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

• ; Department of Organic Chemistry, Biochemistry and Catalysis, Research Centre of Applied Organic Chemistry, 90-92 Panduri Street, RO-050663 Bucharest, Romania 10.3762/bjoc.19.130 Abstract Mechanically interlocked molecules (MIMs) have been important synthetic targets in supramolecular chemistry due to their

• –azide cycloaddition; mechanically interlocked structures; [2]rotaxanes; Introduction Since its birth, in the late sixties [1][2][3], the field of mechanically interlocked molecules (MIMs), including rotaxanes, has gained significant attention culminating by recognition with a Nobel prize in Chemistry

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

• cations. These molecules could serve as models for enzyme active centres and present intriguing catalytic features. Additionally, a separate and equally intriguing group of molecules that can be achieved by taking advantage of the hybrid porphyrin–crown ether compounds includes mechanically interlocked

• 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

Light-responsive rotaxane-based materials: inducing motion in the solid state

• Adrian Saura-Sanmartin

Beilstein J. Org. Chem. 2023, 19, 873–880, doi:10.3762/bjoc.19.64

• molecular materials, the development of a wide variety of suitable compounds is essential. The use of stimuli-responsive molecules has paved the way for the preparation of advanced functional materials [6][7][8][9][10]. In this scenario, mechanically interlocked molecules (MIMs) have postulated as ideal

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

• '-binaphthyl-2,2'-diol (BINOL) unit as a stereogenic element in mechanically interlocked molecules (MIMs). We describe the synthesis and properties of such BINOL-based chiral MIMs, together with their use in further diastereoselective modifications, their application in asymmetric catalysis, and their use in

• 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

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

• synthesis of crown ether-based rotaxanes in 1995, crown ethers played a crucial role in the development of mechanically interlocked molecules (MIMs) [22][23]. This rotaxane synthesis was facilitated by the formation of a threaded complex (pseudorotaxane) between a secondary ammonium ion and dibenzo-24-crown

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

• receptors for molecular recognition of anionic species, pH sensors, mechanically interlocked molecules, molecular machines, and molecular reactors. Keywords: anion recognition; catenane; chalcogen bonding; click reaction; molecular reactor; hydrogen bonding; pH sensor; rotaxane; supramolecular; 1,2,3

• imidazoles [8][9], polypyrroles [10][11], and indole moieties [12][13], as part of supramolecular receptors, triazole heterocycles containing macrocycles have recently been introduced as new host molecules for the selective recognition of ions, mechanically interlocked molecules (MIMs), supramolecular

• mechanically interlocked molecules and molecular machines. We will not concern ourselves in this review with the applications of metal complexes based on N-heterocyclic carbene coordination chemistry, derived of triazoliums or with applications as ionic liquids [26][27][28]. 2. Anion recognition Due to the

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

• -conjugated polymers [29][30][31]. On the other hand, γ-CD is relatively less employed in the synthesis of mechanically interlocked molecules despite of its ability to form interesting 1:2 inclusion complexes, and there are only few examples of rotaxane and catenane featuring γ-CD as an interlocked macrocycle

• , suggesting intercomponent stabilization could play an important role in directing higher level structures in mechanically interlocked molecules, reminiscent to the intra-strands interactions that stabilize high-order structures in (bio)polymers. Conclusion In summary, complex hetero[n]rotaxanes have been

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

• radical cation or dication. For over 20 years, TTFs have been key building blocks for the construction of redox-switchable mechanically interlocked molecules (MIMs) and their electrochemical operation has been thoroughly investigated. In this review, we provide an introduction into the field of TTF-based

• MIMs and their applications. A brief historical overview and a selection of important examples from the past until now are given. Furthermore, we will highlight our latest research on TTF-based rotaxanes. Keywords: artificial molecular machines; mechanically interlocked molecules; molecular switches

• [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

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

• a preliminary study of a [6]catenane synthesis featuring the CB[6]-mediated azide–alkyne cycloaddition (CBAAC) using phenanthroline-based building blocks [24]. To further explore the applicability and generality of the CBAAC in the construction of mechanically interlocked molecules, we report here

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

• ; pillar[5]arene; [1]rotaxane; self-assembly; Introduction The construction and dynamic motion of the mechanically interlocked molecules (MIMs) have attracted significant research interests due to their intrinsic self-assembled nature and potential applications in various aspects [1][2][3][4]. Pseudo[1

• mechanically interlocked molecules, but also developed the potential applications of pillar[5]arene in supramolecular chemistry. The design and construction of diverse mechanically interlocked molecules are underway in our laboratory. single crystal structure of pillar[5]arene 2a. Single crystal structure of

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

The effect of permodified cyclodextrins encapsulation on the photophysical properties of a polyfluorene with randomly distributed electron-donor and rotaxane electron-acceptor units

• Aurica Farcas,
• Ana-Maria Resmerita,
• Pierre-Henri Aubert,
• Flavian Farcas,
• Iuliana Stoica and
• Anton Airinei

Beilstein J. Org. Chem. 2014, 10, 2145–2156, doi:10.3762/bjoc.10.222

• used to synthesize copolymers with smaller electrochemical and optical band gaps, so that materials with improved electronic and optical properties can be obtained [17]. The construction of mechanically interlocked molecules such as rotaxanes and polyrotaxanes with native cyclodextrins (CDs) as

Substitution effect and effect of axle’s flexibility at (pseudo-)rotaxanes

• Friedrich Malberg,
• Jan Gerit Brandenburg,
• Werner Reckien,
• Oldamur Hollóczki,
• Stefan Grimme and
• Barbara Kirchner

Beilstein J. Org. Chem. 2014, 10, 1299–1307, doi:10.3762/bjoc.10.131

• ][2][3]. They are mechanically interlocked molecules consisting of a macrocycle, called “wheel”, threaded on a linear chain, termed “axle”, see Figure 1 for examples. Typically, the axle has at least one recognition site – often hydrogen bond donors or acceptors [4][5] – for the wheel, because most

Synthesis and characterization of low-molecular-weight π-conjugated polymers covered by persilylated β-cyclodextrin

• Aurica Farcas,
• Ana-Maria Resmerita,
• Andreea Stefanache,
• Mihaela Balan and
• Valeria Harabagiu

Beilstein J. Org. Chem. 2012, 8, 1505–1514, doi:10.3762/bjoc.8.170

• materials for use in molecular devices, the construction of mechanically interlocked molecules, such as rotaxanes and polyrotaxanes, has attracted considerable attention [19][20][21][22][23]. A rotaxane assembly comprises a macrocyclic component (host) encircling an axle (guest) through noncovalent

• polymeric architectures. Moreover, the fabrication of mechanically interlocked molecules, such as polyrotaxanes, has been investigated as a method for the further improvement of thermal and electro-optical properties through the insulating backbones of conjugated polymers [20][21][22][23][24]. The studies

• ability of cross-coupling reaction of BT and DOF to proceed close to the cavity surface of PS-βCD, which will provide a deeper insight into the use of these new host molecules (more soluble in nonpolar organic solvents) for the construction of mechanically interlocked molecules with conjugated polymers