Switchable molecular tweezers: design and applications

• Pablo Msellem,
• Maksym Dekthiarenko,
• Nihal Hadj Seyd and
• Guillaume Vives

Beilstein J. Org. Chem. 2024, 20, 504–539, doi:10.3762/bjoc.20.45

• switching unit that exhibits similar chiroptical switching properties [50]. During the writing of this review, Lee et al. reported molecular tweezers presenting an allosteric response with hard–soft cooperativity [51]. Tweezers 19 is based on a terpyridine ligand substituted in a 6,6” position by azacrown

• form is able to bind diamine guests between the two porphyrins in the apical position for each zinc center. However, it has been observed that the closing can also be induced directly by diamine guests such as DABCO. This system exhibits an allosteric response with positive cooperativity as the binding

Synthesis of π-conjugated polycyclic compounds by late-stage extrusion of chalcogen fragments

• Aissam Okba,
• Pablo Simón Marqués,
• Kyohei Matsuo,
• Naoki Aratani,
• Hiroko Yamada,
• Gwénaël Rapenne and
• Claire Kammerer

Beilstein J. Org. Chem. 2024, 20, 287–305, doi:10.3762/bjoc.20.30

• reactive as a thin-film on a glass substrate, with the generation of the desired perylene upon photoirradiation with a blue LED (λ = 470 nm) [62]. Finally, cooperativity of light and heat was demonstrated on a crystalline sample of sulfoxide 4a, where photoirradiation enhanced the SO-extrusion process at

Molecular basis for protein–protein interactions

• Brandon Charles Seychell and
• Tobias Beck

Beilstein J. Org. Chem. 2021, 17, 1–10, doi:10.3762/bjoc.17.1

• modelled by the McGhee–von Hippel model of nonspecific protein binding to a surface [86]. In this model, the association with nucleic acids, quantified by KNA, is dependent on the cooperativity coefficient ω, which is based on the protein–protein association constant. A ω value of 1 represents no

• cooperativity, whereas as a value greater than 1000 represents a high cooperativity, with the assembly occurring in two steps. CCMV shows a low cooperativity, and thus assembles gradually [87]. In contrast, HBV binds to RNA with a high cooperativity, resulting in a quantified assembly [88]. These results show

Synthesis and investigation of quadruplex-DNA-binding, 9-O-substituted berberine derivatives

• Jonas Becher,
• Daria V. Berdnikova,
• Heiko Ihmels and
• Christopher Stremmel

Beilstein J. Org. Chem. 2020, 16, 2795–2806, doi:10.3762/bjoc.16.230

• other parameters such as binding-site size, cooperativity between ligands, ionic strength, the enthalpy of the DNA denaturation, and on the binding constant and enthalpy of the ligand binding at the melting temperature. However, the binding constant is determined at temperatures below Tm and the

Optical detection of di- and triphosphate anions with mixed monolayer-protected gold nanoparticles containing zinc(II)–dipicolylamine complexes

• Lena Reinke,
• Julia Bartl,
• Marcus Koch and
• Stefan Kubik

Beilstein J. Org. Chem. 2020, 16, 2687–2700, doi:10.3762/bjoc.16.219

• presence of a certain anion but also whether the respective solution contains the analyte within a certain concentration range. A better understanding of the effect of the surface composition of such nanoparticles on the sensitivity of detection and the cooperativity of the receptor units is now required

NMR Spectroscopy of supramolecular chemistry on protein surfaces

• Peter Bayer,
• Anja Matena and
• Christine Beuck

Beilstein J. Org. Chem. 2020, 16, 2505–2522, doi:10.3762/bjoc.16.203

• this case the resulting binding curves can be either hyperbolic, best fitting a model with n equal sites, or sigmoidal, which fits best to a cooperative binding model [98][99]. It needs to be kept in mind that the Hill coefficient obtained from the latter model is a measure of cooperativity and not

Complexation of chiral amines by resorcin[4]arene sulfonic acids in polar media – circular dichroism and diffusion studies of chirality transfer and solvent dependence

• Bartosz Setner and
• Agnieszka Szumna

Beilstein J. Org. Chem. 2019, 15, 1913–1924, doi:10.3762/bjoc.15.187

• transfer was observed in the form of diastereotopic proton splitting. The exchange between complexed and free species is fast on the NMR timescale, indicating that even for tetradentate ligands, for which a high degree of cooperativity is expected, the complexes are highly dynamic in polar medium

Recent applications of chiral calixarenes in asymmetric catalysis

• Mustafa Durmaz,
• Erkan Halay and
• Selahattin Bozkurt

Beilstein J. Org. Chem. 2018, 14, 1389–1412, doi:10.3762/bjoc.14.117

• the inherent chirality of calix[4]arene for α-chloroacetophenone and ortho-chloroacetophenone. The results clearly showed the effect of both denticity of ketone reactant and cooperativity between normal and inherent chirality on the selectivity. More recently, Al(III)–calix[4]arene complexes 116a–c

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

Correlation effects and many-body interactions in water clusters

• Andreas Heßelmann

Beilstein J. Org. Chem. 2018, 14, 979–991, doi:10.3762/bjoc.14.83

• explicitly or implicitly influenced by a water environment. An example for this is the hydrogen-bond cooperativity effect that can have a significant impact on the properties of the bare solute molecules [1]. In order to describe such phenomena, computer simulations have become an indispensable tool, since

Phosphodiester models for cleavage of nucleic acids

• Satu Mikkola,
• Tuomas Lönnberg and
• Harri Lönnberg

Beilstein J. Org. Chem. 2018, 14, 803–837, doi:10.3762/bjoc.14.68

Electron-deficient pyridinium salts/thiourea cooperative catalyzed O-glycosylation via activation of O-glycosyl trichloroacetimidate donors

• Mukta Shaw,
• Yogesh Kumar,
• Rima Thakur and
• Amit Kumar

Beilstein J. Org. Chem. 2017, 13, 2385–2395, doi:10.3762/bjoc.13.236

• amplified in the presence of other cocatalysts known as “cooperative catalysis” [23]. In particular, cooperativity between Brønsted acids and hydrogen-bonding cocatalysts such as thiourea derivatives has attracted much interest [24][25][26][27][28][29]. Despite the broad application of cooperative catalysis

• conclusion, we have disclosed an efficient and general protocol for the glycosylation of trichloroacetimidate glycosyl donors using the concept of cooperativity between an electron-deficient pyridinium salt and an aryl thiourea derivative. 1H NMR studies divulge that a 1,2-adduct formation between the

Chemical systems, chemical contiguity and the emergence of life

• Terrence P. Kee and
• Pierre-Alain Monnard

Beilstein J. Org. Chem. 2017, 13, 1551–1563, doi:10.3762/bjoc.13.155

• harvest light (here a ruthenium tris(bipyridine) and catalyse reactions, or polymers such RNA ribozymes that are both genotype (information component) and phenotype (catalyst). (C) The systems approach offers insight into the increased level of cooperativity necessary to grasp the complexity of living

Towards open-ended evolution in self-replicating molecular systems

• Herman Duim and
• Sijbren Otto

Beilstein J. Org. Chem. 2017, 13, 1189–1203, doi:10.3762/bjoc.13.118

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

• polymers had been previously discussed as scaffolds for the design of multiple ligands of high affinity [8]. Nevertheless, well-defined model systems in which the influence of rigidity and regularity on cooperativity of binding was systematically investigated have not been reported so far. Rigid linear

• investigation of cooperativity of multiple host–guest interactions using AFM has been reported by several groups [40][41][42][43][44][45]. Huskens and co-workers measured the supramolecular interactions between a β-CD-modified planar surface and mono-, di- and trivalent adamantane guest molecules attached to an

Creating molecular macrocycles for anion recognition

• Amar H. Flood

Beilstein J. Org. Chem. 2016, 12, 611–627, doi:10.3762/bjoc.12.60

• triazolophane; so it was a fortuitous and pleasant discovery that, with pyridyl rings [19], 2:1 sandwich complexes form around iodide (Figure 7). In fact, we saw such extreme positive cooperativity that we could not clearly distinguish the 1:1 affinity and reported instead just a fix on the 2:1 stability

• fitting of 1H NMR titration data. Both software have their limitations but their usage as tools to unravel complex equilibria is without parallel. Cooperativity of ion–pair complexation The most recent undertaking of ion pairing is to make it a feature and to examine, in glorious detail, how ion pairs can

• be bound cooperatively inside designed macrocycles [28]. When positive cooperativity emerges, novel selectivity can be engineered [22]. Despite this possibility, we recognized that a deep understanding of ion pairing is still in its infancy. Ultimately, we quantified the cooperativity involved in the

Assembly of synthetic Aβ miniamyloids on polyol templates

• Sebastian Nils Fischer and
• Armin Geyer

Beilstein J. Org. Chem. 2015, 11, 2646–2653, doi:10.3762/bjoc.11.284

• esterification of boronic acids needs the exclusion of water, which becomes more difficult for larger hydrophilic molecules such as polyols ond oligopeptides. In order to investigate this question, (Hot=Tap)2 was also esterified with peptide boronic acid 1. No cooperativity is expected because the Hot=Tap dimer

• the Hot=Tap oligomer. The mixture of azide 9, 2-formylphenylboronic acid (14) and LVFFA shows a single signal set for the esterified product (Figure 8). Another advantage of this system is the cooperativity of imine formation and esterification, because the imino nitrogen coordinates the boron atom

Discrete multiporphyrin pseudorotaxane assemblies from di- and tetravalent porphyrin building blocks

• Mirko Lohse,
• Larissa K. S. von Krbek,
• Sebastian Radunz,
• Suresh Moorthy,
• Christoph A. Schalley and
• Stefan Hecht

Beilstein J. Org. Chem. 2015, 11, 748–762, doi:10.3762/bjoc.11.85

• ] to life science [13][14][15][16][17] have benefited from the development of the basic concepts of molecular recognition, templation [18], self-assembly [19], or self-sorting [20][21], just to name a few. More recently, multivalent binding [22][23][24] and cooperativity [25][26] have attracted

First principle investigation of the linker length effects on the thermodynamics of divalent pseudorotaxanes

• Andreas J. Achazi,
• Doreen Mollenhauer and
• Beate Paulus

Beilstein J. Org. Chem. 2015, 11, 687–692, doi:10.3762/bjoc.11.78

• different linkers. The shortest linker shows a much larger chelate cooperativity than the longer linkers due to non-innocent linkers that contribute to the binding. To analyze the individual contributions to the binding, we perform first principle calculations of the model system shown in Figure 1, which is

• contributions, enthalpic and entropic temperature effects as well as solvent effects are included in our simulations in order to compare to experimentally obtained Gibbs energy of association. Results and Discussion In order to investigate the cooperativity effects of the binding between divalent host molecules

• the electronic association energy for the n0 guest in the divalent case with the doubled value of the monovalent (Ph@C8) system, an electronic cooperativity effect of 9.7 kJ/mol is discovered. When the linker length is increased, this electronic cooperativity effect is lost, and a lower electronic

Towards the sequence-specific multivalent molecular recognition of cyclodextrin oligomers

• Michael Kurlemann and
• Bart Jan Ravoo

Beilstein J. Org. Chem. 2014, 10, 2428–2440, doi:10.3762/bjoc.10.253

• interaction between n-butyl and α-CD these systems have a negative chelate cooperativity and open adducts are preferentially formed. As soon as two adamantane moieties are present, the complementary systems have a positive chelate cooperativity and double-stranded structures are favored over open adducts. In

• , with non-complementary strands aggregates of higher stoichiometry are generated. Keywords: cooperativity; cyclodextrins; molecular recognition; multivalency; sequence specificity; Introduction Multivalency is the interaction of a receptor and a ligand with at least two recognition motifs on each

• 18 and β-CD cannot be quantified by ITC measurements. Therefore, the binding constant was overestimated to be 102 M−1 as well. Based on these assumptions the chelate cooperativity is 0.03 for the system 1/8 and 0.02 for the system 3/8. Both values are significantly lower than 1. This indicates

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

• gradual transition was observed for PNA4, suggesting weak cooperativity in the stacking interaction. The presence of three pyrene residues (PNA6) instead, induce a strong self-aggregation of the PNA alone; this assembling process is favoured by the presence of DNA1 and to a lesser extent DNA2 (Figure 2

Towards allosteric receptors – synthesis of β-cyclodextrin-functionalised 2,2’-bipyridines and their metal complexes

• Christopher Kremer,
• Gregor Schnakenburg and
• Arne Lützen

Beilstein J. Org. Chem. 2014, 10, 814–824, doi:10.3762/bjoc.10.77

• ” is used by enzymes and proteins [6], which stands for cooperative effects in the binding of more than one substrate to different sites of a receptor. After binding of the first substrate (the effector), the receptor changes its conformation, and by this enhancing (positive allosteric cooperativity

• ) or hampering (negative allosteric cooperativity) the binding of another substrate at a second binding site. This powerful regulatory concept has become quite interesting in supramolecular chemistry, and the development of artificial receptor systems which can be controlled by allosteric effects comes

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

• three synthetic strategies that have been developed to create and strengthen cooperativity, i.e., (i) incorporation of a hydrogen-bonded network; (ii) incorporation of π-stacking moieties; and (iii) coordination of bridging ligands. The thermal ST behavior is commonly expressed in terms of the molar