Selective synthesis of thioethers in the presence of a transition-metal-free solid Lewis acid

• Federica Santoro,
• Matteo Mariani,
• Federica Zaccheria,
• Rinaldo Psaro and
• Nicoletta Ravasio

Beilstein J. Org. Chem. 2016, 12, 2627–2635, doi:10.3762/bjoc.12.259

• a maximum yield of 83% and it can be used only for primary benzylic alcohols. On the contrary Ni nanoparticles act as chemoselective catalysts at room temperature [20]. 1,3,5-Triazo-2,4,6-triphosphorine-2,2,4,4,6,6-hexachloride (TAPC) allows the efficient preparation of thioethers from different

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

• heterogeneous or supported catalysts [15][16][17], solid nanopowders or nanoparticles [18][19], non-metal-based heterogeneous acetylation catalysts [20][21][22], as well as natural marine clays instead of homogeneous catalysts as reaction activators [23]. Even if these methods allow a complete peracetylation of

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

• ]) dispersed on magnetic mesoporous SiO2/CoFe2O4 and CoFe2O4 nanoparticles [39][40] have been reported as catalysts. In addition, the reaction of ethylene carbonate with methanol for the synthesis of DMC was described in the presence of a mesocellular silica foam (MCF) material [41]. These catalysts are easy

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

• cationic dyes. Zhang et al. [4] studied the removal of cobalt and 1-naphthol onto magnetic nanoparticles containing cyclodextrin and iron and Yang et al. [5] proposed a new nanocomposite adsorbent for the simultaneous removal of organic and inorganic substances from water. Here, we propose to use a single

Organic chemistry meets polymers, nanoscience, therapeutics and diagnostics

• Vincent M. Rotello

Beilstein J. Org. Chem. 2016, 12, 1638–1646, doi:10.3762/bjoc.12.161

• just starting to move into nanoparticles. As with the polymers, we started off studying the interactions of recognition element-functionalized nanoparticles with monovalent guests – in this case our old friend flavin where we showed modulation of the flavin redox potentials [21]. Taking this research

• demonstrated this templation with peptides [23] and are (still!) trying to definitively show templation to proteins. As I mentioned above, I am an incessant tinkerer, a trait that has rubbed off on the group. When students mixed complementary versions of the polymers and nanoparticles described above, we were

• nanocomposite materials, including regular structures using diblock copolymers [25][26] and nanoparticle–protein [27][28] and nanoparticle–nucleic acid composites [29]. Concurrently with our 3D self-assembly, we pursued the use of nanoparticles for surface modification. This research has focused on the use of

One-pot synthesis of 4′-alkyl-4-cyanobiaryls on the basis of the terephthalonitrile dianion and neutral aromatic nitrile cross-coupling

• Roman Yu. Peshkov,
• Elena V. Panteleeva,
• Wang Chunyan,
• Evgeny V. Tretyakov and
• Vitalij D. Shteingarts

Beilstein J. Org. Chem. 2016, 12, 1577–1584, doi:10.3762/bjoc.12.153

• being used as components of liquid crystal mixtures [3][4][5][6][7][8], lubricants [9], media for conformational analysis using NMR [10][11][12] and EPR [13] techniques, and nanoparticles-doped liquid crystals [14]. The classic multistage approaches to these compounds, including successive biphenyl

Towards potential nanoparticle contrast agents: Synthesis of new functionalized PEG bisphosphonates

• Souad Kachbi-Khelfallah,
• Maelle Monteil,
• Margery Cortes-Clerget,
• Evelyne Migianu-Griffoni,
• Jean-Luc Pirat,
• Olivier Gager,
• Julia Deschamp and
• Marc Lecouvey

Beilstein J. Org. Chem. 2016, 12, 1366–1371, doi:10.3762/bjoc.12.130

• for biomedical imaging applications, the adsorption of plasmatic proteins on the surface of nanoparticles must be prevented to reduce the hepatic capture and increase the plasmatic time life. In biologic media, metal oxide nanoparticles are not stable and must be coated by biocompatible organic

• the development of superparamagnetic iron oxide nanoparticles (SPIONPs) because of their biocompatibility which allows there in vivo use both for diagnosis in magnetic resonance imaging and in therapy [1][2]. Most often, it is necessary to modify the surface of SPIONPs to increase the metabolic

• obtain the expected HMBP-PEG-COOH 23 in 85% yield. Conclusion In summary, novel bifunctional PEG-HMBPs ligands for the coating of iron oxide nanoparticles have been synthesized. The procedure is efficient to introduce different functional groups such as azide, carboxylic acid, amine permitting further

On the mechanism of imine elimination from Fischer tungsten carbene complexes

• Philipp Veit,
• Christoph Förster and
• Katja Heinze

Beilstein J. Org. Chem. 2016, 12, 1322–1333, doi:10.3762/bjoc.12.125

• –S24). The appearance of a resonance at δ = 9.68 ppm is assigned to a trace amount of W(CO)5(Z-2). A dark precipitate (possibly tungsten nanoparticles [81][82]) forms during the thermolysis. The half-lives at 60, 70, 80, 90 and 100 °C amount to 145.9, 39.4, 28.9, 16.2 and 12.2 h. The time traces fit to

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

• squalenoyl gemcitabine nanoparticles displayed significant Raman scattering signals. They revealed no differences except from the deuterium peak patterns in the silent spectral region of cells. This paves the way for label-free intracellular trafficking studies of squalenoyl nanomedicines. Keywords

• triterpene, to a drug led to the formation of a prodrug that spontaneously self-assembled as nanoparticles in water. The advantage of this approach is a very high drug loading into the nanoparticles and the absence of burst release [5]. The proof of concept of this method has been done using gemcitabine (2

• radioactive labeling 3H,14C has been taken into profit to study the pharmacokinetics, the biodistribution and the metabolism of squalenoyl adenosine nanoparticles [22]. Nevertheless, the synthesis of labeled compounds is chemically challenging, expensive and submitted to drastic regulation rules. In addition

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

• blocking hydrophilic PDMAEMA chains on a hydrophobic chain. These amphiphilic polymers may aggregate in water to form nanoparticles having stimuli-responsive properties. Different hydrophobic segments with different microstructures give the aggregates adjustable properties that can be used for various

• PDI of these two samples sharply decreased below 0.1, which means that the aggregates under these conditions may be uniform. The PDI and the size of nanoparticles used for biomedicine are important. For the human body, the size of these particles should be about 50–200 nm which could be excreted

• without any toxic effects. Larger nanoparticles may eliminate quickly from human body and smaller nanoparticles may block blood capillaries. In this work, pH 7.4 was similar to the pH of human blood and pH 8.5 was in the range of some secretion. In these pH, HBPS-g-PDMAEMA aggregates showed a narrow

Superstructures with cyclodextrins: chemistry and applications III

• Gerhard Wenz and
• Eric Monflier

Beilstein J. Org. Chem. 2016, 12, 937–938, doi:10.3762/bjoc.12.91

• styrene from ethylbenzene [3][4]. Highly porous networks were synthesized by crosslinking β-CD with tetrafluoroterephthalonitrile. These networks were able to almost completely remove pollutants (e.g., bisphenol A) within a short time from wastewater [5]. Stimuli-responsive nanoparticles were assembled by

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

Optimized methods for preparation of 6^I-(ω-sulfanyl-alkylene-sulfanyl)-β-cyclodextrin derivatives

• Eva Bednářová,
• Simona Hybelbauerová and
• Jindřich Jindřich

Beilstein J. Org. Chem. 2016, 12, 349–352, doi:10.3762/bjoc.12.38

• solid surfaces by CDs. Among the solid surfaces, to which CDs were attached, are sorbents for separation techniques or waste water treatment [8] or nanoparticles [6]. In our work, we focused on the preparation of sulfanyl-group-containing CD derivatives – 6I-deoxy-6I-(ω-sulfanyl-alkylene-sulfanyl)-β

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

• 2006 Lipshutz et al. demonstrated that the impregnation of charcoal with an aqueous solution of Cu(NO3)2 in US bath, gave copper nanoparticles: an efficient catalyst in CuAAC [58]. Besides the easier work-up of heterogeneous catalysis, Cu(I)/charcoal also gave a higher yield compared to soluble CuSO4

• ferromagnetic materials by grinding under less-environmentally friendly conditions in this case. The components were prepared using classic methods and the final composite was obtained by ball milling of arc-melted MnBi particles and Fe-Co nanoparticles prepared with the aid of a β-CD/oleic acid complex. The

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

• ] reported the optimal pH values were 7.0 for both free FDH and immobilized FDH onto polydopamine-coated iron oxide nanoparticles (PD-IONPs). The optimum pH values of the both free Pseudomonas sp. 101 FDH and its immobilized form onto glyoxylagarose were reported as 7.0 [16]. The temperature–activity

• quite different depending on the used immobilization procedure. The optimum temperature of C. boidinii FDH immobilized onto magnetite nanoparticles silanized with (3-aminopropyl)triethoxysilane was 42 °C whereas the optimum temperature was 27 °C when this support was further coated with glyoxylagarose

Aggregation behavior of amphiphilic cyclodextrins in a nonpolar solvent: evidence of large-scale structures by atomistic molecular dynamics simulations and solution studies

• Giuseppina Raffaini,
• Fabio Ganazzoli and
• Antonino Mazzaglia

Beilstein J. Org. Chem. 2016, 12, 73–80, doi:10.3762/bjoc.12.8

• nanoaggregates even in apolar solvents. Keywords: aggregation; amphiphilic cyclodextrins; molecular dynamics; nanoparticles; self-assembly; simulations; Introduction Amphiphilic cyclodextrins (aCD) are a class of molecules highly investigated for their self-assembly properties and inherent potential

Effective immobilisation of a metathesis catalyst bearing an ammonium-tagged NHC ligand on various solid supports

• Krzysztof Skowerski,
• Jacek Białecki,
• Stefan J. Czarnocki,
• Karolina Żukowska and
• Karol Grela

Beilstein J. Org. Chem. 2016, 12, 5–15, doi:10.3762/bjoc.12.2

• to the solution. A different valuable concept is the covalent or electrostatic immobilisation of ruthenium initiators on magnetically active nanoparticles. Complexes 5 [37] and 6 [38] presented in Figure 1 can serve as an examples, but others were also prepared [39]. These compounds are carefully

• endeavour aimed at getting a broader perspective. Immobilisation of 8 on iron powder First, we attempted to prepare a model for a magnetically separable catalyst [55]. This idea has been explored previously by attaching tagged Ru complexes to specially designed magnetically active nanoparticles. We wondered

• order to provide fully Fe-supported complex 8. This method for the preparation of a magnetically removable catalyst is obviously less complicated than the reported syntheses of catalysts on magnetic nanoparticles [37][38][39]. The main difference is that the latter materials are much more

Physical properties and biological activities of hesperetin and naringenin in complex with methylated β-cyclodextrin

• Waratchada Sangpheak,
• Jintawee Kicuntod,
• Roswitha Schuster,
• Thanyada Rungrotmongkol,
• Peter Wolschann,
• Nawee Kungwan,
• Helmut Viernstein,
• Monika Mueller and
• Piamsook Pongsawasdi

Beilstein J. Org. Chem. 2015, 11, 2763–2773, doi:10.3762/bjoc.11.297

• -loaded nanoparticles which exhibited significant cytotoxicity at high concentrations (30, 40 and 50 μg/mL) [59]. At low concentration (0.025 mM), naringenin complexed with DM-β-CD exerted a higher effect on MCF-7 and HeLa cells than free naringenin. However, for CaCo-2 cells, the effect of the naringenin

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

• 4 with ferricenium hexafluorophosphate led to a stable biferrocenium polymer while oxidation with Au(III) or Ag(I) allowed the formation of networks with nanosnake morphology, consisting of mixed-valent Fe(II)–Fe(III) polymers that encapsulate metal (Au or Ag) nanoparticles (NPs). These polymers

• biferrocenium motifs recommends them for designing new redox reactions, eventually leading to value-added nanomaterials. Along a different line, in a recent, inventive work Astruc and coworkers [48] demonstrated that triazolylbiferrocenyl-containing polymers can effectively stabilize palladium nanoparticles

• = BPh4 or Cl). Self-assembly of these block copolymers into core–shell spherical micelles was successfully conducted and, by UV/ozonolysis or thermal pyrolysis generating antiferromagnetic CoO species, some of these micelles could be converted into inorganic nanoparticles. With the aim at extending the

Pyridylidene ligand facilitates gold-catalyzed oxidative C–H arylation of heterocycles

• Kazuhiro Hata,
• Hideto Ito,
• Yasutomo Segawa and
• Kenichiro Itami

Beilstein J. Org. Chem. 2015, 11, 2737–2746, doi:10.3762/bjoc.11.295

• elimination steps, we believe that the strongly electron-donating PyC not only facilitates gold(I)-to-gold(III) oxidation in catalysis but also prolongs the catalyst lifetime by preventing the ligand dissociation and formation of inactive gold nanoparticles. Conclusion In summary, we have developed the

Synthesis of bi- and bis-1,2,3-triazoles by copper-catalyzed Huisgen cycloaddition: A family of valuable products by click chemistry

• Zhan-Jiang Zheng,
• Ding Wang,
• Zheng Xu and
• Li-Wen Xu

Beilstein J. Org. Chem. 2015, 11, 2557–2576, doi:10.3762/bjoc.11.276

• , powder or nanoparticles) in the presence or absence of Cu(II) in aqueous media also provides the key active Cu(I) in some CuAAC reactions. As an important supplement to the classic Huisgen cycloaddition promoted by copper catalysis, this review will deal with the copper-catalyzed syntheses of bi- and

Smart molecules for imaging, sensing and health (SMITH)

• Bradley D. Smith

Beilstein J. Org. Chem. 2015, 11, 2540–2548, doi:10.3762/bjoc.11.274

• ]. Nanoparticles containing these self-illuminating molecules enable high sensitivity imaging of deep-tissue target sites in living subjects [40]. A recent spin-off from the squaraine rotaxane project uses homologous croconaine dyes to absorb 800 nm laser light and cleanly convert the energy into heat without

• producing reactive singlet oxygen [41][42][43]. The dyes enable new types of nanoscale heating technologies that release sensitive payload such as dyes, drugs, oligonucleotides, or proteins. The dyes can also be loaded into nanoparticles for anticancer photothermal therapy in preclinical animal models

Aggregation behaviour of amphiphilic cyclodextrins: the nucleation stage by atomistic molecular dynamics simulations

• Giuseppina Raffaini,
• Antonino Mazzaglia and
• Fabio Ganazzoli

Beilstein J. Org. Chem. 2015, 11, 2459–2473, doi:10.3762/bjoc.11.267

• molecules or by dispersion interactions at their lateral surface. We suggest that these aggregates can also form the nucleation stage of larger systems as well as the building blocks of micelles, vesicle, membranes, or generally nanoparticles thus opening new perspectives in the design of aggregates

• correlating their structures with the pharmaceutical properties. Keywords: aggregation; amphiphilic cyclodextrins; micelles; molecular dynamics simulations; nanoparticles; self-assembly; Introduction Inclusion complexes with supramolecular structures formed by native or modified cyclodextrins (CDs) are

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

• Raquel Mejia-Ariza Gavin A. Kronig Jurriaan Huskens Molecular NanoFabrication group, MESA+ Institute for Nanotechnology University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands 10.3762/bjoc.11.260 Abstract Control over the assembly and disassembly of nanoparticles is pivotal for

• their use as drug delivery vehicles. Here, we aim to form supramolecular nanoparticles (SNPs) by combining advantages of the reversible assembly properties of SNPs using host–guest interactions and of a stimulus-responsive moiety. The SNPs are composed of a core of positively charged poly(ethylene imine

• core of the SNPs. Keywords: host–guest interactions; nanoparticles; self-assembly; stimulus-responsive; supramolecular chemistry; Introduction Self-assembly and molecular recognition are two core concepts underlying supramolecular chemistry. These offer convenient and versatile pathways to

Biocatalysis for the application of CO₂ as a chemical feedstock

• Apostolos Alissandratos and
• Christopher J. Easton

Beilstein J. Org. Chem. 2015, 11, 2370–2387, doi:10.3762/bjoc.11.259

• of CO2 to CO through in vitro application of CODH has been of interest as the enzymatic product may be further converted into hydrocarbons through the Fischer–Tropsch process [146]. In work carried out by Armstrong, Ragsdale and coworkers [147][148], metal oxide nanoparticles were functionalised with