Extrusion – back to the future: Using an established technique to reform automated chemical synthesis

• Deborah E. Crawford

Beilstein J. Org. Chem. 2017, 13, 65–75, doi:10.3762/bjoc.13.9

• of material for thorough mixing and processing [5]. The process can be adapted via modulation of the screw, as depicted in Figure 2, to make the process more efficient. An industrial single screw extruder typically has a screw diameter ranging from anywhere between 1 inch and 24 inches. Principally

• , the root diameter (the diameter of the central part of the screw) of the screw increases along its length, this is to i) provide greater free volume at the beginning of the ‘starve-fed’ extruder for maximum feeding of material and ii) to increase the compressive forces at a later stage of the process

• greater mechanical energy may result in a greater amount of frictional heat being produced, particularly in comparison to those segments which provide less vigorous kneading. Both single and twin screw extruders range from 10–443 mm in screw diameter [6] and extrusion processes are scalable to produce

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

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

• and water (with 0.1% formic acid) were used as eluents at a total flow rate of 1.0 mL min−1 with the following gradient method: acetonitrile/water (+ 0.1% formic acid) = 10:90 (0–0.2 min), 10:90 to 90:10 (0.2–4.0 min), and 90:10 (4.0–6.0 min). An Ascentis Express C18 column (length: 3 cm, diameter

• 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

The digital code driven autonomous synthesis of ibuprofen automated in a 3D-printer-based robot

• Philip J. Kitson,
• Stefan Glatzel and
• Leroy Cronin

Beilstein J. Org. Chem. 2016, 12, 2776–2783, doi:10.3762/bjoc.12.276

•  1 for further details). These needles were connected by PTFE tubing (internal diameter 0.8 mm) to a number of automatable syringe pumps which have been developed by our group. These pumps were controlled individually by dedicated Arduino control boards and were coordinated via the process-control

Electron-transfer-initiated benzoin- and Stetter-like reactions in packed-bed reactors for process intensification

• Anna Zaghi,
• Daniele Ragno,
• Graziano Di Carmine,
• Carmela De Risi,
• Olga Bortolini,
• Pier Paolo Giovannini,
• Giancarlo Fantin and
• Alessandro Massi

Beilstein J. Org. Chem. 2016, 12, 2719–2730, doi:10.3762/bjoc.12.268

• was then fabricated by packing a stainless steel column (10 cm length, 4.6 mm internal diameter) with PS-BEMP 5. Pycnometer measurements provided the hold-up volume Vo and the total porosity εtot of R5 [31], whereas the loaded amount of 5 was determined by weighing the filled and empty column. The

• pump (Agilent 1100 micro series), an in-line pressure transducer, a thermostated microreactor holder (Peltier unit), a system to collect fractions and a data acquisition system (Agilent ChemStation). The units were connected by peek tubing (internal diameter 0.01 inch from Upchurch Scientific). The

Interactions between cyclodextrins and cellular components: Towards greener medical applications?

• Loïc Leclercq

Beilstein J. Org. Chem. 2016, 12, 2644–2662, doi:10.3762/bjoc.12.261

• inclusion complex because of the driving force of complexation: hydrophobic interaction. Despite there is no information on the binding constant observed for the inclusion of cholesterol in γ-CD, the cavity internal diameter of the β-CD and its derivatives perfectly matches the size of the sterol molecules

• the diameter of its internal cavity that matches the size of this molecule. Finally, it is noteworthy that all CDs lose their abilities to induce hemolysis, when their cavities are occupied with guest molecules due to a reduced interaction with the erythrocyte membranes [71]. All these observations

Towards the development of continuous, organocatalytic, and stereoselective reactions in deep eutectic solvents

• Davide Brenna,
• Elisabetta Massolo,
• Alessandra Puglisi,
• Sergio Rossi,
• Giuseppe Celentano,
• Maurizio Benaglia and
• Vito Capriati

Beilstein J. Org. Chem. 2016, 12, 2620–2626, doi:10.3762/bjoc.12.258

• using a test tube of reduced diameter (green color in the picture) containing the DES and L-proline, surrounded by an external, larger cylinder filled with a solution of cyclohexanone and 4-nitrobenzaldehyde. The organic solution, fluxed by a HPLC pump onto the bottom of the internal smaller tube, went

Continuous-flow synthesis of primary amines: Metal-free reduction of aliphatic and aromatic nitro derivatives with trichlorosilane

• Riccardo Porta,
• Alessandra Puglisi,
• Giacomo Colombo,
• Sergio Rossi and
• Maurizio Benaglia

Beilstein J. Org. Chem. 2016, 12, 2614–2619, doi:10.3762/bjoc.12.257

• illustrated in Scheme 1, a residence time of 50 minutes was necessary to reach a full conversion of the starting material (Table 1, entry 5). This is mainly due to the bigger internal diameter of the reactor (2.54 mm vs 0.58 mm) which affects the mixing of the reagents [27][28]. Lowering the residence time

Effects of solvent additive on “s-shaped” curves in solution-processed small molecule solar cells

• John A. Love,
• Shu-Hua Chou,
• Ye Huang,
• Guilllermo C. Bazan and
• Thuc-Quyen Nguyen

Beilstein J. Org. Chem. 2016, 12, 2543–2555, doi:10.3762/bjoc.12.249

• images are shown in Figure S8 (Supporting Information File 1). The film cast without DIO has a relatively smooth featureless surface while the film cast with DIO has a rougher surface with relatively large (>100 nm diameter) features. This is consistent with phase separation and the crystallinity seen by

Efficient mechanochemical synthesis of regioselective persubstituted cyclodextrins

• Laszlo Jicsinszky,
• Marina Caporaso,
• Katia Martina,
• Emanuela Calcio Gaudino and
• Giancarlo Cravotto

Beilstein J. Org. Chem. 2016, 12, 2364–2371, doi:10.3762/bjoc.12.230

• , 3b, 4a, 4b, 5b and 6 were carried out in a Retsch PM100 High Speed Planetary Ball Mill. 1500 steel balls of 1 mm diameter (44.94 g) and 50 steel balls of 5 mm diameter (25.54 g, total weight of balls = 70.5 g, V = 15 mL), were placed in a stainless steel jar of 50 mL, with a sun wheel speed of 650

• measurements were made at each point and the values were averaged. Synthesis of per-6-derivatized CDs. Ball milling conditions: 1500 steel balls of 1 mm diameter and 50 steel balls of 5 mm diameter, sun wheel speed 650 min−1, 2 h grinding. Comparison of classic and green methods for the preparation of CD

Solvent-free, visible-light photocatalytic alcohol oxidations applying an organic photocatalyst

• Martin Obst and
• Burkhard König

Beilstein J. Org. Chem. 2016, 12, 2358–2363, doi:10.3762/bjoc.12.229

• 4-methoxyphenyl methyl carbinol from Fluorochem. Riboflavin tetraacetate was synthesized from riboflavin (Acros Organics) according to a procedure reported in the literature [17]. Technical data of the rod mill apparatus: 4 LEDs (455 nm, 700 mA) on a square aluminium frame (inner diameter 35 mm) and

• one LED below the test tube were used. The distance of each LED to the test tube was 10 mm. The diameter of the glass rod was 8 mm and the inner diameter of the test tube was 9 mm. Synthesis General procedure: The substrate and riboflavin tetraacetate were weighed into a mortar in stoichiometric

A detailed view on 1,8-cineol biosynthesis by Streptomyces clavuligerus

• Jan Rinkel,
• Patrick Rabe,
• Laura zur Horst and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2016, 12, 2317–2324, doi:10.3762/bjoc.12.225

• NMR: (2H6)benzene δ = 128.06) [40]. GC–MS analysis An Agilent 7890B gas chromatograph equipped with a HP5-MS silica column (30 m, 0.25 mm inner diameter, 0.50 μm film) connected to an Agilent 5977A inert mass selective detector was used to acquire GC–MS data. Instrumental settings were: (1) inlet

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

• seal. Reactions were monitored by TLC using silica plates 60-F264 on alumina, commercially available from Merk. GC–MS spectra were recorded on a GC–MS Thermo Scientific workstation, formed by a Focus GC (30-m VARIAN-VF-5ms, 0.25 mm diameter capillary column, working on spitless mode, 1.2 mL/min He as

Diels–Alder reactions in confined spaces: the influence of catalyst structure and the nature of active sites for the retro-Diels–Alder reaction

• Ángel Cantín,
• M. Victoria Gomez and
• Antonio de la Hoz

Beilstein J. Org. Chem. 2016, 12, 2181–2188, doi:10.3762/bjoc.12.208

• with 2.0 nm. There is then a unique occasion to compare the catalytic behavior of an amorphous and a crystalline molecular sieve with practically the same pore diameter (Figure 5a,b). As observed in Figure 5a,b, the crystalline structure of zeolites ITQ-33 and ITQ-37 do not favor neither the Diels

• further prove the effect of the structure, the reaction was carried out in presence of MCM-41 materials with different Si/Al ratios, and similar pore diameter. The results are collected in Figure 6a,b. As it could be expected no differences were found in the conversion. Meanwhile, in the case of the

Solvent-free synthesis of novel para-menthane-3,8-diol ester derivatives from citronellal using a polymer-supported scandium triflate catalyst

• Lubabalo Mafu,
• Ben Zeelie and
• Paul Watts

Beilstein J. Org. Chem. 2016, 12, 2046–2054, doi:10.3762/bjoc.12.193

• a flame ionization detector, Econocap-5 column (film thickness 0.25 µm; internal diameter 0.25 mm; length 30 m) and ultra-high purity nitrogen (99.999%) carrier gas. The samples were analysed by using the following method; injector temperature 270 °C, nitrogen flow rate 0.5 mL·min−1, oven

• distillation (Agilent SimDis FAST2887) instrument fitted with a CAP. EXT. 2887/AC column (film thickness 0.88 µm; internal diameter 0.53 mm; length 10 m). Experimental procedures Synthesis of para-menthane-3,8-diol from citronellal Citronellal (30.08 g, 0.193 mol) was added into stirred dilute sulphuric acid

The in situ generation and reactive quench of diazonium compounds in the synthesis of azo compounds in microreactors

• Faith M. Akwi and
• Paul Watts

Beilstein J. Org. Chem. 2016, 12, 1987–2004, doi:10.3762/bjoc.12.186

• reagents used for the reaction, amount of solvent added to facilitate quick dissolution of particulates as they are formed as well as the output of the reaction, i.e., conversion, yield and or even selectivity. The scaled-up synthesis of these compounds in PTFE tubing of 1.5 mm internal diameter is herein

• reactor systems being quite different. It should also be noted that the PTFE tubing is much cheaper than the glass LTF-MS and at the internal diameter of the PTFE tubing used there were no occurrences of blockages witnessed due to precipitate formation. This is particularly important since the amount of

• azo compounds Using two (1 mL) SGE glass syringes and PTFE tubing of 0.5 mm internal diameter, the reactants (diazonium salt and azo coupling component solutions) were fed to an LTF-MS (Volume: 0.2 mL, channel size: 1 mm, geometry: 115 × 60 × 6 mm) microreactor plate (Figure 6). The microreactor plate

Cross-linked cyclodextrin-based material for treatment of metals and organic substances present in industrial discharge waters

• Élise Euvrard,
• Nadia Morin-Crini,
• Coline Druart,
• Justine Bugnet,
• Bernard Martel,
• Cesare Cosentino,
• Virginie Moutarlier and
• Grégorio Crini

Beilstein J. Org. Chem. 2016, 12, 1826–1838, doi:10.3762/bjoc.12.172

• such as cross polarization magic angle spinning (CP MAS) and MAS. The spectra were recorded with a Bruker spectrometer operating at 75.47 MHz and 303 K. The compounds were placed in a zirconium rotor, 4 mm in diameter and 21 mm high. The chemical shifts were recorded relative to tetramethylsilane with

Synthesis and properties of fluorescent 4′-azulenyl-functionalized 2,2′:6′,2″-terpyridines

• Adrian E. Ion,
• Liliana Cristian,
• Mariana Voicescu,
• Masroor Bangesh,
• Augustin M. Madalan,
• Daniela Bala,
• Constantin Mihailciuc and
• Simona Nica

Beilstein J. Org. Chem. 2016, 12, 1812–1825, doi:10.3762/bjoc.12.171

• (Metrohm, 3 mm in diameter) served as working electrode. The counter electrode was a Pt wire of large area. All experimental potentials were referred to Ag wire (Metrohm), used as quasi-reference electrode. The electrochemical measurements were carried out in anhydrous dimethylformamide containing 0.1 M

A flow reactor setup for photochemistry of biphasic gas/liquid reactions

• Josef Schachtner,
• Patrick Bayer and
• Axel Jacobi von Wangelin

Beilstein J. Org. Chem. 2016, 12, 1798–1811, doi:10.3762/bjoc.12.170

• solutions with high attenuation coefficients can be prevented by low-diameter reactor dimensions and flow conditions that favour the formation of thin films along the reactor walls. Energy-saving light bulbs and light-emitting diodes (LEDs) of different wavelengths (red, green, blue, white) were used for

• and gas phase occurs upstream in a T mixer, while the tubular reactor should provide a high surface area for maximum exposure to the light source. For reaction times in the range of 10 s to 20 min, commercial fluorinated ethylene-propylene (FEP)-capillaries with an internal diameter of less than 1 mm

• (here 0.79 mm) were used and coiled around a glass cylinder containing the light source. It is again important to note that the tubing diameter can significantly influence the formation of the slug flow, the magnitude of light absorption, and the back-pressure build-up, which is again dependent on the

Biradical vs singlet oxygen photogeneration in suprofen–cholesterol systems

• Fabrizio Palumbo,
• Francisco Bosca,
• Isabel M. Morera,
• Inmaculada Andreu and
• Miguel A. Miranda

Beilstein J. Org. Chem. 2016, 12, 1196–1202, doi:10.3762/bjoc.12.115

• photolysis cell in right-angle geometry. An excimer laser (LEXTRA50 Lambda Physik) was used for the excitation at 308 nm (laser excitation at 5 low-pulse energies for each molecule). A 5 mm thick (5 cm in diameter) 1050 nm cut-off silicon filter and a 1270 nm interference filter were placed between the diode

Supported bifunctional thioureas as recoverable and reusable catalysts for enantioselective nitro-Michael reactions

• José M. Andrés,
• Miriam Ceballos,
• Alicia Maestro,
• Isabel Sanz and
• Rafael Pedrosa

Beilstein J. Org. Chem. 2016, 12, 628–635, doi:10.3762/bjoc.12.61

• ball milling vessel (cylinder of 5 mL) loaded with two grinding balls with a 7 mm diameter. The vessel was placed in a Mixer Mill MM 200 and the mixture was milled at 5 Hz of vibrational frequency at room temperature until consumption of the starting material (monitored by TLC). The vessel and the

Interactions between 4-thiothymidine and water-soluble cyclodextrins: Evidence for supramolecular structures in aqueous solutions

• Vito Rizzi,
• Sergio Matera,
• Paola Semeraro,
• Paola Fini and
• Pinalysa Cosma

Beilstein J. Org. Chem. 2016, 12, 549–563, doi:10.3762/bjoc.12.54

• [9]. In fact, in the formation of inclusion complexes [10][11][12] the inner diameter of the cavity of the CDs and the size of the guest molecule play an important role. CDs are often described as a toroid having a large and narrow cavity. The wider side is formed by the secondary 2- and 3-hydroxy

• inner diameter of the CD, from 5.7 Å for 2-HP-α-CD to 7.8 Å for 2-HP-β-CD [13], the H3 signals of 2-HP-β-CD, showed a significant variation at all examined H/G ratios (Δδ = −0.0036). However, the observed upfield shift of the H3 protons did not follow a linear trend. The H5 protons exhibited variations

• only at high concentrations of CD (H/G ratio of 10, Δδ = −0.0012). The results indicated that in this case the efficiency of the formation of inclusion complexes was increased by the larger diameter of 2-HP-β-CD. These data were further corroborated by considering the S4TdR protons (see Figure S1B

My maize and blue brick road to physical organic chemistry in materials

• Anne J. McNeil

Beilstein J. Org. Chem. 2016, 12, 229–238, doi:10.3762/bjoc.12.24

• that forms a gel when released. We briefly investigated several methods of increasing sensitivity by lowering the critical gel concentration (cgc) using external (nongelator) modifications. For example, we decreased the cgc by lowering the solvent volume and/or reducing the vial diameter [35]. In a

Thermal and oxidative stability of Atlantic salmon oil (Salmo salar L.) and complexation with β-cyclodextrin

• Daniel I. Hădărugă,
• Mustafa Ünlüsayin,
• Alexandra T. Gruia,
• Cristina Birău (Mitroi),
• Gerlinde Rusu and
• Nicoleta G. Hădărugă

Beilstein J. Org. Chem. 2016, 12, 179–191, doi:10.3762/bjoc.12.20

• diameter, and 0.25 μm film thickness) and a temperature program from 50 °C to 300 °C with a heating rate of 6 °C·min−1 were used. The injector and detector temperatures were set at 300 °C. The carrier gas was helium, the injection volume was 2 μL and a solvent delay time of 7 min was set up for the GC. The

Simple activation by acid of latent Ru-NHC-based metathesis initiators bearing 8-quinolinolate co-ligands

• Julia Wappel,
• Roland C. Fischer,
• Luigi Cavallo,
• Christian Slugovc and
• Albert Poater

Beilstein J. Org. Chem. 2016, 12, 154–165, doi:10.3762/bjoc.12.17

• was set with 1 mm/min. The tested shoulder test bars had a diameter of 37.4 mm and a length of 80 mm. General procedure for the preparation of Ru complexes In a Schlenk flask the corresponding starting material (1 equiv) was dissolved in degassed CH2Cl2. 5,7-Dihalide-8-hydroxyquinoline (20 equiv) and