Radical polymerization by a supramolecular catalyst: cyclodextrin with a RAFT reagent

• Kohei Koyanagi,
• Yoshinori Takashima,
• Takashi Nakamura,
• Hiroyasu Yamaguchi and
• Akira Harada

Beilstein J. Org. Chem. 2016, 12, 2495–2502, doi:10.3762/bjoc.12.244

• β-CD cavity of β-CD-CTA was capped by the CTA unit, inhibiting the molecular recognition property. Crystal structure of the α-CD-DMA and β-CD-DMA complexes We chose N,N-dimethylacrylamide (DMA), acrylic acid (AA), and acrylamide (AAm) as water-soluble vinyl monomers for radical polymerization. Prior

• result in a precipitate, indicating that the affinities of the CDs for AAm were low. Polymerization of vinyl monomers mediated by α-CD-CTA α-CD-CTA-mediated polymerizations of water-soluble vinyl monomers were performed in aqueous media, where the strong molecular recognition property of α-CD is expected

• due to the hydrophobic effect. As a water-soluble radical initiator, we selected 2,2'-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride (VA-044). Two hundred equivalents (equiv) of monomers, 1 equiv of α-CD-CTA, and 0.4 equiv of VA-044 were mixed in water (monomer: 1 mol/kg). After the reactants

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

• this investigation is also presented here in form of simple profile plots. Effect of reaction pH, temperature and flow rate on the reaction conversion Azo coupling reactions involving aromatic amines as coupling agents are carried out in mildly acidic conditions such that a water-soluble protonated

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

• properties leading to a host–guest relationship with organic substances [6][7][8][9]. These cyclic oligosaccharides are water soluble in their native form and are often modified to prepare novel insoluble CD-based materials. Two patents published by Martel et al. [10], and Trotta et al. [11] can be consulted

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

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

• external regulation [4]. I also took on a brutal project, focused on the synthesis of water-soluble analogs of Kemp's triacid. This project was a massive effort, with a huge number of reactions required to optimize the initial steps. We did, however, obtain the desired receptors and observe some

Mutagenic activity of quaternary ammonium salt derivatives of carbohydrates

• Barbara Dmochowska,
• Karol Sikora,
• Anna Woziwodzka,
• Jacek Piosik and
• Beata Podgórska

Beilstein J. Org. Chem. 2016, 12, 1434–1439, doi:10.3762/bjoc.12.138

• design the QAS. All the newly synthesized N-[6-(β-D-glucopyranosyloxy)hexyl]ammonium bromides were water soluble. The identities of all compounds were confirmed by 1H and 13C NMR. Mutagenic activity of QAS QASs are generally recognized as safe compounds. Nevertheless, considering our previous

Synthesis, fluorescence properties and the promising cytotoxicity of pyrene–derived aminophosphonates

• Jarosław Lewkowski,
• Maria Rodriguez Moya,
• Anna Wrona-Piotrowicz,
• Janusz Zakrzewski,
• Renata Kontek and
• Gabriela Gajek

Beilstein J. Org. Chem. 2016, 12, 1229–1235, doi:10.3762/bjoc.12.117

• corresponding aminophosphonate was earlier reported [29]. The aforementioned data suggest possible application of compound 3Aj (and other exhibiting similar emission quantum yield) as molecular probes monitoring micropolarity of the fluorophore environment. On the other hand, water-soluble 4a might be used for

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

• clusters of smaller units. These aggregates were soluble in water due to water soluble PDMAEMA chains. The aggregates were also stable enough because the incorporated HBPS segment is an excellent hydrophobic polymeric chain. To further investigate the behavior of HBPS-g-PDMAEMA aggregates in water, DLS

From steroids to aqueous supramolecular chemistry: an autobiographical career review

• Bruce C. Gibb

Beilstein J. Org. Chem. 2016, 12, 684–701, doi:10.3762/bjoc.12.69

• were working in organic solvents, not water. Throughout my career, water had been just under the surface of all my research endeavors: I had been working towards water-soluble cavitands and making four-helix bundles that assembled via the hydrophobic effect at UBC, I had been working with water-soluble

• zinc complexes at NYU; even non-water-soluble steroids rely in part on the hydrophobic effect to bind. The common denominator was water, “the solvent of life”. However, although we understand water quite well, we are far from fully understanding aqueous solutions [29][30], and to be frank, it’s hard to

• contribute to this understanding if you are working in chloroform. Something had to be done. We examined several approaches to making deep-cavity cavitands water-soluble, but the one that worked best led to what has been commonly called octa-acid (Figure 5) [31][32]. Now we had a host that: 1) was evenly

Elucidation of a masked repeating structure of the O-specific polysaccharide of the halotolerant soil bacteria Azospirillum halopraeferens Au4

• Elena N. Sigida,
• Yuliya P. Fedonenko,
• Alexander S. Shashkov,
• Nikolay P. Arbatsky,
• Evelina L. Zdorovenko,
• Svetlana A. Konnova,
• Vladimir V. Ignatov and
• Yuriy A. Knirel

Beilstein J. Org. Chem. 2016, 12, 636–642, doi:10.3762/bjoc.12.62

• carbohydrate and glycolipid parts [15] followed by fractionation of the released water-soluble carbohydrate portion by Sephadex G-50 Superfine size-exclusion chromatography. It was demonstrated that the OPS contained 2-O-methyl-6-deoxyhexose, L-rhamnose (Rha), D-fucose (Fuc), D-xylose (Xyl), and D-glucose (Glc

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

New synthetic strategies for xanthene-dye-appended cyclodextrins

• Milo Malanga,
• Andras Darcsi,
• Mihaly Balint,
• Gabor Benkovics,
• Tamas Sohajda and
• Szabolcs Beni

Beilstein J. Org. Chem. 2016, 12, 537–548, doi:10.3762/bjoc.12.53

• compound possesses advantageous properties as it can be prepared in gram scale from inexpensive reagents, it is stable in air, it does not adsorb water, and the water soluble co-products formed during the coupling reaction can be easily removed from the reaction crude. All these characteristics make DMT-MM

Regiodefined synthesis of brominated hydroxyanthraquinones related to proisocrinins

• Joyeeta Roy,
• Tanushree Mal,
• Supriti Jana and
• Dipakranjan Mal

Beilstein J. Org. Chem. 2016, 12, 531–536, doi:10.3762/bjoc.12.52

• inhibitory activity against human tumor cell lines SF-268, MCF-7, and NCI-H460, with IC50 values of 7.11, 6.64, and 7.42 μM, respectively [12]. Proisocrinins A–F (6–11), recently isolated from the stalked crinoid Proisocrinus ruberrimus (Figure 1) are the first water soluble natural anthraquinone pigments

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

• esterification of CD was promoted by MW irradiation, while the chitosan coupling used a water-soluble carbodiimide, N-(3-dimethylaminopropyl)-N-ethylcarbodiimide hydrochloride, under US. A mild sonication at rt using HDI enabled efficient CDs reticulation in the presence of lipases (Scheme 7) whose biocatalytic

• substances and to improve the aqueous solubility of poorly water-soluble molecules. α-, β- and γ-CDs were reacted solventless with diphenyl carbonate or carbonyldiimidazole under US (up to 90 °C). These nanosponges may resolve some active ingredients drawbacks, such as instability, degradation, poor

A journey in bioinspired supramolecular chemistry: from molecular tweezers to small molecules that target myotonic dystrophy

• Steven C. Zimmerman

Beilstein J. Org. Chem. 2016, 12, 125–138, doi:10.3762/bjoc.12.14

• ” chromophores obeying the NEP), were an obvious attempt to provide water solubility to a highly aromatic structure. In Roger Adams’ Laboratory, Craig Vanzyl, Greg Hamilton, and I were able to prepare molecular tweezer 4 and several substituted analogs, but none that were water soluble [9][10]. Fortunately, the

• were reported many years ago. Were the water-soluble tweezers we set out to prepare in 1985 ever made? Where does the field stand today? We found that our molecular tweezers are well preorganized for dimerization, limiting their use in water [22], whereas Klärner and colleagues discovered that their

• tweezers 19 and 20 are water-soluble but tend not to self-associate [33]. This has allowed their use in a range of biomolecular recognition applications, which appear quite promising. For example, tweezer 20, also called CLR01, has been found to bind the accessible lysine and arginine groups of proteins

Supramolecular polymer assembly in aqueous solution arising from cyclodextrin host–guest complexation

• Jie Wang,
• Zhiqiang Qiu,
• Yiming Wang,
• Li Li,
• Xuhong Guo,
• Duc-Truc Pham,
• Stephen F. Lincoln and
• Robert K. Prud’homme

Beilstein J. Org. Chem. 2016, 12, 50–72, doi:10.3762/bjoc.12.7

• outline of the annulus is shown for uniformity and simplicity in this review.) Review 1 Host–guest complexation between cyclodextrins and guest-substituted polymers 1.1 Modulation of hydrophobic interactions Hydrophobic interactions of water soluble polymers substituted with either terminal hydrophobic

• guests in aqueous solution may be used to greatly extend supramolecular and polymer chemistry when cyclodextrins and hydrophobes are substituted onto water-soluble polymer backbones. The host–guest complexes formed between the cyclodextrin and hydrophobic substituents represent very specific interactions

• chain such that the uncomplexed portions of the PEG chains are too short for significant interchain interaction to form a water soluble network [82][86][88]. However, when a hydrophobic adamantyl group is substituted onto one end of a low molecular weight PEG chain to form amphiphilic AD-PEG, it is

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

• pharmaceutical, medicine, cosmetics, food and agriculture [29]. β-CD and its derivatives have been widely used to increase the water solubility, stability, and consequent bioavailability of poorly water soluble drugs [30][31][32], such as β-CD in complex with piroxicam [33] and etodolac [34] and DM-β-CD in

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

• norbornene monomer (27) functionalized with a water-soluble bis(terpyridine)ruthenium(II) complex, with dicyclopentadiene as a cross-linking agent (Scheme 12). In the resulted copolymer 28 each Ru complex is associated with two counteranions (chloride), which represents a novelty versus most cation-based

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

• a remarkable self-assembly process that we call Synthavidin (synthetic avidin). A simple example is illustrated in Scheme 5 [44]. A water soluble tetralactam macrocycle with anthracene sidewalls is threaded by squaraine dyes that are flanked by long PEG chains to give highly stable complexes with

Continuous formation of N-chloro-N,N-dialkylamine solutions in well-mixed meso-scale flow reactors

• A. John Blacker and
• Katherine E. Jolley

Beilstein J. Org. Chem. 2015, 11, 2408–2417, doi:10.3762/bjoc.11.262

• product from the water soluble NaOH (Scheme 1). Such separation of biphasic mixtures is known in continuous systems, for example membrane-based separators [26][27]. Mixing is a key parameter for reactions in multiphasic systems and characterisation of material flows within different continuous reactors is

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

• crosslinker/DM-β-CD feed ratio = 3/1). The resulting crosslinked DM-β-CD/PDI polymer is water soluble. The polymer product was purified by dialysis (molecular weight cut off = 10,000) against water. A powder of the DM-β-CD/PDI polymer obtained by freeze-drying was easily redispersed in water with the aid of

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

• be seen from Table 7, catalyst 108c, bearing a water-soluble tag, is active in D2O and in water/methanol mixtures under air and the presence of the tag does not influence the reactivity. Although high conversions were obtained, high catalyst loadings (5–10 mol %) of all catalysts were required. In

Hexacoordinate Ru-based olefin metathesis catalysts with pH-responsive N-heterocyclic carbene (NHC) and N-donor ligands for ROMP reactions in non-aqueous, aqueous and emulsion conditions

• Shawna L. Balof,
• K. Owen Nix,
• Matthew S. Olliff,
• Sarah E. Roessler,
• Arpita Saha,
• Kevin B. Müller,
• Ulrich Behrens,
• Edward J. Valente and
• Hans-Jörg Schanz

Beilstein J. Org. Chem. 2015, 11, 1960–1972, doi:10.3762/bjoc.11.212

• capacity make organic transformations using hydrophilic catalyst in aqueous media very attractive [14][15][16][17][18]. These benefits, coupled with potential applications in biological media [19], have led to the development of various water-soluble catalyst designs [20][21]. Such catalysts contain

• ][51][52][53] and/or solubilization [31][32] in aqueous media. One of the most intriguing applications of water-soluble metathesis catalysts is the production of latexes via ring-opening metathesis polymerization (ROMP) in emulsion. However, to date very few reports have successfully employed well

• develop water-soluble catalyst systems which can perform the task with high activity, substrate range and sufficient hydrolytic stability to access a variety of novel ROMP latexes. We now wish to report the synthesis of two new pH-responsive, Ru-based olefin metathesis catalysts, their ROMP and ring

Effective ascorbate-free and photolatent click reactions in water using a photoreducible copper(II)-ethylenediamine precatalyst

• Redouane Beniazza,
• Natalia Bayo,
• Florian Molton,
• Carole Duboc,
• Stéphane Massip,
• Nathan McClenaghan,
• Dominique Lastécouères and
• Jean-Marc Vincent

Beilstein J. Org. Chem. 2015, 11, 1950–1959, doi:10.3762/bjoc.11.211

• water in the absence of sodium ascorbate is an active area of current research with strong potential for applications in bioconjugation. The water-soluble and photoreducible copper(II)–EDA (EDA = ethylenediamine) complex 1, which has two 4-benzoylbenzoates acting as both counterion and photosensitizer

• photoreduced in water when alkynes were present in solution. The catalytic activity of 1 for click reactions involving a range of water-soluble alkynes and azides, in particular saccharides, was tested under various illumination conditions. Complex 1 was found to exhibit a photolatent character, the

• . A major application of the CuAAC concerns bioconjugation reactions, i.e., the covalent modification of biomolecules [6]. Such reactions typically imply water-soluble alkyne and azide reactants and should thus be performed in an aqueous medium using a water-soluble catalyst. Important limitations for

Antioxidant potential of curcumin-related compounds studied by chemiluminescence kinetics, chain-breaking efficiencies, scavenging activity (ORAC) and DFT calculations

• Adriana K. Slavova-Kazakova,
• Silvia E. Angelova,
• Timur L. Veprintsev,
• Petko Denev,
• Davide Fabbri,
• Maria Antonietta Dettori,
• Maria Kratchanova,
• Vladimir V. Naumov,
• Aleksei V. Trofimov,
• Rostislav F. Vasil’ev,
• Giovanna Delogu and
• Vessela D. Kancheva

Beilstein J. Org. Chem. 2015, 11, 1398–1411, doi:10.3762/bjoc.11.151

• respect to the studied monomers/dimers were encountered. The latter observation may be accounted for by a solvating effect of water derived from hydrogen bonding between the OH groups and water molecules. In contrast to models 1 and 2, where 11 is the best antioxidant, in model 3 the water soluble