Construction of pillar[4]arene[1]quinone–1,10-dibromodecane pseudorotaxanes in solution and in the solid state

• Xinru Sheng,
• Errui Li and
• Feihe Huang

Beilstein J. Org. Chem. 2020, 16, 2954–2959, doi:10.3762/bjoc.16.245

• architectures and chemical topology [12][13][14][15][16][17][18][19][20][21][22][23]. Seeking new systems to produce pseudorotaxanes is currently considered a “hot topic” in supramolecular chemistry. As a new class of supramolecular macrocyclic hosts, pillararenes have received extensive attention in recent

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

• made towards switchable macrocyclic receptors, in which crown ethers are functionalized with a stimuli-responsive unit [14][15]. These studies were mainly motivated by a biomimetic approach and included examples such as crown ethers incorporating photo-responsive azobenzene [15][16] or redox-active

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

• the inclusion compound with Q[8]. Keywords: cucurbit[8]uril; host–guest interaction; inclusion complex; oroxin A; properties; Introduction Cucurbit[n]urils (Q[n]s) are a family of macrocyclic cage compounds synthesized by the condensation of glycoluril and formaldehyde in a strong acidic solution [1

Design and synthesis of a bis-macrocyclic host and guests as building blocks for small molecular knots

• Elizabeth A. Margolis,
• Rebecca J. Keyes,
• Stephen D. Lockey IV and
• Edward E. Fenlon

Beilstein J. Org. Chem. 2020, 16, 2314–2321, doi:10.3762/bjoc.16.192

• molecular knots. The modular second-generation approach to small trefoil knots described herein involves electrostatic interactions between an electron-rich bis-macrocyclic host compound and electron-deficient guests in the threading step. The bis-macrocyclic host was synthesized in eight steps and 6.6

• ]. Herein the synthesis of a unique bis-macrocyclic host 1 is described (Figure 1). Host 1 was designed to be a second-generation building block in the thread–link–cut (TLC) approach to molecular knots [13]. The two 25-atom macrocycles are electron-rich and complementary to the electron-deficient guests bis

• ), whereas host 1 and guest 3 would lead to a 75 backbone-atom trefoil (and unknotted macrocycle). Results and Discussion The synthesis of bis-macrocyclic host 1 began by breaking the symmetry of naphthalene-1,5-diol (4) by alkylation of one of the alcohols with 2-azidoethyl mesylate to yield azide 5 in 27

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

• that would allow the analyte to become protonated. In order to incorporate both functional parts of a carboxylate, a macrocyclic receptor architecture is desirable. By using a cyclic structure, it is possible to accommodate a solvophobic environment alongside polar functional groups. The benefits of

• positions 8 of the carbazole, using, e.g., amide bonds. Anion receptors containing carbazole and amide functionalities were investigated in numerous works [6][7][8][9]. In some cases, these functionalities were incorporated into macrocyclic systems, thereby offering valuable insight for design criteria. For

• example, a carbazole-urea macrocycle was reported previously [10], however, the binding of anions occurred outside the receptor due to modest dimensions of the macrocyclic cavity. Using click-chemistry, a carbazole-triazole macrocycle, “tricarb”, was prepared that showed the ability to form non-covalent

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

• synthesis of macrocycle 2 was carried out using N,N'-dihexyl-1,4-butanediamide as the template, as represented in Figure 2. While the formation of some macrocyclic product was identified by 1H NMR and MS, it could not be completely separated from impurities (<29% yield after chromatographic purification

An overview on disulfide-catalyzed and -cocatalyzed photoreactions

• Yeersen Patehebieke

Beilstein J. Org. Chem. 2020, 16, 1418–1435, doi:10.3762/bjoc.16.118

• presence of PhSSPh, the new isomer 73 could also be converted to the desired (E,E)-isomer 71. In the total synthesis of the macrocyclic antibiotic antitumor agent (+)-hitachimycin, Smith used a disulfide-catalyzed isomerization [32] to synthesize the intermediate 75 with an E-configuration, which was

[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

• the macrocyclic host affected the stereochemistry of the reaction. Moreover, we studied photodecarboxylation reactions initiated by the phthalimide chromophore [17][18][19] and applied them in cyclizations with memory of chirality [20] and diastereoselective peptide cyclizations [21

Anthelmintic drug discovery: target identification, screening methods and the role of open science

• Frederick A. Partridge,
• Ruth Forman,
• Carole J. R. Bataille,
• Graham M. Wynne,
• Marina Nick,
• Angela J. Russell,
• Kathryn J. Else and
• David B. Sattelle

Beilstein J. Org. Chem. 2020, 16, 1203–1224, doi:10.3762/bjoc.16.105

• cattle treated annually is hundreds of millions [1]. Treatment of horses, other equids, and companion animals is also a major use of anthelmintics. Anthelmintic drug discovery has been a continued emphasis in the animal health industry, driven by the spread of resistance to the macrocyclic lactones [2

• macrocyclic lactone is an effective microfilaricide but does not kill the adult nematodes. Ivermectin must therefore be administered annually or twice-annually for many years to eliminate the parasite in the population. Progress has been impressive: onchocerciasis has been largely controlled as a public

• action of anthelmintic compounds, since it has been recognised that we do not fully understand how many anthelmintics work – for example the concentrations of macrocyclic lactones that paralyse worms in vitro are much greater than the concentration achieved by effective doses in vivo [147]. Several

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

• , baicalein contains three phenolic hydroxy groups, which are easily oxidized to the quinone derivative and appear green, therefore, it has limited use in pharmaceuticals on account of its poor aqueous solubility and stability [31]. The cucurbit[n]urils (Q[n]s n = 5–8, 10, …) are macrocyclic hosts with a

• hydrophobic rigid cavity [32] (Figure 1). cucurbit[n]urils have a unique combination of properties including rigid highly symmetric structures, relatively large hydrophobic cavities and high thermal and chemical stability [33][34]. Cucurbit[n]urils are a type of macrocyclic drug carrier similar to macrocyclic

Understanding the role of active site residues in CotB2 catalysis using a cluster model

• Keren Raz,
• Ronja Driller,
• Thomas Brück,
• Bernhard Loll and
• Dan T. Major

Beilstein J. Org. Chem. 2020, 16, 50–59, doi:10.3762/bjoc.16.7

• different cellular compartments [1][2]. More specifically, the enigmatic class of terpene cyclases is responsible for converting linear aliphatic oligoprenyl diphosphates into various chemically complex macrocyclic products. The resulting terpene scaffolds and their functionalized terpenoid analogues

Starazo triple switches – synthesis of unsymmetrical 1,3,5-tris(arylazo)benzenes

• Andreas H. Heindl and
• Hermann A. Wegner

Beilstein J. Org. Chem. 2020, 16, 22–31, doi:10.3762/bjoc.16.4

• their isomerization properties [3][4]. Also, the incorporation of AB units into cyclic [5] or macrocyclic structures can control the switching, depending, i.a., on symmetry and ring strain [6][7][8][9]. By combining these approaches, half-lives can be tuned from milliseconds to years. The incorporation

Synthesis of novel sulfide-based cyclic peptidomimetic analogues to solonamides

• José Brango-Vanegas,
• Luan A. Martinho,
• Lucinda J. Bessa,
• Andreanne G. Vasconcelos,
• Alexandra Plácido,
• Alex L. Pereira,
• José R. S. A. Leite and
• Angelo H. L. Machado

Beilstein J. Org. Chem. 2019, 15, 2544–2551, doi:10.3762/bjoc.15.247

• was based on the conservation of the 16-membered macrocyclic scaffold and the apolar tripeptidyl moiety found in the solonamides. Both features are important to guarantee the interference with S. aureus QS [12][13][14][15]. The ester linkage of the lactone core was substituted by the sulfide group

• peptides [40]. Noteworthy, the detected ions A–C always showed the –SCH2CH=NH moiety, confirming the formation of the sulfide group (Schemes S4–S11, Supporting Information File 1). The NMR experiments also confirmed the macrocyclic structure (Supporting Information File 1). The 1H NMR spectra of compounds

Anion-driven encapsulation of cationic guests inside pyridine[4]arene dimers

• Anniina Kiesilä,
• Jani O. Moilanen,
• Anneli Kruve,
• Christoph A. Schalley,
• Perdita Barran and
• Elina Kalenius

Beilstein J. Org. Chem. 2019, 15, 2486–2492, doi:10.3762/bjoc.15.241

• , cation binding to pyridinearene is clearly not as strong as with resorcin[4]arene, which is known for its excellent cation receptor properties. A comparison of these two macrocyclic hosts reveals significant differences in their binding properties. Pyridine[4]arene appears to have a better affinity

Self-assembled coordination thioether silver(I) macrocyclic complexes for homogeneous catalysis

• Zhen Cao,
• Aline Lacoudre,
• Cybille Rossy and
• Brigitte Bibal

Beilstein J. Org. Chem. 2019, 15, 2465–2472, doi:10.3762/bjoc.15.239

• -atropisomer, as revealed by X-ray diffraction. This alkylaryl thioether ligand (L) formed different macrocyclic complexes by coordination with silver(I) salts depending on the nature of the anion: M2L2 for AgOTf and AgOTFA, M6L4 for AgNO3. A discrete M2L complex was obtained in the presence of bulky PPh3AgOTf

• silver(I) catalysts based on sulfur ligands were reported so far, although alkyl thioethers are soft σ-donor ligands such as crown thioethers that were largely developed as macrocyclic ligands for silver(I) [35][36][37][38][39][40][41][42][43]. Interestingly, depending on their design, these known silver

• /cycloisomerization was previously described in high yields (>95%) using 5 mol % catalyst loadings starting from 2-(alkynyl)quinoline-3-carbaldehyde [60][61] with AgOTf catalyst and starting from 2-alkynylbenzaldehyde derivatives [62] in the presence of a macrocyclic pyridine-tetraaza complex of Ag(I) as a catalyst

Photochromic diarylethene ligands featuring 2-(imidazol-2-yl)pyridine coordination site and their iron(II) complexes

• Andrey G. Lvov,
• Max Mörtel,
• Anton V. Yadykov,
• Frank W. Heinemann,
• Valerii Z. Shirinian and
• Marat M. Khusniyarov

Beilstein J. Org. Chem. 2019, 15, 2428–2437, doi:10.3762/bjoc.15.235

• for realization of light-triggered guest uptake/release [52] and light-controlled interconversion between distinct supramolecular assemblies [53]. Ligand 6 featuring two coordination sites in the heteroaryl moiety and bridge provides unique opportunities to construct novel macrocyclic systems. Our

Effect of ring size on photoisomerization properties of stiff stilbene macrocycles

• Sandra Olsson,
• Óscar Benito Pérez,
• Magnus Blom and
• Adolf Gogoll

Beilstein J. Org. Chem. 2019, 15, 2408–2418, doi:10.3762/bjoc.15.233

• of the macrocyclic stiff stilbene diethers, a conformational analysis was undertaken (Figure 6). According to X-ray crystallography, in compound (E)-7 (Scheme 4) the aromatic rings of the two indane units are in the same plane (dihedral angle 180°), whereas in (Z)-7 this angle is 9.1° [21]. In the

• macrocyclic diethers 1a–d, all Z-isomers have a dihedral angle of 12–14°, roughly similar to the one in the crystal structure of (Z)-7. The deviation of this angle from 0° is due to steric interaction between two aromatic protons in position 4 (Figure 9). In the E-isomers, an increasing distortion of the

• stated differently, the obtained yellow oil was purified by CC (pentane/DCM 1:0 to 1:1). The obtained product was dried under high vacuum overnight. Synthesis of macrocyclic stiff stilbene diether (Z)-1a The synthesis followed general procedure B with compound 6a (0.279 g, 0.7 mmol) as starting material

Reversible switching of arylazopyrazole within a metal–organic cage

• Anton I. Hanopolskyi,
• Soumen De,
• Michał J. Białek,
• Yael Diskin-Posner,
• Liat Avram,
• Moran Feller and
• Rafal Klajn

Beilstein J. Org. Chem. 2019, 15, 2398–2407, doi:10.3762/bjoc.15.232

• photochromism in the spiropyran switch [18]. Other recent studies of photochromic systems within macrocyclic and supramolecular hosts [19] include dihydroazulene switches [20] and red-shifted azobenzenes [21][22] inside cucurbiturils and cyclodextrins. The behavior of light-responsive compounds can also be

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

• polymers etc. [14][15]. Noncovalent interactions play a dynamic role in the binding mechanism of triazoles as macrocyclic receptors. It has been reported that the combined effects of both an electron lone pair on the nitrogen of the heterocycle and the acidic C5–H proton make 1,2,3-triazoles interesting

• of 1,4-disubstituted 1,2,3- triazole units [19][20][21][22][23][24]. Macrocyclic ring closure can be achieved by the CuAAC of building blocks functionalized with both azide and alkyne, using [1 + 1], [2 + 2], [n + n] strategies depending on how much triazoles are needed to be included in the

• to be very difficult to further proceed. However, the anion binding property of the corresponding bistriazolium macrocyclic part 5·(BF4)2 (Figure 5) has successfully been investigated using 1H NMR titration experiments in CD3CN. The highest binding affinity was found to be almost similar for both BzO

Multiple threading of a triple-calix[6]arene host

• Veronica Iuliano,
• Roberta Ciao,
• Emanuele Vignola,
• Carmen Talotta,
• Patrizia Iannece,
• Margherita De Rosa,
• Annunziata Soriente,
• Carmine Gaeta and
• Placido Neri

Beilstein J. Org. Chem. 2019, 15, 2092–2104, doi:10.3762/bjoc.15.207

• , daisy-chain pseudorotaxanes, olympiadane, Janus rotaxanes [5]) is generally obtained through a template-approach [9] exploiting the threading process between linear (axle) and macrocyclic (wheel) components. In order to synthesize high-order interpenetrated architectures, much attention has been

Attempted synthesis of a meta-metalated calix[4]arene

• Christopher D. Jurisch and
• Gareth E. Arnott

Beilstein J. Org. Chem. 2019, 15, 1996–2002, doi:10.3762/bjoc.15.195

• yielding transformations to azide and 1,2,3-triazole derivatives which may have application in other areas of research. Keywords: calixarene; inherent chirality; mesoionic carbene; mononitration; ruthenacycle; Introduction Calix[4]arenes are a class of diverse macrocyclic compounds which have been the

Synthesis and anion binding properties of phthalimide-containing corona[6]arenes

• Meng-Di Gu,
• Yao Lu and
• Mei-Xiang Wang

Beilstein J. Org. Chem. 2019, 15, 1976–1983, doi:10.3762/bjoc.15.193

• conveniently by means of a macrocyclic condensation reaction between N-functionalized 3,6-dihydroxyphthalimides and 3,6-dichlorotetrazine under mild conditions in a one-pot reaction manner. The novel macrocycles exist as a mixture of rapidly interconvertible conformers in solution while in the solid state they

• adopt the conformation in which three phthalimide units are cis,trans-orientated. Acting as electron-deficient macrocyclic hosts, the synthesized O6-corona[3]arene[3]tetrazines self-regulated conformational structures to complex anions in the gas phase and in the solid state owing to the anion–π

• operational one-pot reaction fashion on the basis of a nucleophilic aromatic substitution reaction [23][24][25][26][27][28][29][30][31]. To prepare functionalized corona[6]arenes using diethyl terephthalate as a starting material, we observed, however, the formation of a mixture of macrocyclic isomers because

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

• a hydrophobic effect, while the other one has a more directional character, or application of multidentate interaction sites [3]. Macrocyclic compounds with persistent hydrophobic cavities constitute a fundamental class of scaffolds for the construction of supramolecular host–guest complexes in

• cyclodextrines, which, when unmodified, interact with a wide range of hydrophobic guests albeit with low general selectivity and enantioselectivity in particular [6]. In this paper we present a group of synthetic macrocyclic compounds – resorcin[4]arene sulfonic acids (RSAs) and analyze their interactions with

• capable of forming electrostatic interactions. However, in CSAs polar groups are positioned directly on a macrocyclic scaffold, while for RSAs at conformationally labile methylene linkers. Therefore, we think that RSAs are more adaptable than CSAs and are able to enclose guest molecules more tightly (by

Nanopatterns of arylene–alkynylene squares on graphite: self-sorting and intercalation

• Tristan J. Keller,
• Joshua Bahr,
• Kristin Gratzfeld,
• Nina Schönfelder,
• Marcin A. Majewski,
• Marcin Stępień,
• Sigurd Höger and
• Stefan-S. Jester

Beilstein J. Org. Chem. 2019, 15, 1848–1855, doi:10.3762/bjoc.15.180

• the procedure described above) a nanopattern of 1a (5 × 10−7 M), and added a 10−4 M solution of 3 in TCB. STM (Figure 4a) shows – again – bright features in the macrocyclic template of 1a. Again, a slight central depression is visible in the STM image which can attributed to the empty center region of

• images comprising both polymorphs are shown in Supporting Information File 1, Figure S9a and b. Therefore, the PAH coadsorption is a monitor for the alkoxy chain orientation inside the macrocyclic interior (whereas they do not point towards the solution phase here). By adding a solution of 3 at a

Novel macrocycles – and old ones doing new tricks

• Wei Jiang and
• Christoph A. Schalley

Beilstein J. Org. Chem. 2019, 15, 1838–1839, doi:10.3762/bjoc.15.178

• special issue in the Beilstein Journal of Organic Chemistry gathers world-renowned experts in the field to share their very recent results and will surely help stimulate macrocyclic chemistry. Wei Jiang and Christoph A. Schalley Shenzhen, Berlin, July 2019