Identification of volatiles from six marine Celeribacter strains

• Anuj Kumar Chhalodia,
• Jan Rinkel,
• Dorota Konvalinkova,
• Jörn Petersen and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2021, 17, 420–430, doi:10.3762/bjoc.17.38

• pressure: 77.1 kPa, He flow: 23.3 mL min−1, 2) injection volume: 2 μL, 3) splitless injection, 4) temperature program: 5 min isothermic at 50 °C, then increasing with 5 °C min−1 to 320 °C, and 5) He carrier gas flow: 1.2 mL min−1. The parameters of the MS were 1) transfer line temperature: 250 °C, 2) ion

• 2.1L (deuterium lamp, 190–700 nm) and a YMC ChiralART Cellulose-SC column (5 μm; 250 × 20 mm) with a guard column of the same type (30 × 20 mm). The elution was performed with hexane/propanol 60:40 (isocratic) at a flow rate of 10 mL min−1 (36 bar). The UV–vis absorption was monitored at 275 nm

1,2,3-Triazoles as leaving groups: S_NAr reactions of 2,6-bistriazolylpurines with O- and C-nucleophiles

• Dace Cīrule,
• Irina Novosjolova,
• Ērika Bizdēna and
• Māris Turks

Beilstein J. Org. Chem. 2021, 17, 410–419, doi:10.3762/bjoc.17.37

• Agilent Technologies 1200 Series chromatograph equipped with an Agilent XDB-C18 (4.6 × 50 mm, 1.8 µm) column was used. Eluent A: 0.1% TFA solution with 5% v/v MeCN added; eluent B – MeCN. Gradient: 10–95% B 5 min, 95% B 5 min, 95–10% B 2 min. Flow: 1 mL/min. Wavelength of detection was 260 nm. LC–MS was

Coupling biocatalysis with high-energy flow reactions for the synthesis of carbamates and β-amino acid derivatives

• Alexander Leslie,
• Thomas S. Moody,
• Megan Smyth,
• Scott Wharry and
• Marcus Baumann

Beilstein J. Org. Chem. 2021, 17, 379–384, doi:10.3762/bjoc.17.33

• flow process is presented that couples a Curtius rearrangement step with a biocatalytic impurity tagging strategy to produce a series of valuable Cbz-carbamate products. Immobilized CALB was exploited as a robust hydrolase to transform residual benzyl alcohol into easily separable benzyl butyrate. The

• resulting telescoped flow process was effectively applied across a series of acid substrates rendering the desired carbamate structures in high yield and purity. The derivatization of these products via complementary flow-based Michael addition reactions furthermore demonstrated the creation of β-amino acid

• species. This strategy thus highlights the applicability of this work towards the creation of important chemical building blocks for the pharmaceutical and speciality chemical industries. Keywords: biocatalysis; CALB; Curtius rearrangement; flow synthesis; reaction telescoping; Introduction Continuous

The preparation and properties of 1,1-difluorocyclopropane derivatives

• Kymbat S. Adekenova,
• Peter B. Wyatt and
• Sergazy M. Adekenov

Beilstein J. Org. Chem. 2021, 17, 245–272, doi:10.3762/bjoc.17.25

• this reagent are its safety, low cost, and commercial availability. The reagent is compatible with a range of functionalized substrates for the gem-difluorocyclopropanation when using NaI as an initiator (Table 2). Both, electron-rich and comparatively electron-poor examples have been described. Flow

• reaction conditions were also applied to this reaction (Scheme 15). The reagents were premixed in THF at room temperature and injected into a heated reactor fitted with a back pressure regulator to allow operation at temperatures that exceeded the boiling point of the solvent. In this flow chemistry setup

A sustainable strategy for the straightforward preparation of 2H-azirines and highly functionalized NH-aziridines from vinyl azides using a single solvent flow-batch approach

• Michael Andresini,
• Leonardo Degannaro and
• Renzo Luisi

Beilstein J. Org. Chem. 2021, 17, 203–209, doi:10.3762/bjoc.17.20

• Michael Andresini Leonardo Degannaro Renzo Luisi Flow Chemistry and Microreactor Technology FLAME-Lab, Department of Pharmacy – Drug Sciences, University of Bari “A. Moro”, Via E. Orabona 4, Bari, 70125, Italy 10.3762/bjoc.17.20 Abstract The reported flow-batch approach enables the easy

• and potentially automatable method for the synthesis of interesting strained compounds. Keywords: aziridines; 2H-azirines; flow chemistry; green chemistry; organolithium compounds; Introduction Since their conception in the early 1990s, Green Chemistry Principles (GCP) have been applied with

• risks [6]. Recently, a variety of sustainable solvents has been therefore identified, and their use have been combined with those of enabling technologies. In this scenario, the development of continuous flow synthetic methodologies has found its fortune in the past two decades [7][8][9]. Several

1,2,3-Triazoles as leaving groups in S_NAr–Arbuzov reactions: synthesis of C6-phosphonated purine derivatives

• Kārlis-Ēriks Kriķis,
• Irina Novosjolova,
• Anatoly Mishnev and
• Māris Turks

Beilstein J. Org. Chem. 2021, 17, 193–202, doi:10.3762/bjoc.17.19

• an Agilent Technologies 1200 Series system equipped with an XBridge C18 column, 4.6 × 150 mm, particle size 3.5 μm, with a flow rate of 1 mL/min, using eluent A–0.1% TFA/H2O with 5 vol % MeCN and eluent B–MeCN as the mobile phase. The wavelength of detection was 260 nm. Gradient: 30–95% B 5 min, 95

Insight into functionalized-macrocycles-guided supramolecular photocatalysis

• Minzan Zuo,
• Krishnasamy Velmurugan,
• Kaiya Wang,
• Xueqi Tian and
• Xiao-Yu Hu

Beilstein J. Org. Chem. 2021, 17, 139–155, doi:10.3762/bjoc.17.15

• authenticated by isothermal calorimetric titration or fluorescence titration and stopped-flow analysis. Furthermore, the quantum yield and reaction velocity of the photocatalysis can be verified by actinometry and UV–vis measurements. Therefore, with the aid of various analytical and spectroscopic studies, we

Chemical constituents of Chaenomeles sinensis twigs and their biological activity

• Joon Min Cha,
• Dong Hyun Kim,
• Lalita Subedi,
• Zahra Khan,
• Sang Un Choi,
• Sun Yeou Kim and
• Chung Sub Kim

Beilstein J. Org. Chem. 2020, 16, 3078–3085, doi:10.3762/bjoc.16.257

• flow rate of 2 mL/min. Low pressure liquid chromatography (LPLC) was performed with a LiChroprep Lobar-A Si 60 column (Merck, Darmstadt, Germany) and an FMI QSY-0 pump. Open columns packed with silica gel 60 (70–230 and 230–400 mesh; Merck), RP-18 silica gel (230–400 mesh; Merck, Darmstadt, Germany

Controlled decomposition of SF₆ by electrochemical reduction

• Sébastien Bouvet,
• Bruce Pégot,
• Stéphane Sengmany,
• Erwan Le Gall,
• Eric Léonel,
• Anne-Marie Goncalves and
• Emmanuel Magnier

Beilstein J. Org. Chem. 2020, 16, 2948–2953, doi:10.3762/bjoc.16.244

• from the consumption of SF6 at the interface electrode/acetonitrile. The current intensity depends on the SF6 flow in agreement with the 1st Fick’s Law from which the Cottrell equation is originated [29]. The upper limit on time was determined from the straight line reported in the insert figure

UV resonance Raman spectroscopy of the supramolecular ligand guanidiniocarbonyl indole (GCI) with 244 nm laser excitation

• Tim Holtum,
• Vikas Kumar,
• Daniel Sebena,
• Jens Voskuhl and
• Sebastian Schlücker

Beilstein J. Org. Chem. 2020, 16, 2911–2919, doi:10.3762/bjoc.16.240

• a cryogenically-cooled CCD sensor (Princeton Instruments, PyLoN:2KBUV). To avoid the possible interference by sample container material and to eliminate sample degradation by excess exposure to UV light, the liquid sample was circulated in a home-built free-flow system similar to the one employed

Incorporation of a metal-mediated base pair into an ATP aptamer – using silver(I) ions to modulate aptamer function

• Marius H. Heddinga and
• Jens Müller

Beilstein J. Org. Chem. 2020, 16, 2870–2879, doi:10.3762/bjoc.16.236

• eluents at a flow rate of 1 mL/min: trimethylamine/acetic acid 1:1, 10 mM in water (solvent A) and trimethylamine/acetic acid 1:1, 10 mM in water/CH3CN 1:4 (solvent B). Gradient applied: 0–5 min, 3% B; 5–45 min, 3–40% B; 45–50 min, 100% B. The quantification of the sequences was achieved using a Thermo

3-Acetoxy-fatty acid isoprenyl esters from androconia of the ithomiine butterfly Ithomia salapia

• Florian Mann,
• Daiane Szczerbowski,
• Lisa de Silva,
• Melanie McClure,
• Marianne Elias and
• Stefan Schulz

Beilstein J. Org. Chem. 2020, 16, 2776–2787, doi:10.3762/bjoc.16.228

• color patterns (see Supporting Information File 1, Figure S1) [4], are widely distributed, and parapatric in north-eastern Peru [5]. Despite the geographic overlap in distribution, a recent genetic study showed limited gene flow [4]. Reproductive isolation in mimetic butterflies can be driven by

Dawn of a new era in industrial photochemistry: the scale-up of micro- and mesostructured photoreactors

• Emine Kayahan,
• Mathias Jacobs,
• Leen Braeken,
• Leen C.J. Thomassen,
• Simon Kuhn,
• Tom van Gerven and
• M. Enis Leblebici

Beilstein J. Org. Chem. 2020, 16, 2484–2504, doi:10.3762/bjoc.16.202

• flow photoreactors. In this work, we are reviewing structured photoreactors by elaborating on the bottleneck of this field: the development of an efficient scale-up strategy. In line with this, micro- and mesostructured bench-scale photoreactors were evaluated based on a new benchmark called

• designing multiphase photoreactors, and this complicates the design even further [10]. Photoreactions are typically performed in batch reactors. With the process intensification efforts towards green chemistry approaches, continuous flow technologies, micro- and mesostructured flow photoreactors having

• photoreactors with the help of various catalyst structures, beads, static mixers, and/or Taylor flow [4][11]. In addition, these reactors allow safer operation since it is easier to control overheating and the handling of hazardous chemicals in smaller volumes [4][11]. In addition to photomicroreactors, micro

Synthetic approaches to bowl-shaped π-conjugated sumanene and its congeners

• Shakeel Alvi and
• Rashid Ali

Beilstein J. Org. Chem. 2020, 16, 2212–2259, doi:10.3762/bjoc.16.186

• ][26][27][28][29]. Therefore, the area of buckybowls particularly sumanene chemistry is gaining more and more pace which can be seen by the inspection of a flow of publications appearing in the literature day-by-day [26]. As far as our knowledge is concerned, this is the first comprehensive review

Photosensitized direct C–H fluorination and trifluoromethylation in organic synthesis

• Shahboz Yakubov and
• Joshua P. Barham

Beilstein J. Org. Chem. 2020, 16, 2151–2192, doi:10.3762/bjoc.16.183

• to the 83% yield under the standard conditions. This reaction was also demonstrated in continuous flow under similar conditions [139]. 3.2 Polarity matching-guided unactivated C(sp3)–H fluorination 3.2.1 Synthetic applications: In another seminal paper, Tan and co-workers [198] discovered the

• path length of l = 17.7 mm at which distance (from the surface) 90% of the light is absorbed. Flow chemistry provides an elegant means for scaling photochemical reactions [211][212][213][214], primarily due to the shorter path lengths for light transmission provided by flowing the reaction mixture

• through small-diameter (μm–mm) channels. Lectka and co-workers reported the processing of their benzil-photosensitized enone-directed C(sp3)–H fluorination in a custom-built flow reactor, comprised of a syringe pump, a coil of fluorinated ethylene propylene (FEP) tubing (7.5 m; inner diameter 1.6 mm

Clustering and curation of electropherograms: an efficient method for analyzing large cohorts of capillary electrophoresis glycomic profiles for bioprocessing operations

• Ian Walsh,
• Matthew S. F. Choo,
• Sim Lyn Chiin,
• Amelia Mak,
• Shi Jie Tay,
• Pauline M. Rudd,
• Yang Yuansheng,
• Andre Choo,
• Ho Ying Swan and
• Terry Nguyen-Khuong

Beilstein J. Org. Chem. 2020, 16, 2087–2099, doi:10.3762/bjoc.16.176

• Xevo G2S QToF (Waters Corp). The flow rate was set at 0.4 mL/min and a linear gradient was used: 25–49% of buffer A (50 mM ammonium formate solution, pH 4.4) and buffer B (100% ACN) was run across 40 minutes, followed by a 3 min wash step using buffer A. The column was then equilibrated back to 25

• of m/z 400–2000 was used, with an acquisition speed of 1 Hz, and the mass spectrometry was set at the following conditions: 2.75 kV electrospray ionization capillary voltage, 15 V cone voltage, 120 °C ion source temperature, 300 °C desolvation temperature, 800 L/h desolvation gas flow. A lockspray

pH- and concentration-dependent supramolecular self-assembly of a naturally occurring octapeptide

• Goutam Ghosh and
• Gustavo Fernández

Beilstein J. Org. Chem. 2020, 16, 2017–2025, doi:10.3762/bjoc.16.168

• in 40 min at 25 °C ) on a SymmetryPrepTM C18 preparative column (7 µm, 7.8 × 300 mm) at a flow rate of 2 mL/min. Peaks were detected at 214 nm. The desired peak was collected, and the purity was checked in an analytical Symmetry C18 column (5 µm, 4.6 × 250 mm). The single peak demonstrated the purity

Automated high-content imaging for cellular uptake, from the Schmuck cation to the latest cyclic oligochalcogenides

• Rémi Martinent,
• Javier López-Andarias,
• Dimitri Moreau,
• Yangyang Cheng,
• Naomi Sakai and
• Stefan Matile

Beilstein J. Org. Chem. 2020, 16, 2007–2016, doi:10.3762/bjoc.16.167

• employed to generate dose–response curves and to calculate the CP50 value of the transporters, described as the half-maximal cell penetration. In a CAPA, the final fluorescence response is usually recorded by flow cytometry [55][62]. In a HC CAPA, flow cytometry is replaced by HC automated microscopy

• , masking exclusively the mitochondria region, gave a small but significant increase to r2 = 0.983 (Figure 8b). Although optimized toward perfection with stable HGM cells, this increase demonstrated that the HC CAPA adds a precision that is overlooked with flow cytometry. The off-target staining of 26 in

• 0.983 quantified the increase in accuracy achieved moving from a cell-body mask to a mitochondrial mask. This difference revealed that even with fully optimized stable HGM cell lines, whole-cell analyses, such as flow cytometry, of the CAPA contain a small but nonnegligible error that can be removed

A complementary approach to conjugated N-acyliminium formation through photoredox-catalyzed intermolecular radical addition to allenamides and allencarbamates

• Olusesan K. Koleoso,
• Matthew Turner,
• Felix Plasser and
• Marc C. Kimber

Beilstein J. Org. Chem. 2020, 16, 1983–1990, doi:10.3762/bjoc.16.165

• findings on the performance of allenamides. Specifically, the electron-withdrawing group on the allenamide and the nucleophile is examined. We provide evidence for the formation of the N-acyliminium intermediate through direct sample loop and flow injection analysis by HRESIMS, and DFT analysis of the N

• -catalyzed photoredox conditions in the presence of 4-bromoaniline was monitored by direct sample loop and flow injection analysis by HRESIMS [56][57]. After 5 minutes we observed a peak at m/z 284.1129 that corresponded satisfactorily to the expected iminium complex 14a (m/z 284.1129: calcd for [C13H18NO6

• conjugated N-acyliminium intermediate; (b) the calculated HOMO [54] for allenamide 15; (c) the identification of intermediate 14a by direct sample loop and flow injection HRESIMS analysis. Supporting Information Supporting Information File 366: Experimental details, analytical (1H NMR, 13C NMR) and ESIMS

Synergy between supported ionic liquid-like phases and immobilized palladium N-heterocyclic carbene–phosphine complexes for the Negishi reaction under flow conditions

• Edgar Peris,
• Raúl Porcar,
• María Macia,
• Jesús Alcázar,
• Eduardo García-Verdugo and
• Santiago V. Luis

Beilstein J. Org. Chem. 2020, 16, 1924–1935, doi:10.3762/bjoc.16.159

• , Janssen-Cilag, S.A., C/ Jarama 75A, Toledo, Spain 10.3762/bjoc.16.159 Abstract The combination of supported ionic liquids and immobilized NHC–Pd–RuPhos led to active and more stable systems for the Negishi reaction under continuous flow conditions than those solely based on NHC–Pd–RuPhos. The fine tuning

• complexes enabling a simpler recovery and reuse of the catalysts by filtration [5]. Furthermore, the immobilized NHC-complexes can be easily adapted to flow processes using a fix-bed reactor set-up increasing simultaneously the sustainability and the efficiency of the C–C coupling reactions [6][7]. In the

• under continuous flow conditions. Results and Discussion Scheme 1 summarizes the synthetic approach used for the preparation of the functionalized polymers considered in this work. A commercially available PS-DVB bead-type macroporous chloromethylated polymer 1 (Merrifield resin with 20% DVB and 1.2

Design, synthesis and application of carbazole macrocycles in anion sensors

• Alo Rüütel,
• Ville Yrjänä,
• Sandip A. Kadam,
• Indrek Saar,
• Mihkel Ilisson,
• Astrid Darnell,
• Kristjan Haav,
• Tõiv Haljasorg,
• Lauri Toom,
• Johan Bobacka and
• Ivo Leito

Beilstein J. Org. Chem. 2020, 16, 1901–1914, doi:10.3762/bjoc.16.157

• was an opening with an adjustable plastic plug, which can be used to empty the outer filling solution compartment, and the greater standard deviations in the results could be explained by slight differences in the flow of chloride between measurements. These variations in flow rate were likely due to

• variations in the position of the plug as a result of handling the reference electrode while setting up the measurements. This flow of chloride resulted in narrower linear ranges, lower slopes, and poorer detection limits due to the mixed responses to acetate and chloride. The degree of deviation from the

• coefficients for fluoride were due to an abnormally large flow rate of chloride from the reference electrode during a single measurement. This affected the responses for sensors that were used. The ISMs showed modest selectivities. However, incorporating any of the three receptors in the membrane as an

When metal-catalyzed C–H functionalization meets visible-light photocatalysis

• Lucas Guillemard and
• Joanna Wencel-Delord

Beilstein J. Org. Chem. 2020, 16, 1754–1804, doi:10.3762/bjoc.16.147

• of both substrates bearing various functional groups, thus furnishing more than 30 acylated products in moderate to good yields. As the molecular oxygen was the terminal oxidant, the typical high loading of an external oxidant could be avoided. Flow chemistry is an important technology for

• photochemical reactions due to the inherent lack of scalability issues as a consequence of the Beer–Lambert law of absorption. Consequently, continuous-flow chemistry represents one of the few ways in which pharmaceutically relevant quantities of compounds can be synthesized through photoinduced transformations

• [91]. In this context, great advances were also recently achieved in the field of direct C–H functionalization reactions under flow conditions. Persistent improvements enabled the development of innovative flow techniques, encompassing large-scale photochemical procedures, which were successfully

One-pot synthesis of isosorbide from cellulose or lignocellulosic biomass: a challenge?

• Isaline Bonnin,
• Raphaël Mereau,
• Thierry Tassaing and
• Karine De Oliveira Vigier

Beilstein J. Org. Chem. 2020, 16, 1713–1721, doi:10.3762/bjoc.16.143

• this reaction under continuous flow using two catalytic beds. Finally, we emphasize that mechanistic insights on the catalytic conversion of biomass-derived platform molecules are required to make this value chain competitive with respect to the traditional synthesis of chemicals from fossil fuels. In

Pauson–Khand reaction of fluorinated compounds

• Jorge Escorihuela,
• Daniel M. Sedgwick,
• Alberto Llobat,
• Mercedes Medio-Simón,
• Pablo Barrio and
• Santos Fustero

Beilstein J. Org. Chem. 2020, 16, 1662–1682, doi:10.3762/bjoc.16.138

• described, including the use of metals other than cobalt (such as rhodium, iridium, titanium, ruthenium, nickel, and palladium), or the use of CO surrogates such as aldehydes, alcohols and formates. Recently, its utility in flow chemistry has also been described [42]. Intramolecular Pauson–Khand reactions

Antibacterial scalarane from Doriprismatica stellata nudibranchs (Gastropoda, Nudibranchia), egg ribbons, and their dietary sponge Spongia cf. agaricina (Demospongiae, Dictyoceratida)

• Cora Hertzer,
• Stefan Kehraus,
• Nils Böhringer,
• Fontje Kaligis,
• Robert Bara,
• Dirk Erpenbeck,
• Gert Wörheide,
• Till F. Schäberle,
• Heike Wägele and
• Gabriele M. König

Beilstein J. Org. Chem. 2020, 16, 1596–1605, doi:10.3762/bjoc.16.132

• % acetic acid. The gradient began after 0.5 min to 100% acetonitrile (0.1% acetic acid) in 4 min. 2 µL of a 1 mg/mL sample solution was injected to a flow of 0.8 mL/min. HRAPCIMS were recorded on LTQ Orbitrap XL mass spectrometer. HPLC was carried out on a Waters Breeze HPLC system equipped with a 1525µ

• :30 (MeOH/H2O) to 100% MeOH in 25 min, and a flow of 1.5 mL/min was used for separation. The isolated metabolite had a retention time around 13 minutes. 12-Deacetoxy-4-demethyl-11,24-diacetoxy-3,4-methylenedeoxoscalarin C29H42O6, white amorphous solid (12.7 mg); [α]D20 +40.5 (c 0.6, CHCl3); IR (ATR