1,4,6,10-Tetraazaadamantanes (TAADs) with N-amino groups: synthesis and formation of boron chelates and host–guest complexes

• Artem N. Semakin,
• Ivan S. Golovanov,
• Yulia V. Nelyubina and
• Alexey Yu. Sukhorukov

Beilstein J. Org. Chem. 2022, 18, 1424–1434, doi:10.3762/bjoc.18.148

• Tripodal molecules are widely used as chelating ligands for transition metal catalysis [1][2][3], sensors for ions and small molecules [4][5], reagents for surface grafting [6], building blocks for the construction of supramolecular structures [7], polycyclic cage molecules [8], and porous materials [9

• , 21, and 21·HCl as well as the previously described 3O-TAADs 2 do not form such host–guest complexes, although water and methanol molecules are present in their crystal lattices. Thus, the presence of amide/carbamate groups is essential for the assembly of these supramolecular structures. The

• stabilization of the complex through weak hydrophobic interactions of with tert-butyl groups of Boc. We believe that by adjustment of the substituents on the amide/carbamate groups, receptors for supramolecular sensing of alcohols [44] could be designed based on 3N-TAADs of type 4. Further research in this

Cyclodextrin-based Schiff base pro-fragrances: Synthesis and release studies

• Attila Palágyi,
• Jindřich Jindřich,
• Juraj Dian and
• Sophie Fourmentin

Beilstein J. Org. Chem. 2022, 18, 1346–1354, doi:10.3762/bjoc.18.140

• aldehyde due to the supramolecular interaction between aldehyde and β-CD cavity. It follows from Figures 5–7 that heptanal (2h) is released faster with lower pH values, whereas benzaldehyde (2d) and 5-methylfurfural (2j) show opposite trends. It can be attributed to the lower boiling point (153 °C) and

• that CD-based pro-fragrances combine a chemical barrier, as the aldehydes are linked to the CD via imine bond, and a physicochemical (supramolecular) barrier, as we established that aldehydes formed inclusion complexes in aqueous solution with β-CD. We confirmed from the NMR kinetic study of the imine

• bond decomposition that Shiff base hydrolysis is very fast in acidic conditions and slows down when going to higher pH values. Multiple headspace extraction experiments revealed the role of pH and the presence of supramolecular interaction between aldehyde and β-CD on the rate of aldehyde release from

Computational model predicts protein binding sites of a luminescent ligand equipped with guanidiniocarbonyl-pyrrole groups

• Neda Rafieiolhosseini,
• Matthias Killa,
• Thorben Neumann,
• Niklas Tötsch,
• Jean-Noël Grad,
• Alexander Höing,
• Thies Dirksmeyer,
• Jochen Niemeyer,
• Christian Ottmann,
• Shirley K. Knauer,
• Michael Giese,
• Jens Voskuhl and
• Daniel Hoffmann

Beilstein J. Org. Chem. 2022, 18, 1322–1331, doi:10.3762/bjoc.18.137

• interactions with other proteins. Here, we use a computational approach to predict the binding sites of the designed hybrid compound featuring aggregation-induced emission luminophores as a potential supramolecular ligand for 14-3-3ζ in the presence and absence of C-Raf peptides. Our results suggest that the

• prediction of two C2 related, dominating binding sites on 14-3-3ζ that may bind to two of the supramolecular ligand molecules. Keywords: AIE luminophores; fluorescence emission; guanidiniocarbonyl-pyrrole; ligand binding; 14-3-3 protein; Introduction The 14-3-3 protein family was one of the first

• option to modulate, inhibit, or stabilize protein–protein interactions (PPI) is the use of specific supramolecular ligands [7][8]. One well-known example of efficient protein binders is the so-called guanidiniocarbonyl-pyrrole (GCP) developed 20 years ago by Schmuck et al. [9]. These compounds are known

Polymer and small molecule mechanochemistry: closer than ever

• José G. Hernández

Beilstein J. Org. Chem. 2022, 18, 1225–1235, doi:10.3762/bjoc.18.128

• for polymers as force transmission media have been investigated. In 2021, Otsuka and co-workers reported supramolecular hydrogen-bonding systems as alternative mechanical force transducers [67]. Specifically, the authors synthesized tetraarylsuccinonitrile (TASN) derivatives 6 and 8. TASN is a well

• anvils, which hold promise to become standard low-molecular effective transducers of mechanical forces. This, together with the ability of ball milling to facilitate the formation of covalent and noncovalent supramolecular assemblies, could lead to the direct activation of small mechanophores via the

Post-synthesis from Lewis acid–base interaction: an alternative way to generate light and harvest triplet excitons

• Hengjia Liu and
• Guohua Xie

Beilstein J. Org. Chem. 2022, 18, 825–836, doi:10.3762/bjoc.18.83

• optoelectronic properties of a fluorene-based copolymer with an sp2 nitrogen heteroatom via supramolecular coordination [33]. The PL emission in solution showed an obvious red-shifted profile. The polymer LED with different molar equivalents of Lewis acids was investigated. The EL peak wavelength was gradually

• . Regarding the materials developed by Lin et al., supramolecular coordination of PF8-co-DAF8 (13, Figure 5) with Lewis acids played an important role. They selected the more rigid 4,5-diazafluorene (DAF) with nitrogen atoms inserted at the 4 and 5-positons of the fluorene moiety [33]. The heteroatomic

Thiophene/selenophene-based S-shaped double helicenes: regioselective synthesis and structures

• Mengjie Wang,
• Lanping Dang,
• Wan Xu,
• Zhiying Ma,
• Liuliu Shao,
• Guangxia Wang,
• Chunli Li and
• Hua Wang

Beilstein J. Org. Chem. 2022, 18, 809–817, doi:10.3762/bjoc.18.81

• channels (Figures S4 and S8 in Supporting Information File 2), which is a suitable characteristic for helicene compounds used as supramolecular self-assembly units [34][35][36][37][38][39][40][41]. Spectroscopic features of DH-1–3 The UV–vis absorption spectra of DH-1–3 in dichloromethane are shown in

• arrangement in the crystal packing structures of DH-1 and DH-2 indicate that these compounds may be used as supramolecular self-assembly units. Changes in molecular structure may substantially modulate the optical band gap of heteroacenes, and the replacement of heteroatoms from S to Se could fine-tune their

Heteroleptic metallosupramolecular aggregates/complexation for supramolecular catalysis

• Prodip Howlader and
• Michael Schmittel

Beilstein J. Org. Chem. 2022, 18, 597–630, doi:10.3762/bjoc.18.62

• Prodip Howlader Michael Schmittel Center of Micro- and Nanochemistry and (Bio)Technology, Universität Siegen, Organische Chemie I, Adolf-Reichwein-Str. 2, D-57068 Siegen, Germany 10.3762/bjoc.18.62 Abstract Supramolecular catalysis is reviewed with an eye on heteroleptic aggregates/complexation

• allows, as demonstrated by Nature by the multicomponent ATP synthase motor, a more detailed and refined configuration of purposeful machinery. Furthermore, (metallo)supramolecular catalysis is shown to extend beyond the single "supramolecular unit" and to reach far into the field and concepts of systems

• chemistry and information science. Keywords: heteroleptic complexation; information science; supramolecular catalysis; switching catalysis; systems chemistry; Introduction Supramolecular catalysis [1][2][3] for most chemists is associated with a catalytically active capsule providing either activating

Synthesis of a new water-soluble hexacarboxylated tribenzotriquinacene derivative and its competitive host–guest interaction for drug delivery

• Man-Ping Li,
• Nan Yang and
• Wen-Rong Xu

Beilstein J. Org. Chem. 2022, 18, 539–548, doi:10.3762/bjoc.18.56

• water-soluble hexacarboxylated tribenzotriquinacene derivative (TBTQ-CB6) was synthesized and used as a supramolecular drug carrier to load the model anticancer drugs dimethyl viologen (MV) and doxorubicin (DOX) via host–guest interactions. The drugs could be effectively released by spermine (SM), a

• novel TBTQ-based host–guest drug delivery system may have potential use in supramolecular chemotherapy. Keywords: competitive substitution; drug delivery; host–guest chemistry; tribenzotriquinacene; water soluble; Introduction Chemotherapy is considered to be one of the most effective strategies in

• , supramolecular chemotherapy has received considerable attention by utilizing a supramolecular strategy to decrease the cytotoxicity of anticancer drugs to normal cells while preserving their cytotoxicity against cancer cells [11]. Supramolecular systems derived from macrocycles [12][13], such as calix[n]arenes

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

• noncovalent interactions between the subcomponents, MIMs have established themselves as an important subdiscipline of supramolecular chemistry. The introduction of chirality into MIMs is of high interest in order to develop applications in which the chirality can be exploited, e.g., in enantioselective

• Incorporating BINOL into MIMs The introduction of axially chiral BINOL units into interlocked compounds can be achieved by different types of supramolecular template strategies that have been developed for MIM synthesis in the past decades, including passive metal templates [33][34], active metal templates [35

• supramolecular template strategies that have been developed in the past decades, including passive metal templates, active metal templates, anion templates, ammonium crown ether templates, and templates based on π–π interactions. This has opened the way for the application of the resulting chiral MIMs. The

Bioinspired tetraamino-bisthiourea chiral macrocycles in catalyzing decarboxylative Mannich reactions

• Hao Guo,
• Yu-Fei Ao,
• De-Xian Wang and
• Qi-Qiang Wang

Beilstein J. Org. Chem. 2022, 18, 486–496, doi:10.3762/bjoc.18.51

• Mannich reactions; supramolecular catalysis; thiourea; Introduction In the past decades, the development of supramolecular chemistry has enabled abundant host scaffolds and assembly tools for boosting catalytic processes, and stimulated the emergence of supramolecular catalysis [1][2][3][4][5][6][7][8][9

Tetraphenylethylene-embedded pillar[5]arene-based orthogonal self-assembly for efficient photocatalysis in water

• Zhihang Bai,
• Krishnasamy Velmurugan,
• Xueqi Tian,
• Minzan Zuo,
• Kaiya Wang and
• Xiao-Yu Hu

Beilstein J. Org. Chem. 2022, 18, 429–437, doi:10.3762/bjoc.18.45

• supramolecular self-assembled nanosystem based on host–guest interactions between water-soluble tetraphenylethylene-embedded pillar[5]arene (m-TPEWP5) and ammonium benzoyl-ʟ-alaninate (G) in an aqueous medium. The obtained assembly of m-TPEWP5 and G showed aggregation-induced emission (AIE) via the blocking of

• assembled donor to the EsY acceptor present in the nanorod assembly. The system comprising m-TPEWP5, G and EsY displayed moderate FRET efficiency (31%) at a 2:1 molar ratio of donor-to-acceptor. Moreover, the obtained supramolecular nanorod assembly could act as a nanoreactor mimicking natural

• ; supramolecular self-assembly; Introduction Photosynthesis is one of the most significant processes in nature, which balances the energy level in living systems [1][2][3]. In particular, green plants absorb photons of light and convert them into another form of energy through photosynthesis similar to solar

A resorcin[4]arene hexameric capsule as a supramolecular catalyst in elimination and isomerization reactions

• Tommaso Lorenzetto,
• Fabrizio Fabris and
• Alessandro Scarso

Beilstein J. Org. Chem. 2022, 18, 337–349, doi:10.3762/bjoc.18.38

• series of reactions like the carbonyl–ene cyclization of (S)-citronellal preferentially to isopulegol, the water elimination from 1,1-diphenylethanol, the isomerization of α-pinene and β-pinene preferentially to limonene and minor amounts of camphene. The role of the supramolecular catalyst consists in

• compared to many other strong Brønsted or Lewis acids. Keywords: cationic intermediates; encapsulation; organocatalysis; resorcin[4]arene hexamer; supramolecular catalysis; Introduction In enzymatic catalysis, the substrate is selected matching the size, shape and specific functional groups present in

• states of the reaction with impressive accelerations, substrate, and product selectivities. The development of artificial catalytic systems able to activate substrates and to stabilize intermediate species through weak noncovalent interactions is the scope of supramolecular catalysis [1][2][3][4

A Se···O bonding catalysis approach to the synthesis of calix[4]pyrroles

• Qingzhe Tong,
• Zhiguo Zhao and
• Yao Wang

Beilstein J. Org. Chem. 2022, 18, 325–330, doi:10.3762/bjoc.18.36

• . Keywords: calix[4]pyrrole; chalcogen bonding; ketones; Se···O bonding interactions; supramolecular catalysis; Introduction Noncovalent catalysis has been established as one of the fundamental concepts in organic synthesis that enables achieving numerous chemical transformations [1]. Among these

Site-selective reactions mediated by molecular containers

• Rui Wang and
• Yang Yu

Beilstein J. Org. Chem. 2022, 18, 309–324, doi:10.3762/bjoc.18.35

• Rui Wang Yang Yu Center for Supramolecular Chemistry & Catalysis and Department of Chemistry, College of Science, Shanghai University, 99 Shang-Da Road, Shanghai 200444, China 10.3762/bjoc.18.35 Abstract In this review, we summarize various site-selective reactions mediated by molecular

• environment inside the container. The containers include supramolecular structures self-assembled through metal/ligand interactions or hydrogen bonding and open-ended covalent structures such as cyclodextrins and cavitands. Challenges and prospects for the future are also provided. Keywords: confinement

• chemists have developed different kinds of methods to achieve site-selectivity of various reactions, new methodologies that blend with other research fields are still needed. After decades of rapid development, supramolecular chemistry has won two times for Nobel Prizes and already became one of the most

Trichloroacetic acid fueled practical amine purifications

• Aleena Thomas,
• Baptiste Gasch,
• Enzo Olivieri and
• Adrien Quintard

Beilstein J. Org. Chem. 2022, 18, 225–231, doi:10.3762/bjoc.18.26

• formation of protonated amines which evolve spontaneously over time back again to the neutral amine upon release of CO2 from the initial acid. Among the potential acids available for such processes, trichloroacetic acid (TCA) has been used to fuel different supramolecular switches [6][7][8][9][10]. This

• from rotaxanes, cucurbit[8]uril, to supramolecular smart materials [11][12][13][14][15][16]. TCA is also known for its application in the precipitation of proteins through what is believed to be an unfolding of the proteins structures [17][18]. In this context, we hypothesized that TCA could be used to

• equilibrium supramolecular machinery through a temporary protonation returning to the initial state upon time [3][4][5]. While conceptually interesting, in terms of laboratory practicability, it would be desirable to have a faster release of the free amine. For this purpose, a small amount of volatile base

Diametric calix[6]arene-based phosphine gold(I) cavitands

• Gabriele Giovanardi,
• Andrea Secchi,
• Arturo Arduini and
• Gianpiero Cera

Beilstein J. Org. Chem. 2022, 18, 190–196, doi:10.3762/bjoc.18.21

• macrocyclic cavity. Keywords: 1,2,3-alternate conformation; calix[6]arenes; gold(I) catalysis; phosphines; Introduction One of the latest challenges in supramolecular chemistry is the design and development of novel macrocyclic-based entities able to influence the catalytic activities of the metal center [1

• the bonded metal. This crucial aspect prompted their application in supramolecular chemistry as well. Thus, a recent evolution of their chemistry concerns the development of novel architectures in which P(III) compounds are incorporated in cavity-shaped macrocycles [5][6][7][8]. In this scenario

• in controlling the reactivity of gold(I)-catalyzed transformations by means of supramolecular macrocycles, we choose a cycloisomerization of 1,6-enynes as a model reaction [36]. Substrate 1a was reacted in the presence of monomeric gold(I) catalyst A’(AuCl) (2 mol %), using AgSbF6 as the chloride

Synthesis and bioactivity of pyrrole-conjugated phosphopeptides

• Qiuxin Zhang,
• Weiyi Tan and
• Bing Xu

Beilstein J. Org. Chem. 2022, 18, 159–166, doi:10.3762/bjoc.18.17

• investigated the physical properties (enzyme-catalyzed hydrogelation or supramolecular structural transformation) [62][70] and biological properties (cell viability, biostability, and cell-selective growth inhibition) [43][62] of the naphthylacetyl N-terminal-capped phosphopeptides. These studies have produced

Study on the interactions between melamine-cored Schiff bases with cucurbit[n]urils of different sizes and its application in detecting silver ions

• Jun-Xian Gou,
• Yang Luo,
• Xi-Nan Yang,
• Wei Zhang,
• Ji-Hong Lu,
• Zhu Tao and
• Xin Xiao

Beilstein J. Org. Chem. 2021, 17, 2950–2958, doi:10.3762/bjoc.17.204

• Jun-Xian Gou Yang Luo Xi-Nan Yang Wei Zhang Ji-Hong Lu Zhu Tao Xin Xiao Key Laboratory of Macrocyclic and Supramolecular Chemistry of Guizhou Province, Guizhou University, Guiyang 550025, China 10.3762/bjoc.17.204 Abstract Three different complexes, TMeQ[6]-TBT, Q[7]-TBT, and Q[8]-TBT are

• attracted much attention due to its three-branched structure and excellent physical and chemical properties, which is commonly used in many applications including plastic dishes, the main raw material for formaldehyde resin, etc. [15]. Cucurbit[n]urils (Q[n]s, Scheme 1), a kind of supramolecular compound

Polymer chemistry: fundamentals and applications

• Bernhard V. K. J. Schmidt

Beilstein J. Org. Chem. 2021, 17, 2922–2923, doi:10.3762/bjoc.17.200

• supramolecular chemistry for the assembly of polymer fibers and the synthesis of well-defined polysaccharides. In the direction of materials, cryogels and reinforced hydrogels are discussed, as well as 3D-printed poly(caprolactone) biomaterials. In addition, properties of thermoresponsive materials and self

• -healing materials are presented in this thematic issue. Finally, the use of polymerization-induced self-assembly for the synthesis of drug carriers is presented. The issue also shows the multidisciplinary character of polymer science, for example when supramolecular motifs, organic coupling reactions or

Synthesis of a novel aminobenzene-containing hemicucurbituril and its fluorescence spectral properties with ions

• Qingkai Zeng,
• Qiumeng Long,
• Jihong Lu,
• Li Wang,
• Yuting You,
• Xiaoting Yuan,
• Qianjun Zhang,
• Qingmei Ge,
• Hang Cong and
• Mao Liu

Beilstein J. Org. Chem. 2021, 17, 2840–2847, doi:10.3762/bjoc.17.195

• Macrocycles with converging binding sites and functional groups hold a key position in supramolecular chemistry, which has been repeatedly confirmed by classic macrocyclic molecules, such as crown ethers, cyclodextrins, calixarenes, cucurbiturils and their homologues [1]. For the past decades, numerous

• on host–guest interaction and supramolecular systems. Its applications and modifications are being pursued in our laboratory, and the results will be reported in due course. The X-ray structure of nitrobenzene-containing hemicucurbituril 9 (CCDC 2094879). Fluorescence emission spectra (λmax = 349 nm

Host–guest interaction and properties of cucurbit[8]uril with chloramphenicol

• Lin Zhang,
• Jun Zheng,
• Guangyan Luo,
• Xiaoyue Li,
• Yunqian Zhang,
• Zhu Tao and
• Qianjun Zhang

Beilstein J. Org. Chem. 2021, 17, 2832–2839, doi:10.3762/bjoc.17.194

• Lin Zhang Jun Zheng Guangyan Luo Xiaoyue Li Yunqian Zhang Zhu Tao Qianjun Zhang Key Laboratory of Macrocyclic and Supramolecular Chemistry of Guizhou Province, Guizhou University, Guiyang 550025, China 10.3762/bjoc.17.194 Abstract The interaction between cucurbit[8]uril (Q[8]) and chloramphenicol

• properties than CPE alone. Ana I. Ramos et al. [7] studied the inclusion compound of CPE and cyclodextrin and reported its effect on Enterococcus, Bacillus, Staphylococcus and other bacteria. As a new type of supramolecular host compound, cucurbit[n]urils [8][9][10][11][12][13][14][15][16][17][18][19] (Q[n]s

A tribute to Carsten Schmuck

• Jochen Niemeyer,
• Ivo Piantanida and
• Thomas Schrader

Beilstein J. Org. Chem. 2021, 17, 2795–2798, doi:10.3762/bjoc.17.190

• chemistry to advanced supramolecular chemistry, and he always had an open ear for the questions and concerns of students, both in his role as a professor and as the Dean of Chemistry. But he did not stop there: When he had the feeling that the current chemistry textbooks did not fully meet the needs of his

• development of the noncovalent and supramolecular recognition research in the European Research Area (ERA). His personal and scientific engagement was equally intensive with excellent, well-established scientists, and new groups from small scientific communities; for instance, starting collaboration in the

• , at which Carsten was the head of the work group WG0018/05, entitled “Guanidinium as an important anchor group in supramolecular recognition”. At that time, the focus of WG0018/05 was mostly on nonaqueous anion recognition systems and constructs, but during our several discussions and mutual visits

Adjusting the length of supramolecular polymer bottlebrushes by top-down approaches

• Tobias Klein,
• Franka V. Gruschwitz,
• Maren T. Kuchenbrod,
• Ivo Nischang,
• Stephanie Hoeppener and
• Johannes C. Brendel

Beilstein J. Org. Chem. 2021, 17, 2621–2628, doi:10.3762/bjoc.17.175

• straightforward adjustment of the length of polyethylene oxide (PEO)-based supramolecular polymer bottlebrushes (SPBs) in aqueous solutions. These cylindrical structures self-assemble via directional hydrogen bonds formed by benzenetrisurea (BTU) or benzenetrispeptide (BTP) motifs located within the hydrophobic

• the conditions for the assembly process, and are therefore often limited to specific materials. An alternative is the use of molecular motifs capable of forming directional supramolecular interaction forces, such as hydrogen bonds or π-interactions, to guide the one-dimensional (1D) assembly of

• established, commercial polymers in solution [17]. We recently reported the self-assembly of polyethylene oxide (PEO) polymers into cylindrical nanostructures, also called supramolecular polymer bottlebrushes (SPBs), based on the end group modification with hydrogen bond forming benzenetrisurea (BTU) and

Cryogels: recent applications in 3D-bioprinting, injectable cryogels, drug delivery, and wound healing

• Luke O. Jones,
• Leah Williams,
• Tasmin Boam,
• Martin Kalmet,
• Chidubem Oguike and
• Fiona L. Hatton

Beilstein J. Org. Chem. 2021, 17, 2553–2569, doi:10.3762/bjoc.17.171

• allowing syringe injectability [9]. It has been suggested that cryogels are more suitable for this application, as opposed to hydrogels, as a greater number of cells can be contained within the structure. With an exemption for injectable supramolecular hydrogel systems, which have been demonstrated to

In-depth characterization of self-healing polymers based on π–π interactions

• Josefine Meurer,
• Julian Hniopek,
• Johannes Ahner,
• Michael Schmitt,
• Jürgen Popp,
• Stefan Zechel,
• Kalina Peneva and
• Martin D. Hager

Beilstein J. Org. Chem. 2021, 17, 2496–2504, doi:10.3762/bjoc.17.166

• of Photonic Technology (IPHT), e. V. Jena, Albert-Einstein-Straße 9, 07745 Jena, Germany 10.3762/bjoc.17.166 Abstract The self-healing behavior of two supramolecular polymers based on π–π-interactions featuring different polymer backbones is presented. For this purpose, these polymers were

• mechanical behavior was studied using rheology. The activation of the supramolecular interactions results in a breaking of these noncovalent bonds, which was investigated using IR spectroscopy, leading to a sufficient increase in mobility and, finally, a healing of the mechanical damage. This scratch-healing

• behavior was also quantified in detail using an indenter. Keywords: characterization of polymers; π–π-interactions; self-healing polymers; supramolecular polymers; Introduction Damage inflicted on different materials is omnipresent. Consequently, nature established a mechanism dealing with this problem