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Search for "reagent" in Full Text gives 1245 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.

Entry to new spiroheterocycles via tandem Rh(II)-catalyzed O–H insertion/base-promoted cyclization involving diazoarylidene succinimides

  • Alexander Yanovich,
  • Anastasia Vepreva,
  • Ksenia Malkova,
  • Grigory Kantin and
  • Dmitry Dar’in

Beilstein J. Org. Chem. 2024, 20, 561–569, doi:10.3762/bjoc.20.48

Graphical Abstract
  • approach using propiolic acids [39]. The diazo reagent 1a was introduced in the Rh2(esp)2-catalyzed insertion into the O–H bond of phenylpropropiolic acid (9а) to form the intermediate compound 10a (Scheme 2). The cyclization of the latter was carried out in DCM solution under the action of DIPEA (30 mol
  • structure of product 3b has been confirmed by crystallographic data. An approach to the construction of the THF cycle using a diazo reagent and 3-bromopropan-1-ol (13) [41] or similar halogenated OH substrates [42] has already been demonstrated in the literature using selected examples. We first validate
  • reaction products using diazo reagent 1b as an example, but we failed to observe the formation of spirocyclic cyclization products as a result of intramolecular substitution of the bromine atom (Scheme 7). For example, during the attempted cyclization of compound 18, obtained from 2-(bromomethyl)benzoic
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Published 11 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

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  • ]pyridine (13c, 54% combined isolated yield). As shown for N-acylated target compounds 16a–f, the acylation of 6-bromo-2,3-dihydro[1,3]thiazolo[4,5-b]pyridines 13a–c, affording target compounds 14a–c, proceeded under mild conditions with a suitable acyl chloride reagent and triethylamine as base in DCM. It
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Published 01 Mar 2024

Ligand effects, solvent cooperation, and large kinetic solvent deuterium isotope effects in gold(I)-catalyzed intramolecular alkene hydroamination

  • Ruichen Lan,
  • Brock Yager,
  • Yoonsun Jee,
  • Cynthia S. Day and
  • Amanda C. Jones

Beilstein J. Org. Chem. 2024, 20, 479–496, doi:10.3762/bjoc.20.43

Graphical Abstract
  • -workers, it was found that in chlorination reactions, activation of alkenes is not driven by the electrophilicity of the reagent being attacked by an alkene, but instead depends on nucleophile assistance: the alkene becomes more nucleophilic upon interaction with the pendant attacking nucleophile [81]. In
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Published 29 Feb 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
  • , but the second fluorination step occurs only after reaction for several days. In the solid phase, mechanical milling of the diketone substrate with solid Selectfluor in the presence of sodium carbonate [13][14], and reaction of ketones with a strong base and an N–F reagent give rise to the
  • enolization of the monofluoro-diketone intermediates. In addition, imines and α-diboryl ketone derivatives can also be transformed to 2,2-difluoroketones using an N–F electrophilic fluorinating reagent [18]. Alternatively, building blocks containing CF2 units such as ethyl bromodifluoroacetate and
  • , electrophilic reagent to be important. Given the structural similarity of 1,4-diazabicyclo[2.2.2]octane (DABCO) to the Selectfluor system, a 10% v/v mixture of fluorine in nitrogen was passed through a solution of 1a in acetonitrile containing one equivalent of DABCO, using a fluorination apparatus and gas flow
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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
  • compound, but led to the elimination of two fluorine atoms with the formation of 1,1,4,4-tetrafluorobuta-1,3-diene [9]. It was also shown that the reactions of the boron reagent (CAACMe)BH2Li(thf)3 with hydrofluoroolefins, including (Z)-1,1,1,4,4,4-hexafluorobut-2-ene, results in defluoroborylation to form
  • continues to be relevant. One of the methods for the synthesis of allenes was based on the interaction of bromoolefins with organolithium compounds, followed by the elimination of lithium fluoride [29][30][31]. It was logical to assume that in our case a similar reaction of the Grignard reagent 12 with
  • aldehyde 9, elimination of MgBrF results in the formation of allene 11. To confirm our hypothesis, we studied the reaction of haloolefins 3 and 7 with iPrMgCl and BuLi. Thus, olefin 3a in Et2O reacted with iPrMgCl solution in THF at −80 °C to form Grignard reagent 12 and by heating the reaction mixture to
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Published 27 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

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  • mentioning that Hojati et al., in 2013, developed a simple, novel and efficient procedure for the synthesis of BIMs, utilizing 1,3-dibromo-5,5-dimethylhydantoin (DBDMH) as the catalyst (Scheme 3). DBDMH is an N-halo-reagent, which has found widespread applications in industrial processes, due to its economic
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Published 22 Feb 2024

Discovery of unguisin J, a new cyclic peptide from Aspergillus heteromorphus CBS 117.55, and phylogeny-based bioinformatic analysis of UngA NRPS domains

  • Sharmila Neupane,
  • Marcelo Rodrigues de Amorim and
  • Elizabeth Skellam

Beilstein J. Org. Chem. 2024, 20, 321–330, doi:10.3762/bjoc.20.32

Graphical Abstract
  • was evaporated under nitrogen gas flow. The residue was dissolved in 0.5 mL of H2O, and dried using speedvac to remove the residual HCl. The hydrolysates of 1 and 2 as well as authentic amino acid samples were treated with 200 μL of 1 N sodium bicarbonate solution and 100 μL of 1% Marfey’s reagent (Nα
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Published 19 Feb 2024

Elucidating the glycan-binding specificity and structure of Cucumis melo agglutinin, a new R-type lectin

  • Jon Lundstrøm,
  • Emilie Gillon,
  • Valérie Chazalet,
  • Nicole Kerekes,
  • Antonio Di Maio,
  • Ten Feizi,
  • Yan Liu,
  • Annabelle Varrot and
  • Daniel Bojar

Beilstein J. Org. Chem. 2024, 20, 306–320, doi:10.3762/bjoc.20.31

Graphical Abstract
  • instrument company) at 130 rpm in a Multitron 4 incubator (Infors) and transfected at 2 × 106 cells/mL using FectoPro transfection reagent (Polyplus). Protein-containing culture supernatant (0.8 L) was harvested after 120 h, filtered using Polydisc AS 0.45 μm (Whatman, Cytiva) and loaded onto a 5 mL HisExcel
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Published 19 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
  • reactivity in the absence of external reagent (i.e., their photo- and thermal reactivity) has been far less explored than for heteropines. Nowadays, the most common protocol to trigger extrusion from 1,2-dichalcogenins and generate S- and Se-doped π-CPCs still relies on copper (as nanopowder) at high
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Published 15 Feb 2024

Additive-controlled chemoselective inter-/intramolecular hydroamination via electrochemical PCET process

  • Kazuhiro Okamoto,
  • Naoki Shida and
  • Mahito Atobe

Beilstein J. Org. Chem. 2024, 20, 264–271, doi:10.3762/bjoc.20.27

Graphical Abstract
  • electron-transfer to give the corresponding radical species through oxidative X–H bond cleavage. One such species is the amidyl radical, which is broadly synthetically useful as a nitrogen source in hydroamination reactions and as a hydrogen atom transfer (HAT) reagent for remote C–H activation [2][3][4][5
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Published 12 Feb 2024

Nucleophilic functionalization of thianthrenium salts under basic conditions

  • Xinting Fan,
  • Duo Zhang,
  • Xiangchuan Xiu,
  • Bin Xu,
  • Yu Yuan,
  • Feng Chen and
  • Pan Gao

Beilstein J. Org. Chem. 2024, 20, 257–263, doi:10.3762/bjoc.20.26

Graphical Abstract
  • % yield (Scheme 4). This operationally simple protocol enables the rapid development of novel thioetherification reactions using bench-stable alkylthianthrenium salts as the electrophiles. As is well known, alkyl trifluoromethanesulfonate (alkyl-OTf), serving as a potent electrophilic reagent, can also
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Published 08 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
  • side reactions was carried out with benzyl 3-amino-4,4,4-trifluorobutanoate (1a) and benzoic acid (3a) as model substrates. The initial reaction of amine 1a and acid 3a in acetonitrile in the presence of diazotization reagent tert-butyl nitrite with CuI (10 mol %) as catalysts for 2.5 h at room
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Published 02 Feb 2024

Metal-catalyzed coupling/carbonylative cyclizations for accessing dibenzodiazepinones: an expedient route to clozapine and other drugs

  • Amina Moutayakine and
  • Anthony J. Burke

Beilstein J. Org. Chem. 2024, 20, 193–204, doi:10.3762/bjoc.20.19

Graphical Abstract
  • effective ligand in a variety of highly efficient aminocarbonylation reactions with Mo(CO)6 due to its strong basicity and accelerated release of CO from this reagent [21]. The reaction was then screened using two different bidentate ligands, XPhos and XantPhos, and using the previous reaction conditions
  • reactions described in Table 1, involving Mo(CO)6 were 20 °C higher than the reactions described in Table 2 and/or (b) Mo(CO)6 acts as a co-catalyst. An investigative study was thus undertaken to elucidate the effect of the molybdenum reagent on the reaction using a simple model system consisting of aniline
  • and bromobenzene (see Figure S1 and Table S1 in Supporting Information File 1). The experimental design was limited, in that we only monitored the reaction over a 90 min period. Contrary to what was originally believed the reaction without the Mo reagent gave better results during the first 90 min
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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
  • in formation of a homogenous solution, but still no conversion to the sulfated product, even when the temperature was raised to 80 °C [28][29]. Switching the sulfating reagent to SO3·Py or performing the reaction at 150 °C in a microwave did not improve the outcome [30][31]. Since there was no
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Published 30 Jan 2024

Tandem Hock and Friedel–Crafts reactions allowing an expedient synthesis of a cyclolignan-type scaffold

  • Viktoria A. Ikonnikova,
  • Cristina Cheibas,
  • Oscar Gayraud,
  • Alexandra E. Bosnidou,
  • Nicolas Casaretto,
  • Gilles Frison and
  • Bastien Nay

Beilstein J. Org. Chem. 2024, 20, 162–169, doi:10.3762/bjoc.20.15

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  • leading to the isolation of dihydronaphthalenic product 4 in 82% yield (Table 1, entry 4, these conditions will later be taken as the reference). Trying to reduce this reagent stoichiometry only resulted in a poor yield of 4 and in the isolation of aldehyde 3 in 42% yield (Table 1, entry 5). By contrast
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Published 25 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
  • -scale use. Therefore, novel bromination reagents and simple bromination approaches are still required to be established. Very recently, we reported a copper-catalyzed C5-bromination and difluoromethylation reaction of 8-aminoquinolines using ethyl bromodifluoroacetate as bifunctional reagent [30] and
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Published 23 Jan 2024

Visible-light-induced radical cascade cyclization: a catalyst-free synthetic approach to trifluoromethylated heterocycles

  • Chuan Yang,
  • Wei Shi,
  • Jian Tian,
  • Lin Guo,
  • Yating Zhao and
  • Wujiong Xia

Beilstein J. Org. Chem. 2024, 20, 118–124, doi:10.3762/bjoc.20.12

Graphical Abstract
  • radicals. This method allows the efficient synthesis of various indole derivatives without the need of photocatalysts or transition-metal catalysts. Mechanism experiments indicate that the process involves a radical chain process initiated by the homolysis of Umemoto's reagent. This straightforward method
  • trifluoromethyl radical source under light irradiation. Umemoto’s reagent, which is capable of releasing a trifluoromethyl radical via a photoinduced single-electron-transfer (SET) process, is usually employed to enable the trifluoromethylation of unsaturated substrates [25][26][27]. Herein, we report a protocol
  • to furnish trifluoromethylated dihyropyrido[1,2-a]indolones under mild conditions, without the need of photocatalysts or transition metals [28]. Results and Discussion We initialized our study by employing Ru(bpy)3Cl2·6H2O and Umemoto’s reagent to generate trifluoromethyl radicals via a photo
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Published 19 Jan 2024

Photoinduced in situ generation of DNA-targeting ligands: DNA-binding and DNA-photodamaging properties of benzo[c]quinolizinium ions

  • Julika Schlosser,
  • Olga Fedorova,
  • Yuri Fedorov and
  • Heiko Ihmels

Beilstein J. Org. Chem. 2024, 20, 101–117, doi:10.3762/bjoc.20.11

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  • chemicals (Alfa, Merck, Fluorochem or BLDpharm) were of reagent grade and used without further purification. 1H NMR spectra were recorded with a JEOL ECZ 500 (1H: 500 MHz and 13C: 125 MHz) and a Varian VNMR S600 (1H: 600 MHz and 13C: 150 MHz) at T = 25 °C. The 1H NMR and 13C{1H} NMR spectra were referenced
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Published 18 Jan 2024

Multi-redox indenofluorene chromophores incorporating dithiafulvene donor and ene/enediyne acceptor units

  • Christina Schøttler,
  • Kasper Lund-Rasmussen,
  • Line Broløs,
  • Philip Vinterberg,
  • Ema Bazikova,
  • Viktor B. R. Pedersen and
  • Mogens Brøndsted Nielsen

Beilstein J. Org. Chem. 2024, 20, 59–73, doi:10.3762/bjoc.20.8

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  • variety of reactions; that are, phosphite- or Lawesson’s reagent-mediated olefination reactions (to introduce DTF motifs), Ramirez/Corey–Fuchs dibromo-olefinations followed by Sonogashira couplings (to introduce enediynes motifs), and Knoevenagel condensations (to introduce the vinylic diester motif). By
  • -annelated IF-DTF 12 by removal of the tosyl (Ts) group under alkaline conditions, followed by nucleophilic substitution to incorporate the hexyl chain on the pyrrole. Furthermore, treatment of the IF-DTF ketone 4 with Lawesson’s reagent (using a recently established protocol [20]) yielded the large dimer 13
  • smaller fluorene PAH. These compounds were prepared by a Lawesson’s reagent-promoted coupling between fluorenone 5 and the Ts-protected 1,3-dithiole-2-thione building blocks 2 and 3, respectively, shown in Scheme 3 (albeit in modest yields). Fluorene-based DTF compounds have previously been explored in
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Published 15 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
  • (Table 5, entry 10), which had not been achieved using BF3·Et2O as a reagent (see Table 4, entry 10). For the aliphatic alkyne 1k the hydration product 2k was obtained with moderate yield by exploiting the electrogeneration of 2 F/mol of BF3 (Table 5, entry 11). Unfortunately, an increase in the amount
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Published 28 Dec 2023

Long oligodeoxynucleotides: chemical synthesis, isolation via catching-by-polymerization, verification via sequencing, and gene expression demonstration

  • Yipeng Yin,
  • Reed Arneson,
  • Alexander Apostle,
  • Adikari M. D. N. Eriyagama,
  • Komal Chillar,
  • Emma Burke,
  • Martina Jahfetson,
  • Yinan Yuan and
  • Shiyue Fang

Beilstein J. Org. Chem. 2023, 19, 1957–1965, doi:10.3762/bjoc.19.146

Graphical Abstract
  • . To ensure full coverage of CPG in the column by reagent solutions in each of the over one thousand reactions, the synthesizer manufacturer’s recommendation of 1 µmol instead of 0.2 µmol for standard synthetic cycle was used with several minor but critical modifications (see Supporting Information
  • CBP, correct sequence selection by cloning and sequencing, gene construction, sequence confirmation by sequencing to gene expression is successfully established. In theory, using long ODNs for gene and genome construction can save significant amount of reagent and solvent for ODN synthesis because
  • using short ODNs, the gene and genome would need to be covered by ODNs almost two times due to the need of overlaps between adjacent ODNs. In contrast, using long ODNs only negligible portions require double coverage. In terms of reagent consumption and timing, the type of synthesizer makes a
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Published 21 Dec 2023

N-Boc-α-diazo glutarimide as efficient reagent for assembling N-heterocycle-glutarimide diads via Rh(II)-catalyzed N–H insertion reaction

  • Grigory Kantin,
  • Pavel Golubev,
  • Alexander Sapegin,
  • Alexander Bunev and
  • Dmitry Dar’in

Beilstein J. Org. Chem. 2023, 19, 1841–1848, doi:10.3762/bjoc.19.136

Graphical Abstract
  • component into a glutarimide framework employing a Rh2(esp)2-catalyzed N–H insertion with the involvement of N-Boc-α-diazo glutarimide. The new diazo reagent is more stable, soluble and convenient to prepare than the previously suggested one. The approach permits the application of diverse heterocycles
  • with a diazo reagent under neutral conditions may give rise to a separate regioisomer which is different from the product obtained by reaction with an alkyl halide under basic conditions. Recently, we designed a thalidomide analogue 1a in which the phthalimide moiety was replaced with benzotriazole
  • , the proposed diazo reagent 4 possesses several drawbacks, primarily, insufficient stability during storage and comparatively low solubility in non-polar solvents, as well as complications when isolating it in a pure form. This study focuses on the development of a "diazo" technique to incorporate a
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Published 07 Dec 2023

Recent advancements in iodide/phosphine-mediated photoredox radical reactions

  • Tinglan Liu,
  • Yu Zhou,
  • Junhong Tang and
  • Chengming Wang

Beilstein J. Org. Chem. 2023, 19, 1785–1803, doi:10.3762/bjoc.19.131

Graphical Abstract
  • radical and I· played a pivotal as an intermediate step in the production of alkyl iodides B. Compound B could undergo a further elimination reaction to yield various olefins 11. Regarding benzyl substrates, the radical I· demonstrated its efficacy as a reagent for hydrogen atom transfer (HAT
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Published 22 Nov 2023

Cyclodextrins permeabilize DPPC liposome membranes: a focus on cholesterol content, cyclodextrin type, and concentration

  • Ghenwa Nasr,
  • Hélène Greige-Gerges,
  • Sophie Fourmentin,
  • Abdelhamid Elaissari and
  • Nathalie Khreich

Beilstein J. Org. Chem. 2023, 19, 1570–1579, doi:10.3762/bjoc.19.115

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  • hydroxypropyl-β-CD (HPBCD, DS = 5.6) were provided by Roquette Frères (Lestrem, France). Sulfobutyl ether-β-CD (SBE-β-CD, DS = 6.5) was provided by LIGAND Pharmaceuticals (San Diego, CA, USA). Dipalmitoylphosphatidylcholine (DPPC) and trizma base (buffer reagent) were purchased from Sigma-Aldrich, Switzerland
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Published 17 Oct 2023

Secondary metabolites of Diaporthe cameroonensis, isolated from the Cameroonian medicinal plant Trema guineensis

  • Bel Youssouf G. Mountessou,
  • Élodie Gisèle M. Anoumedem,
  • Blondelle M. Kemkuignou,
  • Yasmina Marin-Felix,
  • Frank Surup,
  • Marc Stadler and
  • Simeon F. Kouam

Beilstein J. Org. Chem. 2023, 19, 1555–1561, doi:10.3762/bjoc.19.112

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  • . Experimental General experimental procedures Column chromatography (60.4 cm length × 5.5 cm inner diameter) was carried out on silica gel 230–400 mesh (Merck). Analytical TLC was performed on Merck pre-coated silica gel 60 F254 plates, and spots were detected using ceric sulfate spray reagent and/or diluted
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Published 13 Oct 2023
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