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

• [23][88][90]. Several studies have focused on developing novel crown ether-appended porphyrins with tailored caps, enabling efficient encapsulation of guest molecules through host–guest interactions [47][81][112]. They have shown promise as heme models and multitopic receptors, exhibiting selective

CuAAC-inspired synthesis of 1,2,3-triazole-bridged porphyrin conjugates: an overview

• Dileep Kumar Singh

Beilstein J. Org. Chem. 2023, 19, 349–379, doi:10.3762/bjoc.19.29

• triplet quenching pathways. The construction of water-soluble porphyrin nanospheres was reported by Zhang et al. in 2014 [54] by intramolecular host–guest interactions using porphyrin 126 containing two permethyl-β-cyclodextrin (PM-β-CD) and two dicarboxylatophenyl arms at meso-positions. The synthesis of

Inclusion complexes of the steroid hormones 17β-estradiol and progesterone with β- and γ-cyclodextrin hosts: syntheses, X-ray structures, thermal analyses and API solubility enhancements

• Alexios I. Vicatos,
• Zakiena Hoossen and
• Mino R. Caira

Beilstein J. Org. Chem. 2022, 18, 1749–1762, doi:10.3762/bjoc.18.184

• counterparts prepared by kneading. The occurrence of severe guest disorder in all three cases precluded detailed determination of the host–guest interactions. Despite this limitation, complete chemical formulae were determined for the ternary complexes listed above, as well as that of γ-CD·BES, by combining

Ionic multiresonant thermally activated delayed fluorescence emitters for light emitting electrochemical cells

• Merve Karaman,
• Abhishek Kumar Gupta,
• Subeesh Madayanad Suresh,
• Tomas Matulaitis,
• Lorenzo Mardegan,
• Daniel Tordera,
• Henk J. Bolink,
• Sen Wu,
• Stuart Warriner,
• Ifor D. Samuel and
• Eli Zysman-Colman

Beilstein J. Org. Chem. 2022, 18, 1311–1321, doi:10.3762/bjoc.18.136

• suggests that the conformation of the emitter in the solid state is slightly more conjugated than that in solution or that there are specific host–guest interactions with the DPA unit that perturbs the energy of the excited state. The emission is broader than that of a structurally similar emitter, QAD

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

• Switchable catalysis due to reversible assembly/disassembly Toggling between intra- and intermolecular complexation in nanoswitches Review Catalysis using heteroleptic discrete supramolecular architectures In its early years, supramolecular chemistry mainly focused on host–guest interactions, primarily on

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

• molecule overexpressed in cancer cells, through host–guest competitive substitution since TBTQ-CB6 has a stronger binding affinity toward SM than MV and DOX. The host–guest interactions of the complexes of TBTQ-CB6 with MV, DOX and SM were investigated by NMR spectroscopy and fluorescence spectroscopy. The

• ) derivatives are a class of molecules possessing a rigid bowl-shaped structure and a C3v-symmetric skeleton [21]. Bearing similarity with macrocycles in general, they can act as versatile hosts for encapsulating guest molecules. Over the past two decades, host–guest interactions and self-assembly based on TBTQ

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

• tunable self-assembly, such as vesicles [14][15][16], micelles [17][18][19], nanocrystals [20], coordination-driven assemblies [9][21][22], host–guest interactions [15][23][24][25], etc. In the above systems, catalysts are encapsulated by supramolecular assemblies and thus provide a suitable environment

• dehalogenation reaction with high yields within shorter reaction time is vastly essential and of industrial importance. Herein, we have fabricated a supramolecular AIE-emissive photocatalytic system (m-TPEWP5G–EsY) based on the host–guest interactions between meso-TPE embedded water-soluble pillar[5]arene (m

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

• constructed by three different cucurbiturils and synthesized by guest melamine-cored Schiff bases (TBT) through outer-surface interaction and host–guest interactions. TBT forms a TMeQ[6]-TBT complex with TMeQ[6] through outer-surface interaction, while Q[7]-TBT and Q[8]-TBT form complexes with Q[7,8] through

• host–guest interactions. Among them, Q[7]-TBT is selected as a UV detector for the detection of silver ions (Ag+). This work makes full use of the characteristics of each cucurbituril and melamine-cored Schiff base to construct a series of complexes and these are applied to metal detection. Keywords

• Schiff base reaction and the nucleophilic reaction of haloalkane (Scheme 1 and Supporting Information File 1, Scheme S1) [25]. In addition to retaining the abundant coordination sites of Schiff bases, TBT is also modified with carbon chains of appropriate length for inducing host–guest interactions and

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

• nm, and found to be Ka = (2.1 ± 0.3) × 104 M−1, while the association constant of compound 4 binding to Cu2+ was Ka = (2.8 ± 0.1) × 103 M−1. The macrocycle binds Fe3+ much more strongly than Cu2+. The host–guest interactions between 4 and selected anions, including Cl−, Br−, I−, PF6−, BF4−, HSO4

Photoinduced post-modification of graphitic carbon nitride-embedded hydrogels: synthesis of 'hydrophobic hydrogels' and pore substructuring

• Cansu Esen and
• Baris Kumru

Beilstein J. Org. Chem. 2021, 17, 1323–1334, doi:10.3762/bjoc.17.92

• ). Since then, many synthetic routes have been developed in order to synthesize artificial matter that mimics the performance of natural tissues. Therefore, many reinforcement methods have been suggested, i.e., host–guest interactions [4][5], double network formation [6][7][8], and reinforcer addition [9

Insight into functionalized-macrocycles-guided supramolecular photocatalysis

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

Beilstein J. Org. Chem. 2021, 17, 139–155, doi:10.3762/bjoc.17.15

• have begun to develop artificial supramolecular systems that provide a similar environment to perform various catalytic reactions where substrates are captured via host–guest interactions [3]. In addition, these systems aim to control the product selectivity and the rate of catalytic reactions by

• photocatalytic reaction with a rate acceleration facilitated by supramolecular host–guest interactions and hybrid materials are typically assisted by noncovalent forces, including Coulomb and van der Waals forces, hydrogen bonding, and π–π interactions. For potential supramolecular photocatalysts, they should

• comprehensive investigation of the kinetic and thermodynamic aspects relating to the host–guest interactions and photochemical transformation efficiency of the substrate [10][11]. Thus, this review highlights the supramolecular photocatalytic substrate transformation involving various stoichiometric host–guest

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

• . Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI–TOF MS) was conducted to investigate the complexation properties. However, no signal related to the complex but only peaks of H were found, implying weak host–guest interactions between H and G (Figures S3 and S4

Host–guest interaction of cucurbit[8]uril with oroxin A and its effect on the properties of oroxin A

• Zhishu Zeng,
• Jun Xie,
• Guangyan Luo,
• Zhu Tao and
• Qianjun Zhang

Beilstein J. Org. Chem. 2020, 16, 2332–2337, doi:10.3762/bjoc.16.194

• beneficial biological effects of OA, which include antioxidant, antidiabetic, anticancer, antibacterial, anti-inflammatory and antiviral properties [25][26][27][28][29][30]. Herein, we selected Q[8] as a host molecule and investigated its host–guest interactions with OA, as well as its effect on the

• that the molecular size of the flavonoids and the length of the sugar chains have a greater impact on the assembly mode of supramolecular systems. Results and Discussion Host–guest interactions The host–guest interaction can be effectively observed using 1H NMR spectroscopy, and the mode of action of

• –guest interactions between oroxin A (OA) and cucurbit[8]uril (Q[8]) using 1H NMR, MS, UV–vis and IR spectroscopy. The results showed that OA and Q[8] formed an inclusion compound (OA@Q[8]) with a molar ratio of 1:1 and a binding constant of 1.299 × 107 L·mol−1. In addition, the effect of Q[8] on the

The interaction between cucurbit[8]uril and baicalein and the effect on baicalein properties

• Xiaodong Zhang,
• Jun Xie,
• Zhiling Xu,
• Zhu Tao and
• Qianjun Zhang

Beilstein J. Org. Chem. 2020, 16, 71–77, doi:10.3762/bjoc.16.9

• Xiaodong Zhang Jun Xie Zhiling Xu Zhu Tao Qianjun Zhang Key Laboratory of Macrocyclic and Supramolecular Chemistry of Guizhou Province, Guizhou University, Guiyang 550025, China 10.3762/bjoc.16.9 Abstract The host–guest interactions between baicalein (BALE) and cucurbit[8]uril (Q[8]) and the

• compounds such as calixarenes, crown ethers and cyclodextrins, which can be used to form a stable inclusion complex with the drug, and improving the bioavailability of the drug [34][35]. Herein, we describe the results of the investigations of host–guest interactions between BALE and Q[8] in an aqueous

• solution using 1H NMR, UV–vis and IR spectroscopy, and DTA. The properties of the BALE–Q[8] inclusion complex, such as stability, solubility, in vitro antioxidant activity and release performance were studied by means of UV–vis spectroscopy. Results and Discussion Host–guest interactions Q[8] and BALE in

A chiral self-sorting photoresponsive coordination cage based on overcrowded alkenes

• Constantin Stuckhardt,
• Diederik Roke,
• Wojciech Danowski,
• Edwin Otten,
• Sander J. Wezenberg and
• Ben L. Feringa

Beilstein J. Org. Chem. 2019, 15, 2767–2773, doi:10.3762/bjoc.15.268

• metal centers has been used to control host–guest interactions [25][26][27][28], structural composition [29], and sol–gel transition [30]. However, dithienylethene undergoes a limited structural change upon photoisomerization and, up to now, photoswitchable ligands based on other types of photochromic

Synthesis and anion binding properties of phthalimide-containing corona[6]arenes

• Meng-Di Gu,
• Yao Lu and
• Mei-Xiang Wang

Beilstein J. Org. Chem. 2019, 15, 1976–1983, doi:10.3762/bjoc.15.193

• crystallography then allowed us to understand the host–guest interactions at the molecular level. As illustrated in the molecular structures in Figure 4, above the centroid of each tetrazine ring there resided a chloride or a bromide. The distance of the anion to the centroid of tetrazine ranged from 3.060 Å to

Morphology-tunable and pH-responsive supramolecular self-assemblies based on AB₂-type host–guest-conjugated amphiphilic molecules for controlled drug delivery

• Yang Bai,
• Cai-ping Liu,
• Di Chen,
• Long-hai Zhuo,
• Huai-tian Bu and
• Wei Tian

Beilstein J. Org. Chem. 2019, 15, 1925–1932, doi:10.3762/bjoc.15.188

• neutral pH through host–guest interactions between β-CD and BM. DOX was used as a model drug encapsulated into FSSAs (Scheme 1a,b). The slow release of DOX from DOX-loaded FSSAs was observed at pH 7.4 (Scheme 1b,c). On the contrary, the release rate of DOX increased evidently when the solution pH value

• -assemblies was driven by the pH-induced dissociation of host–guest interactions between BM and β-CD. Controlled release behaviors of drug-loaded supramolecular self-assemblies β-CD-BM2-based SSAs were used as nanocarriers for drug delivery. Doxorubicin (DOX) was first loaded into FSSAs with a drug-loaded

• on the basis of the dissociation of host–guest interactions between β-CD and BM. Cellular toxicity of drug-loaded supramolecular self-assemblies The biocompatibility of drug-free supramolecular self-assemblies is of crucial importance for the further use of these materials as drug carriers. Herein

Complexation of chiral amines by resorcin[4]arene sulfonic acids in polar media – circular dichroism and diffusion studies of chirality transfer and solvent dependence

• Bartosz Setner and
• Agnieszka Szumna

Beilstein J. Org. Chem. 2019, 15, 1913–1924, doi:10.3762/bjoc.15.187

• manifested in chirality transfer. We will also present a crucial and non-intuitive solvent dependence. RSAs (e.g., 1) can be considered as analogues of calix[4]arene sulfonic acids (CSAs) – the class of macrocycles widely studied in the context of various host–guest interactions, especially with various

Host–guest interactions in nor-seco-cucurbit[10]uril: novel guest-dependent molecular recognition and stereoisomerism

• Xiaodong Zhang,
• Wei Wu,
• Zhu Tao and
• Xin-Long Ni

Beilstein J. Org. Chem. 2019, 15, 1705–1711, doi:10.3762/bjoc.15.166

• ]. Keywords: fluorescent; host–guest interaction; macrocycles; molecular recognition; nor-seco-cucurbit[10]uril; pyrene; Introduction Host–guest interactions that trigger molecular recognition are a current topic of interest. For example, understanding the protein–ligand molecular recognition is of paramount

• importance in the study of enzymatic catalysis and allosteric regulation of cell signaling, as well as in the design of efficient drugs that utilize host–guest interactions [1]. Cucurbit[n]urils (Q[n]s or CB[n]s) [2][3] having been viewed to have high potential use in host–guest chemistry in aqueous solution

• ] was functionalized with imidazolidone (host-2, Scheme 1) [28]. Herein, we report the supramolecular host–guest interactions of the two cavities of NS-CB[10]-based host-1 and host-2 with two unsymmetrical ADA-based derivatives (G1 and G2, Scheme 1). As expected, hosts-1 and -2 are capable of

Host–guest interactions between p-sulfonatocalix[4]arene and p-sulfonatothiacalix[4]arene and group IA, IIA and f-block metal cations: a DFT/SMD study

• Valya K. Nikolova,
• Cristina V. Kirkova,
• Silvia E. Angelova and
• Todor M. Dudev

Beilstein J. Org. Chem. 2019, 15, 1321–1330, doi:10.3762/bjoc.15.131

New α- and β-cyclodextrin derivatives with cinchona alkaloids used in asymmetric organocatalytic reactions

• Iveta Chena Tichá,
• Simona Hybelbauerová and
• Jindřich Jindřich

Beilstein J. Org. Chem. 2019, 15, 830–839, doi:10.3762/bjoc.15.80

• complexes [2]. CD derivatives have been increasingly applied in catalysis and biomimetic reactions [3][4] thanks to host–guest interactions and to the non-toxic, chiral skeleton of CDs. More specifically, CDs applied in reactions involving metal catalysis [5], organocatalysis [6] and artificial enzymes [7

Aqueous olefin metathesis: recent developments and applications

• Valerio Sabatino and
• Thomas R. Ward

Beilstein J. Org. Chem. 2019, 15, 445–468, doi:10.3762/bjoc.15.39

• (Figure 1c) through host–guest interactions [61]. Chung and co-workers used a PEG-tethered adamantyl ligand for various metathesis reactions in water and DCM [62]. The authors showed that the catalyst can be easily removed by generating a host–guest complex between silica-grafted β-cyclodextrin and the

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

• 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

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

• effort to better understand the host–guest interactions and the potentials of the secondary lower-rim binding mode, molecular mechanics (OPLS-2005) [42] calculations were performed on complexes, 3@BrC2, 3@BrC3 and 3@BrC6 using Jaguar (Schrödinger) [43][44]. Consequently, the structures are modelled for

• host–guest interactions persist even in these very competitive environments (Table 3, Figures S5 and S9, Supporting Information File 1). Conclusion Host–guest systems formed between C-hexyl-2-bromoresorcinarene (BrC6) and twelve aromatic N-oxides have been characterised using solid-state X-ray

A three-armed cryptand with triazine and pyridine units: synthesis, structure and complexation with polycyclic aromatic compounds

• Claudia Lar,
• Adrian Woiczechowski-Pop,
• Attila Bende,
• Ioana Georgeta Grosu,
• Natalia Miklášová,
• Elena Bogdan,
• Niculina Daniela Hădade,
• Anamaria Terec and
• Ion Grosu

Beilstein J. Org. Chem. 2018, 14, 1370–1377, doi:10.3762/bjoc.14.115

• and the host–guest interactions must be able to equilibrate the previously described ortho–ortho' hindrance and to bring the aromatic rings of the caps to coplanar conformations. In this work, we decided to investigate a new cryptand in which this steric hindrance is removed. Thus, we changed the

• δ 8.49 ppm, marked with a black circle in Figure 2) of cryptand 2 upon titration with 1,5-dihydroxynaphthalene at different host:guest ratios are shown in Figure 3. Next the host–guest interactions were investigated by global non-linear regression analysis using the free tool that is available at