Stereo- and regioselectivity of the hetero-Diels–Alder reaction of nitroso derivatives with conjugated dienes

• Lucie Brulíková,
• Aidan Harrison,
• Marvin J. Miller and
• Jan Hlaváč

Beilstein J. Org. Chem. 2016, 12, 1949–1980, doi:10.3762/bjoc.12.184

• TiO2 nanoparticle assemblies using H2O2 [51]. Geminal chloronitroso compounds are synthesized or in situ generated from their corresponding oximes by chlorination. As halogen source elemental chlorine [52][53][54], nitrosyl chloride [55], alkyl hypochlorites [56], N-chlorourea [57], tert-butyl

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

• with great precision. Bringing together these two very disparate skill sets is, however, quite uncommon. This autobiographical review provides some insight into how my program evolved, as well as giving some idea of where we are going. Keywords: organic synthesis, supramolecular, nanoparticle sensing

• one step further, we created a nanoparticle with a mixed monolayer consisting of hydrogen bonding and aromatic staking sidechains. When we incubated this NP with flavin we observed an increase in binding over time, i.e., we were able to template the particle to the guest [22]. We have since

• 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

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

• ligands. The use of phosphonate ligands to modify the nanoparticle surface drew a lot of attention in the last years for the design of highly functional hybrid materials. Here, we report a methodology to synthesize bisphosphonates having functionalized PEG side chains with different lengths. The key step

• is a procedure developed in our laboratory to introduce the bisphosphonate from acyl chloride and tris(trimethylsilyl)phosphite in one step. Keywords: bisphosphonate; Fe2O3 nanoparticle; polyethylene glycol derivatives; surface ligand synthesis; Introduction Numerous researchers are interested in

Multicomponent reactions: A simple and efficient route to heterocyclic phosphonates

• Mohammad Haji

Beilstein J. Org. Chem. 2016, 12, 1269–1301, doi:10.3762/bjoc.12.121

• substituted isatins 30 with aniline (32) and dimethyl- or diethyl phosphite under solvent-free conditions in the presence of magnetic Fe3O4 nanoparticle-supported phosphotungstic acid as a recyclable catalyst at 80 °C furnished α-aminophosphonates 33 in yields from 80% to 98% depending on the reaction time

• the synthesis of α-aminophosphonates. Phthalocyanine–AlCl catalyzed Kabachnik–Fields reaction of N-Boc-piperidin-4-one with diethyl phosphite and benzylamine. Kabachnik–Fields reaction of isatin with diethyl phosphite and benzylamine. Magnetic Fe3O4 nanoparticle-supported phosphotungstic acid

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

• large excess of gemcitabine was used in the reaction to increase the yield to 72% in respect of the more valuable SQCO2H-d6 (Scheme 4). Nanoparticle formulation of the GemSQ-d6 conjugate and Raman spectroscopy The GemSQ and GemSQ-d6 nanoassembly suspensions (2 mg·mL−1) were prepared in a single step by

• -d6: In a similar manner to the procedure published [19] the prodrugs based nanoparticle suspensions (2 mg·mL−1) were prepared in a single step by dropwise addition of an ethanol solution (4 mg·mL−1) in milli-Q water (1 mL) under vigorous stirring (500 rpm). Formation of NAs occurred immediately

• . After being stirred for 2 min, the nanoparticle suspension was then transferred into a weighted round bottom flask and ethanol was evaporated using a Rotavapor with a preheated water bath (35 °C) setting the vacuum to about 15–50 mbar for about 5 min. Then, the flask was dipped into a water bath (water

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

• interaction and may promote the formation of metal nanoparticle clustering. Cu(I)-based system have been used in alkyne/azide [3 + 2] cycloadditions, while Pd(II)-based catalysts have been used in C–C couplings reactions (Scheme 7) [34]. An example of water-soluble β- and γ-CD/chitosan derivatives have been

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

• designed to facilitate straightforward removal of the metal-containing species after the reaction is completed. Although this idea is simple, the preparation of such sophisticated nanoparticle-supported catalysts is often a complicated multistep procedure. Definitely, the simplest and quickest

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

• . This yielded 136 mg of a slightly yellow solid. 1H NMR (400 MHz, D2O) δ (ppm) 4.78 (m, 2H, Fc), 4.53 (t, 2H, Fc), 4.28 (s, 5H, Fc), 3.85 (t, 2H, CH2CH2NHCO), 3.50 (t, 2H, CH2NHCO), 3.36 (s, 3H, OCH3). Methods Supramolecular nanoparticle assembly as a function of ionic strength For the preparation of

• ), were mixed for 30 s. After mixing, 7.5 µL of Ad8-PAMAM solution in DMSO (6664 µM in Ad moieties) was injected to the previous solution while sonicating. Supramolecular nanoparticle assembly as a function of different stoppers For the preparation of SNPs using 0.2 M NaCl as a function of stoppers at two

• -PAMAM solution in DMSO (3336 µM in Fc moieties) was injected to the previous solution while sonicating. Supramolecular nanoparticle assembly as a function of increasing multivalent guest For the preparation of SNPs in 0.2 M NaCl various aqueous solution of CD-PEI and Ad-PEG and Fc8-PAMAM in DMSO were

Synthesis, structure, and mechanical properties of silica nanocomposite polyrotaxane gels

• Kazuaki Kato,
• Daisuke Matsui,
• Koichi Mayumi and
• Kohzo Ito

Beilstein J. Org. Chem. 2015, 11, 2194–2201, doi:10.3762/bjoc.11.238

• . These toughness and softness properties are attributable to both the characteristic sliding of polymer chains through the immobilized cyclodextrins on the silica nanoparticle and the entropic contribution of the cyclic components to the elasticity of the gels. Keywords: cyclodextrin; gel; mechanical

• property; nanocomposite; polyrotaxane; Introduction Nanocomposite materials, in which nanoparticles are distributed via a matrix such as resin or rubber, exhibit various functions that the matrix material cannot achieve by itself. For instance, polyurethane/magnetic nanoparticle nanocomposite elastomers

• nanoparticles such as carbon black and silica for practical use as tire materials. Because of adhesion of polymer chains to the nanoparticle surfaces, the chain mobility at the interface is considerably suppressed, thereby increasing the elastic modulus of the nanocomposite [2][3][4][5][6]. Although the

Star-shaped tetrathiafulvalene oligomers towards the construction of conducting supramolecular assembly

• Masahiko Iyoda and
• Masashi Hasegawa

Beilstein J. Org. Chem. 2015, 11, 1596–1613, doi:10.3762/bjoc.11.175

• from CHCl3–hexane solution, probably owing to the strong aggregation properties and molecular shape of the stacked 48•+ClO4−, whereas trication 483+(ClO4−)3 produced a nanoparticle having a low internal regularity, presumably owing to the strong intermolecular TTF•+–TTF•+ interaction of 483+. A cast

Preparative semiconductor photoredox catalysis: An emerging theme in organic synthesis

• David W. Manley and
• John C. Walton

Beilstein J. Org. Chem. 2015, 11, 1570–1582, doi:10.3762/bjoc.11.173

• carboxylic acids RCO2H release radicals (R•) in the photo-Kolbé reaction was referred to above. Ni and co-workers showed that vinyl acetate polymerization could be mediated by TiO2 nanoparticle photocatalyzed reactions with carboxylic acids [50]. Kinetic studies established that amongst simple carboxylic

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

• Strategies to achieve controlled nanoparticle aggregation have gained much interest, due to the versatility of such systems and their applications in materials science and medicine. In this article we demonstrate that coiled-coil peptide-induced aggregation based on electrostatic interactions is highly

• sensitive to the length of the peptide as well as the number of presented charges. The quaternary structure of the peptide was found to play an important role in aggregation kinetics. Furthermore, we show that the presence of peptide fibers leads to well-defined nanoparticle assembly on the surface of these

• width of which is highly dependent upon nanoparticle size. However, nanoparticle aggregation induces a spectral red-shift and broadening of the band in the absorption spectrum which depends on the distance between nanoparticles, the density of the assembly and the size of the particles [2][3]. Thus the

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

• glycodendrimers provided competitive binding sites for galectin-1, which diverted galectin-1 from its typical function in cellular aggregation of DU145 cells. Keywords: dendrimer; galectin-1; glycodendrimer; multivalent; nanoparticle; Introduction Galectin-1 is a multivalent protein that mediates biological

• nanoparticles were characterized using dynamic light scattering (DLS) and fluorescence microscopy (FM) when varying ratios of galectin-1 were added to the glycodendrimers. The galectin-1/glycodendrimer nanoparticle aggregates were then used to inhibit the galectin-1 induced aggregation of DU145 human prostate

• very effectively used to organize proteins into biologically active arrays. Results Nanoparticle formation Poly(amidoamine) (PAMAM) dendrimers were used as a multivalent framework to study multivalent protein–carbohydrate interactions. The PAMAM structure is shown in Figure 2a. Second, third, fourth

Exploring monovalent and multivalent peptides for the inhibition of FBP21-tWW

• Lisa Maria Henning,
• Sumati Bhatia,
• Miriam Bertazzon,
• Michaela Marczynke,
• Oliver Seitz,
• Rudolf Volkmer,
• Rainer Haag and
• Christian Freund

Beilstein J. Org. Chem. 2015, 11, 701–706, doi:10.3762/bjoc.11.80

• ± 6 μM in solution whereas it was 17 ± 0.016 μM for hPG-peptide conjugate 2, demonstrating an approximately tenfold overall affinity enhancement. However, when considering that ≈7 peptides are bound per nanoparticle, the actual multivalency effect is small. For both the monovalent ligand and the hPG

• peptide ligand for the WW domains of FBP21 and were able to enhance the binding affinity by presenting it on a multivalent dendritic polyglycerol scaffold by a factor of ten in comparison to the monovalent ligand. However, given that on an average seven peptides are presented on the nanoparticle, this

Synthesis of tripodal catecholates and their immobilization on zinc oxide nanoparticles

• Franziska Klitsche,
• Julian Ramcke,
• Julia Migenda,
• Andreas Hensel,
• Tobias Vossmeyer,
• Horst Weller,
• Silvia Gross and
• Wolfgang Maison

Beilstein J. Org. Chem. 2015, 11, 678–686, doi:10.3762/bjoc.11.77

• monochromator). A) Schematic drawing of a bifunctional anchor molecule and its immobilization on a nanoparticle (NP); B) tripodal catechol derivative, derived from the native bifunctional anchors dopamine and L-DOPA. Catecholates for the immobilization on ZnO NPs. A) XRD pattern of ZnO NPs obtained by the

Formulation development, stability and anticancer efficacy of core-shell cyclodextrin nanocapsules for oral chemotherapy with camptothecin

• Hale Ünal,
• Naile Öztürk and
• Erem Bilensoy

Beilstein J. Org. Chem. 2015, 11, 204–212, doi:10.3762/bjoc.11.22

• Table 2, an increase in the concentration of oil resulted in an increase of nanoparticle size. This effect was attributed to the increase of the viscosity of the organic phase, since the higher the oil concentration is, the more viscous the organic phase becomes. However there is no significant

• electrostatic interaction between the cell membrane and nanoparticle since positively charged CS has the ability to interact with the negatively charged surface membrane of cells via electrostatic forces [45]. The permeation of CPT both in solution form and in nanocapsule formulations across a Caco-2 cell

Formation of nanoparticles by cooperative inclusion between (S)-camptothecin-modified dextrans and β-cyclodextrin polymers

• Thorbjørn Terndrup Nielsen,
• Catherine Amiel,
• Laurent Duroux,
• Kim Lambertsen Larsen,
• Lars Wagner Städe,
• Reinhard Wimmer and
• Véronique Wintgens

Beilstein J. Org. Chem. 2015, 11, 147–154, doi:10.3762/bjoc.11.14

• with a degree of substitution between 4.7 and 9.1% nanoparticles with sizes between 100–400 nm are formed instantly. The nanoparticle formation arises from inclusion formation between hydrophobic chains on the dextran and the CD moieties of the CD polymers. The vacant CD cavities in the nanoparticles

Synthesis of nanodiamond derivatives carrying amino functions and quantification by a modified Kaiser test

• Gerald Jarre,
• Steffen Heyer,
• Elisabeth Memmel,
• Thomas Meinhardt and
• Anke Krueger

Beilstein J. Org. Chem. 2014, 10, 2729–2737, doi:10.3762/bjoc.10.288

• conjugate [11]. We were able to show that the aromatic molecules immobilized by this technique can be further modified using conventional synthetic chemistry [12]. This enables the utilization of such diamond conjugates for biomedical applications as the C–C bound linker between the nanoparticle and the

• crosslink and form a glassy layer around the nanodiamond core upon heating. This reduces the apparent surface loading as complete removal is assumed in the calculation. As can be seen from the results, the modified Kaiser test is a valuable tool for the quantification of amino groups on nanoparticle

Encapsulation of biocides by cyclodextrins: toward synergistic effects against pathogens

• Véronique Nardello-Rataj and
• Loïc Leclercq

Beilstein J. Org. Chem. 2014, 10, 2603–2622, doi:10.3762/bjoc.10.273

• leading to an increase of their contact with microorganisms, promoting the dissolution of silver ions. Their stabilization in aqueous solution is achieved using capped agents (polymers, sodium dodecylsulfate, etc.). Since 2004, the use of β-CD as a silver nanoparticle stabilizer has been described in

Supercritical carbon dioxide: a solvent like no other

• Jocelyn Peach and
• Julian Eastoe

Beilstein J. Org. Chem. 2014, 10, 1878–1895, doi:10.3762/bjoc.10.196

• food products [14] as well as already being an established system for numerous processes [16], including extractions [17], nanoparticle production and modification [18][19][20][21] and polymer processing [22][23][24][25]. Supercritical fluids also make appealing solvents due to the opportunities for

Synthesis of rigid p-terphenyl-linked carbohydrate mimetics

• Maja Kandziora and
• Hans-Ulrich Reissig

Beilstein J. Org. Chem. 2014, 10, 1749–1758, doi:10.3762/bjoc.10.182

• our group [24][25]. When they are coupled by amide bonds to gold nanoparticle and O-sulfated these conjugates gave extremely high binding affinities towards L- and P-selectin in sub-nanomolar concentrations. These results were achieved by a multivalent presentation (ca. 1000–1200 ligands per

• nanoparticle) of the sulfated pyrans [26][27]. We were therefore interested to prepare inhibitors offering only a small number of ligands to get better information about structure–activity relationships and to study the influence of the flexible and rigid spacer units. In this report we present methods for the

Multivalent scaffolds induce galectin-3 aggregation into nanoparticles

• Candace K. Goodman,
• Mark L. Wolfenden,
• Pratima Nangia-Makker,
• Anna K. Michel,
• Avraham Raz and
• Mary J. Cloninger

Beilstein J. Org. Chem. 2014, 10, 1570–1577, doi:10.3762/bjoc.10.162

• the CRD, the glycodendrimer complex would be expected to have a much smaller diameter than the observed values. Considering the large number of copies of dendrimer and protein that are required to form nanoparticle aggregates of the observed sizes, the aggregates are highly monodisperse. Although it

• formation of large, monodisperse nanoparticle aggregates from galectin-3/glycodendrimer solutions is as follows. The glycodendrimer serves to nucleate the aggregation process through the specific binding of lactose into the carbohydrate binding site on galectin-3. Binding of the carbohydrate into the

Glycosystems in nanotechnology: Gold glyconanoparticles as carrier for anti-HIV prodrugs

• Fabrizio Chiodo,
• Marco Marradi,
• Javier Calvo,
• Eloisa Yuste and
• Soledad Penadés

Beilstein J. Org. Chem. 2014, 10, 1339–1346, doi:10.3762/bjoc.10.136

• -containing glyconanoparticles were characterized and the pH-mediated release of the drug from the nanoparticle has been determined. The antiviral activity was tested by evaluating the replication of NL4-3 HIV in TZM-bl infected cells. The proof-of-principle presented in this work aims to introduce gold

• -GNPs [19][20]. The combination of the gold glyconanoparticle properties with the advantage of multiple presentations of drugs, opens-up the possibility for generating multivalent nano delivery systems against HIV, combining on the same nanoparticle scaffold different antiviral inhibitors. Further

Polyglycerol-functionalized nanodiamond as a platform for gene delivery: Derivatization, characterization, and hybridization with DNA

• Li Zhao,
• Yuki Nakae,
• Hongmei Qin,
• Tadamasa Ito,
• Takahide Kimura,
• Hideto Kojima,
• Lawrence Chan and
• Naoki Komatsu

Beilstein J. Org. Chem. 2014, 10, 707–713, doi:10.3762/bjoc.10.64

• further surface functionalization to add more functions to ND [14]. As for gene delivery, on the other hand, DNA was immobilized on the surface of nanoparticles mostly by electrostatic attraction between the negative charge of DNA and the positive charge on the surface of the nanoparticle [15]. In the

One-step synthesis of pyridines and dihydropyridines in a continuous flow microwave reactor

• Mark C. Bagley,
• Vincenzo Fusillo,
• Robert L. Jenkins,
• M. Caterina Lubinu and
• Christopher Mason

Beilstein J. Org. Chem. 2013, 9, 1957–1968, doi:10.3762/bjoc.9.232

• an encapsulated palladium catalyst by Baxendale and Ley, et al. [25], the latter to process multigram quantities in a microwave-assisted Suzuki–Miyaura coupling. A comparison on the use of palladium(0) nanoparticle catalysts on glass-polymer composite materials in batch and flow-through experiments