Co-crystallization of an organic solid and a tetraaryladamantane at room temperature

• Fabian Rami,
• Jan Nowak,
• Felix Krupp,
• Wolfgang Frey and
• Clemens Richert

Beilstein J. Org. Chem. 2021, 17, 1476–1480, doi:10.3762/bjoc.17.103

• . The encapsulation occurs even though the host compound assembling into the crystal lattice is able to also crystallize in solvate-free form [12]. Three tetraaryladamantanes (TAAs) were found to show this behavior as hosts, namely 1,3,5,7-tetrakis(2,4-dimethoxyphenyl)adamantane (TDA), 1,3,5,7-tetrakis

• X-ray crystallography were collected after more than one week. Table 1 lists the details of the structures observed. In case of the TDA/phenol co-crystals (Figure 2a/c), the asymmetric unit is made up of one host and two guest molecules, so the overall stoichiometric ratio is 1:2 (TDA/phenol). One

• group. But again, hydrogen bonds between phenol hydroxy groups and the alkoxy substituent of the crystallization chaperone can be resolved. So, in both co-crystal lattices, hydrogen bonding stabilizes the packing arrangement. For TDA/phenol, the host builds the crystal lattice with TDA molecules in

Design, synthesis and photophysical properties of novel star-shaped truxene-based heterocycles utilizing ring-closing metathesis, Clauson–Kaas, Van Leusen and Ullmann-type reactions as key tools

• Shakeel Alvi and
• Rashid Ali

Beilstein J. Org. Chem. 2021, 17, 1374–1384, doi:10.3762/bjoc.17.96

• applicability in the synthesis of dendrimers as well as C3-tripods and also in the host–guest chemistry [17][18][19][20][21]. This architecturally simple yet effective rigid system was first prepared in 1894 by Kipping [22] involving the trimerization of 3‐phenylpropionic acid under acidic conditions but

Icilio Guareschi and his amazing “1897 reaction”

• Gian Cesare Tron,
• Alberto Minassi,
• Giovanni Sorba,
• Mara Fausone and
• Giovanni Appendino

Beilstein J. Org. Chem. 2021, 17, 1335–1351, doi:10.3762/bjoc.17.93

• state created in 1814 to host Napoleon’s wife Marie Louise, who, incidentally, died the very same year Guareschi was born. Guareschi’s father was a pharmacist. The family pharmacy had been established in the early 1400 and had then been passed from father to son during four centuries. Giovannino

• , generating the colored anion of a diphenylmethane dye that could be isolated after acidification and characterized from the reaction of thymol (3) and of charvachrol. The Guareschi reaction was then applied by Lustgarten to a host of medicinal phenols, and the test is included in various pharmacopoeias for

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

• pores is responsible for the main catalytic activity, such as in carbonaceous materials [47][48]. When a network with full functionality cannot be formed easily, one can form a rigid neutral host and modify the pores subsequently. Herein, the nanoporous system is magnified to macropores in hydrogel

• have been investigated in detail in literature [37][50]. Inspired by these, we now attempt to conduct a pore modification on g-CN-embedded hydrogels by visible-light-induced reaction. HGCM was a host network and the variety of monomers were swollen in the network, polymerized, and purified (Scheme 3

A new glance at the chemosphere of macroalgal–bacterial interactions: In situ profiling of metabolites in symbiosis by mass spectrometry

• Marine Vallet,
• Filip Kaftan,
• Veit Grabe,
• Fatemeh Ghaderiardakani,
• Simona Fenizia,
• Aleš Svatoš,
• Georg Pohnert and
• Thomas Wichard

Beilstein J. Org. Chem. 2021, 17, 1313–1322, doi:10.3762/bjoc.17.91

• the algal host and the locally released and exchanged compounds within the algal chemosphere [3]. Bacterial biofilms on macroalgae can be crucial for developing algae and their interactions with other marine organisms. The exchange of resources in this spatially limited region is of high interest for

• specialised metabolites involved in host–bacteria interactions. In our study, comparative metabolomics using atmospheric pressure scanning microprobe matrix-assisted laser desorption/ionisation high-resolution mass spectrometry (AP-SMALDI-HRMS) enables the identification of specialised metabolites of the

• multicellular host and bacteria interactions can characterise natural products in symbiotic interactions. Algal growth and morphogenesis-promoting factors (AGMPFs) are required for the development of the model organism U. mutabilis [7]. They are provided by a combination of two essential bacteria, Maribacter sp

A comprehensive review of flow chemistry techniques tailored to the flavours and fragrances industries

• Guido Gambacorta,
• James S. Sharley and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2021, 17, 1181–1312, doi:10.3762/bjoc.17.90

Structural effects of meso-halogenation on porphyrins

• Keith J. Flanagan,
• Maximilian Paradiz Dominguez,
• Zoi Melissari,
• Hans-Georg Eckhardt,
• René M. Williams,
• Dáire Gibbons,
• Caroline Prior,
• Gemma M. Locke,
• Alina Meindl,
• Aoife A. Ryan and
• Mathias O. Senge

Beilstein J. Org. Chem. 2021, 17, 1149–1170, doi:10.3762/bjoc.17.88

• few decades. Byrn et al. were the first to observe that porphyrins have a high propensity to form “porous” clathrates and suggested that they can be used as a “porphyrin sponge” [1]. They reported that 5,10,15,20-tetraphenylporphyrin could act like a ‘host’ which could trap a variety of solvent

Enhanced target cell specificity and uptake of lipid nanoparticles using RNA aptamers and peptides

• Roslyn M. Ray,
• Anders Højgaard Hansen,
• Maria Taskova,
• Bernhard Jandl,
• Jonas Hansen,
• Citra Soemardy,
• Kevin V. Morris and
• Kira Astakhova

Beilstein J. Org. Chem. 2021, 17, 891–907, doi:10.3762/bjoc.17.75

• complexation with cluster of differentiation 4 (CD4) and CCR5 or C-X-C motif chemokine receptor 4 (CXCR4) host cell surface receptors [35]. As such, gp160 expression on the host cell surface receptor may not be as adept at facilitating cell entry via receptor-mediated endocytosis. Although in 2009, Zhou et al

Breakdown of 3-(allylsulfonio)propanoates in bacteria from the Roseobacter group yields garlic oil constituents

• Anuj Kumar Chhalodia and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2021, 17, 569–580, doi:10.3762/bjoc.17.51

• preferred gas-phase reaction. The ecology of marine bacteria in their interaction with algae is particularly interesting in which the bacteria can promote the algal growth, but can also kill their host [10][11]. For both processes, the phytohormone indole-3-acetic acid is used as a messenger molecule [10

• ]. For the macroalga Ulva mutabilis the presence of bacteria from the Roseobacter group is even mandatory for proper algal development, and 3-(dimethylsulfonio)propanoate (DMSP) is used as a chemotactic signal by the bacteria attracting them towards the algal host [12]. Many bacteria and fungi also

Biochemistry of fluoroprolines: the prospect of making fluorine a bioelement

• Vladimir Kubyshkin,
• Rebecca Davis and
• Nediljko Budisa

Beilstein J. Org. Chem. 2021, 17, 439–460, doi:10.3762/bjoc.17.40

• whether fluoroprolines are metabolically inert substrates capable of accumulating at a high level in the cells without causing significant disturbances in the physiology of the host microbial organism. The transport and metabolism of proline are important factors that should be considered in engineering

Exploring the possibility of using fluorine-involved non-conjugated electron-withdrawing groups for thermally activated delayed fluorescence emitters by TD-DFT calculation

• Dongyang Chen and
• Eli Zysman-Colman

Beilstein J. Org. Chem. 2021, 17, 210–223, doi:10.3762/bjoc.17.21

• krISC (0.86 × 105 s−1) in the DPEPO host, the EQEmax was only 2.5%, and showed significant efficiency roll-off, reducing to 0.1% at 50 cd·m−2 [21]. A similar study by Monkman, Lee and co-workers investigated the compound 2,6-2CzTRZ, which possessed the smallest ΔEST (0.02 eV) amongst the family of

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

• also discussed. Keywords: host–guest chemistry; macrocycles; noncovalent interactions; supramolecular photocatalysis; Introduction Enzyme-catalyzed reactions are often carried out fantastically in nature via noncovalent interactions of a substrate [1][2]. Inspired by these natural processes, chemists

• 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

• materials that have been exploited for photocatalytic applications, including photocatalytic dye degradations and hydrogen evolution. To successfully perform supramolecular photocatalytic reactions, various photophysical and photochemical properties of the host–guest system need to be considered [4]: i) the

Supramolecular polymerization of sulfated dendritic peptide amphiphiles into multivalent L-selectin binders

• David Straßburger,
• Svenja Herziger,
• Katharina Huth,
• Moritz Urschbach,
• Rainer Haag and
• Pol Besenius

Beilstein J. Org. Chem. 2021, 17, 97–104, doi:10.3762/bjoc.17.10

• , these interactions occur in a multivalent fashion, allowing to overcome drawbacks of the limited strength of noncovalent bonds and to tune the selectivity at the same time [1][2]. The binding of viruses to the membrane of their host cells [3][4][5] as well as the recognition of carbohydrates by lectins

Molecular basis for protein–protein interactions

• Brandon Charles Seychell and
• Tobias Beck

Beilstein J. Org. Chem. 2021, 17, 1–10, doi:10.3762/bjoc.17.1

• known as a capsid [78]. Some viruses also have lipid envelopes containing glycoproteins, which interact with the host cell membrane to facilitate the viral entry into the cell [79]. The simplest explanation for viral capsid assembly is protein assembly units colliding (following Brownian motion) in a

Secondary metabolites of Bacillus subtilis impact the assembly of soil-derived semisynthetic bacterial communities

• Heiko T. Kiesewalter,
• Carlos N. Lozano-Andrade,
• Mikael L. Strube and
• Ákos T. Kovács

Beilstein J. Org. Chem. 2020, 16, 2983–2998, doi:10.3762/bjoc.16.248

• rhizosphere [15][16][17][18][19][20]. Microbial communities can consist of hundreds and thousands of diverse species, which makes investigations very challenging and hard to reproduce. One alternative approach is to establish a host-associated synthetic community, usually with members of the same kingdom

• , with a defined composition but fewer members [19][21]. Lebeis et al. used an artificial community of 38 bacterial strains to demonstrate that plant phytohormones sculpt the root microbiome [19]. In comparison, Niu et al. established a seven-species bacterial community based on host selection to mimic

Selected peptide-based fluorescent probes for biological applications

• Debabrata Maity

Beilstein J. Org. Chem. 2020, 16, 2971–2982, doi:10.3762/bjoc.16.247

• insulin Schmuck and co-workers reported a supramolecular ensemble in combination of a pyrene-tagged amphiphilic peptide beacon (6) and a macrocyclic host (cucurbit[8]uril, CB[8]) for ratiometric fluorescent detection of amino acid derivatives, specific peptides, and proteins in aqueous media (Figure 6

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

• 450001, P. R. China 10.3762/bjoc.16.245 Abstract We report novel pseudorotaxanes based on the complexation between pillar[4]arene[1]quinone and 1,10-dibromodecane. The complexation is found to have a 1:1 host–guest complexation stoichiometry in chloroform but a 2:1 host–guest complexation stoichiometry

• in the solid state. From single crystal X-ray diffraction, the linear guest molecules thread into cyclic pillar[4]arene[1]quinone host molecules in the solid state, stabilized by CH∙∙∙π interactions and hydrogen bonds. The bromine atoms at the periphery of the guest molecule provide convenience for

• the further capping of the pseudorotaxanes to construct rotaxanes. Keywords: host–guest chemistry; pillar[4]arene[1]quinones; pillararenes; pseudorotaxanes; supramolecular chemistry; Introduction Relying on the research of basic science, supramolecular chemistry has become an important mean for

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

• ), cucurbit[7]uril (3), and the two chalcones 1 and 2 in aqueous solution [48]. When the hosts 3 and 4 were mixed with the trans-chalcones 1 and 2 as guests in a 1:1:1:1 ratio, instantly a statistical mixture formed displaying all four possible host–guest complexes. After the exposure to an acid, the ensuing

• specific release of the guest (PF6−) with the consequent disassembly of the cage [Zn4(65')4]8+ (SelfSORT-II). In SelfSORT-II, the host–guest complex [Zn4(64')4]8+•(C6H12) remained intact, while ≈17% decrease in [Zn4(66')4]8+•(NO3−) was observed. The addition of another aliquot of 4-methoxyaniline to

• SelfSORT-II disassembled the host–guest complex [Zn4(64')4]8+•(C6H12) with the concomitant release of the encapsulated cyclohexane thus generating the state SelfSORT-III. In this process, the 1H NMR signals corresponding to [Zn4(66')4]8+•(NO3−) remained unchanged. At last, heating the mixture to 70 °C for

3-Acetoxy-fatty acid isoprenyl esters from androconia of the ithomiine butterfly Ithomia salapia

• Florian Mann,
• Daiane Szczerbowski,
• Lisa de Silva,
• Melanie McClure,
• Marianne Elias and
• Stefan Schulz

Beilstein J. Org. Chem. 2020, 16, 2776–2787, doi:10.3762/bjoc.16.228

• studies on speciation (species formation), as species often consist of multiple subspecies diverging for a number of adaptive traits, such as color pattern or host plants, which can then cause reproductive isolation. As such, they offer an excellent system to study the mechanisms underlying

Selective recognition of ATP by multivalent nano-assemblies of bisimidazolium amphiphiles through “turn-on” fluorescence response

• Rakesh Biswas,
• Surya Ghosh,
• Shubhra Kanti Bhaumik and
• Supratim Banerjee

Beilstein J. Org. Chem. 2020, 16, 2728–2738, doi:10.3762/bjoc.16.223

• ]. It is a principle ubiquitously used in biology to achieve high affinity binding events with examples ranging from protein–carbohydrate interactions to host–pathogen interactions or cell surface adhesion [12][13][14]. The high affinity originates from the simultaneous interactions of multiple sites in

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

• obtain analogues cages in future work to explore the properties of these system in terms of their host–guest chemistry or their magnetic behavior. Experimental General All reagents and solvents were purchased from commercial sources and used as received without any further purification. NMR spectra were

Particle size effect in the mechanically assisted synthesis of β-cyclodextrin mesitylene sulfonate

• Stéphane Menuel,
• Sébastien Saitzek,
• Eric Monflier and
• Frédéric Hapiot

Beilstein J. Org. Chem. 2020, 16, 2598–2606, doi:10.3762/bjoc.16.211

• to be a non-interactive guest towards the CD host [18], meaning that no inclusion compounds could be formed during the course of the reaction. Previous works dealing with this reaction showed that β-CDMts featuring a defined number of mesitylenesulfonate groups could be obtained selectively in

Water-soluble host–guest complexes between fullerenes and a sugar-functionalized tribenzotriquinacene assembling to microspheres

• Si-Yuan Liu,
• Xin-Rui Wang,
• Man-Ping Li,
• Wen-Rong Xu and
• Dietmar Kuck

Beilstein J. Org. Chem. 2020, 16, 2551–2561, doi:10.3762/bjoc.16.207

• hydrophobic effect and to host–guest π–π interactions. Hydrophobic surface simulations showed that TBTQ-(OG)6 and C60 forms an amphiphilic supramolecular host–guest complex, which further assembles to microspheres with diameters of 0.3–3.5 μm, as determined by scanning electron microscopy. Keywords

• : fullerenes; host–guest systems; microspheres; supramolecular chemistry; tribenzotriquinacene; Introduction In the field of supramolecular chemistry, host–guest association through noncovalent interactions is an interesting and exciting topic, especially for the encapsulation of various fullerenes, such as

• C60 and C70 [1][2][3][4][5]. It is generally accepted that good complexation of fullerenes requires host molecules with bowl or basket-like shapes, such as calixarenes [6], corannulenes [7][8][9][10], cyclodextrins [11][12][13], cyclotriveratrylenes [14][15][16], and similar macrocycles [17][18][19

NMR Spectroscopy of supramolecular chemistry on protein surfaces

• Peter Bayer,
• Anja Matena and
• Christine Beuck

Beilstein J. Org. Chem. 2020, 16, 2505–2522, doi:10.3762/bjoc.16.203

• -dimensional proton (1H) NMR spectra have been used to monitor the interactions between smaller molecules for a long time. The advantages comprise the use of non-isotope-labeled molecules and the fast acquisition time. Furthermore, both components - supramolecular host and guest - can in principle be monitored

• methylated lysine and arginine amino acids were determined using competitive 1H NMR titrations [49]. The supramolecular host is added to two competing guest molecules [85]. When the affinity for one of the guests is known, the affinity for the second guest can then be calculated from the relative amounts of

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

• Zhishu Zeng Jun Xie Guangyan Luo Zhu Tao Qianjun Zhang Key Laboratory of Macrocyclic and Supramolecular Chemistry of Guizhou Province, Guizhou University, No. 2708, South Section of Huaxi Avenue, Huaxi, Guiyang 550025, China 10.3762/bjoc.16.194 Abstract In this study, we investigated the host

• the inclusion compound with Q[8]. Keywords: cucurbit[8]uril; host–guest interaction; inclusion complex; oroxin A; properties; Introduction Cucurbit[n]urils (Q[n]s) are a family of macrocyclic cage compounds synthesized by the condensation of glycoluril and formaldehyde in a strong acidic solution [1

• ][2][3]. As a consequence of the specific structural features of Q[n]s, which have two hydrophilic “portals” decorated with partially negatively charged carbonyl groups and a hydrophobic cavity [4], cucurbit[n]urils are able to form host–guest complexes with a range of drugs [5][6][7]. These complexes