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

• which have been shown to be successful by extrusion. Living polymerisation There have been several publications on the use of living anionic polymerisations in the preparation of polystyrene. Höcker et al. have investigated the role of extrusion in i) the preparation of this polymer and ii) the

• sequential postsynthetic modification of polystyrene by isoprene [16]. The authors focus mainly on the engineering aspects of the project rather than the chemical reaction itself. The first part of the process involves the chemical reaction between styrene and s-BuLi, which is employed as an initiator

• large scale. Furthermore, Höcker et al. report the post polymerisation of polystyrene with isoprene, which is actually carried out in the same processing line as the polymerisation of styrene, i.e., styrene is polymerised initially in the extruder barrel and isoprene is fed into the barrel at a later

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

• (DMF) solvent to the α-diketone and generate the corresponding enediolate active species. After having identified the 2-tert-butylimino-2-diethylamino-1,3-dimethylperhydro-1,3,2-diazaphosphorine on polystyrene (PS-BEMP) as the suitable base, packed-bed microreactors (pressure-resistant stainless-steel

• described by Lupton and co-workers [15]. Our group also contributed to this area of research fabricating polystyrene monolithic columns functionalized with thiazolium salt pre-catalysts to perform umpolung racemic processes (benzoin, acyloin, and Stetter reactions) with a good level of efficiency [16]. The

• 1a with 2-chlorobenzaldehyde 2a furnishing the benzoylated benzoin 3aa (double aroylation product) was selected as the benchmark (Table 1). Quite surprisingly, the polystyrene-supported 1,8-diazabicyclo [5.4.0]undec-7-ene 4 (PS-DBU) was completely inefficient (DMF, 35 °C, Ar atmosphere) in both

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

• mixed with PC71BM and cast to form a bulk heterojunction (BHJ) atop poly(3,4-ethylenedioxythiophene) polystyrene sulfate (PEDOT) giving an architecture of ITO/PEDOT/p-SIDT(FBTThCA8)2:PC71BM/Ca/Al. The mass ratio of p-SIDT(FBTThCA8)2:PC71BM was held at 1:1 and cast from a chlorobenzene solution

Selective and eco-friendly procedures for the synthesis of benzimidazole derivatives. The role of the Er(OTf)₃ catalyst in the reaction selectivity

• Natividad Herrera Cano,
• Jorge G. Uranga,
• Mónica Nardi,
• Antonio Procopio,
• Daniel A. Wunderlin and
• Ana N. Santiago

Beilstein J. Org. Chem. 2016, 12, 2410–2419, doi:10.3762/bjoc.12.235

• hexafluorophosphate ion (PHP) [15], perchloric acid adsorbed on silica gel (HClO4–SiO2) [16], polystyrene sulfonic acid [34], HSO3Cl in 2-propanol [35], trimethylsilyl chloride (TMSCl) [36], or Amberlite (IR-120) [37]. It is worth mentioning that these previously reported catalysts required longer reaction times than

Comparing blends and blocks: Synthesis of partially fluorinated diblock polythiophene copolymers to investigate the thermal stability of optical and morphological properties

• Pierre Boufflet,
• Sebastian Wood,
• Jessica Wade,
• Zhuping Fei,
• Ji-Seon Kim and
• Martin Heeney

Beilstein J. Org. Chem. 2016, 12, 2150–2163, doi:10.3762/bjoc.12.205

• hot (80 °C) chlorobenzene gave the number average molecular weight (Mn) of P3OT-b-F-P3OT 2:1 as 55 kg/mol against polystyrene standards. Although this is higher than the theoretical Mn (ca. 39 kg/mol for a monomer:catalyst ratio of 200:1), it is likely due to the removal of lower molecular weight

• oligomers during Soxhlet extraction as well as the known overestimation of molecular weight for polythiophenes when measured by GPC against polystyrene standards [50][51]. Accounting for the purification, the Mn of P3OT-b-F-P3OT 2:1 is in reasonable agreement with the ratio of H and F blocks as determined

• , using two PL mixed B columns in series, and calibrated against narrow polydispersity polystyrene standards. Films for PESA, UV–visible absorption and Raman spectroscopy, were prepared by spin-coating from hot (ca. 150 °C) solution in 1,2,4-trichlorobenzene (5 mg/mL) at 3000 rpm for 2 minutes. Dropcast

Ionic liquids as transesterification catalysts: applications for the synthesis of linear and cyclic organic carbonates

• Maurizio Selva,
• Alvise Perosa,
• Sandro Guidi and
• Lisa Cattelan

Beilstein J. Org. Chem. 2016, 12, 1911–1924, doi:10.3762/bjoc.12.181

• ) catalysts are achieved by the dispersion of liquid organic salts on highly porous materials, amongst which montmorillonite clays, modified silica, and polystyrene-based solids are the most frequently used [36][37]. Some very recent examples described the production of biodiesel via the transesterification

• summarizes the reaction mechanism proposed for the synthesis of DMC. The same paper described also the results obtained by supporting the imidazolium salt onto a polystyrene resin (PS). This catalytic system proved to be highly stable and no loss of activity was detected after 200 h of reaction performed in

Rearrangements of organic peroxides and related processes

• Ivan A. Yaremenko,
• Vera A. Vil’,
• Dmitry V. Demchuk and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2016, 12, 1647–1748, doi:10.3762/bjoc.12.162

• the presence of H2O2 and arsenic-containing ion exchange resins on polystyrene as the catalyst (Table 4) [203][205]. The mechanism of the oxidation of ketones 58a–f by hydrogen peroxide in the presence of arsonated polystyrene 60 as the catalyst is shown in Scheme 17. First, hydrogen peroxide reacts

• with the arsonic acid 60 to form peroxyarsonic acid 61 or it adds to ketones 58a–f to form vicinal hydroperoxyalkanols 63. In the second step the peroxyarsonic acid 61 adds to ketones 58a–f or the vicinal hydroperoxyalkanols 63 interact with arsonated polystyrene 60 under formation of perester 62

Synthesis and characterization of benzodithiophene and benzotriazole-based polymers for photovoltaic applications

• Desta Gedefaw,
• Marta Tessarolo,
• Margherita Bolognesi,
• Mario Prosa,
• Renee Kroon,
• Wenliu Zhuang,
• Patrik Henriksson,
• Kim Bini,
• Ergang Wang,
• Michele Muccini,
• Mirko Seri and
• Mats R. Andersson

Beilstein J. Org. Chem. 2016, 12, 1629–1637, doi:10.3762/bjoc.12.160

• measurment was performed at 135 °C. The concentration of the samples was 0.5 mg/mL, which was filtered (filter: 0.45 μm) prior to the analysis. The relative molecular masses were calculated by calibration relative to polystyrene standards. Square-wave voltammetric measurements were carried out on a CH

3,6-Carbazole vs 2,7-carbazole: A comparative study of hole-transporting polymeric materials for inorganic–organic hybrid perovskite solar cells

• Wei Li,
• Munechika Otsuka,
• Takehito Kato,
• Yang Wang,
• Takehiko Mori and
• Tsuyoshi Michinobu

Beilstein J. Org. Chem. 2016, 12, 1401–1409, doi:10.3762/bjoc.12.134

• GULLIVER 1500 equipped with a pump (PU-2080 Plus), an absorbance detector (RI-2031 Plus), and two Shodex GPC KF-803 columns (8.0 mm I.D. × 300 mm L) based on a conventional calibration curve using polystyrene standards. Tetrahydrofuran (40 °C) was used as a carrier solvent at the flow rate of 1.0 mL min−1

Stimuli-responsive HBPS-g-PDMAEMA and its application as nanocarrier in loading hydrophobic molecules

• Yongsheng Chen,
• Li Wang,
• Haojie Yu,
• Zain-Ul-Abdin,
• Ruoli Sun,
• Guanghui Jing,
• Rongbai Tong and
• Zheng Deng

Beilstein J. Org. Chem. 2016, 12, 939–949, doi:10.3762/bjoc.12.92

• nanocarriers for loading guest molecules is dynamic. It has been widely studied in applications including drug controlled release, smart sensing, catalysis, and modeling. In this paper, a graft copolymer (hyperbranched polystyrene)-g-poly[2-(dimethylamino)ethyl methacrylate] (HBPS-g-PDMAEMA) was synthesized

• aggregates were capable to encapsulate small hydrophobic molecules. These newly prepared HBPS-g-PDMAEMA nanocarriers might be used in, e.g., medicine or catalysis. Keywords: amphiphilic polymer; hyperbranched polystyrene; phase transition; poly[2-(dimethylamino)ethyl methacrylate] (PDMAEMA); stimuli

• attractive to academia and industry in recent years due to their special chemical and physical properties. In comparison with their linear counterpart, these polymers afford promising applications such as drug delivery [15][16][17], gene delivery [18][19][20][21] and catalysis [22][23]. Polystyrene is a

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

• nanoparticles [10][11][12], inorganic solids [13][14], and different polystyrene derivatives [15][16][17][18][19][20]. Bifunctional thioureas were first supported on PEG [21], and later on different materials such as poly(methylhydrosiloxane) [16], polystyrene [18][19][20][21][22], and magnetic nanoparticles

Amino-functionalized (meth)acryl polymers by use of a solvent-polarity sensitive protecting group (Br-t-BOC)

• Helmut Ritter,
• Monir Tabatabai and
• Markus Herrmann

Beilstein J. Org. Chem. 2016, 12, 245–252, doi:10.3762/bjoc.12.26

• × columns with 10,000, 1,000 und 100 Å). The system was calibrated with polystyrene standards with a molecular range from 575 g/mol to 3,114,000 g/mol. THF was used as eluent at a flow rate of 1 mL min−1. Materials Commercial reagents and solvents were purchased from Sigma-Aldrich, Merck and Fluka. If not

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

• ), respectively. Gel permeation chromatography was used to determine molecular weights and the polydispersity index (PDI). The measurements were run in THF against a polystyrene standard using following arrangement: a Merck Hitachi L6000 pump, separation columns of Polymer Standards Service (5 µm grade size) and

• chromatography (GPC) against polystyrene standards). Tensile test values for shoulder test bars initiated with complexes 1–4. Supporting Information Crystallographic data for complexes 2a and 2b have also been deposited with the CCDC, nos. 1439204 and 1439205, and can be obtained free of charge from http

Recent advances in metathesis-derived polymers containing transition metals in the side chain

• Ileana Dragutan,
• Valerian Dragutan,
• Bogdan C. Simionescu,
• Albert Demonceau and
• Helmut Fischer

Beilstein J. Org. Chem. 2015, 11, 2747–2762, doi:10.3762/bjoc.11.296

• the atom-transfer radical polymerization of methyl methacrylate or styrene to obtain poly(methyl methacrylate) and polystyrene devoid of colored traces of catalyst, a very important requirement for special applications, e.g., in dentistry, medical devices, housewares, and food packaging. In another

Enantioselective additions of copper acetylides to cyclic iminium and oxocarbenium ions

• Jixin Liu,
• Srimoyee Dasgupta and
• Mary P. Watson

Beilstein J. Org. Chem. 2015, 11, 2696–2706, doi:10.3762/bjoc.11.290

• polystyrene bead through the C7 hydroxy group. In 2007, Ma and co-workers reported the first enantioselective, copper-catalyzed alkynylation of a pyridinium ion (Scheme 6) [26]. This reaction employs an N-acylpyridinium ion generated in situ and a CuI/Indabox catalyst. Ma found that the identity of base and

Synthesis and photophysical characteristics of polyfluorene polyrotaxanes

• Aurica Farcas,
• Giulia Tregnago,
• Ana-Maria Resmerita,
• Pierre-Henri Aubert and
• Franco Cacialli

Beilstein J. Org. Chem. 2015, 11, 2677–2688, doi:10.3762/bjoc.11.288

• . The FTIR (KBr pellets) spectra were obtained on a Bruker Vertex 70 spectrophotometer. The molecular weights of copolymers were determined by GPC in THF by using a Water Associates 440 instrument and polystyrene (Pst) calibrating standards. DSC was performed with a Mettler Toledo DSC-12E calorimeter

Assembly of synthetic Aβ miniamyloids on polyol templates

• Sebastian Nils Fischer and
• Armin Geyer

Beilstein J. Org. Chem. 2015, 11, 2646–2653, doi:10.3762/bjoc.11.284

• obtained by routine solid-phase peptide synthesis on chloro-(2'-chloro)trityl polystyrene (CTC resin) and coupling of the unprotected boronic acid as the final building block. The C-terminal boronic acids need careful exclusion of water because of the reversible linkage to the resin, while no special

Olefin metathesis in air

• Lorenzo Piola,
• Fady Nahra and
• Steven P. Nolan

Beilstein J. Org. Chem. 2015, 11, 2038–2056, doi:10.3762/bjoc.11.221

• this increased stability diminished the activity of 21 when compared to 15 [52]. In 2000, Dowden [53] and co-workers reported the use of a polystyrene-supported ruthenium complex 24 (Scheme 5); a variation of the Hoveyda–Grubbs catalyst. It could be reused up to 5 times without loss of activity and

Cross-metathesis of polynorbornene with polyoctenamer: a kinetic study

• Yulia I. Denisova,
• Maria L. Gringolts,
• Alexander S. Peregudov,
• Liya B. Krentsel,
• Ekaterina A. Litmanovich,
• Arkadiy D. Litmanovich,
• Eugene Sh. Finkelshtein and
• Yaroslav V. Kudryavtsev

Beilstein J. Org. Chem. 2015, 11, 1796–1808, doi:10.3762/bjoc.11.195

• and tetrahydrofurane for PCOE as a solvent, the flow rate of 1 mL/min, sample volume of 100 μL, and sample concentration of 1 mg/mL. The molar mass and its dispersity (Ð) were calculated by a standard procedure relative to polystyrene standards. Light scattering was studied on a Photocor Complex

Grubbs–Hoveyda type catalysts bearing a dicationic N-heterocyclic carbene for biphasic olefin metathesis reactions in ionic liquids

• Maximilian Koy,
• Hagen J. Altmann,
• Benjamin Autenrieth,
• Wolfgang Frey and
• Michael R. Buchmeiser

Beilstein J. Org. Chem. 2015, 11, 1632–1638, doi:10.3762/bjoc.11.178

• index detector. For calibration, polystyrene standards with 800 < Mn < 2,000,000 g/mol were used. ICP–OES measurements were carried out using a Spectro Acros device (Ametek GmbH; Meerbusch, Germany). Calibration was done with Ru standards containing 0.1, 0.5, 1.0 and 5.0 ppm. Mass spectra were recorded

Robust bifunctional aluminium–salen catalysts for the preparation of cyclic carbonates from carbon dioxide and epoxides

• Yuri A. Rulev,
• Zalina Gugkaeva,
• Victor I. Maleev,
• Michael North and
• Yuri N. Belokon

Beilstein J. Org. Chem. 2015, 11, 1614–1623, doi:10.3762/bjoc.11.176

• polystyrene standards supplied by Sigma-Aldrich. General procedures for compounds (4–10) 3-(tert-Butyl)-2-hydroxybenzaldehyde (4) Prepared as described in previous work [24]. 1H NMR (400 MHz, CDCl3) δ 11.77 (s, 1H), 9.85 (s, 1H), 7.52 (d, J = 7.7 Hz, 1H), 7.39 (d, J = 7.7 Hz, 1H), 7.00–6.95 (m, 1H), 1.45 (s

• referenced to polystyrene standards. Synthesis of cyclic and polycarbonates. Synthesis of salen ligands 8a and 8b. The preparation of aluminum complexes 1, 2 and 10. Possible formation of a dinuclear complex from 1 by treatment with H2O and Et3N. Coupling of CO2 and styrene oxide promoted by complexes 1, 2

Chiroptical properties of 1,3-diphenylallene-anchored tetrathiafulvalene and its polymer synthesis

• Masashi Hasegawa,
• Junta Endo,
• Seiya Iwata,
• Toshiaki Shimasaki and
• Yasuhiro Mazaki

Beilstein J. Org. Chem. 2015, 11, 972–979, doi:10.3762/bjoc.11.109

• )2 and P(t-Bu)3·HBF4 salt in the presence of CsCO3, to give the chiral copolymer of (R)-PTDPA and (S)-PTDPA, respectively, after purification by column chromatography on polystyrene Bio-beads. By using gel permeation chromatography (GPC), the number-average molecular weights (Mn) of the collected

• flow rate of 0.5 mL/min. Polystyrene standards with a narrow distribution of molecular weight (Mw: 580–377, 400) were used for molecular weight calibration. Synthesis of 8: To a solid mixture of dried CuI (5.7 g, 30 mmol) and LiBr (2.6 g, 30 mmol) was added dropwise acetyl ester 7 (6.7 g, 15 mmol) in

• -polar polystyrene gel (Bio-beads S-X3 Support) with the elution of toluene. The crude product was further purified reprecipitation with toluene-hexane, yielding copolymer of (R)-PTDPA as an orange-brown powder (24 mg, 26%). The number-average molecular weight (Mn) was estimated to be 5.6 × 103, and its

Peptide–polymer ligands for a tandem WW-domain, an adaptive multivalent protein–protein interaction: lessons on the thermodynamic fitness of flexible ligands

• Katharina Koschek,
• Vedat Durmaz,
• Oxana Krylova,
• Marek Wieczorek,
• Shilpi Gupta,
• Martin Richter,
• Alexander Bujotzek,
• Christina Fischer,
• Rainer Haag,
• Christian Freund,
• Marcus Weber and
• Jörg Rademann

Beilstein J. Org. Chem. 2015, 11, 837–847, doi:10.3762/bjoc.11.93

• ) was selected and synthesized on Rink amide polystyrene resin. For attachment to the polymer carriers the N-cysteinylated peptide CGPPPRGPPPR-NH2 (P2) was prepared, containing a free N-terminus in order to enable the attachment to polymers via native chemical ligation or Michael addition to maleimide

Multivalent polyglycerol supported imidazolidin-4-one organocatalysts for enantioselective Friedel–Crafts alkylations

• Tommaso Pecchioli,
• Manoj Kumar Muthyala,
• Rainer Haag and
• Mathias Christmann

Beilstein J. Org. Chem. 2015, 11, 730–738, doi:10.3762/bjoc.11.83

• and various families of branched polymers such as dendrimers, dendritic-hybrid and hyperbranched polymers are used as macromolecular support for catalysis [10][11][12]. Linear polymers such as poly(ethylene glycol) (PEG) [13] or non-cross-linked polystyrene (NCPS) [14] are readily available but suffer

• of solid support such as polystyrene may lead to the disadvantage of operating in heterogeneous media. In contrast to the stepwise syntheses of dendrimers and dendron hybrids, the hyperbranched polymers can be easily obtained in kilogram scale through one-pot reactions [10], maintaining properties

Automated solid-phase synthesis of oligosaccharides containing sialic acids

• Chian-Hui Lai,
• Heung Sik Hahm,
• Chien-Fu Liang and
• Peter H. Seeberger

Beilstein J. Org. Chem. 2015, 11, 617–621, doi:10.3762/bjoc.11.69

• automated method for chemical sialylation. Monosaccharide building blocks 4, 5 [14], 6, 7 [21], 8, 9 [21], and 10 [5] were employed for these syntheses. Merrifield polystyrene resin equipped with a photocleavable linker, 11, was placed in the reaction chamber of the automated synthesizer and the coupling