic compounds, widely used both in organic chemistry and in electrochemistry as raw materials for the preparation of different molecules of pharmaceutical and industrial interest [1][2][3][4][5][6][7][8][9]. Among the different organic transformations involving alkynes, their hydration is a
PDF
Album
Supp Info
Full Research Paper
Published 28 Dec 2023

Aldiminium and 1,2,3-triazolium dithiocarboxylate zwitterions derived from cyclic (alkyl)(amino) and mesoionic carbenes

  • Nedra Touj,
  • François Mazars,
  • Guillermo Zaragoza and
  • Lionel Delaude

Beilstein J. Org. Chem. 2023, 19, 1947–1956, doi:10.3762/bjoc.19.145

Graphical Abstract
  • report described the preparation of a CAAC·CS2 zwitterion. Thus, in 2009 Bertrand et al. obtained the betaine 2 by reacting the free carbene 1 with a slight excess of CS2 in THF at room temperature (Scheme 1) [62]. The starting material that featured a bulky and rigid spirocyclic alkyl group derived from
PDF
Album
Supp Info
Full Research Paper
Published 20 Dec 2023

Studying specificity in protein–glycosaminoglycan recognition with umbrella sampling

  • Mateusz Marcisz,
  • Sebastian Anila,
  • Margrethe Gaardløs,
  • Martin Zacharias and
  • Sergey A. Samsonov

Beilstein J. Org. Chem. 2023, 19, 1933–1946, doi:10.3762/bjoc.19.144

Graphical Abstract
  • ligand from its bound position and allowing the ligand to approach the protein from a very distant position to the binding sites. Materials and Methods Structures and parameters Ligand preparation GAG structures used in the study consist of two parts: 1. the part from the experimental structure (heparin
  • 1C4 conformation for the IdoA2S ring was chosen as it was shown to be the essentially dominant conformation in the microsecond scale simulations performed by Sattelle et al. as it is energetically more favorable than the 2SO conformation [40]. Complex preparation The obtained ligands were docked using
PDF
Album
Supp Info
Full Research Paper
Published 19 Dec 2023

Construction of diazepine-containing spiroindolines via annulation reaction of α-halogenated N-acylhydrazones and isatin-derived MBH carbonates

  • Xing Liu,
  • Wenjing Shi,
  • Jing Sun and
  • Chao-Guo Yan

Beilstein J. Org. Chem. 2023, 19, 1923–1932, doi:10.3762/bjoc.19.143

Graphical Abstract
  • readily available reagents, mild conditions, satisfactory yields, broad substrate scope, high molecular convergence, and atomic economy. The synthetic applications of this annulation reaction in heterocyclic chemistry might be significant. Experimental General procedure for the preparation of dihydrospiro
  • , 125.5, 117.4, 109.9, 95.0, 52.3, 44.4, 37.0, 20.9 ppm; IR (KBr) ν: 2960, 2936, 2870, 2211, 1717, 1626, 1498, 1445, 1367, 1268, 1193, 1112, 1090, 1009, 903, 868, 815 cm−1; HRMS–ESI TOF (m/z): [M + Na]+ calcd for C34H26N4O2Na, 545.1956; found, 545.1948. General procedure for the preparation of
  • , 127.5, 127.0, 124.4, 111.6, 110.4, 52.2, 51.1, 44.4, 36.8 ppm; IR (KBr) ν: 2924, 2853, 1721, 1608, 1484, 1456, 1430, 1340, 1170, 812 cm−1; HRMS–ESI TOF (m/z): [M + H]+ calcd for C34H27ClN3O4, 576.1685; found, 576.1683. General procedure for the preparation of dihydrospiro[indoline-3,5'-[1,2]diazepines
PDF
Album
Supp Info
Full Research Paper
Published 18 Dec 2023

Biphenylene-containing polycyclic conjugated compounds

  • Cagatay Dengiz

Beilstein J. Org. Chem. 2023, 19, 1895–1911, doi:10.3762/bjoc.19.141

Graphical Abstract
  • -dibora-2,5-cyclohexadiene structure (Scheme 16) in addition to a π-extended linear POA (Scheme 17) [50]. The preparation of v- and z-shaped POAs 77 and 78 was carried out starting from 2-bromobiphenylene (74). Initial steps involved ortho-directed lithiation and subsequent treatment with Me3SiCl
PDF
Album
Review
Published 13 Dec 2023
Other Beilstein-Institut Open Science Activities