Ligand effects, solvent cooperation, and large kinetic solvent deuterium isotope effects in gold(I)-catalyzed intramolecular alkene hydroamination

• Ruichen Lan,
• Brock Yager,
• Yoonsun Jee,
• Cynthia S. Day and
• Amanda C. Jones

Beilstein J. Org. Chem. 2024, 20, 479–496, doi:10.3762/bjoc.20.43

• thioureas and the reaction is favored at lower concentrations, an impact proposed to be due to hydrogen bonding driven self-association of the substrate [55]. In other Bronsted acid-catalyzed processes, thioureas and ureas are both effective substrates, with higher reactivity associated with thioureas

Substitution reactions in the acenaphthene analog of quino[7,8-h]quinoline and an unusual synthesis of the corresponding acenaphthylenes by tele-elimination

• Ekaterina V. Kolupaeva,
• Narek A. Dzhangiryan,
• Alexander F. Pozharskii,
• Oleg P. Demidov and
• Valery A. Ozeryanskii

Beilstein J. Org. Chem. 2024, 20, 243–253, doi:10.3762/bjoc.20.24

• the present work, we succeeded in filling this gap by growing crystals of base 5 from pure acetonitrile. It turned out that molecule 5 is capable of self-association through multiple C–H…N–H-bond-like contacts involving pyridyl C(3)H and C(4)H protons (Figure 5). These intermolecular contacts, whose

• overlap (с). Again, π-stacking and H-bonding (blue dotted lines) strongly dominate in this structure. Fragment of the crystal packing of neutral dipyridoacenaphthene 5 showing self-association via multiple C–H…N contacts (blue dotted lines) between three independent molecules. Structure of

Complexes of resorcin[4]arene with secondary amines: synthesis, solvent influence on “in-out” structure, and theoretical calculations of non-covalent interactions

• Waldemar Iwanek

Beilstein J. Org. Chem. 2023, 19, 1525–1536, doi:10.3762/bjoc.19.109

• role in their self-association and the formation of larger supramolecular structures such as dimers [3], hexamers [4][5], octamers [6], and nano-aggregates [7]. The stability of these structures is highly reliant on the type of solvent used. Most of the works are studies of non-polar environments such

Constrained thermoresponsive polymers – new insights into fundamentals and applications

• Patricia Flemming,
• Alexander S. Münch,
• Andreas Fery and
• Petra Uhlmann

Beilstein J. Org. Chem. 2021, 17, 2123–2163, doi:10.3762/bjoc.17.138

Supramolecular polymers with reversed viscosity/temperature profile for application in motor oils

• Jan-Erik Ostwaldt,
• Christoph Hirschhäuser,
• Stefan K. Maier,
• Carsten Schmuck and
• Jochen Niemeyer

Beilstein J. Org. Chem. 2021, 17, 105–114, doi:10.3762/bjoc.17.11

• seen as a neutral analogue of the GCP motif. Due to the missing ionic interactions, the self-association is weaker, but still sufficiently strong, in aprotic solvents such as chloroform (Ka > 106 M−1) [27]. As for the LU, we chose the 1,1’-binaphthyl-2,2’-diamine (BINAM) backbone. The attachment of the

Chiral anion recognition using calix[4]arene-based ureido receptors in a 1,3-alternate conformation

• Tereza Horáčková,
• Jan Budka,
• Vaclav Eigner,
• Wen-Sheng Chung,
• Petra Cuřínová and
• Pavel Lhoták

Beilstein J. Org. Chem. 2020, 16, 2999–3007, doi:10.3762/bjoc.16.249

• dissolves all anionic species tested, (ii) prevents the receptor molecule from self-association, and (iii) reduces the complexation constants to values easily measurable by 1H NMR titrations. A solution of an anion was gradually added to a solution of 7 or 8 in DMSO-d6 to obtain various calixarene/anion

The charge-assisted hydrogen-bonded organic framework (CAHOF) self-assembled from the conjugated acid of tetrakis(4-aminophenyl)methane and 2,6-naphthalenedisulfonate as a new class of recyclable Brønsted acid catalysts

• Svetlana A. Kuznetsova,
• Alexander S. Gak,
• Yulia V. Nelyubina,
• Vladimir A. Larionov,
• Han Li,
• Michael North,
• Vladimir P. Zhereb,
• Alexander F. Smol'yakov,
• Artem O. Dmitrienko,
• Michael G. Medvedev,
• Igor S. Gerasimov,
• Ashot S. Saghyan and
• Yuri N. Belokon

Beilstein J. Org. Chem. 2020, 16, 1124–1134, doi:10.3762/bjoc.16.99

• polymeric matrix and the low availability of the active sites to the substrates due to diffusion problems. Additionally, the self-association of catalytic centers on flexible polymeric chains may negatively influence the expected activity of the immobilized catalyst. Moreover, the degradation of cross

1,2,3-Triazolium macrocycles in supramolecular chemistry

• Mastaneh Safarnejad Shad,
• Pulikkal Veettil Santhini and
• Wim Dehaen

Beilstein J. Org. Chem. 2019, 15, 2142–2155, doi:10.3762/bjoc.15.211

• macrocycle has been reported by Nakamura and his co-workers containing three 1,2,3-triazolium and carbazole moieties 12 (Figure 10). π–π stacking interactions and the self-association ability of the synthesized macrocycle are increased in comparison with its neutral analogue due to the decreased electron

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

• study their solution-phase self-association characteristics and DNA molecular-recognition properties [17]. The authors showed a measurable difference in solution-phase self-assembly character with enhanced DNA association characteristics by replacing the formamide head group in thiazotropsin A with

• ). This has been attributed to strong self-association (dimerization) in an antiparallel, head-to-tail orientation in aqueous solution during complex formation with duplex DNA oligomers verified via NOE experiments [61]. They further reported several structurally diverse MGBs, derived from distamycin, in

The use of 4,4,4-trifluorothreonine to stabilize extended peptide structures and mimic β-strands

• Yaochun Xu,
• Isabelle Correia,
• Tap Ha-Duong,
• Nadjib Kihal,
• Jean-Louis Soulier,
• Julia Kaffy,
• Benoît Crousse,
• Olivier Lequin and
• Sandrine Ongeri

Beilstein J. Org. Chem. 2017, 13, 2842–2853, doi:10.3762/bjoc.13.276

• observed for the central residue upon replacement of Ser by the β-branched Thr residue and the incorporation of a trifluoromethyl group in Thr or allo-Thr further increases the β-propensity of these residues. The presence of self-association involving intermolecular β-sheet formation was not detectable

Creating molecular macrocycles for anion recognition

• Amar H. Flood

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

• solvents that avoid ion pairing. But, in those cases, the triazolophanes then start to self-associate [17][19]. The story of macrocycle self-association is still unfolding in our hands. None of the multiequilibria fitting would be possible without the use of appropriate software. This allows me to

• where its properties begin to depart from cyanostar’s. This planarity leads to extremely high self-association behavior. While a crystal structure has so far been elusive, the pattern of molecular packing has been examined from studies of surface assembly. We inspected the tricarb macrocycle’s surface

• clean self-association into 2D patterns of fused rosettes (Figure 17c). This pattern allowed us to readily discern binding of iodide anions as bright features constituting a pattern with the same unit-cell dimensions as the parent honeycomb. These macrocycles had another characteristic that was

Determination of formation constants and structural characterization of cyclodextrin inclusion complexes with two phenolic isomers: carvacrol and thymol

• Miriana Kfoury,
• David Landy,
• Steven Ruellan,
• Lizette Auezova,
• Hélène Greige-Gerges and
• Sophie Fourmentin

Beilstein J. Org. Chem. 2016, 12, 29–42, doi:10.3762/bjoc.12.5

• phase solubility profiles are generally apparent values that combine several effects on the guest solubility: inclusion complexation, self-association of poorly soluble guests, self-aggregation of CD:guest complexes, as well as non-inclusion interaction and micelles formation [38]. The solubilizing

Conformational equilibrium in supramolecular chemistry: Dibutyltriuret case

• Karina Mroczyńska,
• Małgorzata Kaczorowska,
• Erkki Kolehmainen,
• Ireneusz Grubecki,
• Marek Pietrzak and
• Borys Ośmiałowski

Beilstein J. Org. Chem. 2015, 11, 2105–2116, doi:10.3762/bjoc.11.227

• association or the relative population of rotamers [50]. In the current study these forces coexist with other ones in the same molecule. Results and Discussion Studies by NMR techniques Properties of 1 The dilution studies for 1 provided its self-association constant Kself = 170 M−1 (CDCl3, rt, Supporting

• resolution mass spectrometry (HRMS) for the study of the association processes of 1 with benzoate 5 and naphthyridine 10 anions and to examine self-association of 1. The ESI–HRMS was previously successfully used for the study of complexation of triuret derivative with cations [44] and has been demonstrated

• self-association and deprotonation of 1; [12 − H+]−(m/zcalc = 515.3305, Figure S36: m/zmeas = 515.33185; Figure S37: m/zmeas = 515.33213). Less intensive signal observed at ESI(−)–HRMS mass spectrum of 1∙∙∙10 (Figure S37) can be assigned to singly charged anions formed via protonation of naphthyridine

Star-shaped tetrathiafulvalene oligomers towards the construction of conducting supramolecular assembly

• Masahiko Iyoda and
• Masashi Hasegawa

Beilstein J. Org. Chem. 2015, 11, 1596–1613, doi:10.3762/bjoc.11.175

• File 1). The self-association behavior is significantly affected by the solvent. While no association was observed in benzene-d6 solution in the concentration ranges of 0.7–21 mM even at low temperatures, a larger K2 value was estimated in CDCl3–CD3CN solution (3:7 v/v, K2 = 5.01 ± 0.98 M−1 at 293 K

• ). Moreover, only a small concentration dependence of the chemical shift, which could not be used for determination of the K2 value, was observed in acetone–CS2 solution owing to very weak self-association. These results clearly suggest that the association behavior is driven by intermolecular π–π, S···S, and

• /or S···H interactions in solution. Note that these K2 values of 23 in the neutral state are similar to that of the mixed valence dimer (TTF•+ + TTF) (K2 = 6.0 M−1) and much larger than that of the π-dimer (TTF•+ + TTF•+) (K2 = 0.6 M−1) described in the literature [61]. Strong self-association of 23

Synthesis of photoresponsive cholesterol-based azobenzene organogels: dependence on different spacer lengths

• Yuchun Ren,
• Bin Wang and
• Xiuqing Zhang

Beilstein J. Org. Chem. 2015, 11, 1089–1095, doi:10.3762/bjoc.11.122

• new classes of organogelator architectures have been systematically studied because of their reversible gel process and unique directional self-association through weak van der Waals interactions [16][17]. Up to now, numerous attempts have been made to develop novel supramolecular architectures, which

Glycoluril–tetrathiafulvalene molecular clips: on the influence of electronic and spatial properties for binding neutral accepting guests

• Yoann Cotelle,
• Marie Hardouin-Lerouge,
• Stéphanie Legoupy,
• Olivier Alévêque,
• Eric Levillain and
• Piétrick Hudhomme

Beilstein J. Org. Chem. 2015, 11, 1023–1036, doi:10.3762/bjoc.11.115

• realized on this system [59]. By comparison with these results observed for molecular clip 15 [58], it is clear that clips 1–3 exhibit [(TTF)2]+˙ mixed-valence dimer and/or (TTF+˙)2 dimer species but their self-association organization could not be yet demonstrated. The presence of more or less sterically

Effect of cyclodextrin complexation on phenylpropanoids’ solubility and antioxidant activity

• Miriana Kfoury,
• David Landy,
• Lizette Auezova,
• Hélène Greige-Gerges and
• Sophie Fourmentin

Beilstein J. Org. Chem. 2014, 10, 2322–2331, doi:10.3762/bjoc.10.241

• obtained from phase-solubility are generally apparent values because they combine several effects on the guest solubility: inclusion complexation, self-association of poorly soluble guests, self-aggregation of CD/guest complexes, as well as non-inclusion interaction and micelles formation [18]. Our

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

• pyrene units, showed a weak excimer emission, due to weak self-association (this band tend to disappear with dilution, see Supporting Information File 1, Figure S16), which underwent a dramatic enhancement when PNA2 was bound to DNA1, whereas it remained unchanged by addition of DNA2 (Figure 2b and

• 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

Biantennary oligoglycines and glyco-oligoglycines self-associating in aqueous medium

• Svetlana V. Tsygankova,
• Alexander A. Chinarev,
• Alexander B. Tuzikov,
• Nikolai Severin,
• Alexey A. Kalachev,
• Juergen P. Rabe,
• Alexandra S. Gambaryan and
• Nicolai V. Bovin

Beilstein J. Org. Chem. 2014, 10, 1372–1382, doi:10.3762/bjoc.10.140

• . Here, we synthesized biantennary oligoglycines and studied them in order to determine the necessary and sufficient conditions for self-association. More specifically, we investigated the combination of structure elements, such as the n value, the type of terminal substituents, and the type of

Molecular architecture with carbohydrate functionalized β-peptides adopting 3₁₄-helical conformation

• Nitin J. Pawar,
• Navdeep S. Sidhu,
• George M. Sheldrick,
• Dilip D. Dhavale and
• Ulf Diederichsen

Beilstein J. Org. Chem. 2014, 10, 948–955, doi:10.3762/bjoc.10.93

• -like structures and can be used for helical self-association towards protein-like assemblies mimicking secondary structures and eventually acting as inhibitors for protein–protein interaction [13][14]. In addition, β-peptide 314-helices furnish an ideal structural backbone for the well-organized

3-Pyridinols and 5-pyrimidinols: Tailor-made for use in synergistic radical-trapping co-antioxidant systems

• Luca Valgimigli,
• Daniele Bartolomei,
• Riccardo Amorati,
• Evan Haidasz,
• Jason J. Hanthorn,
• Susheel J. Nara,
• Johan Brinkhorst and
• Derek A. Pratt

Beilstein J. Org. Chem. 2013, 9, 2781–2792, doi:10.3762/bjoc.9.313

• the concentration of the HBA solvent and fit to Equation 2 [25]. In the case of compound 6b, similar analysis was repeated using IR peak height in place of peak area and essentially indistinguishable results were obtained. In order to confirm the absence of self-association of the test compounds and

• to calibrate the spectrometer response, linear regression plots (Absorbance versus [ArOH]) in CCl4 were preliminarily recorded in the range 1–10 mM. Deviation from linearity was observed only in the case of 7b, allowing the determination of its self-association equilibrium constant as Kself = 121

True and masked three-coordinate T-shaped platinum(II) intermediates

• Manuel A. Ortuño,
• Salvador Conejero and
• Agustí Lledós

Beilstein J. Org. Chem. 2013, 9, 1352–1382, doi:10.3762/bjoc.9.153

• addition and reductive elimination (OA/RE) scenario via hydride Pt(IV) 48 and subsequent methane release yield the corresponding solvent adduct 49, from which self-association generates the cyclic tetramer 50. Indeed, when good coordinating agents such as acetonitrile are added, the reaction slows down. A

Enhancement of efficiency in organic photovoltaic devices containing self-complementary hydrogen-bonding domains

• Rohan J. Kumar,
• Jegadesan Subbiah and
• Andrew B. Holmes

Beilstein J. Org. Chem. 2013, 9, 1102–1110, doi:10.3762/bjoc.9.122

• expression for dimerization derived from a two-state equilibrium (Equation 1, fit shown in Figure 3) [25]. It should be noted that Equation 1 describes the simplest two-state model of association, namely dimerization, but can also be used to fit a two-state isodesmic self-association interaction; the two

• concentration is shown in Figure 4. The films were found to contain interconnected fibrous nanostructures approximately 85–110 nm in width at both concentrations; however, the structures appeared to be more regular in films cast from solutions at higher concentrations. Hydrogen-bond-mediated self-association of

• chemical shift of other protons in molecules bearing a cyanopyridone motif is unprecedented and at least three scenarios may be invoked to explain this observation. Since the 1H chemical shift data can support either a dimerization or isodesmic self-association model as the initial self-assembly step, both

Palladium-catalyzed C–N and C–O bond formation of N-substituted 4-bromo-7-azaindoles with amides, amines, amino acid esters and phenols

• Rajendra Surasani,
• Dipak Kalita,
• A. V. Dhanunjaya Rao and
• K. B. Chandrasekhar

Beilstein J. Org. Chem. 2012, 8, 2004–2018, doi:10.3762/bjoc.8.227

• -deficient pyridine ring. The pKa value of 7-azaindole is ~4.9, and it undergoes self-association through hydrogen-bonding to form a dimer in solution and phototautomerizes by an excited-state double-proton-transfer (ESDPT) process [1][48]. In the presence of copper or palladium catalysts azaindole undergoes

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

• squaramide based catalysts VIII and IX are structurally similar, they have quite different properties. Catalyst IX is a self-association-free compound [21], while catalyst VIII forms associates, and the stereoselectivity of the reaction in its presence depends on the catalyst concentration [22]. The

• , also afforded the product in good yield and selectivity (Table 3, entry 9). As the squaramide-type catalyst IX is known to be self-association-free [21], the increase in enantioselectivity at higher temperatures can be attributed to the thermodynamic control of the conjugate addition. At the same time