An overview of recent advances in duplex DNA recognition by small molecules

• Sayantan Bhaduri,
• Nihar Ranjan and
• Dev P. Arya

Beilstein J. Org. Chem. 2018, 14, 1051–1086, doi:10.3762/bjoc.14.93

• , thereby changing the efficiency of the FRET process between the two fluorophores and exhibiting a significant red shift in the emission spectrum. Moreover, the conjugate 43 could be used as an attractive tool for imaging of nuclear DNA in the cells due to its low cytotoxicity. A series of water-soluble

Polysubstituted ferrocenes as tunable redox mediators

• Sven D. Waniek,
• Jan Klett,
• Christoph Förster and
• Katja Heinze

Beilstein J. Org. Chem. 2018, 14, 1004–1015, doi:10.3762/bjoc.14.86

• for oxidation or reduction processes, respectively. This avoids the often kinetically hindered direct ET between electrode and substrate and diminishes overoxidation or overreduction of the substrate. Redox-active ferrocenyl derivatives find application in redox flow batteries [15], with water soluble

Nanoreactors for green catalysis

• M. Teresa De Martino,
• Loai K. E. A. Abdelmohsen,
• Floris P. J. T. Rutjes and
• Jan C. M. van Hest

Beilstein J. Org. Chem. 2018, 14, 716–733, doi:10.3762/bjoc.14.61

• encapsulated and the best results were achieved when the enzyme was in the lumen (Figure 3b), highlighting the advantage of enzyme compartmentalization and shielding. The explanation for this improved performance is the enlarged contact area between (hydrophobic) substrate and (water soluble) enzyme. Moreover

• . The utility of these dendrimers in hydrogenation reactions resulted in efficient reactions that proceeded with unprecedented selectivity of 99%. Moreover, this system is one of the first of bimetallic catalytic systems to be used for hydrogenation reactions in water. Water soluble dendrimer-stabilized

• (X = I or Br) in water [100]. Other examples of water-soluble dendrimers are peptide- and glycol-based dendrimers [102][103]. As a result of their compositional versatility, they have been reported in many applications for biomedical engineering (e.g., glycopeptide dendrimers for drug delivery [104

Heterogeneous Pd catalysts as emulsifiers in Pickering emulsions for integrated multistep synthesis in flow chemistry

• Katharina Hiebler,
• Georg J. Lichtenegger,
• Manuel C. Maier,
• Eun Sung Park,
• Renie Gonzales-Groom,
• Bernard P. Binks and
• Heidrun Gruber-Woelfler

Beilstein J. Org. Chem. 2018, 14, 648–658, doi:10.3762/bjoc.14.52

• stabilisation of dispersed drops in a continuous phase. In 2010, Crossley et al. [29] put forward the idea that catalyst particles may both act simultaneously as an emulsifier in Pickering emulsions and serve as the catalyst in which water-soluble reactants and oil-soluble reactants react at the oil–water

Enzyme-free genetic copying of DNA and RNA sequences

• Marilyne Sosson and
• Clemens Richert

Beilstein J. Org. Chem. 2018, 14, 603–617, doi:10.3762/bjoc.14.47

• , the 3'-amine was protected with an azidomethyloxycarbonyl (Azoc) protecting group. This protecting group can be rapidly removed under non-denaturing conditions after incorporation by the complementary nucleotide using the Staudinger reaction with a water-soluble phosphine (Figure 11). This protocol

• assay is another approach to avoid stalling due to inhibition. As mentioned in the Introduction, ligation reactions had been achieved by Naylor and Gilham in aqueous media in presence of a water-soluble carbodiimide as condensing reagent [7]. Likewise, Sulston et al. had used EDC to oligomerize AMP in

Stimuli-responsive oligonucleotides in prodrug-based approaches for gene silencing

• Françoise Debart,
• Christelle Dupouy and
• Jean-Jacques Vasseur

Beilstein J. Org. Chem. 2018, 14, 436–469, doi:10.3762/bjoc.14.32

Fluorogenic PNA probes

• Tirayut Vilaivan

Beilstein J. Org. Chem. 2018, 14, 253–281, doi:10.3762/bjoc.14.17

• oligonucleotides or analogues. One notable example is the use of a labeled PNA probe in combination with water-soluble cationic conjugated polyelectrolytes (CCP) for the FRET-based detection of DNA [114]. The CCP is typically an extended π-conjugated system, such as oligophenylene/fluorene with appending

Recent applications of click chemistry for the functionalization of gold nanoparticles and their conversion to glyco-gold nanoparticles

• Vivek Poonthiyil,
• Thisbe K. Lindhorst,
• Vladimir B. Golovko and
• Antony J. Fairbanks

Beilstein J. Org. Chem. 2018, 14, 11–24, doi:10.3762/bjoc.14.2

• acetylene-functionalized Thermomyces lanuginosus lipase was then attached to these azide-functionalized water-soluble AuNPs by CuAAC (Scheme 7). It was found that the enzyme retained its activity after the click reaction. However, the vast excesses of both Cu (a one million-fold excess relative to the azide

• catalyst. In order to circumvent this solubility problem, a homogenous water/THF solvent system was used, wherein a solution of the AuNPs in THF was added to either an aqueous solution containing water-soluble alkyne derivatives, or to a THF/water solution of organic soluble alkyne derivatives. The amount

• -AuNPs and ATT-AuNPs (Figure S3) are also provided in Supporting Information File 1. Whenever water-soluble ligands are used to perform exchange reactions on Cit-AuNPs, the wine-red colour of the AuNP solution (which corresponds to the dispersed state of the AuNPs as can be confirmed by TEM), and the SPR

Binding abilities of a chiral calix[4]resorcinarene: a polarimetric investigation on a complex case of study

• Marco Russo and
• Paolo Lo Meo

Beilstein J. Org. Chem. 2017, 13, 2698–2709, doi:10.3762/bjoc.13.268

• have also been studied as hydrogelators [22][23]. Moreover, water soluble chiral calix[4]resorcinarenes have been recently designed and used as chiral shift reagents for NMR applications [24][25][26][27]. The possibility to introduce chiral groups onto the CA scaffold is particularly intriguing from

Synthesis of naturally-derived macromolecules through simplified electrochemically mediated ATRP

• Paweł Chmielarz,
• Tomasz Pacześniak,
• Katarzyna Rydel-Ciszek,
• Izabela Zaborniak,
• Paulina Biedka and
• Andrzej Sobkowiak

Beilstein J. Org. Chem. 2017, 13, 2466–2472, doi:10.3762/bjoc.13.243

• ][36], and neurodegenerative diseases [27]. PtBA was selected as functional arm of polymer stars because it can be readily transformed to poly(acrylic acid) via deprotection, yielding polyelectrolytes. Such polymers are one of the most extensively studied, industrially important, water-soluble

Structural diversity in the host–guest complexes of the antifolate pemetrexed with native cyclodextrins: gas phase, solution and solid state studies

• Magdalena Ceborska,
• Magdalena Zimnicka,
• Aneta Aniela Kowalska,
• Kajetan Dąbrowa and
• Barbara Repeć

Beilstein J. Org. Chem. 2017, 13, 2252–2263, doi:10.3762/bjoc.13.222

• studied. Native CDs are water-soluble cyclic oligosaccharides, products of starch degradation, which contain six (α-CD), seven (β-CD) or eight glucopyranose units (γ-CD), accordingly, linked by α-1,4-glycosidic bonds (Figure 1b). They are toroid-like shaped and possess a cone-like hydrophobic cavity of

Phosphonic acid: preparation and applications

• Charlotte M. Sevrain,
• Mathieu Berchel,
• Hélène Couthon and
• Paul-Alain Jaffrès

Beilstein J. Org. Chem. 2017, 13, 2186–2213, doi:10.3762/bjoc.13.219

• water soluble catalysts [21], or to improve the water solubility of drug-chelate supramolecular assemblies (e.g., calixarene) [22][23]. The water solubility of phosphonic acid is strongly improved when the phosphonic acid is deprotonated (basic media). It is not rare to observe, when preparing NMR tubes

• with triphenylphosphine functionalized either by two or three phosphonic acid sodium salts; the former being more water soluble than the later [24]. This behavior is associated to the fact that the trisphosphonic acid sodium salt was already solvated at the solid state. The high polarity of the

• . First, a mechanochemical cracking yielded carboradical intermediates that were reacted with red phosphorus and then oxidized in the presence of air to produce graphene phosphonic acid 137 [116] (Figure 39). This material which is water soluble was used as a non-toxic flame-retardant. Conclusion

Superstructures with cyclodextrins: Chemistry and applications IV

• Gerhard Wenz

Beilstein J. Org. Chem. 2017, 13, 2157–2159, doi:10.3762/bjoc.13.215

• -dienes and bulky stoppers in the presence of CDs (so-called rotaxa-polymerization) was further applied for the syntheses of water-soluble polyisoprene polyrotaxanes [25]. Furthermore, ABA-type block-copolyrotaxanes could be synthesized using this polymerization technique controlled by RAFT chain transfer

Solid-state studies and antioxidant properties of the γ-cyclodextrin·fisetin inclusion compound

• Joana M. Pais,
• Maria João Barroca,
• Maria Paula M. Marques,
• Filipe A. Almeida Paz and
• Susana S. Braga

Beilstein J. Org. Chem. 2017, 13, 2138–2145, doi:10.3762/bjoc.13.212

• , neuroprotecting, and suppression or prevention of tumors. The present work describes the preparation of a water-soluble, solid inclusion compound of fisetin with gamma-cyclodextrin (γ-CD), a cyclic oligosaccharide approved for human consumption. A detailed physicochemical analysis of the product is carried out

• GRAS status (list of food additives that are ‘generally recognized as safe’) [9]. The present work describes the preparation of a water-soluble, solid inclusion compound of fisetin with γ-CD (see Scheme 1 for structure and atom labeling). The formation of the γ-CD·fisetin inclusion compound as a solid

An efficient Pd–NHC catalyst system in situ generated from Na₂PdCl₄ and PEG-functionalized imidazolium salts for Mizoroki–Heck reactions in water

• Nan Sun,
• Meng Chen,
• Liqun Jin,
• Wei Zhao,
• Baoxiang Hu,
• Zhenlu Shen and
• Xinquan Hu

Beilstein J. Org. Chem. 2017, 13, 1735–1744, doi:10.3762/bjoc.13.168

• materials via a simple method. Their corresponding water soluble Pd–NHC catalysts, in situ generated from the imidazolium salts L1–L3 and Na2PdCl4 in water, showed impressive catalytic activity for aqueous Mizoroki–Heck reactions. The kinetic study revealed that the Pd catalyst derived from the imidazolium

• –Pd bonds under aqueous reaction conditions often restricted the reuse of the catalyst and led to undesired residues. Therefore, in recent years, efforts have been turned to the development of water-soluble non-phosphine ligands [28][29][30][31][32][33][34]. In this context, N-heterocyclic carbenes

• functionalization of the N atom of the NHC ring allows for the possible incorporation of water soluble moieties, thus providing more opportunities for water soluble catalyst design [37][38][39]. Since the pioneering report of a sulfonate-functionalized NHC ligand by Shaughnessy [40], a number of water-soluble NHC

Molecular recognition of N-acetyltryptophan enantiomers by β-cyclodextrin

• Spyros D. Chatziefthimiou,
• Mario Inclán,
• Petros Giastas,
• Athanasios Papakyriakou,
• Konstantina Yannakopoulou and
• Irene M. Mavridis

Beilstein J. Org. Chem. 2017, 13, 1572–1582, doi:10.3762/bjoc.13.157

• structure; Introduction Cyclodextrins (CDs) are cyclic, water-soluble carbohydrates with a rather non-polar cavity that can host a variety of organic molecules (guests) and form inclusion complexes [1]. The guest molecules may be completely or partly enclosed inside the cavity depending on their size and

One-pot synthesis of block-copolyrotaxanes through controlled rotaxa-polymerization

• Jessica Hilschmann,
• Gerhard Wenz and
• Gergely Kali

Beilstein J. Org. Chem. 2017, 13, 1310–1315, doi:10.3762/bjoc.13.127

• other polymerization techniques, such as atom transfer radical polymerization, because of the lack of toxic metal additives, and because of good control exerted in aqueous solution. The water-soluble bifunctional CTA S,S′-bis(α,α′-dimethyl-α′′-acetic acid)trithiocarbonate (DMATC) was selected because it

• polyrotaxane synthesis since it is highly water-soluble and provides a sufficiently high binding constant for isoprene [24][25]. Results and Discussion In a first trial, statistical RAFT copolymerization of isoprene complexed in RAMEB was performed with water-soluble bulky comonomers, namely N-[tris

Kinetic analysis of mechanoradical formation during the mechanolysis of dextran and glycogen

• Naoki Doi,
• Yasushi Sasai,
• Yukinori Yamauchi,
• Tetsuo Adachi,
• Masayuki Kuzuya and
• Shin-ichi Kondo

Beilstein J. Org. Chem. 2017, 13, 1174–1183, doi:10.3762/bjoc.13.116

• disclosed the formation of polystyrene on the cotton [18]. In a previous paper, we reported the synthesis of water-soluble graft polymeric prodrugs through the mechanochemical reaction of HEC and methacryloyl derivatives of 5-fluorouracil [19]. We also discussed the nature of drug release from the polymeric

Interactions between shape-persistent macromolecules as probed by AFM

• Johanna Blass,
• Jessica Brunke,
• Franziska Emmerich,
• Cédric Przybylski,
• Vasil M. Garamus,
• Artem Feoktystov,
• Roland Bennewitz,
• Gerhard Wenz and
• Marcel Albrecht

Beilstein J. Org. Chem. 2017, 13, 938–951, doi:10.3762/bjoc.13.95

• -Str. 1, 21502 Geesthacht, Germany Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ), Forschungszentrum Jülich GmbH, Lichtenbergstr. 1, 85748 Garching, Germany 10.3762/bjoc.13.95 Abstract Water-soluble shape-persistent cyclodextrin (CD) polymers with amino-functionalized

• than one polymer molecule might be involved. Conclusion In conclusion, regular water-soluble shape-persistent CD polymers based on poly(phenylene butadiynylene) were prepared by a straightforward Glaser coupling/click chemistry approach, which can be attached to planar silicon surfaces as well as AFM

The effect of cyclodextrin complexation on the solubility and photostability of nerolidol as pure compound and as main constituent of cabreuva essential oil

• Joyce Azzi,
• Pierre-Edouard Danjou,
• David Landy,
• Steven Ruellan,
• Lizette Auezova,
• Hélène Greige-Gerges and
• Sophie Fourmentin

Beilstein J. Org. Chem. 2017, 13, 835–844, doi:10.3762/bjoc.13.84

• their high potential to solubilize, stabilize and protect flavors and food ingredients [10][11][12][13]. CDs are non-toxic water-soluble cyclic oligosaccharides composed of six, seven or eight α-(1→4) glucopyranose units giving rise, respectively, to α-, β- and γ-CDs [14]. Their most notable

• characteristic is their ability to form inclusion complexes with poorly soluble guest molecules which are entrapped in the hydrophobic cavity of CDs. Chemical modifications of the hydroxy groups of CDs can be performed to obtain water-soluble CD derivatives like hydroxypropyl-β-CD (HP-β-CD), methylated CDs

Fluorescent carbon dots from mono- and polysaccharides: synthesis, properties and applications

• Stephen Hill and
• M. Carmen Galan

Beilstein J. Org. Chem. 2017, 13, 675–693, doi:10.3762/bjoc.13.67

• our knowledge, the first reported example involving a carbohydrate moiety (Scheme 1) [18]. The water-soluble nanoparticles exhibited an amorphous core, as deduced by X-ray diffraction (XRD), while Fourier-transformed infrared (FTIR) spectroscopy analysis indicated the presence of a range of oxygen

• ideal balance of cation and anion valence was found when using CuSO4 which afforded CDs with QY of up to 9.5%, in-line with the state-of-the-art at the time. As an alternative, Kang et al. showed the following year that nitrogen-doped water-soluble fluorescent CDs could be afforded in a one-step

• hydrophobic red fluorescent CDs via surface passivation and polymer coating, in which hydrophilic anhydride groups of the polymer can react with PEG-diamine, via a ring-opening to afford a free acid and an amide-linked SPA, lead to water-soluble CDs ready for bio-labelling applications. The CDs were then

Continuous-flow synthesis of highly functionalized imidazo-oxadiazoles facilitated by microfluidic extraction

• Ananda Herath and
• Nicholas D. P. Cosford

Beilstein J. Org. Chem. 2017, 13, 239–246, doi:10.3762/bjoc.13.26

• demonstrated that a liquid–liquid microextraction unit can be utilized to remove high polar water soluble solvents and impurities from products. This scalable method provides the desired oxadiazole derivatives at a rate of ≈0.5 g/h and represents a significant advantage over batch synthesis. We anticipate that

Interactions between photoacidic 3-hydroxynaphtho[1,2-b]quinolizinium and cucurbit[7]uril: Influence on acidity in the ground and excited state

• Jonas Becher,
• Daria V. Berdnikova,
• Darinka Dzubiel,
• Heiko Ihmels and
• Phil M. Pithan

Beilstein J. Org. Chem. 2017, 13, 203–212, doi:10.3762/bjoc.13.23

• cavity. In contrast, if the hydroxy group of the ligand points far outside the binding pocket of CB[7] the ESPT is comparable to the one observed with the non-complexed ligand [28]. Recently, we discovered that the 8-hydroxybenzo[b]quinolizinium ion (1a, Figure 1) represents an efficient water-soluble

• derivatives may be modulated by supramolecular interactions. Considering the ability of this class of compounds to operate as DNA-binding ligands [56] or water-soluble chemosensors [57], we anticipate that the combination of these properties with the potential for modulation by host–guest assembly may widen

Dynamics and interactions of ibuprofen in cyclodextrin nanosponges by solid-state NMR spectroscopy

• Monica Ferro,
• Franca Castiglione,
• Nadia Pastori,
• Carlo Punta,
• Lucio Melone,
• Walter Panzeri,
• Barbara Rossi,
• Francesco Trotta and
• Andrea Mele

Beilstein J. Org. Chem. 2017, 13, 182–194, doi:10.3762/bjoc.13.21

• . Ibuprofen is the API of many nonsteroidal anti-inflammatory formulations widely used in the treatment of fever, rheumatoid arthritis and other inflammatory diseases [10]. From the chemical viewpoint, ibuprofen is the (RS)-2-(4-(2-methylpropyl)phenyl)propanoic acid. Its sodium salt is water-soluble and

A new class of organogelators based on triphenylmethyl derivatives of primary alcohols: hydrophobic interactions alone can mediate gelation

• Wangkhem P. Singh and
• Rajkumar S. Singh

Beilstein J. Org. Chem. 2017, 13, 138–149, doi:10.3762/bjoc.13.17

• the gel were carried out using scanning electron microscopy, FTIR spectroscopy, rheology and powder XRD techniques. This gel also showed a good absorption profile for a water soluble dye. Given the non-polar nature of this molecule, gel formation is likely to be mediated by hydrophobic interactions

• industries. But most of these dyes are toxic and harmful to the environment. Discharge of waste water generated during use of these water-soluble dyes without proper pretreatment creates a serious environmental and health hazard. Hence, development of simple and reliable methods to remove dyes from the

• [38][39]. Hence, small molecules based molecular gels have recently emerged as a new class of materials which can be used in the removal of water-soluble toxic dyes. We reasoned that TPM-G12 gel (being non-polar) can perhaps be utilized for removal of water-soluble dyes having appreciable hydrophobic