Direct alkenylation of indolin-2-ones by 6-aryl-4-methylthio-2H-pyran-2-one-3-carbonitriles: a novel approach

• Sandeep Kumar,
• Ramendra Pratap,
• Abhinav Kumar,
• Brijesh Kumar,
• Vishnu K. Tandon and
• Vishnu Ji Ram

Beilstein J. Org. Chem. 2013, 9, 809–817, doi:10.3762/bjoc.9.92

• of the weak noncovalent interactions operating in the supramolecular architectures of alkenylated indoline-2-ones and to explain the relative stability of one of the tautomers with respect to the others. Keywords: alkenylation; dibenzo[d,f][1,3]diazepin-6(7H)-one; indolin-2-one; ketene dithioacetal

• (bcp) were calculated for the different dimers by using the atoms in molecules theory [43]. The bond critical points observed between the interacting atoms confirm the presence of weak noncovalent interactions between the two molecules of 8yc. The value of electron density (ρ), Laplacian of the

The β-cyclodextrin/benzene complex and its hydrogen bonds – a theoretical study using molecular dynamics, quantum mechanics and COSMO-RS

• Jutta Erika Helga Köhler and
• Nicole Grczelschak-Mick

Beilstein J. Org. Chem. 2013, 9, 118–134, doi:10.3762/bjoc.9.15

• ). The β-CD dimers are connected with hydrogen bonds on their O2/O3 sides (Figure 1). Investigations of such “flat energy hypersurfaces” due to hydrogen bonds and noncovalent interactions demand several theoretical methods to capture the entire network of forces on which they rely. Molecular dynamics

• vertical position (higher in energy by only 0.29 kcal mol−1); both conformers were thermodynamically allowed. The HOMO/LUMO gap of the empty β-CD with about 12 eV was lowered to about 10 eV in the complex. The β-CD/benzene inclusion complex was formed only by weak noncovalent interactions, which influence

Synthesis and characterization of low-molecular-weight π-conjugated polymers covered by persilylated β-cyclodextrin

• Aurica Farcas,
• Ana-Maria Resmerita,
• Andreea Stefanache,
• Mihaela Balan and
• Valeria Harabagiu

Beilstein J. Org. Chem. 2012, 8, 1505–1514, doi:10.3762/bjoc.8.170

• materials for use in molecular devices, the construction of mechanically interlocked molecules, such as rotaxanes and polyrotaxanes, has attracted considerable attention [19][20][21][22][23]. A rotaxane assembly comprises a macrocyclic component (host) encircling an axle (guest) through noncovalent

• interactions; bulky groups (also known as stoppers) are attached at the ends of the axle to prevent dethreading of the host. In the past few years many authors have demonstrated that the encapsulation of conjugated polymers into macrocycle cavities plays an important role in the construction of diverse

Organocatalytic asymmetric addition of malonates to unsaturated 1,4-diketones

• Sergei Žari,
• Tiiu Kailas,
• Marina Kudrjashova,
• Mario Öeren,
• Ivar Järving,
• Toomas Tamm,
• Margus Lopp and
• Tõnis Kanger

Beilstein J. Org. Chem. 2012, 8, 1452–1457, doi:10.3762/bjoc.8.165

• investigated the organocatalytic approach to the asymmetric desymmetrization of the title compounds with malonates. Three types of organocatalysts providing noncovalent interactions were used for this purpose: Cinchona alkaloids (I–V), thiourea derivatives (VI, VII) and squaramide derivatives (VIII, IX

Enantioselective supramolecular devices in the gas phase. Resorcin[4]arene as a model system

• Caterina Fraschetti,
• Matthias C. Letzel,
• Antonello Filippi,
• Maurizio Speranza and
• Jochen Mattay

Beilstein J. Org. Chem. 2012, 8, 539–550, doi:10.3762/bjoc.8.62

• simplified models under conditions, such as the gas phase, in which the noncovalent interactions in the guest–host complex are not perturbed by effects owing to the medium. As biological function and morphology are strongly correlated, knowledge of the supramolecular host–guest structures is expected to shed

• light on their biological functions. From the beginning of evolutionary processes right up to the present biodiversity, life relies on biological specificity, which arises from the fact that individual biomolecules “communicate” through noncovalent interactions. Resorcin[4]arenes are an important class

• structural factor: the cyclochirality of the receptor’s cavity. Conclusion The high enantioselectivity found in biochemical systems is essentially due to several intimate noncovalent interactions. In living systems a covalent bond between a neurotransmitter and its macromolecular target cannot be imagined

Azobenzene dye-coupled quadruply hydrogen-bonding modules as colorimetric indicators for supramolecular interactions

• Yagang Zhang and
• Steven C. Zimmerman

Beilstein J. Org. Chem. 2012, 8, 486–495, doi:10.3762/bjoc.8.55

• ]. Noncovalent hydrogen bonding, electrostatic interactions, π–π stacking and metal coordination have been used alone and in concert to assemble a broad range of building blocks, from small molecules [4][5][6][7] to polymers [8][9] including dendrimers [10][11]. Among these noncovalent interactions, hydrogen

Highly efficient cyclosarin degradation mediated by a β-cyclodextrin derivative containing an oxime-derived substituent

• Michael Zengerle,
• Florian Brandhuber,
• Christian Schneider,
• Franz Worek,
• Georg Reiter and
• Stefan Kubik

Beilstein J. Org. Chem. 2011, 7, 1543–1554, doi:10.3762/bjoc.7.182

• degradation and, in particular, the observed enantioselectivity are good indications that noncovalent interactions between the cyclodextrin ring and the substrate, presumably involving the inclusion of the cyclohexyl moiety of cyclosarin into the cyclodextrin cavity, contribute to the mode of action. Among

• (9.22) and 4-formylpyridine oxime (8.57) one would expect the opposite trend. The pronounced activity of the investigated cyclodextrin derivatives, in particular of 1b, also indicates that noncovalent interactions, most probably the inclusion of the apolar cyclohexyl moiety of GF into the cyclodextrin

• derivatives on GF degradation and, in particular, the observed enantioselectivity are good indications for noncovalent interactions between the cyclodextrin ring and the substrate, presumably involving the inclusion of the cyclohexyl moiety of cyclosarin into the cyclodextrin cavity, which contribute to the

Supramolecular chemistry II

• Christoph A. Schalley

Beilstein J. Org. Chem. 2011, 7, 1541–1542, doi:10.3762/bjoc.7.181

• sciences on the other. In the life sciences, the networks of noncovalent interactions between the constituents of cells, for example, have shifted into the current focus. Self-assembly, templation, self-sorting and multivalent binding all contribute to setting up the extremely complex architecture of a

RAFT polymers for protein recognition

• Alan F. Tominey,
• Julia Liese,
• Sun Wei,
• Klaus Kowski,
• Thomas Schrader and
• Arno Kraft

Beilstein J. Org. Chem. 2010, 6, No. 66, doi:10.3762/bjoc.6.66

• the protein surface – in other words they encourage polymer/protein self-assembly in order to maximize attractive noncovalent interactions. A second major advantage of multivalent polymeric hosts is their rapid and efficient synthesis at low cost as well as the high proteolytic stabilities of most

Recognition properties of receptors consisting of imidazole and indole recognition units towards carbohydrates

• Monika Mazik and
• André Hartmann

Beilstein J. Org. Chem. 2010, 6, No. 9, doi:10.3762/bjoc.6.9

• complexes [1][2][3][4][5] provides much of the inspiration for the design of artificial carbohydrate receptors which use noncovalent interactions for sugar binding [6][7][8][9][10][11][12][13][14][15][16][17][18]. Such receptors provide valuable model systems to study the underlying principles of

• receptors 1–6 and carbohydrates 6a, 7a, 8a, 9 and 11. Examples of noncovalent interactions indicated by molecular modeling calculationsa for the complexes formed between receptor 4 and sugar 8a or 8b. Acknowledgements Financial support by the Deutsche Forschungsgemeinschaft (German Research Foundation) is