Aromatic C–H bond functionalization through organocatalyzed asymmetric intermolecular aza-Friedel–Crafts reaction: a recent update

• Anup Biswas

Beilstein J. Org. Chem. 2023, 19, 956–981, doi:10.3762/bjoc.19.72

• the reaction partners in a highly ordered three dimensional transition state through noncovalent interactions (like H-bonding, π–π interactions) thus promoting the stereoselective reaction. Examples of covalent bonding organocatalysts are amines [6][7], N-heterocyclic carbenes [8][9], phosphines [10

• –Crafts reaction has also been explored under the influence of organocatalysis. However, here organocatalysts act as Brønsted acids which form noncovalent interactions (H-bonding) with the imine nitrogen to enhance the electrophilicity of the imine component. In addition, by selecting suitable imine

• resonance-assisted accumulation of negative charge on C6 enabled the carbon to add to the electrophile selectively from the Re face of the imine plane because of substrate–catalyst H-bonding interactions (see transition state 51). Beside multiple noncovalent interactions, π–π stacking between the

Synthesis, structure, and properties of switchable cross-conjugated 1,4-diaryl-1,3-butadiynes based on 1,8-bis(dimethylamino)naphthalene

• Semyon V. Tsybulin,
• Ekaterina A. Filatova,
• Alexander F. Pozharskii,
• Valery A. Ozeryanskii and
• Anna V. Gulevskaya

Beilstein J. Org. Chem. 2023, 19, 674–686, doi:10.3762/bjoc.19.49

• . Noncovalent interactions of molecules in crystals and packing effects do not allow one to strictly judge the charge transfer in the oligomers 5. Therefore, we analyzed their UV–vis spectra (Table 3, Figure 8). The functional groups R are located at the far ends of the oligomeric chain and, from the steric

A new oxidatively stable ligand for the chiral functionalization of amino acids in Ni(II)–Schiff base complexes

• Alena V. Dmitrieva,
• Oleg A. Levitskiy,
• Yuri K. Grishin and
• Tatiana V. Magdesieva

Beilstein J. Org. Chem. 2023, 19, 566–574, doi:10.3762/bjoc.19.41

• stability of the (S)- and (R)-diastereomers which is related to the conformational flexibility of the template. The rigidity of the chiral Ni–Schiff base complexes is mainly determined by the noncovalent interactions in the Ni coordination environment. Among them, the most important is the π-stacking

• were performed for the model diastereomeric α-ʟ- and α-ᴅ-alanine complexes derived from new ligand L7; the approach for visualization of the noncovalent interactions suggested in [43] was applied. The images obtained for the ʟ- and ᴅ-(AlaNi)L7 complexes are given in Figure 2. The types of interactions

Computational studies of Brønsted acid-catalyzed transannular cycloadditions of cycloalkenone hydrazones

• Manuel Pedrón,
• Jana Sendra,
• Irene Ginés,
• Tomás Tejero,
• Jose L. Vicario and
• Pedro Merino

Beilstein J. Org. Chem. 2023, 19, 477–486, doi:10.3762/bjoc.19.37

• events in which all bonds involved in the cycloaddition are formed and broken and (ii) a second one consisting of the deprotonation of the nitrogen yielding a neutral compound and liberating the catalyst. The comparative quantitative analysis of the noncovalent interactions (NCI) [35][36] of fused

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

• mechanophores. Moreover, it was demonstrated that the hydrogen bonds of the diarylurea linkages also acted as supporting units to maintain the activated mechanophores (radicals) for a longer time [67]. Overall, this new strategy, which harnesses the power of noncovalent interactions by ball milling [68][69][70

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

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

• chemical energy [4][5][6]. Mainly, both antenna molecules and proteins on the thylakoid membrane are combined to form a light-harvesting system through noncovalent interactions. Inspired by photosynthesis, extensive research has been devoted to construct energy transfer systems for the better utilization

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

• 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

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

• important fields in modern chemistry [13][14][15]. It is based on a wide range of noncovalent interactions between molecules [16][17][18] and has been applied to a variety of research areas including molecular recognition, molecular devices, nanochemistry, catalysis, etc. [13][14][15][16][17][18]. By

• organic compounds. Within the molecular container, guest molecules can be encapsulated with a certain orientation and conformation through various noncovalent interactions. In this mode, the molecular container can act as reaction template and give rise to selective products. For example, the molecular

• prefunctionalization and deprotection synthetic procedures. Based on the logical concept of protecting groups, noncovalent interactions can be considered, because they can be built up in situ and are weak enough to let the substrate dissociate from the “protecting template” easily, omitting the complicated

Recent advances in the asymmetric phosphoric acid-catalyzed synthesis of axially chiral compounds

• Alemayehu Gashaw Woldegiorgis and
• Xufeng Lin

Beilstein J. Org. Chem. 2021, 17, 2729–2764, doi:10.3762/bjoc.17.185

• on the reactivity, but little on the enantiocontrol. In general, biaryl-2-amines with electron-donating groups showed higher reactivity than those with electron-withdrawing groups (Scheme 6). CPA 5 activates the reaction by creating a rigid and narrow chiral pocket, thus leading to better noncovalent

• interactions with the substrates. Moreover, the SPA ligand loading of 1 mol % is effective for this reaction under mild conditions [50]. Moreover, Shi, Lin and co-workers reported the first Pd(II)-catalyzed directed atroposelective C–H allylation of 2-(naphthalen-1-yl)aniline derivatives 14 with methacrylates

Halides as versatile anions in asymmetric anion-binding organocatalysis

• Lukas Schifferer,
• Martin Stinglhamer,
• Kirandeep Kaur and
• Olga García Macheño

Beilstein J. Org. Chem. 2021, 17, 2270–2286, doi:10.3762/bjoc.17.145

• the cationic reactive species. Keywords: anion binding; asymmetric catalysis; halide anions; hydrogen donors; noncovalent interactions; Introduction Halogens and the respective anionic halides occupy an essential role in natural and chemical processes [1][2][3][4]. While in chemical syntheses

• , the regulation of membrane potentials is one of such applications, in which the transport of chloride anions is facilitated by noncovalent hydrogen bonding interactions (Figure 1a) [6]. Noncovalent interactions are in fact one of the essential factors for the molecular recognition in enzymatic

• design of more efficient H-donor catalyst structures, offering additional noncovalent interactions in order to provide extra coordination points with the anion, substrate and/or reagent. The most important approaches in this direction used to date are presented in the following. (Thio)urea and squaramide

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

• ‘guests’ within the crystal lattice, through hydrogen-bonding and van der Waals forces. Thereafter, research over the crystal engineering of porphyrins has focused on the noncovalent interactions, such as hydrogen bonds and halogen bonds, or metal coordination interactions [2][3][4][5][6][7][8][9][10][11

Beyond ribose and phosphate: Selected nucleic acid modifications for structure–function investigations and therapeutic applications

• Christopher Liczner,
• Kieran Duke,
• Gabrielle Juneau,
• Martin Egli and
• Christopher J. Wilds

Beilstein J. Org. Chem. 2021, 17, 908–931, doi:10.3762/bjoc.17.76

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

• , hydrophobic cavities, and specific guest recognition), they can provide a suitable environment to realize photocatalysis via noncovalent interactions with different substrates. In this minireview, we emphasized the photochemical transformation and catalytic reactivity of different guests based on the binding

• 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

• noncovalent interactions, mimicking the natural enzymatic catalysis. Especially macrocycles provide a convenient method for the construction of supramolecular catalytic systems since macrocycles can act as both a stabilizer and electron transporter in supramolecular systems. In addition to that, the main

Supramolecular polymers with reversed viscosity/temperature profile for application in motor oils

• Jan-Erik Ostwaldt,
• Christoph Hirschhäuser,
• Stefan K. Maier,
• Carsten Schmuck and
• Jochen Niemeyer

Beilstein J. Org. Chem. 2021, 17, 105–114, doi:10.3762/bjoc.17.11

• identification of one compound as a promising VII. Keywords: noncovalent interactions; polymers; ring-chain transformation; supramolecular chemistry; viscosity; Introduction Viscosity index improvers (VIIs) are used to counteract the loss of viscosity of working fluids (such as motor oils) at elevated

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

• self-assembly turns out to be crucial in obtaining supramolecular polymers suitable for interactions with biological targets [16]. Peptide amphiphiles provide access to supramolecular structures in this competitive environment by taking advantage of nature’s versatile toolbox of noncovalent

• interactions [17][18]. By a careful design of the corresponding building blocks, extensive multilateral hydrogen bonds between the amino acid sequences of the oligopeptide backbone lead to secondary structures that direct the equilibrium to polymeric nano-scaled assemblies. A well-studied receptor making use

Selected peptide-based fluorescent probes for biological applications

• Debabrata Maity

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

• membrane-bound receptors interact strongly with short peptidic segments of a larger protein chain, for example, recognition of the RGD sequence (arginine–glycine–aspartic acid; Arg–Gly–Asp) by integrin receptors. They use noncovalent interactions including salt bridges [5]. Vancomycin, a glycopeptide

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

• undemanding building blocks. The plethora of self-sorting systems depends on either the geometric fit of their global shapes and/or matching of their local interactions. Various noncovalent interactions, such as H‐bonding [8][9], metal–ligand coordination [10][11][12][13], electrostatic interactions [14], π

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

• -8 (DBC8, Figure 1), which bind through noncovalent interactions. In detail, these interactions are strong hydrogen bonds between ether oxygen atoms and ammonium protons. In addition, weaker C–H···O hydrogen bonds with the CH2 groups adjacent to the ammonium nitrogen as well as π–π-interactions

• @NDIC8, which even results in dethreading of the pseudorotaxane, may give rise to new switching modes in more complex molecular structures. Overall, these findings demonstrate the benefit of detailed and systematic studies on the noncovalent interactions cohering the components of switchable MIMs for the

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

• : 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

pH- and concentration-dependent supramolecular self-assembly of a naturally occurring octapeptide

• Goutam Ghosh and
• Gustavo Fernández

Beilstein J. Org. Chem. 2020, 16, 2017–2025, doi:10.3762/bjoc.16.168

• secondary structures, which lead to nanostructured materials [16][17]. Noncovalent interactions, such as hydrogen bonding, van der Waals interactions, hydrophobic interactions, electrostatic interactions, and π–π interactions [18][19][20][21][22] are common driving forces in peptide self-assembly. These

• noncovalent interactions can also be designed to be responsive to various external stimuli, such as heat, pH, light, enzymes, metal ions, and chemical triggers [23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39]. In this regard, a particularly relevant property of peptide assemblies is their

Synthesis, antiinflammatory activity, and molecular docking studies of bisphosphonic esters as potential MMP-8 and MMP-9 inhibitors

• Abimelek Cortes-Pacheco,
• María Adelina Jiménez-Arellanes,
• Francisco José Palacios-Can,
• José Antonio Valcarcel-Gamiño,
• Rodrigo Said Razo-Hernández,
• María del Carmen Juárez-Vázquez,
• Adolfo López-Torres and
• Oscar Abelardo Ramírez-Marroquín

Beilstein J. Org. Chem. 2020, 16, 1277–1287, doi:10.3762/bjoc.16.108

• small molecular volume increases the pharmacokinetic abilities of the compounds. In addition, 3 and 4 have a greater dipole moment compared to 5 and 6. The hydrogen-bond formation and the noncovalent interactions are influenced by the dipole moment. This means that an increased dipole moment can improve

• to a methyl moiety of Val398 and with Leu187, with distances below 3.5 Å. For MMP-9, the ligands were even more exposed to the solvent, although many more noncovalent interactions were seen between the catalytic site and the molecules (Figure 5). Conclusion In this work, we reported the two-step

Understanding the role of active site residues in CotB2 catalysis using a cluster model

• Keren Raz,
• Ronja Driller,
• Thomas Brück,
• Bernhard Loll and
• Dan T. Major

Beilstein J. Org. Chem. 2020, 16, 50–59, doi:10.3762/bjoc.16.7

• potential. Additionally, structural analysis revealed that each cation was stabilized by noncovalent interactions, such as π–cation and dipole–cation interactions. A comparison of the transition state structures in the gas phase vs the active site model is shown in Table 2. These findings suggest that the

Why do thioureas and squaramides slow down the Ireland–Claisen rearrangement?

• Dominika Krištofíková,
• Juraj Filo,
• Mária Mečiarová and
• Radovan Šebesta

Beilstein J. Org. Chem. 2019, 15, 2948–2957, doi:10.3762/bjoc.15.290

• quantum-chemical calculations employing long-range corrected hybrid density ωB97X-D functional [42]. This dispersion-corrected functional displays very balanced overall performances and has demonstrated excellent treatment of noncovalent interactions [43], which are very important in our studied system

Influence of the cis/trans configuration on the supramolecular aggregation of aryltriazoles

• Sara Tejera,
• Giada Caniglia,
• Rosa L. Dorta,
• Andrea Favero,
• Javier González-Platas and
• Jesús T. Vázquez

Beilstein J. Org. Chem. 2019, 15, 2881–2888, doi:10.3762/bjoc.15.282

• diffraction; Introduction Structures self-assembled by noncovalent interactions give rise to supramolecular architectures with specific physical and/or chemical properties. Gels are colloid systems in which the dispersed phase has combined with the dispersion medium to yield a semisolid material. Gels from