Beyond symmetric self-assembly and effective molarity: unlocking functional enzyme mimics with robust organic cages

• Keith G. Andrews

Beilstein J. Org. Chem. 2025, 21, 421–443, doi:10.3762/bjoc.21.30

• versions. Recent advances using hexameric resorcin[4]arene-based capsules [122][123][124] (Figure 4B and C), notably by Tiefenbacher [105][125][126][127][128][129][130][131][132][133], have demonstrated substrate-controlled selectivities that vary from the bulk phase due to the stabilization of cations in

• ) Self-assembling capsules can perform hydrophobic catalysis [116][117]. (B) Resorcin[4]arene building block. (C) Hexameric resorcin[4]arene-based capsules [122] include structural water. The cavity can stabilize cations (substrates or transition states) and perform catalysis using dual activation of a

HFIP as a versatile solvent in resorcin[n]arene synthesis

• Hormoz Khosravi,
• Valeria Stevens and
• Raúl Hernández Sánchez

Beilstein J. Org. Chem. 2024, 20, 2469–2475, doi:10.3762/bjoc.20.211

• from intermolecular dehydration, nowadays known as alkyl resorcin[4]arene. Forty years later in 1980, Höegberg noticed that short alkyl chain resorcin[n]arenes develop stereoisomers in the reaction mixture; however, since the condensation reaction is reversible, once the macrocycle adopts the bowl

Switchable molecular tweezers: design and applications

• Pablo Msellem,
• Maksym Dekthiarenko,
• Nihal Hadj Seyd and
• Guillaume Vives

Beilstein J. Org. Chem. 2024, 20, 504–539, doi:10.3762/bjoc.20.45

Complexes of resorcin[4]arene with secondary amines: synthesis, solvent influence on “in-out” structure, and theoretical calculations of non-covalent interactions

• Waldemar Iwanek

Beilstein J. Org. Chem. 2023, 19, 1525–1536, doi:10.3762/bjoc.19.109

• exchange and dispersion interactions in CHCl3 in relation to DMSO are the driving forces behind the placement of sec-amine molecules into the R[4]A cavity and the formation of “in” type complexes. Keywords: complexes; DFT calculations; hydrogen bond; resorcin[4]arene; supramolecular chemistry

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

• Tommaso Lorenzetto Fabrizio Fabris Alessandro Scarso Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca’ Foscari di Venezia, via Torino 155, 30172, Mestre-Venezia, Italy 10.3762/bjoc.18.38 Abstract The hexameric resorcin[4]arene capsule as a self-assembled organocatalyst promotes a

• 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

• [20] or hydrogen bonding units. In the latter case, a key role is played by the resorcin[4]arene 1 as a one-step multigram synthesis product, that spontaneously self-assembles in wet apolar solvents like chloroform or benzene forming a hexameric structure [21] thanks to the formation of a seam of

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

• , calix[4]- [9][10][11][12][13] and resorcin[4]arene [14][15][16][17] are the most exploited cavitands due to their inherent limited flexibility and already proved their ability to control the catalytic activity of late-transition metals and particularly gold(I) catalysts [18][19][20][21][22][23][24][25

• 7.48–7.20 (m, 5H), 6.93 (d, J = 16.2 Hz, 1H), 6.48 (d, J = 16.2 Hz, 1H), 5.73 (ddd, J = 2.7, 1.9, 0.9 Hz, 1H), 4.23–4.14 (m, 4H), 3.28 (dd, J = 1.9, 0.9 Hz, 2H), 3.18 (dd, J = 1.9, 0.9 Hz, 2H), 1.32–1.21 (m, 6H). Selected examples of: a) calix[4]arene-; b) resorcin[4]arene-; c) calix[6]arene-gold(I

Anion-driven encapsulation of cationic guests inside pyridine[4]arene dimers

• Anniina Kiesilä,
• Jani O. Moilanen,
• Anneli Kruve,
• Christoph A. Schalley,
• Perdita Barran and
• Elina Kalenius

Beilstein J. Org. Chem. 2019, 15, 2486–2492, doi:10.3762/bjoc.15.241

• dimeric resorcin[4]arene and pyridine[4]arene capsules, we highlight here unique host–guest properties of pyridinearene capsules. In marked contrast to the corresponding resorcin[4]arene capsules, cation binding is clearly feasible, when anions bind in an exo-site and support cation encapsulation by

• towards the Me4N+ cation was compared to that of resorcin[4]arene, which is known to bind small cations with high affinity. 1, 2 and Me4NPF6 were mixed in 1:1:1 ratio and measured by ESI-QTOF-MS. As seen in Figure 2, the resorcin[4]arene dimer [22 + Me4N]+ was detected as the base peak in the positive

• complexation of solvent was also only detected with the pyridinearene homodimer (for example as the [12 + MeCN + PF6]− ion). This mixed host experiment shows the resorcin[4]arene affinity towards Me4N+ to be higher than that of pyridine[4]arene. Also, the lack of anion and/or solvent complex formation with 2

Fluorinated azobenzenes as supramolecular halogen-bonding building blocks

• Esther Nieland,
• Oliver Weingart and
• Bernd M. Schmidt

Beilstein J. Org. Chem. 2019, 15, 2013–2019, doi:10.3762/bjoc.15.197

• in the field of crystal engineering [1]. Only few supramolecular capsules were reported so far [29], including the resorcin[4]arene capsules of Diederich and co-workers [21][23], triangular macrocycles assembled by self-complemented halogen bonding [20] and halogen bond templated, polyfluorinated

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

• chemistry. In the present study we demonstrate that resorcin[4]arene sulfonic acid (RSA) interacts with chiral amines (amino acid derivatives and aminocavitands) to form inclusion complexes and capsules based on electrostatic interactions. The complexes were characterized by circular dichroism and DOSY NMR

• disintegrative for these complexes. This result is quite non-intuitive and worth attention in the context of formation of supramolecular complexes in polar environment, for which DMSO is most often a first-choice solvent. Keywords: cavitands; chirality; macrocycle; resorcin[4]arene; self-assembly

• cyclodextrines, which, when unmodified, interact with a wide range of hydrophobic guests albeit with low general selectivity and enantioselectivity in particular [6]. In this paper we present a group of synthetic macrocyclic compounds – resorcin[4]arene sulfonic acids (RSAs) and analyze their interactions with

Enantioselective supramolecular devices in the gas phase. Resorcin[4]arene as a model system

• Caterina Fraschetti,
• Matthias C. Letzel,
• Antonello Filippi,
• Maurizio Speranza and
• Jochen Mattay

Beilstein J. Org. Chem. 2012, 8, 539–550, doi:10.3762/bjoc.8.62

• counterion effects. Keywords: diastereomeric complexes; gas phase enantioselectivity; kinetics; mass spectrometry; resorcin[4]arene receptor; Review Enzymes are macromolecular assemblies that make up the machinery whose structures and dynamics enable and support life functions. They are invariably

• , strongly dependent on the isomeric structure of the used guest [10]. Resorcin[4]arene molecules are characterized by three main contact regions [11]: (1) The down-region is the cavity of the receptor, which can be hydrophilic or lipophilic depending on the nature of the lateral chains; (2) The external

• the attention will be focussed on the most recent results obtained by our group with this particular kinetic method. Methodology The proton-bound [M∙H∙G]+ aggregates (M: chiral hosting resorcin[4]arene; G: guest biomolecule) were generated by electrospray ionization (ESI) of M/G methanolic mixtures

Molecular recognition of organic ammonium ions in solution using synthetic receptors

• Andreas Späth and
• Burkhard König

Beilstein J. Org. Chem. 2010, 6, No. 32, doi:10.3762/bjoc.6.32

Size selective recognition of small esters by a negative allosteric hemicarcerand

• Holger Staats and
• Arne Lützen

Beilstein J. Org. Chem. 2010, 6, No. 10, doi:10.3762/bjoc.6.10

• resorcinarene moieties in different directions so that they cannot act cooperatively in the binding of the substrate. Keywords: allosteric receptors; 2,2′-bipyridine; hemicarcerand; molecular recognition; resorcin[4]arene; Introduction Nature uses allosteric effects in a very elegant manner to control

• derivatives of this first example of an allosteric hemicarcerand and their metal complexes formed upon coordination to metal salts or complexes like AgBF4, CuBF4, [Cuphen]BF4, or [(CO)5ReCl] [28]. Among these, bis(resorcin[4]arene) substituted 2,2′-bipyridine 2 is a structural isomer of 1 differing only in