Calixazulenes: azulene-based calixarene analogues – an overview and recent supramolecular complexation studies

• Paris E. Georghiou,
• Shofiur Rahman,
• Abdullah Alodhayb,
• Hidetaka Nishimura,
• Jaehyun Lee,
• Atsushi Wakamiya and
• Lawrence T. Scott

Beilstein J. Org. Chem. 2018, 14, 2488–2494, doi:10.3762/bjoc.14.225

• -hydrocarbon calix[4]azulenes which have been synthesized in good yields by their method. This allowed studying their supramolecular properties. This report is of our latest work on the solution-state supramolecular complexation of one of these calix[4]azulenes, namely tetrakis(5,7-diphenyl)calix[4]azulene or

• investigated. Keywords: azulene; calixarenes; calixazulenes; supramolecular chemistry; tetraalkylammonium salts; Introduction Among the great variety of synthetic macrocyclic molecular receptors which have been reported, those that are referred to by their generic name “calixarene” loom large [1][2][3]. The

• just a few. Reinhoudt has recently presented an overview of the historical evolution of the chemistry of the calixarenes [1]. Supramolecular applications, in particular, of many of the great number of creative derivatives of calixarenes which have been and continue to be synthesized are widely being

Efficient catalytic alkyne metathesis with a fluoroalkoxy-supported ditungsten(III) complex

• Henrike Ehrhorn,
• Janin Schlösser,
• Dirk Bockfeld and
• Matthias Tamm

Beilstein J. Org. Chem. 2018, 14, 2425–2434, doi:10.3762/bjoc.14.220

• molybdenum propylidyne precursors to form chelate complexes of type IV [31][32][33][34]. These catalysts were especially successful in the construction of supramolecular materials such as ethynylene-linked polymers [11][35], porous networks [36] and molecular cages [37][38][39][40][41][42][43]. Furthermore

Coordination-driven self-assembly of discrete Ru₆–Pt₆ prismatic cages

• Aderonke Ajibola Adeyemo and
• Partha Sarathi Mukherjee

Beilstein J. Org. Chem. 2018, 14, 2242–2249, doi:10.3762/bjoc.14.199

• supramolecular chemistry leading to the formation of a single major product. Keywords: arene–ruthenium(II); heterometallic cages; platinum metalloligand; self-assembly; supramolecular architectures; Introduction Coordination-driven self-assembly of discrete architectures has evolved as a unique protocol to

• construct elegant supramolecular architectures of different shapes, sizes and functionalities over the last two decades [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23]. These 2D and 3D-supramolecular architectures mostly comprise pure organic ligands as electron-rich

• [47][48][49][50][51] and host–guest chemistry [52][53][54][55][56] among others. The cardinal prerequisites to obtain these self-assembled supramolecular architectures include stoichiometry and conformational complementarity on the binding sites of the building blocks [57][58][59][60][61]. However

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

• Xiayang Huang Xinghua Zhang Tianxin Qian Junwei Ma Lei Cui Chunju Li School of Chemical and Environmental Engineering, Shanghai Institute of Technology, 100 Hai-Quan Road, Shanghai 201418, P. R. China Department of Chemistry, Center for Supramolecular Chemistry and Catalysis, Shanghai University

• , 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

• delivery, supramolecular amphiphiles, etc. Experimental 2,2’-OEtBP4 was synthesized according to our previously reported method [47]. P and B were purchased from Shanghai Aladdin Bio-Chem Technology Co.,LTD. 1H NMR and 13C NMR spectra were recorded on a Bruker AV500 instrument. The fluorescence emission

Dynamic light scattering studies of the effects of salts on the diffusivity of cationic and anionic cavitands

• Anthony Wishard and
• Bruce C. Gibb

Beilstein J. Org. Chem. 2018, 14, 2212–2219, doi:10.3762/bjoc.14.195

• light scattering; Hofmeister effect; ion–ion interactions; water; Introduction Although all life on planet Earth depends on aqueous solutions, our understanding of aqueous supramolecular chemistry is limited. As a result, as Smith has eloquently pointed out [1], the effects of buffers and salts on

• [4][10][11]. Although many attempts have been made to amend these and other classical models [4], success has been limited because of our lack of understanding of the specific supramolecular properties of individual ions. There is therefore an opportunity for supramolecular chemists (who by their

Synthesis and post-functionalization of alternate-linked-meta-para-[2ⁿ.1ⁿ]thiacyclophanes

• Wout De Leger,
• Koen Adriaensen,
• Koen Robeyns,
• Luc Van Meervelt,
• Joice Thomas,
• Björn Meijers,
• Mario Smet and
• Wim Dehaen

Beilstein J. Org. Chem. 2018, 14, 2190–2197, doi:10.3762/bjoc.14.192

• ; Introduction The ability of cyclophanes to form three-dimensional cavities is interesting for various potential applications, e.g., as supramolecular hosts. Synthetic procedures towards novel cyclophanes have attracted much interest in the scientific community [1][2][3][4]. An interesting subclass of

• homodithiacalix[4]arenes by dynamic covalent chemistry [12][13][14]. Functionalization of homothiacalix[4]arenes was made possible by changing the precursors before macrocyclization (Scheme 1) [12]. Recently, pillar[n]arenes have attracted much interest as new supramolecular receptors due to their pillar-shaped

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

• contemporary research challenge. Tetrathiafulvalenes (TTFs) are one of the most versatile and widely used molecular redox switches to generate and control molecular motion. TTF can easily be implemented as functional unit into molecular and supramolecular structures and can be reversibly oxidized to a stable

• ; supramolecular chemistry; tetrathiafulvalene; Introduction Undoubtedly, the exploration of nature’s molecular machines in the last century led to a paradigm change of how we think about working and organization processes on the molecular level [1][2][3]. Inspired by the way how energy and concentration

• molecules, the mechanical bond provides cohesive supramolecular assemblies with unique properties and a high flexibility and mobility of the subcomponents in a small molecular space. To control molecular motion, one of the most important construction principles to transform a simple MIM into an AMM is to

Evaluation of dispersion type metal···π arene interaction in arylbismuth compounds – an experimental and theoretical study

• Ana-Maria Preda,
• Małgorzata Krasowska,
• Lydia Wrobel,
• Philipp Kitschke,
• Phil C. Andrews,
• Jonathan G. MacLellan,
• Lutz Mertens,
• Marcus Korb,
• Tobias Rüffer,
• Heinrich Lang,
• Alexander A. Auer and
• Michael Mehring

Beilstein J. Org. Chem. 2018, 14, 2125–2145, doi:10.3762/bjoc.14.187

• applications in the field of supramolecular chemistry [10][11][12] and pharmacology are of interest [13][14][15]. Lately, several studies regarding the metal···π interactions in organometallic compounds of antimony and bismuth [16][17][18][19] have been reported including intramolecular [20][21][22] and

• compounds of the type Ar3Bi (Ar = C4H3NMe, C4H3O, C4H3S, C4H3Se) [28][29]. Other state of the art examples on the formation of supramolecular assemblies via dispersion type metal···π arene intermolecular interactions [10][11] were summarized by Caracelli et al., and recently Tiekink classified this type of

• interaction as one of the emerging intermolecular interactions that are of particular interest to coordination chemists with regard to supramolecular chemistry [12]. However, most reports on main group metal···π interactions are based on the description of the single crystal structures and lack a profound

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

• bis(benzylalkylammonium) axle [19], where the stereoselective formation of the pseudo[3]rotaxane with endo-alkyl orientation VIII was observed [19]. Calixarene macrocycles [22] have found numerous applications in several areas of supramolecular chemistry, such as (bio)molecular recognition [23] and

A switchable [2]rotaxane with two active alkenyl groups

• Xiu-Li Zheng,
• Rong-Rong Tao,
• Rui-Rui Gu,
• Wen-Zhi Wang and
• Da-Hui Qu

Beilstein J. Org. Chem. 2018, 14, 2074–2081, doi:10.3762/bjoc.14.181

• polymers. Keywords: alkenyl bond; functional crown ether; stimuli-responsiveness; switchable rotaxane; Introduction Along with the development of supramolecular chemistry, much attention has been paid to the design and synthesis of novel and complicated mechanical interlocked molecules (MIMs) [1][2][3][4

• , which act as important precursors for constructing stimuli-responsive supramolecular materials [21][22]. Rotaxanes [23][24][25][26][27][28][29][30][31], as one of the most important MIMs, have been deeply investigated because of their excellent properties and convenient synthesis. By introducing various

Synthesis and supramolecular self-assembly of glutamic acid-based squaramides

• Juan V. Alegre-Requena,
• Marleen Häring,
• Isaac G. Sonsona,
• Alex Abramov,
• Eugenia Marqués-López,
• Raquel P. Herrera and
• David Díaz Díaz

Beilstein J. Org. Chem. 2018, 14, 2065–2073, doi:10.3762/bjoc.14.180

• derivative; organogel; self-assembly; squaramide; supramolecular gel; Introduction Since their discovery, squaramides have gained importance across different fields from chemistry to biomedicine due to their synthetic versatility and wide applicability [1]. These compounds, formed by two amine units

• crystal engineering [13][14][15][16][17]. Despite their isosteric relationship with ureas, which have become key synthons in supramolecular chemistry [18][19], there are only a few reports on the formation of self-assembled supramolecular gels using squaramide derivatives [20][21][22][23]. Along this line

• , supramolecular or physical gels have received great attention during the last decade [24][25] due to their unique architectures and potential applications in many areas such as biomedicine (mainly hydrogels), health care and catalysis, among others [26][27][28][29]. In contrast to chemical gels [30], physical

Coordination-driven self-assembly vs dynamic covalent chemistry: versatile methods for the synthesis of molecular metallarectangles

• Li-Li Ma,
• Jia-Qin Han,
• Wei-Guo Jia and
• Ying-Feng Han

Beilstein J. Org. Chem. 2018, 14, 2027–2034, doi:10.3762/bjoc.14.178

• , Ministry of Education, Anhui Normal University, Wuhu 241002, China 10.3762/bjoc.14.178 Abstract Supramolecular coordination assemblies have a range of potential applications in chemical and biological sciences. Herein, simple modular methods for the synthesis of metallarectangles are described. The

• self-assembly; dynamic covalent chemistry; half-sandwich rhodium complex; metallarectangles; one-pot reaction; supramolecular chemistry; Introduction Over the past two decades, supramolecular structures with organometallic half-sandwich fragments have attracted much attention, including

• coordination-driven self-assembly has been proven to be a powerful tool to construct supramolecular architectures with controlled shapes and sizes [18][19][20][21][22][23][24][25][26][27][28][29][30]. Using this strategy, a host of exciting supramolecular structures have been constructed by using two

A self-assembled photoresponsive gel consisting of chiral nanofibers

• Lei Zou,
• Dan Han,
• Zhiyi Yuan,
• Dongdong Chang and
• Xiang Ma

Beilstein J. Org. Chem. 2018, 14, 1994–2001, doi:10.3762/bjoc.14.174

• absorption spectroscopy, circular dichroism, scanning electron microscopy and rheological techniques. This work provides a new method for facile synthesis of chiro-optical gels. Keywords: chirality; nanostructure; organogel; photoresponse; self-assembly; Introduction Supramolecular gels [1][2] immobilized

• ], and chemosensing [13][14]. Among the supramolecular gels, the low-molecular-weight gels (LMWGs) [15][16] are those that self-assemble into gels in organic solvents with molecular weights of <2000 Da. The weak noncovalent intermolecular interactions between LMWGs make them more sensitive to external

• formation of supramolecular structure. To investigate the potential photoresponsiveness of compound 3, the UV–vis absorption spectrum was measured to trace photochemical and photophysical properties of the solution of compound 3 (1.0 × 10−5 M in chloroform). As shown in Figure 2, the azobenzene trans-isomer

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

• concentration. Second, the dye should not be fully absorbed in the hydrophobic domain of an aggregate to be easily released into solution after any changes that occur with the molecule/aggregate. In this context premicellar aggregates are good candidates to design supramolecular systems for recognition and

• complex formation was calculated as a difference between free energy of calix[4]arene + ADP/ATP complex and isolated calix[4]arene and ADP/ATP dianion. The complex structures corresponding to the minimum energy as well as supramolecular binding motif of ADP and ATP are presented in Figure 4. As can be

• seen ADP more effectively embeds into the molecular cleft formed by two ammonium moieties due to a good host–guest geometric size and/or shape complementarity (Figure 4a and c). The three phosphate groups of ATP have a larger size and cannot realize a similar supramolecular motif in the complex. For

Rational design of boron-dipyrromethene (BODIPY) reporter dyes for cucurbit[7]uril

• Mohammad A. Alnajjar,
• Jürgen Bartelmeß,
• Robert Hein,
• Pichandi Ashokkumar,
• Mohamed Nilam,
• Werner M. Nau,
• Knut Rurack and
• Andreas Hennig

Beilstein J. Org. Chem. 2018, 14, 1961–1971, doi:10.3762/bjoc.14.171

• -dipyrromethene (BODIPY) dyes as a new class of fluorophores for the design of reporter dyes for supramolecular host–guest complex formation with cucurbit[7]uril (CB7). The BODIPYs contain a protonatable aniline nitrogen in the meso-position of the BODIPY chromophore, which was functionalized with known binding

• transfer; supramolecular chemistry; Introduction Cucurbit[n]urils (CBn, n = 5–8, 10, and 14) are a class of macrocyclic host molecules which are water soluble, nontoxic, and are able to bind a large variety of neutral and cationic guests in their inner cavity with high affinity [1][2][3][4]. This unique

• −1 for the cyclohexylmethylammonium cation, 5.3 × 103 M−1 for the anilinium cation and 1.4 × 105 M−1 for the benzylammonium cation in the 10 mM citrate buffer in 30% (v/v) ACN in water. As another advantage over previously established supramolecular reporter dyes, the absorption maximum of the

Synthesis and characterization of π–extended “earring” subporphyrins

• Haiyan Guan,
• Mingbo Zhou,
• Bangshao Yin,
• Ling Xu and
• Jianxin Song

Beilstein J. Org. Chem. 2018, 14, 1956–1960, doi:10.3762/bjoc.14.170

• 3Pd is further red-shifted and more intense. Keywords: aromaticity; earring subporphyrin; π-extended; supramolecular chemistry; Findings Since its first synthesis in 2006 [1][2], subporphyrin, the lowest homolog of porphyrins, has received considerable attention [3][4][5][6][7][8] due to its 14π

Recent advances in materials for organic light emitting diodes

• Eli Zysman-Colman

Beilstein J. Org. Chem. 2018, 14, 1944–1945, doi:10.3762/bjoc.14.168

• obtained his Ph.D. from McGill University in 2003. He then completed two postdoctoral fellowships, one in supramolecular chemistry at the Organic Chemistry Institute, University of Zurich and the other in inorganic materials chemistry at Princeton University. After beginning his career in Canada, he moved

An amphiphilic pseudo[1]catenane: neutral guest-induced clouding point change

• Tomoki Ogoshi,
• Tomohiro Akutsu and
• Tada-aki Yamagishi

Beilstein J. Org. Chem. 2018, 14, 1937–1943, doi:10.3762/bjoc.14.167

• upon addition of a neutral guest, 1,4-dicyanobutane. The supramolecular structural change contributed to a significant increase in the hydrophobic ratio of the molecule, which induced insolubilization of 3 in aqueous media at 20 °C and a decrease of the clouding point temperature. Neutral guest

• -responsive LCST changes are very rare, while there have been some examples of LCST control using ionic chemical stimuli [5][6]. Results and Discussion Supramolecular structure and clouding point of bicyclic compound 3 The bicyclic compound 3 was prepared using a copper(I)-catalyzed alkyne–azide cycloaddition

• supramolecular structure of 3 by 1H NMR spectroscopy. In CDCl3, the signals from the alkyl chain of 3 (blue peaks, a–e, Figure 2) were observed upfield compared with the ones of the model compound 4 (Figure 2a). This is due to an aromatic shielding by the pillar[5]arene cavity, indicating that 3 mainly formed a

Asymmetric Michael addition reactions catalyzed by calix[4]thiourea cyclohexanediamine derivatives

• Zheng-Yi Li,
• Hong-Xiao Tong,
• Yuan Chen,
• Hong-Kui Su,
• Tangxin Xiao,
• Xiao-Qiang Sun and
• Leyong Wang

Beilstein J. Org. Chem. 2018, 14, 1901–1907, doi:10.3762/bjoc.14.164

• and yields of the Michael reactions. Supramolecular catalysis has drawn tremendous interest in the past few years [15][16][17][18][19][20][21][22][23]. In this context, calixarenes are ideal supramolecular macrocyclic scaffolds for the design of molecular receptors and organocatalysts due to their

• nitrostyrene 7a lacking substituents has minimal steric hindrance and tends to bind with the calixarene cavity by supramolecular host–guest interactions which could further improve the enantioselectivity. In addition, electronic effects of the substituents on the aromatic ring showed a significant influence on

• supramolecular host–guest interaction with the calixarene to form a stable transition state A. Then, another hydrogen bond is formed between the nitrogen atom of the tertiary amine group in A and acetylacetone in its enol form, leading to the formation of a ternary complex B. Finally, nucleophilic attack of

A hemicryptophane with a triple-stranded helical structure

• Augustin Long,
• Olivier Perraud,
• Erwann Jeanneau,
• Christophe Aronica,
• Jean-Pierre Dutasta and
• Alexandre Martinez

Beilstein J. Org. Chem. 2018, 14, 1885–1889, doi:10.3762/bjoc.14.162

• part). They display recognition properties toward neurotransmitters and carbohydrates, and can act as molecular switches and supramolecular catalysts [11]. Their C3 symmetry makes them promising candidates to build molecular cages displaying a triple helical arrangement of the linkers. Furthermore, we

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

• in view of low cost, ease of use and high sensitivity of optical sensing modalities, but remains a challenge since BPs are considered as unlabeled analytes. With the development of the host–guest concept in supramolecular chemistry, the indicator displacement assay (IDA), pioneered by Prof. Anslyn

Recent advances in hypervalent iodine(III)-catalyzed functionalization of alkenes

• Xiang Li,
• Pinhong Chen and
• Guosheng Liu

Beilstein J. Org. Chem. 2018, 14, 1813–1825, doi:10.3762/bjoc.14.154

• asymmetric induction. The NH group engages hydrogen bonding with the acetoxy groups located at an iodine(III) center to form two nine-membered rings, which were confirmed by the crystal structure of the iodine(III) reagent 16 [53]. The hydrogen bonding effect is crucial to a supramolecular helical chiral

Host–guest complexes of conformationally flexible C-hexyl-2-bromoresorcinarene and aromatic N-oxides: solid-state, solution and computational studies

• Rakesh Puttreddy,
• Ngong Kodiah Beyeh,
• S. Maryamdokht Taimoory,
• Daniel Meister,
• John F. Trant and
• Kari Rissanen

Beilstein J. Org. Chem. 2018, 14, 1723–1733, doi:10.3762/bjoc.14.146

• ], coordination chemistry [12][13], biological systems [14] and especially for host–guest (H–G) chemistry [15]. Resorcinarenes can be modified at either the upper rim 2-position, lower rim, or both, to deliver supramolecular structures with the required structure for a given function [16][17][18]. We have shown

• various upper-rim substituents, differing lower-rim alkyl chain length, specific guests, and selective solvents, have made resorcinarenes an attractive platform for H–G applications. Through careful rational supramolecular design via self-assembly processes, our lab and others have combined simple 1:1 H–G

• building blocks into dimers [29][30][31], hexamers [32] or supramolecular chains (1D), sheets (2D), or lattice (3D) networks [15]. The detailed analysis of the molecular level interactions of these systems also has enabled our research to design constructs with specific individual molecular and electronic

Design, synthesis and structure of novel G-2 melamine-based dendrimers incorporating 4-(n-octyloxy)aniline as a peripheral unit

• Cristina Morar,
• Pedro Lameiras,
• Attila Bende,
• Gabriel Katona,
• Emese Gál and
• Mircea Darabantu

Beilstein J. Org. Chem. 2018, 14, 1704–1722, doi:10.3762/bjoc.14.145

• block copolymers and G-0 monomeric or dimeric dendritic liquid crystals with photochromic azobenzene mesogens. The present ab initio study explores a previously unknown use of 4-(n-octyloxy)aniline in the synthesis, structure and supramolecular behaviour of new dendritic melamines. Results: Starting

• (ethynyl)-s-triazine and various icosanyloxyphenylazides) with liquid crystalline and luminescent properties [22]. On the other hand, mesogenic supramolecular perylene bisimide assemblies with a number of 2-amino-4,6-bis[(4-alkoxy)phenylamino]-s-triazines [23], amphiphilic azobenzene-containing linear

Synthesis of diamido-bridged bis-pillar[5]arenes and tris-pillar[5]arenes for construction of unique [1]rotaxanes and bis-[1]rotaxanes

• Ying Han,
• Li-Ming Xu,
• Cui-Yun Nie,
• Shuo Jiang,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2018, 14, 1660–1667, doi:10.3762/bjoc.14.142

• ]rotaxane and [1]rotaxane are one of particular supramolecular assembly system and are considered as an important building block in the construction of diverse MIMs [5][6][7][8][9][10]. [1]Rotaxane has a macrocyclic wheel component connected with a self-locked chain axle, and a bulky stopper at the terminal

• explosive development on the construction of various supramolecular devices and diverse responsive materials has been reported by using diverse functionalized pillararenes [33][34][35]. Due to easily preparation and suitable cavity, functionalized pillar[5]arenes were widely used as wheel component for

• feature was obtained in the five single crystals. That is, the longer chain of methyl (ethyl) oxyalkoxybenzoate not only does not inserted in the cavity of the pillar[5]arene to form the pseudo[1]rotaxane, but also does not thread to the cavity of the neighbouring pillar[5]arene to form the supramolecular