Nucleoside macrocycles formed by intramolecular click reaction: efficient cyclization of pyrimidine nucleosides decorated with 5'-azido residues and 5-octadiynyl side chains

• Jiang Liu,
• Peter Leonard,
• Sebastian L. Müller,
• Constantin Daniliuc and
• Frank Seela

Beilstein J. Org. Chem. 2018, 14, 2404–2410, doi:10.3762/bjoc.14.217

• analysis of the cyclic ketones muscone and civetone [1]. Other classical examples are cyclic peptides such as valinomycin and cyclic oligosaccharides like cyclodextrins [2][3][4]. The literature has been recently reviewed [5]. Also, oligonucleotides form cyclic structures commonly existing in plasmid DNA

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

• , medicine, and environment. Cyclodextrins [1][2][3][4], cucurbiturils [5][6][7][8][9][10][11], and calixarenes [12][13][14][15][16][17][18][19][20] have been widely used in aqueous supramolecular chemistry. In the past ten years, the chemistry of pillar[n]arenes has developed very quickly because of their

Tetrathiafulvalene – a redox-switchable building block to control motion in mechanically interlocked molecules

• Hendrik V. Schröder and
• Christoph A. Schalley

Beilstein J. Org. Chem. 2018, 14, 2163–2185, doi:10.3762/bjoc.14.190

• , extended π-surfaces [64] of TTF derivatives can have a stabilizing effect upon complexation. TTF (1) also forms inclusion complexes with neutral host molecules such as cyclodextrins (Figure 6). This complexation is mainly driven by the hydrophobic effect. α-Cyclodextrin (6) molecules encapsulate the

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

• -flat wheels, such as calixarenes or cyclodextrins, are threaded along an axle to give a pseudo[3]rotaxane architecture V–VII (Figure 2), where three sequential stereoisomers can arise. We showed that this stereoisomerism can be effectively controlled when two calix[6]arene wheels are threaded along a

Synthesis of new p-tert-butylcalix[4]arene-based polyammonium triazolyl amphiphiles and their binding with nucleoside phosphates

• Vladimir A. Burilov,
• Guzaliya A. Fatikhova,
• Mariya N. Dokuchaeva,
• Ramil I. Nugmanov,
• Diana A. Mironova,
• Pavel V. Dorovatovskii,
• Victor N. Khrustalev,
• Svetlana E. Solovieva and
• Igor S. Antipin

Beilstein J. Org. Chem. 2018, 14, 1980–1993, doi:10.3762/bjoc.14.173

• binding sites offering multipoint interactions with a substrate for the effective complexation [13]. Calix[4]arenes and their thia analogues have many advantages over other macrocycles that are frequently used as synthetic receptors, such as cyclodextrins [14], cucurbiturils [15], and pillararenes [16

Strong binding and fluorescence sensing of bisphosphonates by guanidinium-modified calix[5]arene

• Jie Gao,
• Zhe Zheng,
• Lin Shi,
• Si-Qi Wu,
• Hongwei Sun and
• Dong-Sheng Guo

Beilstein J. Org. Chem. 2018, 14, 1840–1845, doi:10.3762/bjoc.14.157

• particularly suitable for the detection of analytes lacking chromophores. The key factor in IDA is the rational design of artificial receptors that are capable of binding analytes strongly and specifically. Calixarenes are the third generation of macrocyclic receptors after crown ethers and cyclodextrins. Due

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

• substrates, indeed, have been considered a class of probe guests of choice for investigating the formation of host–guest inclusion complexes with cyclodextrins [38][39][40][41] and calixresorcinarenes [42], because of both their easy accessibility and the fact that their molecular properties can be largely

• , similar to the one used for the synthesis of CyCaNSs. However, severer reaction conditions are needed, due to a different number of reactive azide groups as compared, for instance, with the much more effective heptakis(6-azido-6-deoxy)cyclodextrins. The materials obtained have been successfully tested as

Recent applications of chiral calixarenes in asymmetric catalysis

• Mustafa Durmaz,
• Erkan Halay and
• Selahattin Bozkurt

Beilstein J. Org. Chem. 2018, 14, 1389–1412, doi:10.3762/bjoc.14.117

• asymmetric catalysis has received considerable interest and witnessed significant progress in recent years [2][3][4]. Calixarenes are considered as the third generation of supramolecular hosts after cyclodextrins and crown ethers [5][6]. Due to their easy preparation and readily modification at either the

On the design principles of peptide–drug conjugates for targeted drug delivery to the malignant tumor site

• Eirinaios I. Vrettos,
• Gábor Mező and
• Andreas G. Tzakos

Beilstein J. Org. Chem. 2018, 14, 930–954, doi:10.3762/bjoc.14.80

• vehicles and formulates like nanoparticles [24] and calixarenes or cyclodextrins [25][26], where the cytotoxic drug is loaded and can be released at the malignant tumor site; b) installation of labile chemical groups to the tumor microenvironment (i.e., low pH) able to mask the cytotoxic drug and form a

Crystal structure of the inclusion complex of cholesterol in β-cyclodextrin and molecular dynamics studies

• Elias Christoforides,
• Andreas Papaioannou and
• Kostas Bethanis

Beilstein J. Org. Chem. 2018, 14, 838–848, doi:10.3762/bjoc.14.69

• increased safety in NPC animal models [12]. Moreover, superstructures of cyclodextrins like mono-lactose-appended β-CD [13] and biocleavable pluronic/β-CD-based polyrotaxanes [14] as well as PEG-lipid micelles (DSPE-PEG) in combination with HP-β-CD [15] have shown enhanced therapeutic effects and exhibit a

Phosphodiester models for cleavage of nucleic acids

• Satu Mikkola,
• Tuomas Lönnberg and
• Harri Lönnberg

Beilstein J. Org. Chem. 2018, 14, 803–837, doi:10.3762/bjoc.14.68

• departure of the 5´-linked nucleoside by a factor of 107. The mechanistic proposal has partly been based on Breslow’s studies on hydrolysis of 4-tert-butylcatechol cyclic phosphate by regioisomers of β-cyclodextrins bearing two imidazole groups [60]. This reverse reaction of the cyclization of 4-tert

An uracil-linked hydroxyflavone probe for the recognition of ATP

• Márton Bojtár,
• Péter Zoltán Janzsó-Berend,
• Dávid Mester,
• Dóra Hessz,
• Mihály Kállay,
• Miklós Kubinyi and
• István Bitter

Beilstein J. Org. Chem. 2018, 14, 747–755, doi:10.3762/bjoc.14.63

• the same fluorescence response with an association constant of 5.7∙104 M−1, however, the exact effect of various sized cyclodextrins on the complexation of flavones with ATP is currently unknown and will be the subject of an upcoming study by our group. To ascertain this method of signal transduction

Binding abilities of polyaminocyclodextrins: polarimetric investigations and biological assays

• Marco Russo,
• Daniele La Corte,
• Annalisa Pisciotta,
• Serena Riela,
• Rosa Alduina and
• Paolo Lo Meo

Beilstein J. Org. Chem. 2017, 13, 2751–2763, doi:10.3762/bjoc.13.271

• ][31][32][33][34][35]. Cyclodextrins (CDs), in particular, constitute appealing systems due to their biocompatibility, which allowed them to be approved by the FDA as human friendly products [36]. Thus, polycationic CDs might be used in principle as bimodal ligands for the simultaneous internalization

• protonation step at each polyamine branch occurs. This suggests the presence of strong intrachain interactions before protonation. Binding abilities of AmCDs towards p-nitroaniline derivatives 1–4 p-Nitroanilines constitute a good class of probe molecules for testing the microscopic behaviour of cyclodextrins

• investigated. Cyclodextrins have been already reported to change the transformation efficiency of different E. coli strains, although not in a standardized manner. Different cyclodextrin derivatives can cause from a 10-fold decrement up to a four-fold increment in the number of transformants compared to

Binding abilities of a chiral calix[4]resorcinarene: a polarimetric investigation on a complex case of study

• Marco Russo and
• Paolo Lo Meo

Beilstein J. Org. Chem. 2017, 13, 2698–2709, doi:10.3762/bjoc.13.268

• [6][7] to catalysis [8][9] and drug carriers [10][11][12][13]. Unlike the more popular cyclodextrins (CDs), CAs are exclusively obtained by chemical synthesis [14][15][16][17][18]. Therefore, they are particularly suitable for designing tailored systems with peculiar properties and abilities. This

• the viewpoint of the methodologies for investigating host–guest binding equilibria. In fact, simple polarimetry has been recently demonstrated to be an appealing and versatile tool for studying the host–guest interactions that imply cyclodextrins (CDs) [41][42][43][44][45], as well as for a reliable

• . Moreover, some p-nitroaniline derivatives were selected, because this class of molecules have been already proven as excellent probe guests to assess the microscopic interactions controlling the binding abilities of cyclodextrins [43][44][45][49][50][51][52][53]. Results and Discussion Synthesis and

Synthesis and supramolecular properties of regioisomers of mononaphthylallyl derivatives of γ-cyclodextrin

• Markéta Bláhová,
• Sergey K. Filippov,
• Lubomír Kováčik,
• Jiří Horský,
• Simona Hybelbauerová,
• Zdenka Syrová,
• Tomáš Křížek and
• Jindřich Jindřich

Beilstein J. Org. Chem. 2017, 13, 2509–2520, doi:10.3762/bjoc.13.248

• . Keywords: γ-cyclodextrin; naphthylallyl derivatives; regioselective alkylation; supramolecular properties; synthesis; Introduction Cyclodextrins [1] (CDs) are cyclic oligosaccharides with a cone-shaped cavity formed by α-1,4-linked D-glucopyranose units. The most widely used CDs are α-, β-, and γ-CD with

Structural diversity in the host–guest complexes of the antifolate pemetrexed with native cyclodextrins: gas phase, solution and solid state studies

• Magdalena Ceborska,
• Magdalena Zimnicka,
• Aneta Aniela Kowalska,
• Kajetan Dąbrowa and
• Barbara Repeć

Beilstein J. Org. Chem. 2017, 13, 2252–2263, doi:10.3762/bjoc.13.222

• /bjoc.13.222 Abstract The complexation of the antifolate pemetrexed (PTX) with native cyclodextrins was studied. This process, along with the findings gathered for the structurally related folic acid was treated as a model for exploiting host–guest interactions of this class of guest molecules in the

• ; pemetrexed; supramolecular chemistry; Introduction Herein, supramolecular host–guest complexes of the potent folic acid inhibitor pemetrexed (PTX, Figure 1a) with native cyclodextrins (α-, β- and γ-CDs, Figure 1b) in the gas phase (MS), in solution (NMR, UV–vis) and in the solid state (Raman, FTIR–ATR) were

Superstructures with cyclodextrins: Chemistry and applications IV

• Gerhard Wenz

Beilstein J. Org. Chem. 2017, 13, 2157–2159, doi:10.3762/bjoc.13.215

• Gerhard Wenz Saarland University, Organic Macromolecular Chemistry, Campus C4 2, 66123 Saarbrücken, Germany 10.3762/bjoc.13.215 Keywords: cyclodextrins; superstructures; Superstructures are generally formed from molecules through non-covalent interactions, which can be either attractive or

• repulsive. The first examples of superstructures formed by attractive intermolecular forces were complexes of crown ethers [1], cryptands [2] and spherands [3], which were recognized by the 1987 Nobel Prize in Chemistry. In addition, inclusion compounds of cyclodextrins (CDs), cyclic oligomers of glucose

• agents [26]. The exciting world of CD polyrotaxanes, including self-healing materials [27], was highlighted at a special session “Smart Polymers and Materials from Cyclodextrins: Novel Designs and Functions” at the 253rd ACS National Meeting in San Francisco in spring 2017. This Thematic Series in the

Solid-state studies and antioxidant properties of the γ-cyclodextrin·fisetin inclusion compound

• Joana M. Pais,
• Maria João Barroca,
• Maria Paula M. Marques,
• Filipe A. Almeida Paz and
• Susana S. Braga

Beilstein J. Org. Chem. 2017, 13, 2138–2145, doi:10.3762/bjoc.13.212

• are liposome derivatives) [20], and cyclodextrin inclusion complexes [21][22][23]. Cyclodextrins (CDs) are naturally occurring cyclic oligosaccharides produced by bacterial degradation of starch. Native CDs have six to eight α-D-glucose units linked by α-1,4 bonds, being called α-, β- and γ-CDs

• , respectively [24], and are able to solubilize hydrophilic molecules such as nutraceuticals or pharmaceuticals, providing that these have the adequate size and geometry to fit into the CDs cavities [25][26][27][28]. Nowadays, native cyclodextrins are approved by the FDA and the WHO/FAO Joint Committee with the

• cavity of γ-CD, which undergoes a slight geometric rearrangement in order to better accommodate fisetin. This host, the largest of the commercially available native cyclodextrins, is the most compatible with the size of flavonoid compounds. A smaller cyclodextrin, such as β-CD, is not able to fully

Intramolecular glycosylation

• Xiao G. Jia and
• Alexei V. Demchenko

Beilstein J. Org. Chem. 2017, 13, 2028–2048, doi:10.3762/bjoc.13.201

• extended to a number of useful applications including the synthesis of branched structures by Takahashi and cyclodextrins by Fukase discussed below. Thus, Takahashi et al. considered both flexible succinoyl and the rigid phthaloyl tether, but based on the outcome of the computational studies of relative

• synthesis of cyclodextrins is very challenging: controlling α-gluco stereoselectivity, and especially the final cyclization, represent a great challenge. For example, in Ogawa’s synthesis of α-cyclodextrin the chain assembly was non-stereoselective and the cyclization was achieved in only 21% yield [75

Influence of the milling parameters on the nucleophilic substitution reaction of activated β-cyclodextrins

• László Jicsinszky,
• Kata Tuza,
• Giancarlo Cravotto,
• Andrea Porcheddu,
• Francesco Delogu and
• Evelina Colacino

Beilstein J. Org. Chem. 2017, 13, 1893–1899, doi:10.3762/bjoc.13.184

• effect on the nucleophilic reaction. Keywords: cyclodextrins; milling parameters; nucleophilic substitution; planetary ball mill; Introduction Their hollow structures make cyclodextrins (CDs) a class of carbohydrates that can form inclusion complexes with organic molecules, inorganic salts and complex

• findings lend support to the idea that mechanical activation can induce chemical reactivity [29] and selectivity [30] which is different to that observed in solution, which can be further complicated by the inclusion complex formation property of cyclodextrins. How exactly the milling parameters influence

Molecular recognition of N-acetyltryptophan enantiomers by β-cyclodextrin

• Spyros D. Chatziefthimiou,
• Mario Inclán,
• Petros Giastas,
• Athanasios Papakyriakou,
• Konstantina Yannakopoulou and
• Irene M. Mavridis

Beilstein J. Org. Chem. 2017, 13, 1572–1582, doi:10.3762/bjoc.13.157

• structure; Introduction Cyclodextrins (CDs) are cyclic, water-soluble carbohydrates with a rather non-polar cavity that can host a variety of organic molecules (guests) and form inclusion complexes [1]. The guest molecules may be completely or partly enclosed inside the cavity depending on their size and

One-pot synthesis of block-copolyrotaxanes through controlled rotaxa-polymerization

• Jessica Hilschmann,
• Gerhard Wenz and
• Gergely Kali

Beilstein J. Org. Chem. 2017, 13, 1310–1315, doi:10.3762/bjoc.13.127

• properties [6][11][12][13]. One of the most important class of important macrocycles, applied in polyrotaxane chemistry, are cyclodextrins (CDs) because they are nontoxic, biodegradable and available in industrial scale. Furthermore, CDs can be simply functionalized by modification of the hydroxy groups [14

Glycoscience@Synchrotron: Synchrotron radiation applied to structural glycoscience

• Serge Pérez and
• Daniele de Sanctis

Beilstein J. Org. Chem. 2017, 13, 1145–1167, doi:10.3762/bjoc.13.114

• few thousand entries for carbohydrate crystal structures, among which a limited number of molecules are relevant to glycobiology. With the exception of sucrose and cyclic compounds, such as cyclodextrins or cyclo-amyloses, carbohydrates are reluctant to crystallize in form and size suitable for X-ray

Glyco-gold nanoparticles: synthesis and applications

• Federica Compostella,
• Olimpia Pitirollo,
• Alessandro Silvestri and
• Laura Polito

Beilstein J. Org. Chem. 2017, 13, 1008–1021, doi:10.3762/bjoc.13.100

• -glycolic acid)-PLGA NPs, liposomes), many examples in literature report on the development of gold-based glyco nanoparticles as efficient system to delivery payloads. In this contest, AuNPs modified with lactose moieties and β-cyclodextrins have been reported by Vargas-Berenguel et al. [87]. The authors

Interactions between shape-persistent macromolecules as probed by AFM

• Johanna Blass,
• Jessica Brunke,
• Franziska Emmerich,
• Cédric Przybylski,
• Vasil M. Garamus,
• Artem Feoktystov,
• Roland Bennewitz,
• Gerhard Wenz and
• Marcel Albrecht

Beilstein J. Org. Chem. 2017, 13, 938–951, doi:10.3762/bjoc.13.95

• polyconjugated polymers ranged from 6 to 16 nm, depending on the side groups and the method of determination [9][10][11]. Among many supramolecular interactions, such as hydrogen bonding, π–π-interactions or hydrophobic host–guest interactions [12][13][14][15][16], the interactions of cyclodextrins (CDs) with