Particle size effect in the mechanically assisted synthesis of β-cyclodextrin mesitylene sulfonate

• Stéphane Menuel,
• Sébastien Saitzek,
• Eric Monflier and
• Frédéric Hapiot

Beilstein J. Org. Chem. 2020, 16, 2598–2606, doi:10.3762/bjoc.16.211

• considerable attention as it may be unique in features to selectively direct the reaction pathway. In the continuation of our work on the synthesis of modified cyclodextrins (CDs) via mechanochemical activation, we sought to discriminate the contribution of supramolecular effects and grinding during the course

• bioavailability [11][12][13]. In our previous studies, CDs acted either as reactants [14][15], or as additives [16][17], and were shown to display supramolecular interactions with the other reaction partners. We demonstrated that the formation of CD/substrate supramolecular complexes favored the dispersion of the

• lacking at this stage. Indeed, grinding provokes comminution of the reactants and may greatly alter the physical properties of the materials with potential effects on the reactivity. To assess the contribution of both grinding and supramolecular effects on the reactivity, we got rid of the supramolecular

Thermodynamic and electrochemical study of tailor-made crown ethers for redox-switchable (pseudo)rotaxanes

• Henrik Hupatz,
• Marius Gaedke,
• Hendrik V. Schröder,
• Julia Beerhues,
• Arto Valkonen,
• Fabian Klautzsch,
• Sebastian Müller,
• Felix Witte,
• Kari Rissanen,
• Biprajit Sarkar and
• Christoph A. Schalley

Beilstein J. Org. Chem. 2020, 16, 2576–2588, doi:10.3762/bjoc.16.209

• Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany Department of Chemistry, University of Jyvaskyla P. O. Box 35, 40014 Jyväskylä, Finland 10.3762/bjoc.16.209 Abstract Crown ethers are common building blocks in supramolecular chemistry and are frequently applied as cation sensors or as subunits in

• ; redox chemistry; rotaxanes; supramolecular chemistry; Introduction Pedersen discovered crown ethers in 1967 while searching for multidentate ligands for the vanadyl group [1][2][3]. He was later awarded the Nobel Prize in Chemistry for his studies on the crown ether selective binding properties towards

Water-soluble host–guest complexes between fullerenes and a sugar-functionalized tribenzotriquinacene assembling to microspheres

• Si-Yuan Liu,
• Xin-Rui Wang,
• Man-Ping Li,
• Wen-Rong Xu and
• Dietmar Kuck

Beilstein J. Org. Chem. 2020, 16, 2551–2561, doi:10.3762/bjoc.16.207

• hydrophobic effect and to host–guest π–π interactions. Hydrophobic surface simulations showed that TBTQ-(OG)6 and C60 forms an amphiphilic supramolecular host–guest complex, which further assembles to microspheres with diameters of 0.3–3.5 μm, as determined by scanning electron microscopy. Keywords

• : fullerenes; host–guest systems; microspheres; supramolecular chemistry; tribenzotriquinacene; Introduction In the field of supramolecular chemistry, host–guest association through noncovalent interactions is an interesting and exciting topic, especially for the encapsulation of various fullerenes, such as

• their binding affinities to C60 [25][26][27][28]. Georghiou et al. [29] synthesized the tris(thianthreno)-annelated triquinacene 4, and Cao et al. [30] constructed the tris(naphtho)triquinacene 5, bearing six annelated benzofuran units, and they investigated the supramolecular interaction of these hosts

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

• interaction of proteins with their interaction partners, both biomolecules and synthetic ligands. In recent years, the focus in chemistry has kept expanding from targeting small binding pockets in proteins to recognizing patches on protein surfaces, mostly via supramolecular chemistry, with the goal to

• modulate protein–protein interactions. Here we present NMR methods that have been applied to characterize these molecular interactions and discuss the challenges of this endeavor. Keywords: molecular recognition; NMR; protein ligand interaction; protein surfaces; supramolecular chemistry; Introduction In

• as distance of targeted residues and their dynamics - must be taken into account. Supramolecular chemistry is ideally suited to address these challenges because it merges the knowledge of non-covalent molecular recognition with the possibility to combine multiple recognition units into one molecule

Recent developments in enantioselective photocatalysis

• Callum Prentice,
• James Morrisson,
• Andrew D. Smith and
• Eli Zysman-Colman

Beilstein J. Org. Chem. 2020, 16, 2363–2441, doi:10.3762/bjoc.16.197

• followed by a separate enantioselective catalysis step that will not be covered in this review [17][18][19]. Examples using cage complexes or other supramolecular reagents also lie outside the scope of this review. As all enantioselective photocatalysis requires a secondary mode of catalysis to induce

Hierarchically assembled helicates as reaction platform – from stoichiometric Diels–Alder reactions to enamine catalysis

• David Van Craen,
• Jenny Begall,
• Johannes Großkurth,
• Leonard Himmel,
• Oliver Linnenberg,
• Elisabeth Isaak and
• Markus Albrecht

Beilstein J. Org. Chem. 2020, 16, 2338–2345, doi:10.3762/bjoc.16.195

• providing the stereoinformation necessary for induction during the C–C bond formation. Catalytic approaches for C–C bond-forming reactions even found their way into the relatively young field of supramolecular chemistry, e.g., regioselective Diels–Alder reactions within supramolecular hosts as described by

• off the stereoselectivity [13]. Herein we investigated the induction pathway and significantly optimized the stereoselectivity of the reaction. Furthermore, a catalytic approach was introduced which paves the way to the final goal of supramolecular stereoselective catalysis with hierarchical helicates

Host–guest interaction of cucurbit[8]uril with oroxin A and its effect on the properties of oroxin A

• Zhishu Zeng,
• Jun Xie,
• Guangyan Luo,
• Zhu Tao and
• Qianjun Zhang

Beilstein J. Org. Chem. 2020, 16, 2332–2337, doi:10.3762/bjoc.16.194

• Zhishu Zeng Jun Xie Guangyan Luo Zhu Tao Qianjun Zhang Key Laboratory of Macrocyclic and Supramolecular Chemistry of Guizhou Province, Guizhou University, No. 2708, South Section of Huaxi Avenue, Huaxi, Guiyang 550025, China 10.3762/bjoc.16.194 Abstract In this study, we investigated the host

• that the molecular size of the flavonoids and the length of the sugar chains have a greater impact on the assembly mode of supramolecular systems. Results and Discussion Host–guest interactions The host–guest interaction can be effectively observed using 1H NMR spectroscopy, and the mode of action of

Synthetic approaches to bowl-shaped π-conjugated sumanene and its congeners

• Shakeel Alvi and
• Rashid Ali

Beilstein J. Org. Chem. 2020, 16, 2212–2259, doi:10.3762/bjoc.16.186

• generation of versatile functional organic materials. On the basis of this concept, in recent years, a handful of appealing molecules and materials have been synthesized and due to which nanotechnology as well as supramolecular chemistry are continuously attracting the recent attention of researchers

• later to this report, in a really dazzling manner, the groups of Rogachev, Hirao, and Petrukhina reported a novel organometallic sandwich supramolecular complex [Na+(18-crown-6)(THF)2][Cs(C21H11‒)2]‒ (138) encapsulating the cesium cation between the sumanenyl anions in a concave manner [69]. To this

pH- and concentration-dependent supramolecular self-assembly of a naturally occurring octapeptide

• Goutam Ghosh and
• Gustavo Fernández

Beilstein J. Org. Chem. 2020, 16, 2017–2025, doi:10.3762/bjoc.16.168

• ability to undergo significant changes in their morphologies and secondary structures in response to pH stimuli. For instance, hydrogen bonding interactions are strongly influenced by the pH value, leading to a collapse of the supramolecular aggregates when an acid or base is added [4]. The pH

Synergy between supported ionic liquid-like phases and immobilized palladium N-heterocyclic carbene–phosphine complexes for the Negishi reaction under flow conditions

• Edgar Peris,
• Raúl Porcar,
• María Macia,
• Jesús Alcázar,
• Eduardo García-Verdugo and
• Santiago V. Luis

Beilstein J. Org. Chem. 2020, 16, 1924–1935, doi:10.3762/bjoc.16.159

• Edgar Peris Raul Porcar Maria Macia Jesus Alcazar Eduardo Garcia-Verdugo Santiago V. Luis Dpt. of Inorganic and Organic Chemistry, Supramolecular and Sustainable Chemistry Group, University Jaume I, Avda Sos Baynat s/n, E-12071-Castellon, Spain Discovery Chemistry, Janssen Research and Development

Design, synthesis and application of carbazole macrocycles in anion sensors

• Alo Rüütel,
• Ville Yrjänä,
• Sandip A. Kadam,
• Indrek Saar,
• Mihkel Ilisson,
• Astrid Darnell,
• Kristjan Haav,
• Tõiv Haljasorg,
• Lauri Toom,
• Johan Bobacka and
• Ivo Leito

Beilstein J. Org. Chem. 2020, 16, 1901–1914, doi:10.3762/bjoc.16.157

• sensor development, the results obtained in this work emphasize the importance of evaluating the binding behavior of receptors in real sensor membranes. Keywords: anion sensors; carboxylates; ionophores; macrocycles; sensor prototype; Introduction In 2013, Otto S. Wolfbeis asked the supramolecular

Models of necessity

• Timothy Clark and
• Martin G. Hicks

Beilstein J. Org. Chem. 2020, 16, 1649–1661, doi:10.3762/bjoc.16.137

• representations, is non-redundant in order to avoid dependencies within the ML process. These requirements are imposed by external conditions and likely future applications. Requirement (1), for instance, must in future include supramolecular chemistry, which means that the models should be able to reproduce

Five-component, one-pot synthesis of an electroactive rotaxane comprising a bisferrocene macrocycle

• Natalie Lagesse,
• Luca Pisciottani,
• Maxime Douarre,
• Pascale Godard,
• Brice Kauffmann,
• Vicente Martí-Centelles and
• Nathan D. McClenaghan

Beilstein J. Org. Chem. 2020, 16, 1564–1571, doi:10.3762/bjoc.16.128

• prove a valuable component for the construction of novel redox-active supramolecular systems, such as rotaxanes with strongly binding H-bonding templating sites, or indeed juxtaposed into existing functional architectures and benchmark variants. Results and Discussion Synthesis Our first approach to the

Heterogeneous photocatalysis in flow chemical reactors

• Christopher G. Thomson,
• Ai-Lan Lee and
• Filipe Vilela

Beilstein J. Org. Chem. 2020, 16, 1495–1549, doi:10.3762/bjoc.16.125

• ][188][189][190]. Supramolecular photocatalysts are an interesting class of materials which utilise non-bonding interactions to control photochemical processes, a biomimetic strategy that imitates enzyme catalysis [191]. Supramolecular self-assemblies and coordination polymers based on perylene diimide

• (PDI) aggregates have become a popular choice of heterogeneous photocatalyst. As PDI is a large, planar, polyaromatic hydrocarbon molecule, it spontaneously forms ordered 1D supramolecular assemblies through efficient π–π stacking and side chain interactions [192]. Despite the PDI units having only non

Highly selective Diels–Alder and Heck arylation reactions in a divergent synthesis of isoindolo- and pyrrolo-fused polycyclic indoles from 2-formylpyrrole

• Carlos H. Escalante,
• Eder I. Martínez-Mora,
• Carlos Espinoza-Hicks,
• Alejandro A. Camacho-Dávila,
• Fernando R. Ramos-Morales,
• Francisco Delgado and
• Joaquín Tamariz

Beilstein J. Org. Chem. 2020, 16, 1320–1334, doi:10.3762/bjoc.16.113

• for each reaction and in most cases showed a good correlation with the ZPE-corrected energy (Table 6). All the endo approaches were lower in energy than the exo approaches, reaching the TSs from the supramolecular complexes (SCs) [53]. For most of the cycloadditions, the difference in energy of the

• intermolecular interactions (NCIs) between aromatic rings (π···π) [58][59] and alkyl and aromatic ring (Csp3–H)···π stackings [59][60][61][62] are widely recognized, from both the experimental and theoretical viewpoint, as a major factor governing the conformational equilibrium, supramolecular assembly and

• ]indole-1,3-diones 21a–g by aromatization of 9e–f, 9h–k and 9m.a Preparation of derivatives 22a–e by formylation of octahydropyrrolo[3,4-e]indole-1,3-diones 9.a Calculated [M06-2X/6-31+G(d,p)] relative ZPE-corrected energy (kcal/mol) of the supramolecular complexes (SCs), TSs and adducts (ADs) located on

[3 + 2] Cycloaddition with photogenerated azomethine ylides in β-cyclodextrin

• Margareta Sohora,
• Leo Mandić and
• Nikola Basarić

Beilstein J. Org. Chem. 2020, 16, 1296–1304, doi:10.3762/bjoc.16.110

• decarboxylation and [3 + 2] cycloaddition take place in the ternary complex, whereas such a reactivity from bulky adamantane 3 is less likely. This proof of principle that decarboxylation and cycloaddition can be performed in the β-CD cavity has a significant importance for the design of new supramolecular

• achieved by use of supramolecular chemistry [36][37]. For example, stereoselectivity has been reported for photochemical reactions taking place in the inclusion complexes with CD [38][39][40][41] or structurally modified CDs [42][43][44][45][46][47]. Since β-CD is often used in pharmaceutical applications

• . Irradiation of such a complex leads to decarboxylation and formation of the reactive intermediate, azomethine ylide, within the supramolecular host. The subsequent [3 + 2] cycloaddition within the inclusion complex gives heterocyclic cycloadducts, even though it is conducted in aqueous solvent in which ylides

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

• synthetic protocols for the matrix synthesis hamper the routine use of MOFs and COFs in industry, even for the production of high-added-value products. Recently, new supramolecular porous materials named hydrogen-bonded organic frameworks (HOFs) or supramolecular organic frameworks (SOFs) have been

• , crystalline, supramolecular frameworks may be neutral, for example, those built by mutual interactions of multitopic carboxylic acids [25][26][27][28][29]. Alternatively, they can be constructed from components possessing oppositely charged multitopic tectons, in which case the framework becomes a charge

Synthesis of esters of diaminotruxillic bis-amino acids by Pd-mediated photocycloaddition of analogs of the Kaede protein chromophore

• Esteban P. Urriolabeitia,
• Pablo Sánchez,
• Alexandra Pop,
• Cristian Silvestru,
• Eduardo Laga,
• Ana I. Jiménez and
• Carlos Cativiela

Beilstein J. Org. Chem. 2020, 16, 1111–1123, doi:10.3762/bjoc.16.98

• Esteban P. Urriolabeitia Pablo Sanchez Alexandra Pop Cristian Silvestru Eduardo Laga Ana I. Jimenez Carlos Cativiela Instituto de Síntesis Química y Catálisis Homogénea, ISQCH (CSIC - Universidad de Zaragoza), Pedro Cerbuna 12, E-50009 Zaragoza, Spain Supramolecular Organic and Organometallic

Recent applications of porphyrins as photocatalysts in organic synthesis: batch and continuous flow approaches

• Rodrigo Costa e Silva,
• Luely Oliveira da Silva,
• Aloisio de Andrade Bartolomeu,
• Timothy John Brocksom and
• Kleber Thiago de Oliveira

Beilstein J. Org. Chem. 2020, 16, 917–955, doi:10.3762/bjoc.16.83

• (bpy)3)]2+, [Ir(ppy)3], eosin Y, and 4CzTPN [12] (Figure 3). However, some porphyrin and metalloporphyrin derivatives possess adequate potentials to be applied as photoredox catalysts in C–C and C-heteroatom bond formations [10][22]. Furthermore, supramolecular porphyrin-containing molecules, such as

• photoinduced cycloaddition of carbon dioxide with epoxides [56]. The synthesis of a 3D supramolecular framework, [{Mn(TCPP)0.5(H2O)}·2H2O]n, where Mn(TCPP) is Mn(II) meso-tetrakis(4-carboxyphenyl)porphyrin, was derived from MnCl2·6H2O and TCPP. The cycloaddition product, a cyclic carbonate, was obtained from

Exploring the scope of DBU-promoted amidations of 7-methoxycarbonylpterin

• Anna R. Bockman and
• Jeffrey M. Pruet

Beilstein J. Org. Chem. 2020, 16, 509–514, doi:10.3762/bjoc.16.46

• attractive scaffold in the field of supramolecular chemistry, due to their well-defined donor/acceptor hydrogen-bonding arrays [10][11]. One limitation often encountered with the synthesis of structurally diverse pterins is the notorious insolubility in most solvents. This can be dealt with by preemptive

• new pterins. As such, any reaction which expedites the synthesis of pterin derivatives, especially those which bypass the insolubility, is of great importance to both medicinal and supramolecular chemists. We first reported the application of DBU as a crucial additive in the synthesis of pterins used

• which required extreme forcing conditions to react. Conclusion The DBU-promoted amidation of 7-methoxycarbonylpterin is a useful method for rapidly generating new pterin derivatives, for medicinal or supramolecular purposes. A paramount benefit of this reaction is its ability to bypass the notorious

Architecture and synthesis of P,N-heterocyclic phosphine ligands

• Wisdom A. Munzeiwa,
• Bernard Omondi and
• Vincent O. Nyamori

Beilstein J. Org. Chem. 2020, 16, 362–383, doi:10.3762/bjoc.16.35

• block for the assembly of homo and hetero-organometallic complexes. The 3- and 4-pyridylphosphine derivatives 5 have also been successfully used as templates for assembling supramolecular structures and coordination polymers [54][59]. Halogenated ring-fused pyridine reagents can also be used to generate

Halogen-bonding-induced diverse aggregation of 4,5-diiodo-1,2,3-triazolium salts with different anions

• Xingyu Xu,
• Shiqing Huang,
• Zengyu Zhang,
• Lei Cao and
• Xiaoyu Yan

Beilstein J. Org. Chem. 2020, 16, 78–87, doi:10.3762/bjoc.16.10

• ], diiodoacetylene [15] and iodo/bromoethynyl moieties [16] have revealed that the XB-donors interacting with XB-acceptors (a nucleophilic region) are in approximately linear orientation. Besides, linearity, tunability and hydrophobicity (features of the XB ) are widely applied in crystal engineering, supramolecular

The interaction between cucurbit[8]uril and baicalein and the effect on baicalein properties

• Xiaodong Zhang,
• Jun Xie,
• Zhiling Xu,
• Zhu Tao and
• Qianjun Zhang

Beilstein J. Org. Chem. 2020, 16, 71–77, doi:10.3762/bjoc.16.9

• Xiaodong Zhang Jun Xie Zhiling Xu Zhu Tao Qianjun Zhang Key Laboratory of Macrocyclic and Supramolecular Chemistry of Guizhou Province, Guizhou University, Guiyang 550025, China 10.3762/bjoc.16.9 Abstract The host–guest interactions between baicalein (BALE) and cucurbit[8]uril (Q[8]) and the

Photocontrolled DNA minor groove interactions of imidazole/pyrrole polyamides

• Sabrina Müller,
• Jannik Paulus,
• Jochen Mattay,
• Heiko Ihmels,
• Veronica I. Dodero and
• Norbert Sewald

Beilstein J. Org. Chem. 2020, 16, 60–70, doi:10.3762/bjoc.16.8

• -isomer [35]. The photostationary state depends on the nature of the azobenzene, but also on the concentration, as the azobenzene is known to form supramolecular assemblies at high concentration, compromising photoconversion [11][12]. When the concentration of polyamide P1 was reduced to 0.8 mM, 80% of

Influence of the cis/trans configuration on the supramolecular aggregation of aryltriazoles

• Sara Tejera,
• Giada Caniglia,
• Rosa L. Dorta,
• Andrea Favero,
• Javier González-Platas and
• Jesús T. Vázquez

Beilstein J. Org. Chem. 2019, 15, 2881–2888, doi:10.3762/bjoc.15.282

• stabilization of the supramolecular aggregation of bis(4-bromophenyl)triazoles. The trans or cis spatial disposition of the triazole rings is highly important for gelation, with the cis configuration having higher propensity. Keywords: circular dichroism; cis/trans configuration; gels; triazole; X-ray

• diffraction; Introduction Structures self-assembled by noncovalent interactions give rise to supramolecular architectures with specific physical and/or chemical properties. Gels are colloid systems in which the dispersed phase has combined with the dispersion medium to yield a semisolid material. Gels from

• supramolecular studies and report herein the ability of ditriazoles to form gels, their physical properties, as well as the dependence of these properties on the cis/trans relative configuration. Results and Discussion A large set of mono- and ditriazoles was synthesized using cycloaddition reactions based on