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Search for "uracil" in Full Text gives 56 result(s) in Beilstein Journal of Organic Chemistry.

Synthesis of benzo[f]quinazoline-1,3(2H,4H)-diones

  • Ruben Manuel Figueira de Abreu,
  • Peter Ehlers and
  • Peter Langer

Beilstein J. Org. Chem. 2024, 20, 2708–2719, doi:10.3762/bjoc.20.228

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  • Ruben Manuel Figueira de Abreu Peter Ehlers Peter Langer Universität Rostock, Institut für Chemie, Albert-Einstein-Str. 3a, 18059 Rostock, Germany 10.3762/bjoc.20.228 Abstract We report the synthesis of polycyclic uracil derivatives. The method is based on palladium-catalysed Sonogashira–Hagihara
  • was studied by UV–vis and fluorescence spectroscopy. Keywords: cross-coupling; cyclization; heterocycles; palladium; Introduction Nucleobases contain the coded information and give DNA and RNA their typical structure. As a nucleobase, uracil is involved in numerous vital processes and is therefore a
  • promising target and candidate for the development of new drugs against a wide range of diseases [1][2][3][4]. As it is not contained in the DNA, it could be used to distinguish between DNA and RNA-based pharmaceutical targets. In previous years, uracil has been successfully used in the development of
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Published 28 Oct 2024

Efficient modification of peroxydisulfate oxidation reactions of nitrogen-containing heterocycles 6-methyluracil and pyridine

  • Alfiya R. Gimadieva,
  • Yuliya Z. Khazimullina,
  • Aigiza A. Gilimkhanova and
  • Akhat G. Mustafin

Beilstein J. Org. Chem. 2024, 20, 2599–2607, doi:10.3762/bjoc.20.219

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  • are widely used in pharmacology due to their pronounced biological activities and low toxicities. The introduction of a hydroxy function into uracil and pyridine molecules has led to compounds with antioxidant, anti-inflammatory, and immunomodulatory activity (3-hydroxy-6-methyl-2-ethylpyridine, 5
  • by РсМ. As described in [13] to a three-necked flask of 100 mL capacity, equipped with a mechanical stirrer, a thermometer, and a reflux condenser, containing 10 mL of distilled water, was added 0.023 mol of the corresponding uracil 1 or 4, followed by the addition of 11 mL of a previously prepared
  • 24% NaOH solution to the obtained suspension. To the obtained thick mass 0.034 mol of (NH4)2S2O8 was added in portions under stirring, after which the calculated amount of the corresponding PcM was added. The reaction mixture was stirred at 60 °C for 4 h (for uracil 4–8 h). After cooling the reaction
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Published 16 Oct 2024

Synthesis of 1,4-azaphosphinine nucleosides and evaluation as inhibitors of human cytidine deaminase and APOBEC3A

  • Maksim V. Kvach,
  • Stefan Harjes,
  • Harikrishnan M. Kurup,
  • Geoffrey B. Jameson,
  • Elena Harjes and
  • Vyacheslav V. Filichev

Beilstein J. Org. Chem. 2024, 20, 1088–1098, doi:10.3762/bjoc.20.96

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  • of the University of Auckland, Level 2, 3A Symonds Street, Auckland 1142, New Zealand 10.3762/bjoc.20.96 Abstract Nucleoside and polynucleotide cytidine deaminases (CDAs), such as CDA and APOBEC3, share a similar mechanism of cytosine to uracil conversion. In 1984, phosphapyrimidine riboside was
  • development of more potent CDA and APOBEC3 inhibitors. Keywords: APOBEC3; cytidine deaminase; enzyme activity; inhibitor; nucleoside; nucleotide; zebularine; Introduction Spontaneous hydrolytic deamination of cytosine to uracil (Figure 1A) is very slow under ambient conditions [1], but it is greatly
  • (MDS) and chronic myelomonocytic leukaemia (CMML) [8]. In normal human cells, the enzyme family A3 [9][10][11][12] disables pathogens by scrambling ssDNA by cytosine to uracil mutation (Figure 1A) [9][10][13][14]. However, several enzymes, particularly A3A, A3B, A3H and A3G, deaminate cytosine in human
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Published 15 May 2024

Synthesis and properties of 6-alkynyl-5-aryluracils

  • Ruben Manuel Figueira de Abreu,
  • Till Brockmann,
  • Alexander Villinger,
  • Peter Ehlers and
  • Peter Langer

Beilstein J. Org. Chem. 2024, 20, 898–911, doi:10.3762/bjoc.20.80

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  • Abstract The development of a new and straightforward chemoselective method for the synthesis of uracil-based structures by combining Suzuki–Miyaura and Sonogashira–Hagihara cross-coupling is reported. The methodology was applied to synthesize a series of novel compounds. The tolerance of the combination
  • of different functional groups was tested. The influence of different functional groups on the physical properties was studied by ultraviolet–visible (UV–vis) and fluorescence spectroscopy, providing new insights into the potential applications of uracil-based structures. Keywords: catalysis; cross
  • -coupling; fluorescence; heterocycles; regioselectivity; Introduction Organic life is a complex interplay of many different building blocks. One of these building blocks is uracil. Discovered for the first time in 1901 by Alberto Ascoli, it is now known to be one of the four nucleobases of RNA [1]. It
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Published 22 Apr 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

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  • this case, intramolecular radical trapping by the uracil nucleobase was preferred, leading to the formation of the cyclized alkyl radical D. Continuous radical recombination furnished dimer 4. Conclusion We observed additive-controlled inter- and intramolecular chemoselectivity in the hydroamination of
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Published 12 Feb 2024

Ferrocenoyl-adenines: substituent effects on regioselective acylation

  • Mateja Toma,
  • Gabrijel Zubčić,
  • Jasmina Lapić,
  • Senka Djaković,
  • Davor Šakić and
  • Valerije Vrček

Beilstein J. Org. Chem. 2022, 18, 1270–1277, doi:10.3762/bjoc.18.133

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  • kinetic and thermodynamic control of the acylation reaction. Results and Discussion It was shown that the reaction between the pyrimidine anion (uracil, thymine, or 5-fluorouracil) and FcCOCl in N,N-dimethylformamide (DMF) proceeded in a full regiospecific mode [19]. In the purine series, however, the
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Published 19 Sep 2022

Chemical and chemoenzymatic routes to bridged homoarabinofuranosylpyrimidines: Bicyclic AZT analogues

  • Sandeep Kumar,
  • Jyotirmoy Maity,
  • Banty Kumar,
  • Sumit Kumar and
  • Ashok K. Prasad

Beilstein J. Org. Chem. 2022, 18, 95–101, doi:10.3762/bjoc.18.10

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  • , University of Delhi, Delhi- 110 015, India 10.3762/bjoc.18.10 Abstract Conformationally restricted diastereomeric homoarabinofuranosylpyrimidines (AZT analogue), i.e., (5′R)-3′-azido-3′-deoxy-2′-O,5′-C-bridged-β-ᴅ-homoarabinofuranosylthymine and -uracil had been synthesized starting from diacetone ᴅ
  • ]. Azidofuranoside 11 on acetolysis with acetic acid/acetic anhydride/sulfuric acid (100:10:0.1) at room temperature afforded an anomeric mixture of 1,2,5,6-tetra-O-acetyl-3-azido-3-deoxy-α,β-ᴅ-allofuranose (12a,b), which on Vorbrüggen base coupling [29] with thymine and uracil in the presence of N,O-bis
  • anomeric triacetylated sugars 19a,b with thymine and uracil in the presence of BSA and TMSOTf in acetonitrile afforded nucleosides 20a,b, respectively in high yields. The deacetylation of these nucleosides was carried out using K2CO3 in a solvent mixture of methanol and water (9:1) to afford nucleoside 21a
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Published 11 Jan 2022

Chemical approaches to discover the full potential of peptide nucleic acids in biomedical applications

  • Nikita Brodyagin,
  • Martins Katkevics,
  • Venubabu Kotikam,
  • Christopher A. Ryan and
  • Eriks Rozners

Beilstein J. Org. Chem. 2021, 17, 1641–1688, doi:10.3762/bjoc.17.116

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  • uracil with fluorine or trifluoromethyl improved PNA binding affinity for complementary DNA and RNA [127]. Moreover, fluorination increased the cellular uptake of PNAs [127]. Fluorinated uracil derivatives are also useful probes for studying different binding modes of PNA using 19F NMR [128]. PNA
  • any Watson–Crick base pairing scheme, AOVP lowered the stability of PNA duplexes with complementary DNA and RNA [132]. Similarly, vinyl-modified purine (AVP) effectively crosslinked with thymine in DNA and with uracil in RNA. The crosslinking resulted in inhibition of Dicer processing of microRNA
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Published 19 Jul 2021

Double-headed nucleosides: Synthesis and applications

  • Vineet Verma,
  • Jyotirmoy Maity,
  • Vipin K. Maikhuri,
  • Ritika Sharma,
  • Himal K. Ganguly and
  • Ashok K. Prasad

Beilstein J. Org. Chem. 2021, 17, 1392–1439, doi:10.3762/bjoc.17.98

Graphical Abstract
  • literature search regarding double-headed nucleosides disclosed that these modified nucleosides were constituted with any two naturally occurring nucleobases, i.e., adenine, guanine, thymine, uracil, and cytosine [9][10] or one naturally occurring nucleobase and one heterocyclic/carbocyclic moiety either
  • ]. Nielsen and co-workers [42] additionally synthesized 2′-(N-benzoylcytosin-1-yl)methylarabinofuranosyl-N-benzoylcytosine (7) from uridine using a similar methodology. Thus, the nucleophilic epoxide ring opening in spironucleoside 2 with uracil in DMF in a N1-regioselective manner afforded the TIPDS
  • -protected double-headed nucleoside 5 having two uracil bases (the additional uracil being attached through a methylene linker to the 2′-position of arabinouracil). Subsequently, the two uracil bases of the TIPDS-protected double-headed nucleoside 5 were converted to N-benzoylated cytosines in a three-step
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Published 08 Jun 2021

Antiviral therapy in shrimp through plant virus VLP containing VP28 dsRNA against WSSV

  • Santiago Ramos-Carreño,
  • Ivone Giffard-Mena,
  • Jose N. Zamudio-Ocadiz,
  • Alfredo Nuñez-Rivera,
  • Ricardo Valencia-Yañez,
  • Jaime Ruiz-Garcia,
  • Maria Teresa Viana and
  • Ruben D. Cadena-Nava

Beilstein J. Org. Chem. 2021, 17, 1360–1373, doi:10.3762/bjoc.17.95

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  • ® Fast Advanced Master Mix kit (Applied Biosystems, USA). Amplification reactions of 20 μL were prepared by mixing 23.33 ng of DNA, 0.3 μM of each primer, and 0.15 μM of TaqMan probe, and the qPCR was performed following Durand and Lightner [51] methodology. In summary, 2.0 min at 50 °C for uracil-N
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Published 01 Jun 2021

A comprehensive review of flow chemistry techniques tailored to the flavours and fragrances industries

  • Guido Gambacorta,
  • James S. Sharley and
  • Ian R. Baxendale

Beilstein J. Org. Chem. 2021, 17, 1181–1312, doi:10.3762/bjoc.17.90

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Published 18 May 2021

Beyond ribose and phosphate: Selected nucleic acid modifications for structure–function investigations and therapeutic applications

  • Christopher Liczner,
  • Kieran Duke,
  • Gabrielle Juneau,
  • Martin Egli and
  • Christopher J. Wilds

Beilstein J. Org. Chem. 2021, 17, 908–931, doi:10.3762/bjoc.17.76

Graphical Abstract
  • simplicity combined with the five natural bases, adenine (A), cytosine (C), guanine (G), thymine (T) and uracil (U, in RNA) belies the fact that both DNA and RNA are decorated with chemical modifications. For a catalogue of natural modifications in DNA, see https://dnamod.hoffmanlab.org/ [1], and in RNA, see
  • modification is accommodated in an A'-form duplex [75]. Interestingly, an unconventional C–H···O hydrogen bond was observed between the amide’s carbonyl oxygen and the nearby uracil C6–H6. The thermal stability of this modified duplex was, however, quite similar to native RNA. Typically, there is a decrease of
  • (R) or (S) starting material, respectively. These simple nucleic acid building blocks were first synthesized in 1971 by Ueda et al. [96]. The group was able to synthesize adenine, cytosine, and uracil GNA analogues by reacting these bases with glycerol α-chlorohydrin or glycidol. The following year
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Published 28 Apr 2021

Microwave-assisted multicomponent reactions in heterocyclic chemistry and mechanistic aspects

  • Shivani Gulati,
  • Stephy Elza John and
  • Nagula Shankaraiah

Beilstein J. Org. Chem. 2021, 17, 819–865, doi:10.3762/bjoc.17.71

Graphical Abstract
  • intermediate D which on the loss of a water molecule yields the products 87 (Scheme 31). Choudhury and co-workers [83] disclosed a three-component reaction of substituted arylglyoxal monohydrate 33, 6-amino-1,3-disubstituted uracil 86 and substituted thiols 88 under microwave conditions using acetic acid as a
  • under microwave conditions delivered the desired product in better yields than the reflux strategy. Scheme 33 depicts the most probable pathway for the desired products 89 and 90. Initially, an acid-catalyzed reaction between arylglyoxal and amino uracil yields intermediate A. Nucleophilic addition of
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Published 19 Apr 2021

Anion exchange resins in phosphate form as versatile carriers for the reactions catalyzed by nucleoside phosphorylases

  • Julia N. Artsemyeva,
  • Ekaterina A. Remeeva,
  • Tatiana N. Buravskaya,
  • Irina D. Konstantinova,
  • Roman S. Esipov,
  • Anatoly I. Miroshnikov,
  • Natalia M. Litvinko and
  • Igor A. Mikhailopulo

Beilstein J. Org. Chem. 2020, 16, 2607–2622, doi:10.3762/bjoc.16.212

Graphical Abstract
  • substrates of the phosphorolysis of uridine, thymidine, and 1-(β-ᴅ-arabinofuranosyl)uracil (Ara-U) catalyzed by recombinant E. coli uridine (UP) and thymidine (TP) phosphorylases. α-ᴅ-Pentofuranose-1-phosphates (PF-1Pis) obtained by phosphorolysis were used in the enzymatic synthesis of nucleosides. It was
  • attracted the attention of researchers. Recently, the phosphorolysis of commercially available uridine (Urd), thymidine (Thd), and 1-(β-ᴅ-arabinofuranosyl)uracil (Ara-U) under the action of recombinant (i) uridine phosphorylase (UP) and thymidine phosphorylase (TP) from E. coli [28], and (ii) thermostable
  • enzymatic syntheses of biologically important purine nucleosides, on the other hand (Scheme 1). As might be expected, the replacement of phosphate buffer with Dowex-nPi in the phosphorolysis of uridine (Urd), thymidine (Thd), and 1-(β-ᴅ-arabinofuranosyl)uracil (Ara-U) slowed down the reaction rate and
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Published 22 Oct 2020

Synthesis of 3(2)-phosphonylated thiazolo[3,2-a]oxopyrimidines

  • Ksenia I. Kaskevich,
  • Anastasia A. Babushkina,
  • Vladislav V. Gurzhiy,
  • Dmitrij M. Egorov,
  • Nataly I. Svintsitskaya and
  • Albina V. Dogadina

Beilstein J. Org. Chem. 2020, 16, 1947–1954, doi:10.3762/bjoc.16.161

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  • establish from the 1H and 13C NMR spectral data. The signals of the vinyl proton of the uracil moiety are represented by quartets (4JHH = 1.4 Hz) in the δH 8.1 ppm region (quartet at δH 6 ppm for 6-methyl-5-oxo isomer). In the 13C NMR spectra, the signals of ethylene carbons of the uracil ring are presented
  • the N3 nitrogen atom of the uracil fragment followed by cyclization. The mixture of phosphonylated 5-oxothiazolopyrimidines 8c and 9c was separated by column chromatography and the 1Н, 13С, and 31Р NMR spectral data of the individual thiazolopyrimidine isomers did not allow convincing assignment. In
  • the 1H NMR spectra, the proton of the thiazole ring of both isomers is represented by a doublet signal in the low field region at δH 7.91 (3JHP = 3.2 Hz) and 8.41 ppm (3JHP = 7.5 Hz), whereas the corresponding proton of the uracil ring resonated as a singlet at δH 6.61 and 6.71 ppm, respectively. Note
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Published 10 Aug 2020

Extension of the 5-alkynyluridine side chain via C–C-bond formation in modified organometallic nucleosides using the Nicholas reaction

  • Renata Kaczmarek,
  • Dariusz Korczyński,
  • James R. Green and
  • Roman Dembinski

Beilstein J. Org. Chem. 2020, 16, 1–8, doi:10.3762/bjoc.16.1

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  • hexacarbonyl complexes; Nicholas reaction; nucleosides; propargyl cation; Introduction Nucleoside analogs are molecules of high pharmacological interest for the treatment of various conditions, especially cancer and viral diseases [1][2][3][4][5]. The substitution at C-5 of the uracil nucleobase provides a
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Published 02 Jan 2020

Glycosylation reactions mediated by hypervalent iodine: application to the synthesis of nucleosides and carbohydrates

  • Yuichi Yoshimura,
  • Hideaki Wakamatsu,
  • Yoshihiro Natori,
  • Yukako Saito and
  • Noriaki Minakawa

Beilstein J. Org. Chem. 2018, 14, 1595–1618, doi:10.3762/bjoc.14.137

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  • 28, by treating with 2,4-bis(trimethylsilyl)uracil (29) and excess diisopropylethylamine (DIPEA) in the presence of TMSOTf, gave 4’-thiouridine derivative 30 in a good yield. The reaction stereoselectively proceeded and resulted the predominant formation of the β-anomer due to steric hindrance of the
  • subjected to the Pummerer-type glycosylation mediated by hypervalent iodine. Treatment of 36 with bis(trifluoroacetoxy)iodobenzene (PIFA) and uracil in the presence of trimethylsilyl trifluoromethanesulfonate (TMSOTf) and triethylamine gave a 5:1 mixture of 4’-thiouridine derivative 37 in 55% yield. The
  • consecutive inter-/intramolecular SN2 reactions of 66 by selenide anion gave a 4-seleno sugar 67 in an excellent yield. After converting 67 to the corresponding selenoxide, the resulting 68 was immediately treated with uracil or N4-benzoylcytosine under the same conditions for Pummerer-type glycosylation to
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Published 28 Jun 2018

Mechanochemistry of nucleosides, nucleotides and related materials

  • Olga Eguaogie,
  • Joseph S. Vyle,
  • Patrick F. Conlon,
  • Manuela A. Gîlea and
  • Yipei Liang

Beilstein J. Org. Chem. 2018, 14, 955–970, doi:10.3762/bjoc.14.81

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  • latter reaction rapidly decomposed during work-up in solution. Regioselective and stereoselective glycosidation of adenine, N6-benzoyladenine, N4-benzoylcytosine, thymine and uracil to the corresponding β-N9-purine or β-N1-pyrimidine ribosides was achieved on gram scales under Vorbrüggen-type conditions
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Published 27 Apr 2018

Phosphodiester models for cleavage of nucleic acids

  • Satu Mikkola,
  • Tuomas Lönnberg and
  • Harri Lönnberg

Beilstein J. Org. Chem. 2018, 14, 803–837, doi:10.3762/bjoc.14.68

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  • guanidinium compound. This low basicity was suggested to be a central factor behind the catalytic activity. A clarification of the mechanism of guanidine-based catalysis has more recently been attempted by anchoring a 2,4-diamino-1,3,5-triazine core to the N3 of uracil bases of UpU by two side arms, each
  • containing uracil or guanine base were cleaved exceptionally fast [82]. No mechanistic explanation was given. Interestingly, these two bases may undergo deprotonation under mildly basic conditions (pKa ≈ 9) in contrast to adenine and cytosine. Aliphatic amines are poor catalysts for the cleavage of RNA. The
  • hydrogen bonding to the carbonyl groups of uracil base and the other cyclen serves as an electrophilic catalyst by interacting with the phosphodiester linkage. The tetra- and penta-cations of 2,6-bis(1,4,7,10-tetraazacyclododecan-1-ylmethyl)pyridine (11b) have given similar results. The possible role of
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Published 10 Apr 2018

An uracil-linked hydroxyflavone probe for the recognition of ATP

  • Márton Bojtár,
  • Péter Zoltán Janzsó-Berend,
  • Dávid Mester,
  • Dóra Hessz,
  • Mihály Kállay,
  • Miklós Kubinyi and
  • István Bitter

Beilstein J. Org. Chem. 2018, 14, 747–755, doi:10.3762/bjoc.14.63

Graphical Abstract
  • a uracil nucleobase to the known 4’-dimethylamino-hydroxyflavone fluorophore. Results: The complexation of this scaffold with ATP is already known. The complex is held together by stacking and electrostatic interactions. To achieve multi-point recognition, we designed the uracil-appended version of
  • . Conclusions: The first, uracil-containing fluorescent ATP probe based on a hydroxyflavone fluorophore was synthesized and evaluated. A selective complexation with ATP was observed and a ratiometric response in the excitation spectrum. Keywords: ATP sensing; base-pairing; fluorescent probes; 3-hydroxyflavone
  • way to enhance the selectivity. Since ATP has one adenine nucleobase, a simple uracil/thymine unit appended to a neutral chemosensor operating mainly through π-interaction could be a good model for investigation. We selected DMHF as the fluorophore and core scaffold because of its easy synthesis and
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Published 03 Apr 2018

Fluorogenic PNA probes

  • Tirayut Vilaivan

Beilstein J. Org. Chem. 2018, 14, 253–281, doi:10.3762/bjoc.14.17

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  • uracils have also been extensively studied as fluorescent nucleobases in the context of aegPNA. Modifications have invariably been made at the 5-position of uracil, which could be functionalized by various aromatics or alkynes via palladium-catalyzed cross couplings of the corresponding iodouridine
  • derivative. 5-Benzothiophene- and 5-benzofuran-modified uracil in aegPNA exhibited a fluorescence that was marginally sensitive to the environment [195]. When incorporated into PNA, benzothiophene-uracil exhibited an increased fluorescence compared to the free nucleoside. The opposite effect was observed
  • with benzofuran-uracil, and the fluorescence was almost completely quenched when G was the flanking nucleobase. Significant fluorescence enhancement with a small blue-shift of the emission maxima was observed upon duplex formation with DNA for both modified uracil derivatives. Unfortunately, the
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Published 29 Jan 2018

Polarization spectroscopy methods in the determination of interactions of small molecules with nucleic acids – tutorial

  • Tamara Šmidlehner,
  • Ivo Piantanida and
  • Gennaro Pescitelli

Beilstein J. Org. Chem. 2018, 14, 84–105, doi:10.3762/bjoc.14.5

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Published 08 Jan 2018

Enzymatic separation of epimeric 4-C-hydroxymethylated furanosugars: Synthesis of bicyclic nucleosides

  • Neha Rana,
  • Manish Kumar,
  • Vinod Khatri,
  • Jyotirmoy Maity and
  • Ashok K. Prasad

Beilstein J. Org. Chem. 2017, 13, 2078–2086, doi:10.3762/bjoc.13.205

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  • ) in 98% yield. The glycosyl donor 7a,b was prepared from acetolysis of compound 6 with acetic acid/acetic anhydride/sulfuric acid (100:10:0.1) in 93% yield. The Vorbrüggen coupling [17] of 7a,b with uracil in the presence of N,O-bis(trimethylsilyl)acetamide (BSA) and trimethylsilyltrifluoromethane
  • 95% yield, which on Vorbrüggen coupling with uracil under earlier used base-coupling conditions afforded the corresponding acetylated nucleoside 13 in 92% yield. Subsequent deacetylation of nucleosides 13 followed by concomitant cyclization with 2 M NaOH solution in water/dioxane (1:1) afforded 2′-O
  • Vorbrüggen coupling of tetraacetylated sugar derivatives 7a,b and 12a,b: synthesis of acetylated nucleosides 8 and 13. Similar as described in [18] to a stirred solution of compound 7a,b (3.0 g, 5.97 mmol) and nucleobase uracil (1.0 g, 8.9 mmol) in anhydrous acetonitrile (25 mL), N,O-bis(trimethylsilyl
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Published 05 Oct 2017

Mechanochemical N-alkylation of imides

  • Anamarija Briš,
  • Mateja Đud and
  • Davor Margetić

Beilstein J. Org. Chem. 2017, 13, 1745–1752, doi:10.3762/bjoc.13.169

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  • considered for LAG in mechanosynthesis. A comparison of results with literature values demonstrates the benefits of mechanosynthesis. For instance, alkylation of theobromine (14) [34] in a microwave reactor in solution gives two side-products, an O-alkylated and a uracil ring-opened product (induced by base
  • . For instance in the reaction of uracil (17) or 7,8-dimethylalloxazine (36). The required substrate 36 was prepared by mechanochemical condensation [35] of alloxane (34) and 4,5-dimethyl-1,2-phenylenediamine (35) in the presence of p-toluenesulfonic acid [36][37] (Scheme 3). The α-dione/α-diamine
  • . Computational section To elucidate reasons for the observed regioselectivities, the reactions of uracil and 7,8-dimethylalloxazine with benzylamine and ethyl bromide were studied by DFT calculations using the B3LYP/6-311+G**//B3LYP/6-31G*+ZPVE method. The transition-state calculations of the SN2 reaction of
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Published 22 Aug 2017

Effect of uridine protecting groups on the diastereoselectivity of uridine-derived aldehyde 5’-alkynylation

  • Raja Ben Othman,
  • Mickaël J. Fer,
  • Laurent Le Corre,
  • Sandrine Calvet-Vitale and
  • Christine Gravier-Pelletier

Beilstein J. Org. Chem. 2017, 13, 1533–1541, doi:10.3762/bjoc.13.153

Graphical Abstract
  • temperature [52] but, even at 0 °C, the components in the reaction mixture were largely degraded. The protection of uracil nitrogen at N-3 position by an allyl group did not significantly modify the 5’R/5’S ratio (Table 2, entry 3). Increasing the bulkiness of the ketal protecting group by introducing an
  • uracil (Table 2, entry 8) did not significantly change the 5’R/5’S ratio. In both cases, using 3.5 equivalents of Grignard reagent was required to complete the reaction. In order to improve this reverse diastereoselectivity, we envisaged the use of a more bulky protecting group, such as the
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Published 04 Aug 2017
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