Synthesis and herbicidal activities of aryloxyacetic acid derivatives as HPPD inhibitors

• Man-Man Wang,
• Hao Huang,
• Lei Shu,
• Jian-Min Liu,
• Jian-Qiu Zhang,
• Yi-Le Yan and
• Da-Yong Zhang

Beilstein J. Org. Chem. 2020, 16, 233–247, doi:10.3762/bjoc.16.25

• [10][19][32][33][34]. The results show that two main interactions exist between I12 and the AtHPPD active site (Figure 4), as was observed for mesotrione; the 1,3-dicarbonyl unit is chelated to the iron ion, and the aromatic ring moiety formed π–π interactions with Phe403 and Phe360. Electron

Preparation of anthracene-based tetraperimidine hexafluorophosphate and selective recognition of chromium(III) ions

• Qing-Xiang Liu,
• Feng Yang,
• Zhi-Xiang Zhao,
• Shao-Cong Yu and
• Yue Ding

Beilstein J. Org. Chem. 2019, 15, 2847–2855, doi:10.3762/bjoc.15.278

• anthracene, and the dihedral angle between two perimidine units of each arm was determined to be 18.1(4)°. Two of the four perimidine groups were parallel to the anthracene plane, with intramolecular π–π interactions [43] being present in this setup (with a face-to-face distance of 3.566(1) Å between

• intermolecular π–π interactions between perimidine moieties (with a face-to-face distance of 3.558(4) Å and a center-to-center distance of 3.566(1) Å), as shown in Supporting Information File 1, Figure S1a. Besides, a 2D supramolecular layer was formed by the 1D supramolecular chains through two types of C–H···F

Emission solvatochromic, solid-state and aggregation-induced emissive α-pyrones and emission-tuneable 1H-pyridines by Michael addition–cyclocondensation sequences

• Natascha Breuer,
• Irina Gruber,
• Christoph Janiak and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2019, 15, 2684–2703, doi:10.3762/bjoc.15.262

• -phenyl ring in C-H···N [36][37][38][39] and C-H···π [40][41][42][43][44][45][46][47][48][49] interactions (Figure 2, for details, see Supporting Information File 1). It is noteworthy to mention that there are no significant π···π interactions in the solid-state structure of 5a (for details, see

Synthesis of benzo[d]imidazo[2,1-b]benzoselenoazoles: Cs₂CO₃-mediated cyclization of 1-(2-bromoaryl)benzimidazoles with selenium

• Mio Matsumura,
• Yuki Kitamura,
• Arisa Yamauchi,
• Yoshitaka Kanazawa,
• Yuki Murata,
• Tadashi Hyodo,
• Kentaro Yamaguchi and
• Shuji Yasuike

Beilstein J. Org. Chem. 2019, 15, 2029–2035, doi:10.3762/bjoc.15.199

• independent molecules, and the benzimidazole and the fused benzoselenophene rings are virtually coplanar (mean deviation 0.0169 and 0.0359 Å, respectively) to each other. The molecules show head-to-tail (antiparallel) stacking with π···π interactions, with distances between the nearest neighbor atoms on

Synthesis, photophysical and electrochemical properties of pyridine, pyrazine and triazine-based (D–π–)₂A fluorescent dyes

• Keiichi Imato,
• Toshiaki Enoki,
• Koji Uenaka and
• Yousuke Ooyama

Beilstein J. Org. Chem. 2019, 15, 1712–1721, doi:10.3762/bjoc.15.167

• known that D–π–A fluorescent dyes show bathochromic shifts of the λmax,fl and lower Φf values by changing from the solution state to the solid state. This fact is attributed to the delocalization of excitons or excimers due to the formation of intermolecular π–π interactions [48][49][50][51] between the

Host–guest interactions in nor-seco-cucurbit[10]uril: novel guest-dependent molecular recognition and stereoisomerism

• Xiaodong Zhang,
• Wei Wu,
• Zhu Tao and
• Xin-Long Ni

Beilstein J. Org. Chem. 2019, 15, 1705–1711, doi:10.3762/bjoc.15.166

• guests in its cavity through host-stabilized charge-transfer or π–π interactions [14][15]. This novel property of Q[8] has been utilized as molecular container for biological substrates [16][17], as well as in the construction of various supramolecular assemblies with specific structures and properties

Recent advances on the transition-metal-catalyzed synthesis of imidazopyridines: an updated coverage

• Gagandeep Kour Reen,
• Ashok Kumar and
• Pratibha Sharma

Beilstein J. Org. Chem. 2019, 15, 1612–1704, doi:10.3762/bjoc.15.165

Reversible end-to-end assembly of selectively functionalized gold nanorods by light-responsive arylazopyrazole–cyclodextrin interaction

• Maximilian Niehues,
• Patricia Tegeder and
• Bart Jan Ravoo

Beilstein J. Org. Chem. 2019, 15, 1407–1415, doi:10.3762/bjoc.15.140

• aggregates can be realized more or less efficiently through various approaches based on supramolecular interactions like metal–metal and π–π interactions [11], DNA mediated [12] or by host–guest chemistry [13]. Most of these approaches require selective functionalization of the ends of the AuNR and take

Selenophene-containing heterotriacenes by a C–Se coupling/cyclization reaction

• Pierre-Olivier Schwartz,
• Sebastian Förtsch,
• Astrid Vogt,
• Elena Mena-Osteritz and
• Peter Bäuerle

Beilstein J. Org. Chem. 2019, 15, 1379–1393, doi:10.3762/bjoc.15.138

• of the heterotriacenes should be expected planar, a slight curvature of the π-system was found for DST 3, whose α-carbon atoms are bent relative to the central thiophene plane by about 2.5 degrees (Figure 2b). This effect might be due to strong intermolecular π–π interactions in pairs of molecules

• stacked and offset molecules leading to π–π interactions with distances as close as 3.42 Å for DST 3 (Figure 3a and b), 3.24 to 3.49 Å for DTS 2 (Figure S6a–c in Supporting Information File 1), and 3.28 to 3.58 Å for DSS 4 (Figure S8a–c in Supporting Information File 1). Interestingly, the symmetry of the

• DST 3: (a) partial overlap of stacked and displaced molecules leading to π–π interactions with distances down to 3.42 Å (side view); (b) and top view (64% molecular overlap). (c) Intermolecular interactions between heteroatoms and hydrogen-heteroatoms (labelled cyan and blue, respectively). DFT

Mechanochemical synthesis of hyper-crosslinked polymers: influences on their pore structure and adsorption behaviour for organic vapors

• Sven Grätz,
• Sebastian Zink,
• Hanna Kraffczyk,
• Marcus Rose and
• Lars Borchardt

Beilstein J. Org. Chem. 2019, 15, 1154–1161, doi:10.3762/bjoc.15.112

• explained by the strong interactions of the benzene molecules with the aromatic surface of the polymer via π–π interactions. The rather strong adsorption at the inner surface is overlapped by pore filling due to a condensation-like effect. Thereby, swelling results in a reversible structural change

Solid-phase synthesis of biaryl bicyclic peptides containing a 3-aryltyrosine or a 4-arylphenylalanine moiety

• Iteng Ng-Choi,
• Àngel Oliveras,
• Lidia Feliu and
• Marta Planas

Beilstein J. Org. Chem. 2019, 15, 761–768, doi:10.3762/bjoc.15.72

• , the cyclization of linear peptides through aryl–aryl bond formation confers a relative conformational constraint on the peptide scaffold. Moreover, the resulting biaryl motif is able to participate in π–π interactions with aromatic and hydrophobic residues, and also in π-cation interactions with

Adhesion, forces and the stability of interfaces

• Robin Guttmann,
• Johannes Hoja,
• Christoph Lechner,
• Reinhard J. Maurer and
• Alexander F. Sax

Beilstein J. Org. Chem. 2019, 15, 106–129, doi:10.3762/bjoc.15.12

• even known. Instead, attraction is attributed to π–π interactions or CH–π interactions of unclear physical origin. That deformation of molecules induces static multipoles is also not well known; the bending of non-polar planar molecules that have a quadrupole as their lowest static multipole (e.g

Targeting the Pseudomonas quinolone signal quorum sensing system for the discovery of novel anti-infective pathoblockers

• Christian Schütz and
• Martin Empting

Beilstein J. Org. Chem. 2018, 14, 2627–2645, doi:10.3762/bjoc.14.241

• hydrophobic interactions were observed in the tail region, in particular with leucins 189 and 208 as well as Y258. Mutations at these specific residues indicated that the π–π interactions of Y258 are crucial for M64's full inhibition with respect to pyocyanin production, which was only weakly inhibited in an

Synthesis of 3-aminocoumarin-N-benzylpyridinium conjugates with nanomolar inhibitory activity against acetylcholinesterase

• Nisachon Khunnawutmanotham,
• Cherdchai Laongthipparos,
• Patchreenart Saparpakorn,
• Nitirat Chimnoi and
• Supanna Techasakul

Beilstein J. Org. Chem. 2018, 14, 2545–2552, doi:10.3762/bjoc.14.231

• the amide group and dimethoxy substituents on the chromene ring to the amino acid residues Tyr72, Tyr124, Trp286, and Tyr341 in the PAS; and (5) the hydrogen atoms of phenyl ring to Glu202 and a methoxy group to Ser293. Moreover, C–H–π and π–π interactions were found for compound 9h. The C–H–π

• interactions were found between hydrogen atoms of the methoxy group to the PAS amino acid residue Tyr72 and the pyridinium ring to the CAS amino acid residue Phe338, whereas π–π interactions were found among the chromene ring, pyridinium, and phenyl ring to Trp286, Phe338, and Trp86, respectively. When the

• chromene ring moved away from Tyr72 in the PAS; thus, compounds 9e and 9i lost H-bond interactions to Tyr72. Moreover, the C–H–π interactions of compounds 9e and 9i to Tyr72 became weaker. All other H-bonds, C–H–π and π–π interactions of 9e and 9i to amino acid residues in the binding site were similar to

Calixazulenes: azulene-based calixarene analogues – an overview and recent supramolecular complexation studies

• Paris E. Georghiou,
• Shofiur Rahman,
• Abdullah Alodhayb,
• Hidetaka Nishimura,
• Jaehyun Lee,
• Atsushi Wakamiya and
• Lawrence T. Scott

Beilstein J. Org. Chem. 2018, 14, 2488–2494, doi:10.3762/bjoc.14.225

• columnar arrays [17]. In this type of array the host molecules which are in 1,3-alternate conformations align in a “head-to-tail” fashion with the C60 molecules able to be accommodated within the opposite clefts. Furthermore, within such an arrangement, in addition to the “face-to-face” π–π interactions

Synthesis of a water-soluble 2,2′-biphen[4]arene and its efficient complexation and sensitive fluorescence enhancement towards palmatine and berberine

• Xiayang Huang,
• Xinghua Zhang,
• Tianxin Qian,
• Junwei Ma,
• Lei Cui and
• Chunju Li

Beilstein J. Org. Chem. 2018, 14, 2236–2241, doi:10.3762/bjoc.14.198

• , respectively. π···π interactions, hydrophobic interactions and electrostatic attractions should play important roles in the association process. Although having similar structures, these two guests gave very different association constants. The substitution of 1,3-dioxole for two methoxy groups in P, affording

Evaluation of dispersion type metal···π arene interaction in arylbismuth compounds – an experimental and theoretical study

• Ana-Maria Preda,
• Małgorzata Krasowska,
• Lydia Wrobel,
• Philipp Kitschke,
• Phil C. Andrews,
• Jonathan G. MacLellan,
• Lutz Mertens,
• Marcus Korb,
• Tobias Rüffer,
• Heinrich Lang,
• Alexander A. Auer and
• Michael Mehring

Beilstein J. Org. Chem. 2018, 14, 2125–2145, doi:10.3762/bjoc.14.187

• is built up via C–HPh···π intermolecular contacts of T-shape. Noteworthy, polymorph 2a showed bismuth···π and π···π interactions leading to 1D ribbons in the solid state, while 2b did not reveal Bi···π interactions. Thus, it is concluded that Bi···π, π···π and C–H···π interactions must be of similar

• contribute to the overall dispersion from π···π interactions. In case of polymorph 1c the results of the quantification of the interaction energies reveal that this structure is actually not dominated by Bi···π arene interaction, but rather consists of dimers connected by strong π···π interaction (Figure 16

• , 1c-2-1 with −64 kJ mol−1) which are connected by two weaker Bi···π arene contacts (Figure 16, 1c-1-1, −47 kJ mol−1). Figure 17 shows the comparison of the distortion and the interaction energies of Bi···π arene and π stacking dimers. As for BiPh3, Bi···π arene and π···π interactions are of comparable

Calix[6]arene-based atropoisomeric pseudo[2]rotaxanes

• Carmine Gaeta,
• Carmen Talotta and
• Placido Neri

Beilstein J. Org. Chem. 2018, 14, 2112–2124, doi:10.3762/bjoc.14.186

• addition, the biphenyl portion of 2+ hosted inside the calix cavity was involved in π···π interactions with the aromatic walls (Figures S11–S13, Supporting Information File 1) and C–H···π interactions with the tert-butyl groups of the calixarene wheel (Figure S13, Supporting Information File 1

A self-assembled photoresponsive gel consisting of chiral nanofibers

• Lei Zou,
• Dan Han,
• Zhiyi Yuan,
• Dongdong Chang and
• Xiang Ma

Beilstein J. Org. Chem. 2018, 14, 1994–2001, doi:10.3762/bjoc.14.174

• -isomers of azobenzene can stack with each other via π–π interactions. Further, the acylamino group of the glutamic acid moiety at the center of the molecule also promotes this aggregation through hydrogen bonding interactions. Finally, the chirality of glutamic acid may be magnified along with the

Diazirine-functionalized mannosides for photoaffinity labeling: trouble with FimH

• Femke Beiroth,
• Tomas Koudelka,
• Thorsten Overath,
• Stefan D. Knight,
• Andreas Tholey and
• Thisbe K. Lindhorst

Beilstein J. Org. Chem. 2018, 14, 1890–1900, doi:10.3762/bjoc.14.163

• binding site, undergoing interactions with the protein surface, which add to affinity. Especially CH–π or π–π interactions of a sugar ligand with the side chains of Y48 and Y137, called the “tyrosine gate” [19][20], are known to considerably increase the affinity of a specific mannoside for FimH

Host–guest complexes of conformationally flexible C-hexyl-2-bromoresorcinarene and aromatic N-oxides: solid-state, solution and computational studies

• Rakesh Puttreddy,
• Ngong Kodiah Beyeh,
• S. Maryamdokht Taimoory,
• Daniel Meister,
• John F. Trant and
• Kari Rissanen

Beilstein J. Org. Chem. 2018, 14, 1723–1733, doi:10.3762/bjoc.14.146

• receptor renders the receptor slightly electron deficient further facilitating π–π interactions. With the larger N-oxide guests 10–12, though the shift changes of the guest are not strong enough to conclusively indicate endo complexation, clear changes in the hydroxy groups suggest interaction via hydrogen

A conformationally adaptive macrocycle: conformational complexity and host–guest chemistry of zorb[4]arene

• Liu-Pan Yang,
• Song-Bo Lu,
• Arto Valkonen,
• Fangfang Pan,
• Kari Rissanen and
• Wei Jiang

Beilstein J. Org. Chem. 2018, 14, 1570–1577, doi:10.3762/bjoc.14.134

• structures may provide an explanation for their surprising binding behaviors. Multiple non-covalent interactions, including C–H···O hydrogen bonds, cation···π, C–H···π and π···π interactions, are involved in all the cases. Undoubtedly, cation···π interactions between the core quaternary ammonium ions of the

Hyper-reticulated calixarene polymers: a new example of entirely synthetic nanosponge materials

• Alberto Spinella,
• Marco Russo,
• Antonella Di Vincenzo,
• Delia Chillura Martino and
• Paolo Lo Meo

Beilstein J. Org. Chem. 2018, 14, 1498–1507, doi:10.3762/bjoc.14.127

• and shape of the guest. It is worth noting that CaNS4 shows better sequestration abilities than CaNS2 towards 6 and 8. This may be justified admitting that the presence of the aromatic linker unit favors the interaction with the aromatic dye, due to the occurrence of effective π···π interactions with

• is confirmed to depend on a fine balance between different factors, namely Coulomb and π···π interactions, and steric effects. The importance of a compromise between these factors for the complexation into calixresorcinarenes has been recently assessed [42]. Moreover, in analogy with the bahavior

• sequestering agents towards model pollutants such as p-nitroaniline derivatives and dyes. Our results indicate that the absorption equilibrium is affected by a combination of hydrophobic effects, Coulomb and π…π interactions, as a function of the molecular size and shape. Moreover, significant pH-dependent

Steric “attraction”: not by dispersion alone

• Ganna Gryn’ova and
• Clémence Corminboeuf

Beilstein J. Org. Chem. 2018, 14, 1482–1490, doi:10.3762/bjoc.14.125

• interaction distances. In the present work, we have performed a direct comparison between the sp2 and sp3-rich hydrocarbons and quantified the ECpen term of their intermolecular interactions. The electrostatic effects are, not surprisingly, important in systems with strong π–π interactions. Our results

Recent advances in phosphorescent platinum complexes for organic light-emitting diodes

• Cristina Cebrián and
• Matteo Mauro

Beilstein J. Org. Chem. 2018, 14, 1459–1481, doi:10.3762/bjoc.14.124