Active-metal template clipping synthesis of novel [2]rotaxanes

• Cătălin C. Anghel,
• Teodor A. Cucuiet,
• Niculina D. Hădade and
• Ion Grosu

Beilstein J. Org. Chem. 2023, 19, 1776–1784, doi:10.3762/bjoc.19.130

• , reported by Sauvage in 1983 [14], the synthetic strategies employed to access MIMs, including catenanes, rotaxanes and molecular knots, have grown in number and complexity of the obtained structures [15]. Thus, currently, synthesis of rotaxanes is usually performed through clipping, capping, snaping or

Tying a knot between crown ethers and porphyrins

• Maksym Matviyishyn and
• Bartosz Szyszko

Beilstein J. Org. Chem. 2023, 19, 1630–1650, doi:10.3762/bjoc.19.120

• supramolecular architectures [45], e.g., catenanes [73], rotaxanes [74], and catalytic systems [75]. Pelegrino and co-workers reported on crowned porphyrinoids demonstrating interesting photophysical properties [71]. The crown ether part was also demonstrated to play a role of a linker between two porphyrin

• molecules, e.g., catenanes and rotaxanes (Figure 16C). The formation of such compounds would eventually result in the formation of a unique group of three-dimensional ligands with co-existing porphyrin-like and crown ether cavities. The perspective article has highlighted the wide range of crown ether

Cyclodextrins as building blocks for new materials

• Miriana Kfoury and
• Sophie Fourmentin

Beilstein J. Org. Chem. 2023, 19, 889–891, doi:10.3762/bjoc.19.66

• science that require high performance with minimal environmental impact. They are involved in the construction of interlocked molecules (rotaxanes and catenanes), supramolecular polymers, artificial enzymes, hydrogels, metal–organic frameworks, supramolecular solvents, fibers, nanotubes, nanoparticles

Supramolecular approaches to mediate chemical reactivity

• Pablo Ballester,
• Qi-Qiang Wang and
• Carmine Gaeta

Beilstein J. Org. Chem. 2022, 18, 1463–1465, doi:10.3762/bjoc.18.152

• and stereocontrol of the reaction depends on the conformational rigidity of the macrocyclic framework and a synergy between the thiourea and tertiary amine sites. Recently, many efforts were focused on the synthesis and applications of mechanically interlocked molecules (MIMs), such as catenanes and

BINOL as a chiral element in mechanically interlocked molecules

• Matthias Krajnc and
• Jochen Niemeyer

Beilstein J. Org. Chem. 2022, 18, 508–523, doi:10.3762/bjoc.18.53

• stereoselective chemosensing. Given the growing importance of mechanically interlocked molecules and the key advantages of the privileged chiral BINOL backbone, we believe that this research area will continue to grow and deliver many useful applications in the future. Keywords: axial chirality; BINOL; catenanes

• ; interlocked molecules; rotaxanes; Introduction In the last decades the synthesis and application of mechanically interlocked molecules (MIMs), such as catenanes and rotaxanes, has gained more and more attention [1][2][3][4]. MIMs offer conceptually new possibilities through their unique structure, with

• thread also leads to a desymmetrization of the BINOL-based macrocycle (loss of C2 symmetry), as seen by 13C NMR spectroscopy. Stoddart and co-workers also used their π–π-recognition approach for the synthesis of BINOL-containing cationic catenanes [47][48]. They employed BINOL-based macrocycles

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

• , including molecular switches, molecular logic gates, molecular machines, supramolecular polymers, etc. [6][7][8][9][10][11]. Pseudorotaxanes not only are used as the supramolecular precursors for the synthesis of rotaxanes and catenanes but also play an important role in the construction of supramolecular

Using multiple self-sorting for switching functions in discrete multicomponent systems

• Amit Ghosh and
• Michael Schmittel

Beilstein J. Org. Chem. 2020, 16, 2831–2853, doi:10.3762/bjoc.16.233

• -interlocked catenanes. When both cages were mixed without C70, the dynamic combinatorial library (DCL) of seven compositionally distinct mixed-ligand Zn4L6 cages was observed (Figure 5b). An efficient self-sorting was only observed after the addition of the guest C70. As expected, the cage [Zn4(8')6]8

A heterobimetallic tetrahedron from a linear platinum(II)-bis(acetylide) metalloligand

• Matthias Hardy,
• Marianne Engeser and
• Arne Lützen

Beilstein J. Org. Chem. 2020, 16, 2701–2708, doi:10.3762/bjoc.16.220

• sophisticated cage-in-ring structures [6][7], interlocked rings [8] and catenanes [9][10][11][12] or giant spheres [13][14]. Increasing the structural complexity, however, usually implies growing synthetic efforts that have to be made to obtain the necessary organic ligands [15][16][17]. A great way to simplify

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

• Sauvage, Stoddart, and Feringa for their work on molecular machines [4]. Sauvage [5] and Stoddart [6] extensively used macrocycles in their ground-breaking work on catenanes, rotaxanes, knots, and other topologically novel compounds. Exciting advances in the field of molecular topology continue with novel

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

• analogous experiment was done with benzoate, due to the precipitation of an insoluble ferrocenium complex [40]. 2.4. Mechanically interlocked catenanes containing 1,2,3-triazolium macrocycles Mechanically interlocked molecules like rotaxane and catenane have attracted much attention in the field of

• nanoscale molecular machines and switches [41] and their importance has been recognized by the 2016 Nobel prize. Anion recognition can be used as an impediment for rotary movement in the rotaxane structure. Besides, catenanes possessing a mechanically interlocked ring, have attracted considerable attention

• , we will focus on describing the behavior of three different 1,2,3-triazolium macrocycles including 1,2,3-triazolium catenanes, containing dinaphtho-24-crown-8 (DN24C8) and naphthalenediimide (NDI) moieties at different pH values. 4.1. pH sensors based on 1,2,3-triazolium macrocycles Different methods

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

• ]. Among the self-assembly processes, those that lead to the formation of interlocked and/or interpenetrated supramolecular structures have inspired many scientists [5][6][7][8]. The synthesis of interlocked molecules such as rotaxanes, catenanes, and high-order architectures (e.g., polyrotaxanes, suitanes

• -catenanes [25]. On the basis of these results, we were also able to assemble high-order architectures by double-threading of bis-calix[6]arene hosts with ammonium axles [27]. In particular, handcuff (pseudo)rotaxane architectures (e.g., 32+ in Figure 2) [27] were obtained by double-threading of bis-calix[6

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

• building blocks for the construction of complex molecular topology such as rotaxanes and catenanes [12][13][14][15]. For example, by making use of hydrophobic-driven binding of simple alkyl groups in water to α-CD, Ogino has reported one first example of a rotaxane assembly featuring an alkyldiamine

• interested in exploiting the binding capability of γ-CD in the construction of high order [n]rotaxanes and [n]catenanes. Here, we report our work on the synthesis of multiring, hetero[n]rotaxane containing γ-CD and cucurbit[6]uril (CB[6]) as the macrocyclic components in an aqueous medium. Because of the

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

• [9] "for the design and synthesis of molecular machines" is an outstanding appreciation of the public and scientific community. Mechanically interlocked molecules (MIMs) such as rotaxanes [10] or catenanes [11] are ideally suited for the construction of AMMs. In comparison to covalently linked

• rotaxanes is achieved by stoppering reactions, while catenanes can be made by macrocyclization of the pseudorotaxane thread. Therefore, we discuss in the following section reports of important pseudorotaxanes and inclusion complexes that contributed to major developments of TTF-based MIMs and AMMs. The

• encircled. This TTF-based system is an intriguing example of synergetic molecular motions triggered by redox stimuli. 6. Catenanes Catenanes consist of at least two intertwined macrocycles which are mechanically interlocked. The structure cannot be opened without breaking a covalent bond. In contrast to

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

• axle. In all the examined cases, the 1,2,3-alternate and cone atropoisomers are, respectively, the kinetic and the thermodynamic ones. Keywords: atropoisomers; calixarene; conformation; pseudorotaxane; social isomerism; Introduction Mechanomolecules [1][2][3][4], such as rotaxanes and catenanes show

• interesting properties as nanodevices for catalysis [5][6][7][8], recognition, and sensing [9][10][11][12][13]. Beyond these ascertained potentialities, interpenetrated architectures show fascinating structures that still stimulate the imagination of scientists. An amazing aspect of rotaxanes and catenanes is

• stereoisomeric directional pseudo[2]rotaxanes, rotaxanes, and catenanes. Also in this case [38], we were able to obtain a stereoselective threading of the cone calix[6]arene-wheel with alkylbenzylammonium axles (Figure 4b), in which the endo-alkyl pseudo[2]rotaxane stereoisomer was the favoured one [38]. The

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

• best of our knowledge, the use of a dynamic supramolecular structural change of 3 to induce an LCST change is the first example in this area. Thus, this work may open the way for the design of a new generation of molecular assembly systems using supramolecular structures such as rotaxane, catenanes

A pyridinium/anilinium [2]catenane that operates as an acid–base driven optical switch

• Sarah J. Vella and
• Stephen J. Loeb

Beilstein J. Org. Chem. 2018, 14, 1908–1916, doi:10.3762/bjoc.14.165

• derivatize, [2]rotaxanes are deemed easier to fine-tune from a structural perspective than [2]catenanes. Although we were able to create an optically sensitive [2]catenane molecular shuttle with the bis(pyridinium)ethane and benzylanilinium recognition motifs, we could not achieve the true ON/OFF, bistable

Efficient catenane synthesis by cucurbit[6]uril-mediated azide–alkyne cycloaddition

• Antony Wing Hung Ng,
• Chi-Chung Yee,
• Kai Wang and
• Ho Yu Au-Yeung

Beilstein J. Org. Chem. 2018, 14, 1846–1853, doi:10.3762/bjoc.14.158

• Antony Wing Hung Ng Chi-Chung Yee Kai Wang Ho Yu Au-Yeung Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China 10.3762/bjoc.14.158 Abstract We report here the efficient synthesis of a series of [3]catenanes featuring the use of cucurbit[6]uril to

• simultaneously mediate the mechanical and covalent bond formations. By coupling the mechanical interlocking with covalent macrocyclization, formation of topological isomers is eliminated and the [3]catenanes are formed exclusively in good yields. The efficient access to these [3]catenanes and the presence of

• other recognition units render them promising building blocks for the construction of other high-order interlocked structures. Keywords: azide–alkyne cycloaddition; catenane; click chemistry; cucurbit[6]uril; mechanical bond; Introduction Catenanes are topologically non-trivial molecules possessing

Superstructures with cyclodextrins: Chemistry and applications IV

• Gerhard Wenz

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

• , belong to this category and have been known since the pioneering work of Friedrich Cramer in 1951 [4][5]. Superstructures can also be held together by repulsive forces, so-called mechanical bonds [6], as exemplified in catenanes, rotaxanes, and knots [7]. Because of their restricted mobility, rotaxanes

Complexation of molecular clips containing fragments of diphenylglycoluril and benzocrown ethers with paraquat and its derivatives

• Leonid S. Kikot',
• Catherine Yu. Kulygina,
• Alexander Yu. Lyapunov,
• Svetlana V. Shishkina,
• Roman I. Zubatyuk,
• Tatiana Yu. Bogaschenko and
• Tatiana I. Kirichenko

Beilstein J. Org. Chem. 2017, 13, 2056–2067, doi:10.3762/bjoc.13.203

• these studies led to the preparation of rotaxanes and catenanes, and to the elaboration of the principles of molecular machines, for which J. Fraser Stoddart [4][5][6], Jean-Pierre Sauvage [7][8] and Bernard L. Feringa [9][10] received the Nobel Prize in chemistry in 2016. In addition to Stoddart, the

• observed for other complexes of the clips 1–5 with paraquat derivatives 8–10. This is typical for most pseudorotaxanes and catenanes and an evidence of the fairly stable host–guest inclusion complexes [33][34]. The ability of the obtained clips 1–5 to act as receptors for the guests 7–10 in solution was

Creating molecular macrocycles for anion recognition

• Amar H. Flood

Beilstein J. Org. Chem. 2016, 12, 611–627, doi:10.3762/bjoc.12.60

• can be programmed to move and change shape (rotaxanes and catenanes) had hooked my attention. Quite apart from his gift for creating new molecules that are also functional, the number of people who shared co-authorship with him intrigued me. Joining Professor Stoddart’s laboratory in 2002 as a

A journey in bioinspired supramolecular chemistry: from molecular tweezers to small molecules that target myotonic dystrophy

• Steven C. Zimmerman

Beilstein J. Org. Chem. 2016, 12, 125–138, doi:10.3762/bjoc.12.14

• therapeutic agents for myotonic dystrophy using a rational design approach that heavily relies on principles of supramolecular chemistry. How this work was influenced by that of others in the field and the evolution of each area of research is highlighted with selected examples. Keywords: catenanes

Supramolecular polymer assembly in aqueous solution arising from cyclodextrin host–guest complexation

• Jie Wang,
• Zhiqiang Qiu,
• Yiming Wang,
• Li Li,
• Xuhong Guo,
• Duc-Truc Pham,
• Stephen F. Lincoln and
• Robert K. Prud’homme

Beilstein J. Org. Chem. 2016, 12, 50–72, doi:10.3762/bjoc.12.7

• blocks in supramolecular structures and functional materials. These are exemplified by catenanes [20][21], rotaxanes [21][22][23][24][25], polyrotaxanes [24][25][26][27][28][29], polymers and polymer networks [12][22][26][30][31][32][33][34]. The focus of this review is on recent developments in the

Supramolecular chemistry: from aromatic foldamers to solution-phase supramolecular organic frameworks

• Zhan-Ting Li

Beilstein J. Org. Chem. 2015, 11, 2057–2071, doi:10.3762/bjoc.11.222

• have always been my favorite. When I performed my postdoctoral research in Denmark, I used fluorine-containing precursors to build catenanes [8], and many years later, I utilized fluorine as a hydrogen bonding acceptor to develop aromatic amide and triazole foldamers [9][10]. Postdoctoral research at

• the University of South Denmark: donor–acceptor interaction-driven catenanes From October 1994 to December 1995, I performed postdoctoral research with Professor Jan Becher at Odense University (currently University of South Denmark) in Denmark. Through his research career, Professor Becher studied

• core [11]. Using this method, I could prepare bimacrocycle 3 in a short time. This macrocycle was used to template the formation of the so-called tetracationic “blue box” [12][13] from 4 and 5 to give rise to the unique pseudo[3]catenanes 6a and 6b (Scheme 2), together with a trace amount of [2

Selected synthetic strategies to cyclophanes

• Sambasivarao Kotha,
• Mukesh E. Shirbhate and
• Gopalkrushna T. Waghule

Beilstein J. Org. Chem. 2015, 11, 1274–1331, doi:10.3762/bjoc.11.142

• demonstrate the extensive use of RCM in the synthesis of different metallophanes involving ferrocenophane (e.g., 206) [160] and other metallophanes [161][162][163][164]. The synthesis of mechanically interlocked molecules such as catenanes and rotaxanes which are used to assemble molecular machines, sensors

Thiophene-based donor–acceptor co-oligomers by copper-catalyzed 1,3-dipolar cycloaddition

• Stefanie Potratz,
• Amaresh Mishra and
• Peter Bäuerle

Beilstein J. Org. Chem. 2012, 8, 683–692, doi:10.3762/bjoc.8.76

• popular and reached high significance in materials synthesis, because high yields and easy to purify products are typically obtained [13][14]. The click chemistry approach was successfully employed to synthesize various oligomers [15][16][17], catenanes and rotaxanes [18], dendrimers [11][19][20], and