Syntheses and chemical properties of β-nicotinamide riboside and its analogues and derivatives

• Mikhail V. Makarov and
• Marie E. Migaud

Beilstein J. Org. Chem. 2019, 15, 401–430, doi:10.3762/bjoc.15.36

• with sodium methoxide in methanol. The triflate removal was conducted by an ion exchange step using a saturated aqueous solution of sodium chloride followed by an extraction with THF to remove the excess of nicotinamide and sodium trifluoromethanesulfonate byproducts (Scheme 7). The above described

Thiol-free chemoenzymatic synthesis of β-ketosulfides

• Adrián A. Heredia,
• Martín G. López-Vidal,
• Marcela Kurina-Sanz,
• Fabricio R. Bisogno and
• Alicia B. Peñéñory

Beilstein J. Org. Chem. 2019, 15, 378–387, doi:10.3762/bjoc.15.34

• CAL-B. It is worth noting that this amount represents a ≈8 fold decrease of used enzyme as compared to the corresponding small scale reaction (Table 2, entry 8). After 24 h, we were delighted to find that no enolester was detected by TLC monitoring, and after extraction and silica gel column

Silanediol versus chlorosilanol: hydrolyses and hydrogen-bonding catalyses with fenchole-based silanes

• Falco Fox,
• Jörg M. Neudörfl and
• Bernd Goldfuss

Beilstein J. Org. Chem. 2019, 15, 167–186, doi:10.3762/bjoc.15.17

• hydrolyses and temperature resulting in further condensation products [50][51], leaves no comparison possible. At H2O/THF reflux conditions, the hydrolysis of dichlorosilane 13 yields silanediol 1 with >99% yield, after a reaction time of two seconds (Scheme 4, addition of H2O, with instant extraction with

Unexpected loss of stereoselectivity in glycosylation reactions during the synthesis of chondroitin sulfate oligosaccharides

• Teresa Mena-Barragán,
• José L. de Paz and
• Pedro M. Nieto

Beilstein J. Org. Chem. 2019, 15, 137–144, doi:10.3762/bjoc.15.14

• of a fluorous-assisted approach for the synthesis of CS oligosaccharides. The use of a fluorous tag allows the rapid isolation of fluorinated intermediates by performing a simple extraction from fluorous silica gel [27][28][29][30][31][32]. Moreover, this method maintains the advantages of solution

• intermediates by simple fluorous solid-phase extraction (F-SPE). Interestingly, the fluorous tag would be introduced by acylation using commercially available heptadecafluoroundecanoyl chloride and its deprotection would not involve any additional step at the end of the synthesis. N-Trifluoroacetyl (N-TFA

Fabrication of supramolecular cyclodextrin–fullerene nonwovens by electrospinning

• Hiroaki Yoshida,
• Ken Kikuta and
• Toshiyuki Kida

Beilstein J. Org. Chem. 2019, 15, 89–95, doi:10.3762/bjoc.15.10

• of C60 throughout the fibers. Two additional experiments were performed to confirm the presence of the CD–C60 inclusion complex indirectly. One investigated C60 extraction by toluene washing of the nonwovens. Toluene is a good solvent for C60, but UV–vis absorption peaks assignable to C60 are not

A convenient and practical synthesis of β-diketones bearing linear perfluorinated alkyl groups and a 2-thienyl moiety

• Ilya V. Taydakov,
• Yuliya M. Kreshchenova and
• Ekaterina P. Dolotova

Beilstein J. Org. Chem. 2018, 14, 3106–3111, doi:10.3762/bjoc.14.290

• extractants in solvent–solvent extraction processes [4], in preparation of volatile complexes for chemical vapour deposition (CVD) technique [5][6], in syntheses of luminescent compounds [7], as starting materials in organic and heterocyclic chemistry [8][9] and in many other practical applications [10][11

Volatiles from the hypoxylaceous fungi Hypoxylon griseobrunneum and Hypoxylon macrocarpum

• Jan Rinkel,
• Alexander Babczyk,
• Tao Wang,
• Marc Stadler and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2018, 14, 2974–2990, doi:10.3762/bjoc.14.277

• [11][12]. Fungal volatiles can be efficiently analysed by trapping, e.g., on charcoal filters with a closed-loop stripping apparatus (CLSA) that was developed by Grob and Zürcher [13], followed by filter extraction and GC–MS analysis of the obtained headspace extracts [14]. The unambiguous compound

N-Acylated amino acid methyl esters from marine Roseobacter group bacteria

• Hilke Bruns,
• Lisa Ziesche,
• Nargis Khakin Taniwal,
• Laura Wolter,
• Thorsten Brinkhoff,
• Jennifer Herrmann,
• Rolf Müller and
• Stefan Schulz

Beilstein J. Org. Chem. 2018, 14, 2964–2973, doi:10.3762/bjoc.14.276

• , interpretation of mass spectra, and verification by synthesis. Results and Discussion The secondary metabolites released by liquid cultures of various roseobacters were collected by extraction via Amberlite XAD-16 resin and analysed by GC/MS. Four of these strains, Roseovarius sp. D12_1.68 and Loktanella sp. F13

Synthesis of unnatural α-amino esters using ethyl nitroacetate and condensation or cycloaddition reactions

• Glwadys Gagnot,
• Vincent Hervin,
• Eloi P. Coutant,
• Sarah Desmons,
• Racha Baatallah,
• Victor Monnot and
• Yves L. Janin

Beilstein J. Org. Chem. 2018, 14, 2846–2852, doi:10.3762/bjoc.14.263

• proceeded in good yield, although care had to be taken during work-up as zinc complexes required the addition of an excess of ammonia to fully break in the course of the extraction. In an attempt to overcome the lack of condensation between ethyl nitroacetate (4) and electron-poor substrates 5j–l, we

Synthesis of a tyrosinase inhibitor by consecutive ethenolysis and cross-metathesis of crude cashew nutshell liquid

• Jacqueline Pollini,
• Valentina Bragoni and
• Lukas J. Gooßen

Beilstein J. Org. Chem. 2018, 14, 2737–2744, doi:10.3762/bjoc.14.252

• properties and industrial applications, for instance in surfactants, plasticizers, resins, soft materials and diverse medical applications [7]. Isolated via cold-press or solvent extraction processes, it contains predominantly anacardic acid (1). Upon distillation or any other thermal treatment, anacardic

• is added in excess. The main difficulty is that thermal purification of CNSL would inevitably lead to decarboxylation, and that unpurified CNSL, as it is obtained in an extraction process, contains a wealth of side components, many of which act as catalyst poisons. However, if an ethenolysis could be

• -hexene followed by a hydrogenation and thus, selectively obtain the target product 2-hydroxy-6-tridecylbenzoic acid (3). Results and Discussion Ethenolysis of crude CNSL After thorough optimization, we found that natural CNSL, a highly viscous brown oil, obtained by ether extraction of cashew nutshells

Synthesis and biological evaluation of 1,2-disubstituted 4-quinolone analogues of Pseudonocardia sp. natural products

• Stephen M. Geddis,
• Teodora Coroama,
• Suzanne Forrest,
• James T. Hodgkinson,
• Martin Welch and
• David R. Spring

Beilstein J. Org. Chem. 2018, 14, 2680–2688, doi:10.3762/bjoc.14.245

• . Bacterial cultures were grown for eight hours in the presence of each compound, followed by extraction of the pyocyanin under acidic conditions [22]. This was then quantified by measurement of the OD520, which corresponds to absorption by the toxin. The results are shown in Figure 4, normalised by the

Learning from B₁₂ enzymes: biomimetic and bioinspired catalysts for eco-friendly organic synthesis

• Keishiro Tahara,
• Ling Pan,
• Toshikazu Ono and
• Yoshio Hisaeda

Beilstein J. Org. Chem. 2018, 14, 2553–2567, doi:10.3762/bjoc.14.232

• electronic conductivity and nonvolatility. Thus, 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF4]) was utilized as the solvent in the dechlorination of DDT [110]. During the extraction process, the product and 1 were separated in the organic solvent and ionic liquid layers, respectively. The ionic

Quinolines from the cyclocondensation of isatoic anhydride with ethyl acetoacetate: preparation of ethyl 4-hydroxy-2-methylquinoline-3-carboxylate and derivatives

• Nicholas G. Jentsch,
• Jared D. Hume,
• Emily B. Crull,
• Samer M. Beauti,
• Amy H. Pham,
• Julie A. Pigza,
• Jacques J. Kessl and
• Matthew G. Donahue

Beilstein J. Org. Chem. 2018, 14, 2529–2536, doi:10.3762/bjoc.14.229

• gram of substrate) with subsequent stirring at room temperature for one hour. The isatoic anhydride products 9a–h typically precipitate out of solution and are readily collected by vacuum filtration. This reverse aqueous quench provides sufficiently pure material without the need for extraction with

• have the same outcome, typically resulting in oiling out of the product, and requiring organic solvent extraction. The yields ranged from modest (47%) to excellent (97%) on scales from 1 gram up to 25 gram batches with spectral data matching known quinolones [26]. A plausible mechanism for the

Microfluidic light-driven synthesis of tetracyclic molecular architectures

• Javier Mateos,
• Nicholas Meneghini,
• Marcella Bonchio,
• Nadia Marino,
• Tommaso Carofiglio,
• Xavier Companyó and
• Luca Dell’Amico

Beilstein J. Org. Chem. 2018, 14, 2418–2424, doi:10.3762/bjoc.14.219

• for the synthesis of biologically active natural compounds [16] and industrially relevant drugs [17] reminiscent of the bioactive tetralinolic pharmacophore core [18]. Acidic treatment of 4a generated, after a simple extraction, the corresponding α,β-unsaturated compound 7a in 97% yield. A further

The mechanochemical synthesis of quinazolin-4(3H)-ones by controlling the reactivity of IBX

• Md Toufique Alam,
• Saikat Maiti and
• Prasenjit Mal

Beilstein J. Org. Chem. 2018, 14, 2396–2403, doi:10.3762/bjoc.14.216

• , after extraction of the reaction mixture with DCM, followed by silica gel column chromatography with ethyl acetate/hexane 1:5 as eluent provided product 3a (684 mg, 68%). a) Explosion was observed when an arylamine was mixed with aldehydes in the presence of IBX. b) Benzamide was found to be unreactive

Assessing the possibilities of designing a unified multistep continuous flow synthesis platform

• Mrityunjay K. Sharma,
• Roopashri B. Acharya,
• Chinmay A. Shukla and
• Amol A. Kulkarni

Beilstein J. Org. Chem. 2018, 14, 1917–1936, doi:10.3762/bjoc.14.166

• the throughput in the start or anywhere else gets changed in the sequence. This is very important for synthesis steps where downstream processing is also in sequence. Usually time scales for work-up procedures like extraction, crystallization, solvent switch etc. are longer compared to the main

• . The impurities of the pyrazole were removed by passing it to the continuous countercurrent extraction E1. Here a solvent exchange process takes place between toluene and water. The pyrazole was then concentrated using automated rotary evaporator RE1. The concentrated product was diluted with DMSO

• aqueous NaOH through pump P4 which is heated to 140 °C through HE1. In-line extraction and purification happen in packed bed column reactor R6 by water and hexane which are pumped through pump P35 and P36. The resulting biphasic solution passes through gravity operated liquid–liquid separator S2 with

Two new 2-alkylquinolones, inhibitory to the fish skin ulcer pathogen Tenacibaculum maritimum, produced by a rhizobacterium of the genus Burkholderia sp.

• Dandan Li,
• Naoya Oku,
• Atsumi Hasada,
• Masafumi Shimizu and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2018, 14, 1446–1451, doi:10.3762/bjoc.14.122

• a culture of strain MBAF1239, isolated from a rhizosphere of Welsh onion (Allium fistulosum). A 16S rDNA sequence analysis identified MBAF1239 as Burkholderia sp. within the B. cepacia complex (DDBJ accession number LC194190). Fermentation, extraction, and isolation Burkholderia sp. MBAF1239 was

• culture was inoculated into 100 mL of the IMM-HS production medium (glucose 1%, K2HPO4 0.36%, KH2PO4 0.41%, MgSO4·7H2O 0.02%, CaCl2·2H2O 0.01%, FeSO4·7H2O 0.002%, NH4Cl 0.1%, biotin 0.0001%, and L-histidine 0.4%), and shaken at 200 rpm at 30 °C for 4 days. For the extraction of secondary metabolites, 100

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

• %) close to that of the theoretical protein-free value [60][61]. Due to the accessibility of calf thymus and its high DNA content, much of the further work on large-scale extraction of "sodium nucleate" was performed using this tissue. Although details of the grinding actions employed were not always fully

• ) Crude solid ball mill click reaction mixture after removal from copper vessel (left) and during extraction of pure product with DMSO (right). Early low temperature mechanised ball mill as described by Mudd et al. – adapted from reference [78]. Materials used to prepare a smectic phase. Structures of 5

On the design principles of peptide–drug conjugates for targeted drug delivery to the malignant tumor site

• Eirinaios I. Vrettos,
• Gábor Mező and
• Andreas G. Tzakos

Beilstein J. Org. Chem. 2018, 14, 930–954, doi:10.3762/bjoc.14.80

• of other types of cancers (breast cancer, bladder cancer, Kaposi's sarcoma) in combination with other anti-cancer agents. Camptothecin (CPT): Camptothecin is a cytotoxic alkaloid collected from extraction of the bark and stem of the Chinese tree ‘Camptotheca acuminata’. It was first isolated and

Volatiles from three genome sequenced fungi from the genus Aspergillus

• Jeroen S. Dickschat,
• Ersin Celik and
• Nelson L. Brock

Beilstein J. Org. Chem. 2018, 14, 900–910, doi:10.3762/bjoc.14.77

• grown on medium 129 were collected on charcoal filters with a closed loop stripping apparatus (CLSA) [23]. After solvent extraction (CH2Cl2) of the filters the extracts were analysed by GC–MS and compounds were identified by comparison of the recorded EI mass spectra to mass spectral libraries and of

Crystal structure of the inclusion complex of cholesterol in β-cyclodextrin and molecular dynamics studies

• Elias Christoforides,
• Andreas Papaioannou and
• Kostas Bethanis

Beilstein J. Org. Chem. 2018, 14, 838–848, doi:10.3762/bjoc.14.69

• animal products like milk [17], butter [18], cheese [19] and eggs [20] which contains more than 90% less cholesterol when treated with β-CD. As consumers are becoming more and more concerned about their eating habits, food companies have developed many techniques to reduce cholesterol, as extraction with

• organic solvents, supercritical carbon dioxide extraction or cholesterol degradation by cholesterol oxidases. But these methods are not selective as other components are also removed and they require expensive equipment and high operational cost [21]. In the past, many studies have been published on the

Volatiles from the xylarialean fungus Hypoxylon invadens

• Jeroen S. Dickschat,
• Tao Wang and
• Marc Stadler

Beilstein J. Org. Chem. 2018, 14, 734–746, doi:10.3762/bjoc.14.62

• and ecologists in volatile secondary metabolites. Volatile natural products can efficiently be captured on charcoal filter traps by using a closed-loop stripping apparatus (CLSA) [6] or on polydimethylsiloxane fibres by application of the solid phase micro-extraction method (SPME) [7], followed by GC

Nanoreactors for green catalysis

• M. Teresa De Martino,
• Loai K. E. A. Abdelmohsen,
• Floris P. J. T. Rutjes and
• Jan C. M. van Hest

Beilstein J. Org. Chem. 2018, 14, 716–733, doi:10.3762/bjoc.14.61

• yield and output [23][24]. Indeed, such a strategy proved to be advantageous for performing reactions in water and minimizing both reaction waste and cost [25][26]. Attempts to support homogeneous metal complexes onto organic or inorganic surfaces to facilitate their removal/extraction from the reaction

• membrane. Furthermore, the nanosystem also facilitated catalyst recycling by normal extraction. 2.2. Polymeric vesicles Polymeric vesicles or polymersomes are synthetic bilayered hollow architectures that are self-assembled from amphiphilic block copolymers [73]. The synthetic nature of polymersomes allows

AuBr₃-catalyzed azidation of per-O-acetylated and per-O-benzoylated sugars

• Jayashree Rajput,
• Srinivas Hotha and
• Madhuri Vangala

Beilstein J. Org. Chem. 2018, 14, 682–687, doi:10.3762/bjoc.14.56

• bicarbonate solution followed by extraction with DCM (2 × 20 mL). The combined organic layers were washed with water, brine and dried over Na2SO4 and concentrated to dryness. The residue was purified by column chromatography on silica gel using petroleum ether (bp 60–70 °C) and EtOAc. Azidation of per O

High-yielding continuous-flow synthesis of antimalarial drug hydroxychloroquine

• Eric Yu,
• Hari P. R. Mangunuru,
• Nakul S. Telang,
• Caleb J. Kong,
• Jenson Verghese,
• Stanley E. Gilliland III,
• Saeed Ahmad,
• Raymond N. Dominey and
• B. Frank Gupton

Beilstein J. Org. Chem. 2018, 14, 583–592, doi:10.3762/bjoc.14.45

• -line extraction of 10. Optimization of the flow process for the synthesis of 12. Optimization of the flow process for the synthesis of 10. Schematic representation for the continuous telescoped process to synthesize 11. Optimization of the flow process for the reductive amination of 12 using a CSTR