Tetrathiafulvalene-based azine ligands for anion and metal cation coordination

• Awatef Ayadi,
• Aziz El Alamy,
• Olivier Alévêque,
• Magali Allain,
• Nabil Zouari,
• Mohammed Bouachrine and
• Abdelkrim El-Ghayoury

Beilstein J. Org. Chem. 2015, 11, 1379–1391, doi:10.3762/bjoc.11.149

• N3–H3···O1 hydrogen bonding. Titration experiments with inorganic anions showed that both ligands are suitable candidates for the sensing of fluoride anions. Ligand L2 was reacted with a Re(I) cation to yield the corresponding rhenium tricarbonyl complex 3. In the crystal structure of the newly

• prepared electroactive rhenium complex the TTF is neutral and the rhenium cation is hexacoordinated. The electrochemical behavior of the three compounds indicates that they are promising for the construction of crystalline radical cation salts. Keywords: azine ligand; fluoride sensing; rhenium

• -responsive receptors for neutral and/or charged guest sensing applications have been prepared [18][19][20][21][22]. On this ground, chemosensors capable of recognizing anionic and/or cationic species constitute an important area of increasing research in supramolecular chemistry, considering the ubiquitous

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

• controlled assembly of nanoparticles by means of biomolecules is crucial for biological and medical applications such as sensing [4], bioimaging [5], and medical diagnostics [6]. Although nanoparticles are also applied as targeted biomarkers and drug-delivery agents to tumor cells [7], only very little is

Design, synthesis and photochemical properties of the first examples of iminosugar clusters based on fluorescent cores

• Mathieu L. Lepage,
• Antoine Mirloup,
• Manon Ripoll,
• Fabien Stauffert,
• Anne Bodlenner,
• Raymond Ziessel and
• Philippe Compain

Beilstein J. Org. Chem. 2015, 11, 659–667, doi:10.3762/bjoc.11.74

• ][44][45][46][47]. We have recently argued the case that the fluoro-substitution of boraindacene was a mean to considerably increase the solubility, the stability and the steric hindrance avoiding the formation of aggregates [48]. In some cases, special sensing properties [49] may be induced by

Fluoride-driven ‘turn on’ ESPT in the binding with a novel benzimidazole-based sensor

• Kai Liu,
• Xiaojun Zhao,
• Qingxiang Liu,
• Jianzhong Huo,
• Bolin Zhu and
• Shihua Diao

Beilstein J. Org. Chem. 2015, 11, 563–567, doi:10.3762/bjoc.11.61

• recognition and sensing, was suggested to be responsible for the fluorescence enhancement with a blue shift of 35 nm in the emission spectrum. Keywords: anion recognition; deprotonation; ESPT; fluoride; ‘turn on’ fluorescence; Introduction Design and synthesis of selective and efficient sensors for various

• anions involved in biological, industrial and environmental processes have drawn a lot of attention [1][2][3]. In recent years, much effort has been devoted to the development of anion fluorescent sensors [4]. Of particular interest concerning anion recognition and sensing was fluoride [5][6][7], as it

• proton transfer (ESPT), as an extensively exploited mechanism in many biological and chemical processes, has been employed poorly in anion recognition and sensing [2][11][12][13][14][15][16]. In the ESPT molecules, a five or six-membered intramolecular hydrogen-bonded ring formed, and a proton/hydrogen

Electrochemical oxidation of cholesterol

• Jacek W. Morzycki and
• Andrzej Sobkowiak

Beilstein J. Org. Chem. 2015, 11, 392–402, doi:10.3762/bjoc.11.45

• of sensing, which have a distinct advantage over conventional enzymatic processes, have recently been developed. Some of these methods are based on the indirect electrochemical oxidation of cholesterol by using bromine species in organic media [69][70]. In a recent method, methylene blue formed an

• inclusion complex with β-cyclodextrin functionalized graphene and emerged as a cholesterol sensing matrix. Methylene blue was then replaced by the cholesterol molecule and moved out in the buffer solution, where it was detected electrochemically by using the differential pulse voltammetric technique [71

• design of mixed biocatalyst pathways for the comprehensive oxidation of cholesterol, and, at the same time, the acquisition of frequent answers with an individual application for biosensorics is of major interest. Sophisticated sensing arrangements including single and complex selective agents may be

Synthesis and chemosensing properties of cinnoline-containing poly(arylene ethynylene)s

• Natalia A. Danilkina,
• Petr S. Vlasov,
• Semen M. Vodianik,
• Andrey A. Kruchinin,
• Yuri G. Vlasov and
• Irina A. Balova

Beilstein J. Org. Chem. 2015, 11, 373–384, doi:10.3762/bjoc.11.43

• type of response, conjugated polymers for sensing are termed as amplifying fluorescent polymers (AFPs) [4]. The mechanism of the response amplification can be explained in terms of the "molecular wire" concept [2][3][4][5][6][7][8][9]. Binding of a single analyte molecule to a single recognition site

• . Such materials find widespread use in sensing of metal ions and anions, detection of explosives and various biomolecules [2−4]. Among the great variety of known conjugated polymers, poly(arylene ethynylene)s (PAEs) are one of the most promising materials in the search for new chemical sensors [7]. A

• wide range of PAEs has been developed in the last decade [2][3][4], for example polymers with ether, ester or carboxylic acid functions [11] and N-containing heterocyclic scaffolds [12] for metal ion sensing; polymers with polycyclic aromatics and rigid groups for the detection of explosives [13]; and

Efficient deprotection of F-BODIPY derivatives: removal of BF₂ using Brønsted acids

• Mingfeng Yu,
• Joseph K.-H. Wong,
• Cyril Tang,
• Peter Turner,
• Matthew H. Todd and
• Peter J. Rutledge

Beilstein J. Org. Chem. 2015, 11, 37–41, doi:10.3762/bjoc.11.6

• derivatives incorporating fluorescent dyes for sensing applications [22][23][24][25]. Looking to extend these systems to incorporate an F-BODIPY motif, we have synthesized the Boc-protected triazolyl-cyclam/F-BODIPY derivatives 3 and 4 from 2,4-dimethyl-1H-pyrrole (5), 4-nitrobenzaldehyde (6, Scheme 2A) and 4

Come-back of phenanthridine and phenanthridinium derivatives in the 21st century

• Lidija-Marija Tumir,
• Marijana Radić Stojković and
• Ivo Piantanida

Beilstein J. Org. Chem. 2014, 10, 2930–2954, doi:10.3762/bjoc.10.312

• within the grooves finely tuned the recognition between various ds-polynucleotides. The sensitivity of spectroscopic response was particularly pronounced for ss-RNA, whereby at weakly acidic pH compound 8 exhibited specific fluorimetric sensing of poly(G) among other studied ss-polynucleotides. Cyclic

• the thermal denaturation and ICD signal-based sensing was highly sensitive to the polynucleotide basepair composition and secondary structure [76]. However, the low solubility of the studied systems hampered NMR studies and the very complex set of possible interactions did not allow accurate

Synthesis and biological evaluation of novel N-α-haloacylated homoserine lactones as quorum sensing modulators

• Michail Syrpas,
• Ewout Ruysbergh,
• Christian V. Stevens,
• Norbert De Kimpe and
• Sven Mangelinckx

Beilstein J. Org. Chem. 2014, 10, 2539–2549, doi:10.3762/bjoc.10.265

• atom was introduced at the α-position of the carbonyl function of the N-acyl chain, have been studied as quorum sensing (QS) modulators and compared with a library of natural N-acylated homoserine lactones (AHLs). The series of novel analogues consists of α-chloro, α-bromo and α-iodo AHL analogues

• ; N-α-haloacylated homoserine lactones; quorum sensing; Introduction Quorum sensing (QS) is the communication system used by bacteria allowing them to adapt to their environment [1]. Bacteria relying on QS secrete signal molecules, called autoinducers, in order to control the expression of specific

• target genes important for phenotype expression (e.g., biofilm formation, bioluminescence, virulence expression, etc.) in a population density dependent manner [2]. The importance of QS for virulence development in pathogenic bacteria nowadays is obvious [3]. Therefore, quorum sensing modulation is seen

Host–guest-driven color change in water: influence of cyclodextrin on the structure of a copper complex of poly((4-hydroxy-3-(pyridin-3-yldiazenyl)phenethyl)methacrylamide-co-dimethylacrylamide)

• Nils Retzmann,
• Gero Maatz and
• Helmut Ritter

Beilstein J. Org. Chem. 2014, 10, 2480–2483, doi:10.3762/bjoc.10.259

• of CD–dye hydrogels by addition of metal ions, as well as the sensing of copper ions using cyclodextrin–dye rotaxane [10][11]. Herewith we thus wish to describe our recent results about the synthesis of a water-soluble polymer bearing a novel azo dye and the presumed formation of complexes with Cu

Synthesis and optical properties of pyrrolidinyl peptide nucleic acid carrying a clicked Nile red label

• Nattawut Yotapan,
• Chayan Charoenpakdee,
• Pawinee Wathanathavorn,
• Boonsong Ditmangklo,
• Hans-Achim Wagenknecht and
• Tirayut Vilaivan

Beilstein J. Org. Chem. 2014, 10, 2166–2174, doi:10.3762/bjoc.10.224

• emission wavelengths, and solvatochromic properties [10]. Applications of Nile red as a staining dye in histology [11][12] and as a probe for the sensing of polarity and hydrophobicity [13] are well-known. Nile red has been used as a DNA label, either as a base modifier [14][15][16], a base replacement [17

• shows several unique properties [26][27][28]. Its potential applications as a probe for DNA sensing are well-established. For example, we have developed singly labeled acpcPNA probes that can give a fluorescence change in response to hybridization to DNA [29][30][31]. Due to its solvatochromic

Photoswitchable precision glycooligomers and their lectin binding

• Daniela Ponader,
• Sinaida Igde,
• Marko Wehle,
• Katharina Märker,
• Mark Santer,
• David Bléger and
• Laura Hartmann

Beilstein J. Org. Chem. 2014, 10, 1603–1612, doi:10.3762/bjoc.10.166

• potential perspectives for the sensing and adhesion of bacteriological targets on various substrates. The examples reported so far make use of azobenzene [16], a well-known photochromic compound offering robustness and straightforward preparation. It is able to reversibly isomerize between an extended and

• . Therefore we will further explore our photoswitchable glycooligomers as tunable glycomimetic ligands and their potential for a variety of biotechnological and biomedical applications such as the sensing and isolation of bacteria as well as the development of antibacterial treatments. Experimental AZO

Pyrene-modified PNAs: Stacking interactions and selective excimer emission in PNA₂DNA triplexes

• Alex Manicardi,
• Lucia Guidi,
• Alice Ghidini and
• Roberto Corradini

Beilstein J. Org. Chem. 2014, 10, 1495–1503, doi:10.3762/bjoc.10.154

• units on stability and sensing According to the occurrence of excimer bands in the fluorescence spectra of the PNA probes (Figure 2 and Figure 4) the presence of pyrene favours self-association of two PNA strands; strong interactions should be observed for PNA2–5 and even stronger for PNA6, i.e., with

Molecular recognition of surface-immobilized carbohydrates by a synthetic lectin

• Melanie Rauschenberg,
• Eva-Corrina Fritz,
• Christian Schulz,
• Tobias Kaufmann and
• Bart Jan Ravoo

Beilstein J. Org. Chem. 2014, 10, 1354–1364, doi:10.3762/bjoc.10.138

• as drugs in various therapies and as recognition units in diagnostics and sensing. However, the development of synthetic lectins poses a phenomenal challenge for supramolecular chemistry [37] because a carbohydrate receptor in order to be useful must not only compete with the strong hydration of

• water with excellent selectivity versus other simple carbohydrates (for example, ~50:1 versus galactose) which also has sufficient affinity for glucose sensing at the concentrations found in blood [38]. On the other hand, we have described a dynamic combinatorial approach to the identification of

Homochiral BINOL-based macrocycles with π-electron-rich, electron-withdrawing or extended spacing units as receptors for C₆₀

• Marco Caricato,
• Silvia Díez González,
• Idoia Arandia Ariño and
• Dario Pasini

Beilstein J. Org. Chem. 2014, 10, 1308–1316, doi:10.3762/bjoc.10.132

• protocol for the preparation of several chiral macrocycles incorporating BINOL (1,1′-bi-2-naphthol) units, through the formation of bridging ester functionalities, which ensure chemical inertness for the purposes of supramolecular sensing, recognition, or self-assembly. We have shown their application in

• the chiroptical sensing of organic or ionic species [26][27][28][29][30][31][32][33][34][35][36][37][38][39]. We have previously reported how some of our systems are able to sense C60 in toluene solutions, and how the recognition behavior is shape selective [28]. In the case of extended [2 + 2

Palladium-catalysed cross-coupling reaction of ultra-stabilised 2-aryl-1,3-dihydro-1H-benzo[d]1,3,2-diazaborole compounds with aryl bromides: A direct protocol for the preparation of unsymmetrical biaryls

• Siphamandla Sithebe and
• Ross S. Robinson

Beilstein J. Org. Chem. 2014, 10, 1107–1113, doi:10.3762/bjoc.10.109

• characteristics, fluoride ion sensing abilities, emissive as well as electron-transporting properties [8][9][10][11]. Three-coordinate boron compounds are electron-poor and strong π-electron acceptors owing to the empty boron pz-orbital, which is capable of significant delocalisation when attached to an organic π

Direct and indirect single electron transfer (SET)-photochemical approaches for the preparation of novel phthalimide and naphthalimide-based lariat-type crown ethers

• Dae Won Cho,
• Patrick S. Mariano and
• Ung Chan Yoon

Beilstein J. Org. Chem. 2014, 10, 514–527, doi:10.3762/bjoc.10.47

• pioneering work of Sousa and coworkers [85][86] in the 1970s, intensive and wide-ranging efforts have been dedicated to the development of crown ether based, fluorescence sensing substances for the detection of metal cations. One goal of our investigations was to show that the synthetic strategies based on

• . Photoreactions of bis-donor-linked bisphthalimides. Indirect approach to the preparation of lariat-type crown ethers. SET-based fluorescence sensing modes according to guest binding. Enhancement of the exciplex formation and fluorescence of bis-crown ether 60 with a Mg2+ sandwich-type binding. Acknowledgements

Charge-transfer interaction mediated organogels from 18β-glycyrrhetinic acid appended pyrene

• Jun Hu,
• Jindan Wu,
• Qian Wang and
• Yong Ju

Beilstein J. Org. Chem. 2013, 9, 2877–2885, doi:10.3762/bjoc.9.324

• molecules (cations, anions), they can potentially be used in biomedicine [11][12][13], sensing [14][15], optoelectronics [16][17], and other applications [18][19]. Among different LMWGs, the two-component gel has attracted recent attention due to their strength, stability and other properties which can be

Novel supramolecular affinity materials based on (−)-isosteviol as molecular templates

• Christina Lohoelter,
• Malte Brutschy,
• Daniel Lubczyk and
• Siegfried R. Waldvogel

Beilstein J. Org. Chem. 2013, 9, 2821–2833, doi:10.3762/bjoc.9.317

• reported. The application of these novel architectures as supramolecular affinity materials was studied. The investigations of these possible affinity materials were carried out with 200 MHz high fundamental frequency quartz crystal microbalances (HFF-QCMs) via gravimetric sensing of the adsorbed analytes

• prerequisite for latter tracing applications, e.g. gravimetric sensing. This superior property is attributed to well accessible molecular voids. As soon as such structures are allowed to collapse the outstanding affinity is not observed anymore. Experimental For preparation and characterization of the

Temperature measurements with two different IR sensors in a continuous-flow microwave heated system

• Jonas Rydfjord,
• Fredrik Svensson,
• Magnus Fagrell,
• Jonas Sävmarker,
• Måns Thulin and
• Mats Larhed

Beilstein J. Org. Chem. 2013, 9, 2079–2087, doi:10.3762/bjoc.9.244

• by creating a uniform axial field, which in this setup surrounds a linear tubular borosilicate glass reactor [17]. The temperature in this setup was measured using an external Optris CT infrared (IR) sensor with a LT22 sensing head (Optris GmbH, Berlin, Germany) situated in the reactor cavity which

Activation of cryptic metabolite production through gene disruption: Dimethyl furan-2,4-dicarboxylate produced by Streptomyces sahachiroi

• Dinesh Simkhada,
• Huitu Zhang,
• Shogo Mori,
• Howard Williams and
• Coran M. H. Watanabe

Beilstein J. Org. Chem. 2013, 9, 1768–1773, doi:10.3762/bjoc.9.205

• organisms remain “silent” within the genome [1][2]. While the biosynthetic machinery appears functional, the genetic loci are frequently (but not always) unexpressed. The activation of such pathways has garnered interest from the scientific community. Quorum sensing refers to the process by which

Synthesis of the calcilytic ligand NPS 2143

• Henrik Johansson,
• Thomas Cailly,
• Alex Rojas Bie Thomsen,
• Hans Bräuner-Osborne and
• Daniel Sejer Pedersen

Beilstein J. Org. Chem. 2013, 9, 1383–1387, doi:10.3762/bjoc.9.154

• ICORE) UFR des Sciences Pharmaceutiques, Bd Becquerel, F-14032 Caen, France 10.3762/bjoc.9.154 Abstract (R)-3 (NPS 2143) is a negative allosteric modulator of the human calcium-sensing receptor (CaSR) and as such represents an important pharmacological tool compound for studying the CaSR. Herein, we

• -aminobutyric acid type B (GABAB) receptors, three taste (TR) receptors, the GPRC6A receptor, the calcium-sensing receptor (CaSR), and seven orphan receptors [4]. Class C GPCRs have proven viable as drug targets, exemplified by the marketed GABAB agonist baclofen, and by cinacalcet (1), a positive allosteric

• have been characterised carefully and the optical purity of (R)-3 was deemed excellent by chiral HPLC (er > 99:1). Moreover, the pharmacological profile of (R)-3 was consistent with that reported in the literature. Marketed calcium-sensing receptor agonist cinacalcet (1), and CaSR antagonists Calhex

Spin state switching in iron coordination compounds

• Philipp Gütlich,
• Ana B. Gaspar and
• Yann Garcia

Beilstein J. Org. Chem. 2013, 9, 342–391, doi:10.3762/bjoc.9.39

Development of peptidomimetic ligands of Pro-Leu-Gly-NH₂ as allosteric modulators of the dopamine D₂ receptor

• Swapna Bhagwanth,
• Ram K. Mishra and
• Rodney L. Johnson

Beilstein J. Org. Chem. 2013, 9, 204–214, doi:10.3762/bjoc.9.24

• recent years, the identification of allosteric modulators for GCPRs has increased significantly. The adenosine, muscarinic, chemokine, dopamine, serotonin, calcium-sensing, and metabotropic glutamate receptors are just some examples of GPCRs for which allosteric modulators have been reported [1][2]. The

A simple and efficient dual optical signaling chemodosimeter for toxic Hg(II)

• Sabir H. Mashraqui,
• Sapna A. Tripathi,
• Sushil S. Ghorpade and
• Smita R. Britto

Beilstein J. Org. Chem. 2012, 8, 1352–1357, doi:10.3762/bjoc.8.155

• ]. Lately, the chemodosimeter-based sensing has gained increasing popularity on account of the irreversible chemical intervention of analytes with the probe molecules. Since the metal ions are disengaged from the chemically modified dosimeters, the process results in the more reliable fluorescence

• absence of significant interferences, especially from the competing Ag+, Cu2+ and Pb2+, the features which may prove conducive to Hg2+-sensing applications in certain circumstances. Spectrophotometric titration of acrithion 2 (2.83 × 10−5 M) with Hg2+ (0–2.83 × 10−4 M) in DMSO–H2O (70:30 v/v) at pH 7.4