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

• and non-planar coronoid polycyclic aromatic hydrocarbons (i.e., butyloxy-substituted kekulene and octulene derivatives) are found to be able to intercalate into the intramolecular nanopores. Keywords: macrocycles; scanning tunneling microscopy; self-assembled monolayers; self-sorting; solid/liquid

• , guest molecules can act as alien species that affect the morphologies of intermolecular nanopores [12]. Another approach for the formation of nanopores relies on the physisorption of shape-persistent macrocycles [13][14]. While there are examples for the deposition of organic molecules into rigid

• the solubility limit can be overcome by appropriate substitution. We recently investigated self-assembled nanoporous networks of shape-persistent macrocycles in which dithiophene-based corner building blocks connect linear oligo(phenylene–ethynylene–butadiynylene)s (OPEBs) to form molecular polygons

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

• 10.3762/bjoc.15.178 Keywords: macrocycles; supramolecular chemistry; Macrocycles [1] are the workhorses in supramolecular chemistry. Many basic supramolecular concepts have been developed through studying crown ethers, cryptands, podands and spherands in the 1970s and 1980s. For these contributions

• , Charles Pedersen, Donald J. Cram and Jean-Marie Lehn were awarded the Nobel Prize in Chemistry in 1987. In the 80s and 90s, Jean-Pierre Sauvage and Sir Fraser Stoddart used macrocycles to realize machine-like molecular motion, and they shared the Nobel Prize in Chemistry in 2016 with Ben Feringa. Clearly

• , macrocycles played a central role for the fundamental science that established supramolecular chemistry as an independent field of chemical research as well as for its applications in contemporary research on functional supramolecules and materials. Nowadays, the use of macrocycles has significantly

Synthesis of a [6]rotaxane with singly threaded γ-cyclodextrins as a single stereoisomer

• Jason Yin Hei Man and
• Ho Yu Au-Yeung

Beilstein J. Org. Chem. 2019, 15, 1829–1837, doi:10.3762/bjoc.15.177

• have been synthesized via a threading-followed-by-stoppering approach. Due to the orthogonal binding of CB[6] to ammonium and γ-CD to biphenylene/tetra(ethylene glycol), the [n]rotaxanes display a specific sequence of the interlocked macrocycles. In addition, despite of the asymmetry of γ-CD with

• respect to the orthogonal plane of the axle, only one stereoisomer of the [6]rotaxane was obtained. Keywords: cucurbit[6]uril; cyclodextrin; macrocycles; mechanostereoisomer; rotaxane; Introduction Cyclodextrins (CDs) are macrocycles composed of glucoses linked via α-1,4-glycosidic bonds. CDs of six (α

• orthogonal binding of γ-CD to biphenylene and tetra(ethylene glycol) and CB[6] to ammonium, [n]rotaxanes of only a specific sequence of the interlocked macrocycles were obtained despite of the possibility of other sequence isomers. In addition, the three γ-CDs in the [6]rotaxane were found to adopt only one

Complexation of 2,6-helic[6]arene and its derivatives with 1,1′-dimethyl-4,4′-bipyridinium salts and protonated 4,4'-bipyridinium salts: an acid–base controllable complexation

• Jing Li,
• Qiang Shi,
• Ying Han and
• Chuan-Feng Chen

Beilstein J. Org. Chem. 2019, 15, 1795–1804, doi:10.3762/bjoc.15.173

• ; macrocycles; macrocyclic arene; Introduction Macrocyclic host molecules [1][2] play a significant role in host–guest chemistry. Compared with noncyclic molecules, the structures of macrocyclic hosts can greatly enhance the host–guest complexation ability through preorganization. Moreover, cyclic structures

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

• ]. Keywords: fluorescent; host–guest interaction; macrocycles; molecular recognition; nor-seco-cucurbit[10]uril; pyrene; Introduction Host–guest interactions that trigger molecular recognition are a current topic of interest. For example, understanding the protein–ligand molecular recognition is of paramount

Synthesis, enantioseparation and photophysical properties of planar-chiral pillar[5]arene derivatives bearing fluorophore fragments

• Guojuan Li,
• Chunying Fan,
• Guo Cheng,
• Wanhua Wu and
• Cheng Yang

Beilstein J. Org. Chem. 2019, 15, 1601–1611, doi:10.3762/bjoc.15.164

• : aggregation; circular dichroism; chirality; click chemistry; macrocycles; pillar[5]arenes; Introduction Planar-chiral compounds are structurally appealing and potentially applicable in various functional materials such as chiral discriminators [1][2], chiral polymers, supramolecular sensors [3] and chiral

• that differs from the common macrocycles is the planar chirality resulting from the different orientations of the alkoxy substituents on the rims. Theoretically, eight conformers can be formed including diastereomeric ones: (Sp,Sp,Sp,Sp,Sp), (Rp,Sp,Sp,Sp,Sp), (Rp,Rp,Sp,Sp,Sp), (Rp,Sp,Rp,Sp,Sp) and

Water inside β-cyclodextrin cavity: amount, stability and mechanism of binding

• Stiliyana Pereva,
• Valya Nikolova,
• Silvia Angelova,
• Tony Spassov and
• Todor Dudev

Beilstein J. Org. Chem. 2019, 15, 1592–1600, doi:10.3762/bjoc.15.163

• ; hydration; macrocycles; thermodynamic characteristics; Introduction Cyclodextrins (CDs), a family of enzymatically modified starches, are widely used as host macrocycles in forming inclusion complexes with various molecular entities of interest to food industry, pharmacology, cosmetics, catalysis, and

An azobenzene container showing a definite folding – synthesis and structural investigation

• Abdulselam Adam,
• Saber Mehrparvar and
• Gebhard Haberhauer

Beilstein J. Org. Chem. 2019, 15, 1534–1544, doi:10.3762/bjoc.15.156

• Abdulselam Adam Saber Mehrparvar Gebhard Haberhauer Institut für Organische Chemie, Universität Duisburg-Essen, Universitätsstr. 7, D-45117 Essen, Germany 10.3762/bjoc.15.156 Abstract The combination of photo-switchable units with macrocycles is a very interesting field in supramolecular

• , whereas by the use of visible light the stretched trans,trans-isomer is formed. By means of quantum chemical calculations and CD spectroscopy we could show that the trans→cis isomerization is spatially directed; that means that one of the two different macrocycles performs a definite clockwise rotation to

• the high dispersion energy in the compact cis,cis-isomer. Keywords: azobenzene; macrocycles; molecular switch; Introduction In supramolecular chemistry rigid scaffolds are required to arrange different recognition units in predefined distances and spatial orientation to each other [1]. One example

A heteroditopic macrocycle as organocatalytic nanoreactor for pyrroloacridinone synthesis in water

• Piyali Sarkar,
• Sayan Sarkar and
• Pradyut Ghosh

Beilstein J. Org. Chem. 2019, 15, 1505–1514, doi:10.3762/bjoc.15.152

• , makes them highly valuable in view of sustainable chemical applications. Thus, the development of organocatalytic nanoreactors with new features is indeed important to address greener organic syntheses. On the other hand, the rational design of heterotopic macrocycles has attracted intense interest as

• of macrocycles with multiple functional groups has been employed as alternative templates to induce the organic environment for catalysis via multiple weak interactions viz. π–π stacking, hydrogen bonding, etc. [25][26][27][28][29]. At the same time, several efforts have been made to develop

• transformations, in particular, for the synthesis of biologically important highly substituted pyrroloacridines in the ecofriendly solvent water. Results and Discussion Synthesis of the macrocycle Considerable efforts in synthesizing multifunctional macrocycles have been dedicated lately for the construction of

2,3-Dibutoxynaphthalene-based tetralactam macrocycles for recognizing precious metal chloride complexes

• Li-Li Wang,
• Yi-Kuan Tu,
• Huan Yao and
• Wei Jiang

Beilstein J. Org. Chem. 2019, 15, 1460–1467, doi:10.3762/bjoc.15.146

• Li-Li Wang Yi-Kuan Tu Huan Yao Wei Jiang Shenzhen Grubbs Institute and Department of Chemistry, Southern University of Science and Technology, Xueyuan Boulevard 1088, Shenzhen 518055, China 10.3762/bjoc.15.146 Abstract Two new tetralactam macrocycles with 2,3-dibutoxynaphthalene groups as

• –guest chemistry; macrocycles; molecular recognition; precious metal chloride complexes; Introduction Macrocyclic receptors are the major workhorses in supramolecular chemistry. Design and synthesis of new macrocyclic receptors with new properties is always attractive but is also challenging [1

• ]. Tetralactam macrocycles with four amide NH residues have been studied for ca. three decades and used in a wide range of fields including molecular recognition, optical sensing, molecular machine etc. [2][3][4][5][6][7][8][9][10][11][12][13]. The amide N−H groups directed into the cavity could form hydrogen

Reaction of oxiranes with cyclodextrins under high-energy ball-milling conditions

• László Jicsinszky,
• Federica Calsolaro,
• Katia Martina,
• Fabio Bucciol,
• Maela Manzoli and
• Giancarlo Cravotto

Beilstein J. Org. Chem. 2019, 15, 1448–1459, doi:10.3762/bjoc.15.145

• , depending on the molar ratio of the CD and epichlorohydrin [40][41][42][43]. As in the HPCD preparations, the aqueous basic solution can crosslink the macrocycles, while the relatively large OH− excess can hydrolyse both the reagent and the simultaneously formed oxirane. In order to prepare bead CDPs

Introduction of an isoxazoline unit to the β-position of porphyrin via regioselective 1,3-dipolar cycloaddition reaction

• Xiujun Liu,
• Xiang Ma and
• Yaqing Feng

Beilstein J. Org. Chem. 2019, 15, 1434–1440, doi:10.3762/bjoc.15.143

• ; isoxazoline; macrocycles; nitrile oxide; porphyrin; Introduction In nature, porphyrin-type compounds play a prominent role in life [1]. It is well known that certain vital functions, like O2 transport, photosynthesis etc. depend on the action of porphyrin–metal complexes [2][3][4][5]. Inspired by the natural

• longer than the distance when MeOH coordinated to the Zn2+ ions [49]. This may attribute to the larger volume of the C6H4CO2Me group than MeOH when closing to the Zn2+ center. In the dimer structure, two planes defined by porphyrin macrocycles are parallel with a distance of 7.11 Å. The bulky substituent

Complexation of a guanidinium-modified calixarene with diverse dyes and investigation of the corresponding photophysical response

• Yu-Ying Wang,
• Yong Kong,
• Zhe Zheng,
• Wen-Chao Geng,
• Zi-Yi Zhao,
• Hongwei Sun and
• Dong-Sheng Guo

Beilstein J. Org. Chem. 2019, 15, 1394–1406, doi:10.3762/bjoc.15.139

• representative candidate of luminescent transition-metal complexes. We determined the association constants of the GC5A–dye complexes by fluorescence titration and discuss the complexation-induced photophysical changes. In addition, a comparison of the complexation behavior of GC5A with that of other macrocycles

• and potential applications according to the diverse photophysical responses are provided. Keywords: calixarene; host–guest complexation; luminescent dyes; macrocycles; photophysical properties; Introduction Fluorescence sensing represents a powerful detection methodology due to its low cost, ease of

• fluorophores through supramolecular encapsulation using artificial macrocyclic hosts has always been an active research area [10][11][12]. The complexes of macrocycles with luminescent dyes not only act as reporter pairs for sensing [13][14][15], but also offer various applications in bioimaging [16][17

Selective detection of DABCO using a supramolecular interconversion as fluorescence reporter

• Indrajit Paul,
• Debabrata Samanta,
• Sudhakar Gaikwad and
• Michael Schmittel

Beilstein J. Org. Chem. 2019, 15, 1371–1378, doi:10.3762/bjoc.15.137

• compounds. Keywords: copper; detection; fluorescence; interconversion; macrocycles; self-assembly; self-sorting; zinc porphyrin; Introduction Since dynamic multicomponent supramolecular structures are nowadays abundant [1][2], the weak intercomponent binding [3][4][5][6][7][8][9] is often instrumentalized

Efficient resolution of racemic crown-shaped cyclotriveratrylene derivatives and isolation and characterization of the intermediate saddle isomer

• Sven Götz,
• Andreas Schneider and
• Arne Lützen

Beilstein J. Org. Chem. 2019, 15, 1339–1346, doi:10.3762/bjoc.15.133

• ; cyclotriveratrylenes; HPLC; macrocycles; racemization; saddle isomer; Introduction Cyclotriveratrylenes (CTVs) [1][2][3][4][5][6][7][8] are cyclic bowl-shaped molecules and belong to the most studied concave host molecules in supramolecular chemistry besides, e.g., calixarenes and resorcinarenes [9], cyclodextrins

Host–guest interactions between p-sulfonatocalix[4]arene and p-sulfonatothiacalix[4]arene and group IA, IIA and f-block metal cations: a DFT/SMD study

• Valya K. Nikolova,
• Cristina V. Kirkova,
• Silvia E. Angelova and
• Todor M. Dudev

Beilstein J. Org. Chem. 2019, 15, 1321–1330, doi:10.3762/bjoc.15.131

• formation reactions. Keywords: complex formation; DFT; group IA; IIA and f-block metal cations; macrocycles; p-sulfonatocalix[4]arene; p-sulfonatothiacalix[4]arene; Introduction If macrocycles are pillars of the supramolecular chemistry, then calixarenes (“calix” = vase + “arene”) are the 3rd pillar after

• ., acetaldehyde – ethanal, CH3CHO) are required in condensation reactions with resorcinol and pyrogallol [1]. Thiacalixarenes are macrocycles (or cyclic oligomers) based on a condensation of the same phenol derivatives and sulfur [2]. They are characterized by a larger cavity size than the conventional

• are not as good as those of other common macrocycles. Two positions (phenolic OH groups and p-positions) in the calixarenes’ structure can be easily modified by subsequent reactions [4]. As a result, calixarenes have a great potential as simple scaffolds to build molecular receptors and multivalent

Bambusuril analogs based on alternating glycoluril and xylylene units

• Tomáš Lízal and
• Vladimír Šindelář

Beilstein J. Org. Chem. 2019, 15, 1268–1274, doi:10.3762/bjoc.15.124

• product. Two disastereomers of the macrocycle were separated and characterized by means of NMR spectroscopy and X-ray crystallography. Conformational changes of these diastereomers were investigated using DFT models and variable-temperature NMR. Keywords: bambusurils; conformers; glycolurils; macrocycles

• ; supramolecular chemistry; Introduction Macrocycles consisting of urea building blocks play an important role in supramolecular chemistry [1]. Urea N–H motifs provide macrocycles with the ability to act as anion receptors due to the stabilizing effect of N–H···anion hydrogen bonding [2][3][4]. Furthermore, the

• investigate the synthesis of bambusuril analogs in which glycoluril and chromophoric units alternate. Here we describe the first results of our efforts. Results and Discussion The preparation of the macrocycles was based on a one-pot reaction of 2,4-dimethylglycoluril and m-xylylene dibromide, a structurally

N-doped carbon dots covalently functionalized with pillar[5]arenes for Fe³⁺ sensing

• Jia Gao,
• Ming-Xue Wu,
• Dihua Dai,
• Zhi Cai,
• Yue Wang,
• Wenhui Fang,
• Yan Wang and
• Ying-Wei Yang

Beilstein J. Org. Chem. 2019, 15, 1262–1267, doi:10.3762/bjoc.15.123

• stretching vibration of C–N at 1433 cm−1 in CCDs was obviously increased because the abundant amino groups of CN-dots reacted with carboxylic acid groups of the CP[5] macrocycles. Powder X-ray diffraction (PXRD) patterns (Figure 1e) of CCDs show the characteristic peaks of CN-dots and CP[5], further

• was lost until 800 °C. Meanwhile, the weight loss of CCDs reached ca. 35 wt %, indicating that ca. 26 wt % of CP[5] macrocycles were covalently grafted on the surface of CN-dots [17][19]. As shown in Figure 2a, the as-synthesized CN-dots material is soluble in water while the CCDs solid is insoluble

• composites, and the highly selective sensing towards Fe3+ is also related to the binding of Fe3+ with CP[5] ring (Figure 3f) [24][27][28]. Conclusion In summary, a promising fluorescent chemical sensing material (CCDs) was synthesized for the first time by covalently attaching CP[5] macrocycles onto the

Steroid diversification by multicomponent reactions

• Leslie Reguera,
• Cecilia I. Attorresi,
• Javier A. Ramírez and
• Daniel G. Rivera

Beilstein J. Org. Chem. 2019, 15, 1236–1256, doi:10.3762/bjoc.15.121

• structural diversification of steroids by means of multicomponent reactions (MCRs) have significantly increased over the last decade. This review covers the most relevant strategies dealing with the use of steroidal substrates in MCRs, including the synthesis of steroidal heterocycles and macrocycles as well

• supramolecular chemistry applications. Keywords: conjugation; heterocycles; macrocycles; multicomponent reactions; steroids; Review 1 Introduction The utilization of multicomponent reactions (MCRs) [1] for the derivatization of biomolecules has continuously grown over the last years. These diversity-oriented

• promise for the future development of peptide pharmaceuticals. 5 Multicomponent synthesis of steroidal macrocycles and cages Since the beginning of this century, the field of macrocycle synthesis has witnessed the emergence of MCRs as effective ring closing procedures, including the cyclization of large

Extending mechanochemical porphyrin synthesis to bulkier aromatics: tetramesitylporphyrin

• Qiwen Su and
• Tamara D. Hamilton

Beilstein J. Org. Chem. 2019, 15, 1149–1153, doi:10.3762/bjoc.15.111

• , simple, room-temperature method for producing tetra-meso-substituted porphyrins with bulky substituents. Keywords: condensation; grinding; mechanochemistry; milling; porphyrin; sterically-hindered; Introduction Porphyrins and related macrocycles such as chlorins, corroles, and bacteriochlorins carry

Design of a double-decker coordination cage revisited to make new cages and exemplify ligand isomerism

• Sagarika Samantray,
• Sreenivasulu Bandi and
• Dillip K. Chand

Beilstein J. Org. Chem. 2019, 15, 1129–1140, doi:10.3762/bjoc.15.109

• : anion binding; double-decker cage; ligand isomerism; macrocycles; palladium; self-assembly; supramolecular; Introduction Coordination-driven self-assembly is a convenient strategy for the construction of supramolecules of desired dimensions via simple synthetic procedures. Well-defined metal–ligand

Molecular recognition using tetralactam macrocycles with parallel aromatic sidewalls

• Dong-Hao Li and
• Bradley D. Smith

Beilstein J. Org. Chem. 2019, 15, 1086–1095, doi:10.3762/bjoc.15.105

• Dong-Hao Li Bradley D. Smith Department of Chemistry and Biochemistry, University of Notre Dame, 236 Nieuwland Science Hall, Notre Dame, Indiana 46556, United States 10.3762/bjoc.15.105 Abstract This review summarizes the supramolecular properties of tetralactam macrocycles that have parallel

• aromatic sidewalls and four NH residues directed into the macrocyclic cavity. These macrocycles are versatile hosts for a large number of different guest structures in water and organic solvents, and they are well-suited for a range of supramolecular applications. The macrocyclic cavity contains a mixture

• effect; macrocycles; rotaxane; supramolecular; Review 1. Introduction A large fraction of host–guest chemistry research uses macrocyclic compounds as the host molecules [1][2]. There are several reasons for this circumstance. Macrocycles are often relatively easy to synthesize and they have inherently

Fabrication, characterization and adsorption properties of cucurbit[7]uril-functionalized polycaprolactone electrospun nanofibrous membranes

• Changzhong Chen,
• Fengbo Liu,
• Xiongzhi Zhang,
• Zhiyong Zhao and
• Simin Liu

Beilstein J. Org. Chem. 2019, 15, 992–999, doi:10.3762/bjoc.15.97

• isotherm model. Keywords: adsorption; cucurbit[7]uril; electrospinning; macrocycles; methylene blue; nanofiber; Introduction Electrospinning is recognized as the most simple and versatile method to fabricate multifunctional nanofibers from the solution or melt of polymers, polymer/nanoparticle mixtures

Synthesis of (macro)heterocycles by consecutive/repetitive isocyanide-based multicomponent reactions

• Angélica de Fátima S. Barreto and
• Carlos Kleber Z. Andrade

Beilstein J. Org. Chem. 2019, 15, 906–930, doi:10.3762/bjoc.15.88

• isocyanide-based multicomponent reactions in the synthesis of macrocycles containing a tetrazole nucleus [30]. The strategy was based on the use of α-isocyano-ω-carboxylic esters 71 via a microwave-mediated Ugi-azide reaction at the beginning of the synthesis and an intramolecular Ugi reaction of

• bifunctional compounds 74 at the end, allowing the obtention of the 16- to 20-membered tetrazolic macrocycles 75 in only five steps (Scheme 14). A similar approach was used shortly afterwards by the same research group in the synthesis of macrocyclic depsipeptides containing a tetrazole nucleus [31]. The

• intramolecular Passerini reaction was performed using bifunctional isocyanocarboxylate (Scheme 15a). Scheme 15b shows three of the 21 depsipeptides macrocycles synthesized by the authors in this study. Ethyl isocyanoacetate (13b) has also been successfully used as starting material to allow consecutive Ugi

Mechanochemistry of supramolecules

• Anima Bose and
• Prasenjit Mal

Beilstein J. Org. Chem. 2019, 15, 881–900, doi:10.3762/bjoc.15.86

• stabilities by exhibiting a decomposition temperature up to 320 °C. In 2013, Severin and co-workers reported the mechanochemical synthesis of large macrocycles with borasiloxane and imine links using a ball mill (Figure 12). In a polycondensation reaction using diamines, 4-formylbenzeneboronic acid and t

• ester cages of type 22 [64]. Mechanochemical synthesis of borasiloxane-based macrocycles. Mechanochemical synthesis of 2-dimensional aromatic polyamides. Nitschke’s tetrahedral Fe(II) cage 25. Mechanochemical one-pot synthesis of the 22-component [Fe4(AD2)6]4− 26, 11-component [Fe2(BD2)3]2− 27 and 5

• thermodynamic control. Preferential formation of hexamer 33 under mechanochemical shaking via non-covalent interactions of peptide chains. Anion templated mechanochemical synthesis of macrocycles cycHC[n] by validating the concept of dynamic covalent chemistry. Hydrogen-bond-assisted [2 + 2]-cycloaddition