New bio-nanocomposites based on iron oxides and polysaccharides applied to oxidation and alkylation reactions

• Daily Rodríguez-Padrón,
• Alina M. Balu,
• Antonio A. Romero and
• Rafael Luque

Beilstein J. Org. Chem. 2017, 13, 1982–1993, doi:10.3762/bjoc.13.194

•  3E). When these agglomerates are observed at higher magnification, they can be seen as independent particles. The three materials displayed a similar particle-size distribution average of around 9 nm, 12 nm and 10 nm for the TiO2-Fe2O3-PS4, Fe2O3-PS4 and Fe2O3-PS4-MNP, respectively (Figure 3B,D,F

• and TEM images of Fe2O3-PS4-MNP. Inset: Particle-size distribution of the obtained nanohybrids. DRIFT spectra of A: TiO2-Fe2O3-PS4 and B: Fe2O3-PS4-MNP nanohybrids. Conversion and selectivity of the oxidation of benzyl alcohol for the three catalytic systems. Conversion and selectivity of the

Solvent-free sonochemistry: Sonochemical organic synthesis in the absence of a liquid medium

• Deborah E. Crawford

Beilstein J. Org. Chem. 2017, 13, 1850–1856, doi:10.3762/bjoc.13.179

• of this, condensation reactions between solid reagents in the complete absence of solvent were carried out successfully by ultrasonic irradiation with the importance of particle size being highlighted. This work increases the potential of sonochemistry in the drive towards a sustainable future

• orange) but there was a clear separation between the two solids, indicating that the variation of particle size and morphology was too great for the reaction to proceed quantitatively. Therefore, both reagents were ground and sieved to both be fine powders of particle size <500 µm. A ca. 0.2 g mixture

• order to overcome this problem, the particle size of both starting materials was reduced further to <200 µm and sonicated for 60 minutes, resulting in a dark red powder (Figure 5). 1H NMR spectroscopy showed that the reaction had fully converted to the desired product – the desired diimine, 1 (Figure 6

Ni nanoparticles on RGO as reusable heterogeneous catalyst: effect of Ni particle size and intermediate composite structures in C–S cross-coupling reaction

• Debasish Sengupta,
• Koushik Bhowmik,
• Goutam De and
• Basudeb Basu

Beilstein J. Org. Chem. 2017, 13, 1796–1806, doi:10.3762/bjoc.13.174

• particle size clearly indicates that the planar surface of RGO effectively prevents the agglomeration of Ni NP during the catalysis. Apart from the characteristic peaks of Ni(0), two additional peaks were observed in the XRD of the recovered catalyst (Figure 3b). These two peaks indicate the presence of Ni

• ], with average particle size of 13 nm (calculated on the basis of Figure 5) and examined its catalytic efficiency in the C–S cross-coupling reaction. We could achieve the C–S coupled thioether product in 82% yield only, which is lower than Ni/RGO-40 (see Supporting Information File 1, Table S1, a Table

• spacing of RGO (inset B; Figure 7b). The particle size of Ni NPs observed from TEM image was almost similar in the before and after catalysis sample, i.e., around 11 nm, indicating the particle agglomeration did not occur during the catalysis. Again, the crystallite size of the Ni(OH)2 was found to be

Mechanochemistry-assisted synthesis of hierarchical porous carbons applied as supercapacitors

• Desirée Leistenschneider,
• Nicolas Jäckel,
• Felix Hippauf,
• Volker Presser and
• Lars Borchardt

Beilstein J. Org. Chem. 2017, 13, 1332–1341, doi:10.3762/bjoc.13.130

• pores. This process finally leads to a higher mesopore volume at the expense of a narrower pore-size distribution (Figure 6). The EG ratio does not impact the particle size of the TiO2 nanostructures and thus the pore-size distributions are similar for all investigated materials (average diameter of 8

Sugar-based micro/mesoporous hypercross-linked polymers with in situ embedded silver nanoparticles for catalytic reduction

• Qing Yin,
• Qi Chen,
• Li-Can Lu and
• Bao-Hang Han

Beilstein J. Org. Chem. 2017, 13, 1212–1221, doi:10.3762/bjoc.13.120

• impurities and dried, resulting in a dark brown solid. The formation process of a AgNPs/SugPOP-1 composite together with the related morphology of the matrix and AgNPs were studied by TEM. As shown in Figure 3a–d, with increased reaction time, the AgNPs gradually grow and the particle size become apparently

• , producing more potential catalytic sites, which can promote the interaction between AgNPs and 4-NP to achieve a good catalytic effect. The catalytic properties of composite materials are closely related to the content and particle size of the AgNPs. If the loading reaction time is short, the content of

Glycoscience@Synchrotron: Synchrotron radiation applied to structural glycoscience

• Serge Pérez and
• Daniele de Sanctis

Beilstein J. Org. Chem. 2017, 13, 1145–1167, doi:10.3762/bjoc.13.114

• average particle size, distribution and shape. Different kinds of samples beside soluble proteins can be studied by this technique including nucleic acids, protein-based complexes, lipids, membrane proteins and surfactants, glycoproteins, virus, polymers and colloids [78][79]. Proteins: SAXS applied to

Continuous-flow processes for the catalytic partial hydrogenation reaction of alkynes

• Carmen Moreno-Marrodan,
• Francesca Liguori and
• Pierluigi Barbaro

Beilstein J. Org. Chem. 2017, 13, 734–754, doi:10.3762/bjoc.13.73

Ultrasound-promoted organocatalytic enamine–azide [3 + 2] cycloaddition reactions for the synthesis of ((arylselanyl)phenyl-1H-1,2,3-triazol-4-yl)ketones

• Gabriel P. Costa,
• Natália Seus,
• Juliano A. Roehrs,
• Raquel G. Jacob,
• Ricardo F. Schumacher,
• Thiago Barcellos,
• Rafael Luque and
• Diego Alves

Beilstein J. Org. Chem. 2017, 13, 694–702, doi:10.3762/bjoc.13.68

• developing agents. Baker silica gel (particle size 0.040–0.063 mm) was used for flash chromatography. A Cole Parmer-ultrasonic processor Model CPX 130, with a maximum power of 130 W, operating at an amplitude of 40% and a frequency of 20 kHz was used. The temperature of the reaction was monitored using an

Fluorescent carbon dots from mono- and polysaccharides: synthesis, properties and applications

• Stephen Hill and
• M. Carmen Galan

Beilstein J. Org. Chem. 2017, 13, 675–693, doi:10.3762/bjoc.13.67

• ), alginic acid (Alg-CDs) and starch (S-CDs) in the presence of PEG-200 under identical microwave conditions (Scheme 20) [54]. TEM analysis of the samples highlighted that a range of morphologies and sizes were obtained depending on the polymer used. For example, S-CDs afforded the smallest particle size

Secondary metabolome and its defensive role in the aeolidoidean Phyllodesmium longicirrum, (Gastropoda, Heterobranchia, Nudibranchia)

• Alexander Bogdanov,
• Cora Hertzer,
• Stefan Kehraus,
• Samuel Nietzer,
• Sven Rohde,
• Peter J. Schupp,
• Heike Wägele and
• Gabriele M. König

Beilstein J. Org. Chem. 2017, 13, 502–519, doi:10.3762/bjoc.13.50

Continuous N-alkylation reactions of amino alcohols using γ-Al₂O₃ and supercritical CO₂: unexpected formation of cyclic ureas and urethanes by reaction with CO₂

• Emilia S. Streng,
• Darren S. Lee,
• Michael W. George and
• Martyn Poliakoff

Beilstein J. Org. Chem. 2017, 13, 329–337, doi:10.3762/bjoc.13.36

• Gases (99.8%). The γ-alumina (PURALOX NWa155) was supplied by SASOL. It was sieved before use, to obtain the desired particle size (125–170 μm), which was used as the catalyst. Reaction mixtures were analysed using GC, GC–MS, 1H and 13C NMR. Compounds 1a–c, 4, 9, 10, 13, 14, 16 were obtained from

A chemoselective and continuous synthesis of m-sulfamoylbenzamide analogues

• Arno Verlee,
• Thomas Heugebaert,
• Tom van der Meer,
• Pavel I. Kerchev,
• Frank Van Breusegem and
• Christian V. Stevens

Beilstein J. Org. Chem. 2017, 13, 303–312, doi:10.3762/bjoc.13.33

• avoided. A general concern is the clogging of the channels. There are numerous reports about handling solids in flow. For example, the use of ultrasound [27][28][29][30][31][32] can reduce the particle size of the precipitates, and preventing the clogging of the small channels. A second example is the

Stabilization of nanosized titanium dioxide by cyclodextrin polymers and its photocatalytic effect on the degradation of wastewater pollutants

• Tamás Zoltán Agócs,
• István Puskás,
• Erzsébet Varga,
• Mónika Molnár and
• Éva Fenyvesi

Beilstein J. Org. Chem. 2016, 12, 2873–2882, doi:10.3762/bjoc.12.286

• Based on particle size measurements the aggregation behavior of nanoTiO2 in the presence and absence of polymer was compared in different media. We studied the effect of NaCl and tap water. The applied nanoTiO2 consists of crystallites of 10–20 nm diameter as evidenced by scanning electron micrographs

• provided by Evonik [41]. However, in aqueous dispersion prepared in our laboratory, these nanocrystallites form – still relatively small – aggregates having a mean size of 50–60 nm (Figure 3 and Figure 4, red curves). The particle size distribution of nanoTiO2 in the absence of destabilizing ions is

• min even this partial stabilizing effect of the polymer seemed to be enough for keeping the catalytic efficiency of the nanocatalyst. In tap water, the stability of nanoTiO2 is similarly diminished as observed for 0.1% NaCl. The mean particle size increased to 4880 nm. It is notable that CMBCD-P

Characterization of the synthetic cannabinoid MDMB-CHMCZCA

• Carina Weber,
• Stefan Pusch,
• Dieter Schollmeyer,
• Sascha Münster-Müller,
• Michael Pütz and
• Till Opatz

Beilstein J. Org. Chem. 2016, 12, 2808–2815, doi:10.3762/bjoc.12.279

• modules (max. 50 bar pressure), a UV–vis spectrometer (set to 285 nm), an automated fraction collector and a control unit. A prepacked 4 g silica gel HP column (particle size 15–40 μm, Büchi) was used. Separation was achieved using a gradient program of eluent A (hexane) and B (ethyl acetate) with a flow

• : 2.1 mm, particle size: 2.7 μm; Supelco) was used at a temperature of 40 °C. The capillary voltage was set to 3500 V and the capillary exit voltage was set according to the respective target mass. High-resolution mass spectrometry High-resolution ESI mass spectrometry was performed on a Waters QTof

• Chiralpak IA-3 column (length: 25 cm, diameter: 4.6 mm, particle size: 3 μm; Daicel) was used at a temperature of 40 °C. Synthetic cannabinoids JWH-018 (1), MDMB-CHMICA (2), MDMB-CHMCZCA (3), and EG-018 (4). Molecular structure of (S)-MDMB-CHMCZCA (3) with numbering scheme. ESI-MSn pattern of 3 (m/z values

Synthesis of three-dimensional porous hyper-crosslinked polymers via thiol–yne reaction

• Mathias Lang,
• Alexandra Schade and
• Stefan Bräse

Beilstein J. Org. Chem. 2016, 12, 2570–2576, doi:10.3762/bjoc.12.252

• (Figure 3) show the amorphous character of the HCPs, which is consistent with the PXRD measurements (see Supporting Information File 1, Figures S3 and S4). The SEM pictures also reveal that HCP 3 consists of particles in the micrometer range while the particle size of HCP 5 is in the sub-micrometre area

Tunable microwave-assisted method for the solvent-free and catalyst-free peracetylation of natural products

• Manuela Oliverio,
• Paola Costanzo,
• Monica Nardi,
• Carla Calandruccio,
• Raffaele Salerno and
• Antonio Procopio

Beilstein J. Org. Chem. 2016, 12, 2222–2233, doi:10.3762/bjoc.12.214

• carrier gas) and by an DSQ II mass detector. Chromatography was performed using a Thermo Scientific Dionex Ultimate 3000 RS, injecting directly onto a Thermo Scientific Hypersil Gold C18 column (50 × 2.1 mm, 1.9 µm particle size), equilibrated in 95% solvent A (0.1% aqueous solution of formic acid), 5

Synthesis of a deuterated probe for the confocal Raman microscopy imaging of squalenoyl nanomedicines

• Eric Buchy,
• Branko Vukosavljevic,
• Maike Windbergs,
• Dunja Sobot,
• Camille Dejean,
• Simona Mura,
• Patrick Couvreur and
• Didier Desmaële

Beilstein J. Org. Chem. 2016, 12, 1127–1135, doi:10.3762/bjoc.12.109

• ), an anticancer chemotherapeutic drug used to treat various solid tumors [6]. Remarkably, the squalene conjugate of gemcitabine (GemSQ) self-assembled in aqueous media as nanoassemblies of around 100 nm mean particle size with a low polydispersity index. The nanosuspension exhibited impressively

Enabling technologies and green processes in cyclodextrin chemistry

• Giancarlo Cravotto,
• Marina Caporaso,
• Laszlo Jicsinszky and
• Katia Martina

Beilstein J. Org. Chem. 2016, 12, 278–294, doi:10.3762/bjoc.12.30

• smaller particle size distribution. To investigate the cosmeto-textile applications of CD-grafted materials, a new fabric based on β-CD-grafted viscose loaded with aescin formulations was prepared. This material was designed for the treatment of venous and lymphatic legs. An efficient US-assisted

• diphenylcarbonate in DMF, have been prepared under MW irradiation (400 W) in 90 min. The optimized method was proven to be a unique opportunity for the large-scale synthesis of CD nanosponges in a high yield and uniform particle size distribution [78]. Ball mill One of the oldest, cheap, and efficient methods to

• planetary or vibratory ball mills and HEBM is a common synonym for HSBM [81]. The lower particle size in grinding produces microdeformation in the ground material crystal lattice, while energy is partially spent in creating microstresses, which eventually slow powder grinding. An efficient wet grinding

Highly stable and reusable immobilized formate dehydrogenases: Promising biocatalysts for in situ regeneration of NADH

• Barış Binay,
• Dilek Alagöz,
• Deniz Yildirim,
• Ayhan Çelik and
• S. Seyhan Tükel

Beilstein J. Org. Chem. 2016, 12, 271–277, doi:10.3762/bjoc.12.29

• Jersey, USA). Sodium formate, Immobead 150 (Polyacrylic matrix, particle size 250 μm, oxirane content ≥200 μmol/g dry support), ethylenediamine (EDA), glutaraldehyde and sodium metaperiodate were obtained from Sigma-Aldrich (St. Louis, MO, USA). All other chemicals used in this study were of analytical

Synthesis of cyclic N¹-pentylinosine phosphate, a new structurally reduced cADPR analogue with calcium-mobilizing activity on PC12 cells

• Ahmed Mahal,
• Stefano D’Errico,
• Nicola Borbone,
• Brunella Pinto,
• Agnese Secondo,
• Valeria Costantino,
• Valentina Tedeschi,
• Giorgia Oliviero,
• Vincenzo Piccialli and
• Gennaro Piccialli

Beilstein J. Org. Chem. 2015, 11, 2689–2695, doi:10.3762/bjoc.11.289

• 4.8 × 150 mm C-18 reversed-phase column (particle size 5 µm) eluted with a linear gradient of CH3CN in 0.1 M triethylammonium bicarbonate (TEAB) buffer (from 0 to 50% in 45 min, flow 1.3 mL/min). UV spectra were recorded on a Jasco V-530 UV spectrophotometer. High-resolution MS spectra were recorded

Size-controlled and redox-responsive supramolecular nanoparticles

• Raquel Mejia-Ariza,
• Gavin A. Kronig and
• Jurriaan Huskens

Beilstein J. Org. Chem. 2015, 11, 2388–2399, doi:10.3762/bjoc.11.260

• steric repulsion is important for achieving SNP stability. SNPs of controlled particle size and good stability (up to seven days) were prepared by fine-tuning the ratio of multivalent and monovalent interactions. Finally, reversibility of the SNPs was confirmed by oxidizing the Fc guest moieties in the

• . These results show that the particle size remains similar for the range of Fc/CD ratios shown here (in the absence of salt). Similar experiments were performed at three different salt concentrations, 0.1, 0.15 and 0.2 M NaCl, while keeping [CD] = 100 µM. Particle formation and growth was observed by DLS

• after 20 min and 3 h. Figure 4 shows an increase of particle size with increasing salt concentration at ionic strengths above 0.1 M, and the effect is stronger after 3 h, indicating a slow growth process. Up to an ionic strength of 0.1 M, however, no change of particle size was apparent. Both host–guest

Preparation of Pickering emulsions through interfacial adsorption by soft cyclodextrin nanogels

• Shintaro Kawano,
• Toshiyuki Kida,
• Mitsuru Akashi,
• Hirofumi Sato,
• Motohiro Shizuma and
• Daisuke Ono

Beilstein J. Org. Chem. 2015, 11, 2355–2364, doi:10.3762/bjoc.11.257

• of β-CD with select oil solvents and the interfacial tension at the oil–water interface [13]. Mathapa et al. described the effect of the particle size formed with the CD–oil complex on the stability of the Pickering emulsion [14]. They also reported that “CD colloidosomes” composed of the CD–oil

• particle size of the primary CD nanogel and the appearance of a new peak at a larger diameter (120 nm) may be due to the self-assembly of the primary CD nanogels at 0.1 wt % concentration in water. The scanning electron microscopy (SEM) measurement was carried out in order to observe the self-assembled

• Information File 1. Dynamic light scattering (DLS) The particle size distribution was measured at 25 °C using DLS6000HL (Otsuka Electronic Co.) equipped with a He-Ne laser (wavelength 632.8 nm). The mean particle diameter was calculated from the diffusion coefficients using the Stokes–Einstein equation. The

Impact of multivalent charge presentation on peptide–nanoparticle aggregation

• Daniel Schöne,
• Boris Schade,
• Christoph Böttcher and
• Beate Koksch

Beilstein J. Org. Chem. 2015, 11, 792–803, doi:10.3762/bjoc.11.89

• approximately 3 nm (Figure 2C). As expected from CD spectroscopy, R1A3 forms α-helical assemblies at pH 9 with an average size of approximately 1 µm but appears to adopt a soluble coiled-coil structure at pH 11 because the particle size decreases to 3 nm. Surprisingly, all other VW05 variants form α-helical

Multivalent dendritic polyglycerolamine with arginine and histidine end groups for efficient siRNA transfection

• Fatemeh Sheikhi Mehrabadi,
• Hanxiang Zeng,
• Mark Johnson,
• Cathleen Schlesener,
• Zhibin Guan and
• Rainer Haag

Beilstein J. Org. Chem. 2015, 11, 763–772, doi:10.3762/bjoc.11.86

• comparable with dPG-NH2 50% and 90%. Average particle size and surface charges of AAdPG/siRNA polyplexes The appropriate particle size and surface charge are critical characteristics of nanoplexes for efficient transfection [29]. Physicochemical characterization of AAdPG/siRNA polyplexes was conducted using

• is comparable to our well-studied vector, dPG-NH2 90%. Post modification of dPG-NH2 with Arg and His did not dramatically affect the physicochemical properties (particle size and zeta potential) of the resulting vectors and their nanoplexes but notably improved cell viability. This can be attributed

Glycodendrimers: tools to explore multivalent galectin-1 interactions

• Jonathan M. Cousin and
• Mary J. Cloninger

Beilstein J. Org. Chem. 2015, 11, 739–747, doi:10.3762/bjoc.11.84

• , and 3:1. Dynamic light scattering Dynamic light scattering was performed using a 90 Plus Particle Size Analyzer (Brookhaven Instruments Corp.) to measure galectin-1/glycodendrimer aggregates at same concentrations and ratios that were used in the fluorescence microscopy assays. Monomeric lactose was