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

• ). They developed tweezers with carboxamidoindole units connected in 4 and 4’ positions to a 2,2’-bipyridine unit for switchable anion recognition [62]. The uncomplexed open conformation displays a very low affinity for anions such as chloride, acetate, or diphosphate (log K < 2). The coordination of

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

• -workers, with a strong focus on using rotaxanes with halogen-bond (XB) donors that act as binding sites for anionic guest molecules [23]. In 2017, Beer and co-workers reported the synthesis of the BINOL-containing chiral [2]rotaxanes 64 and their application for enantioselective anion recognition [63

• ) and two NH donors (on the macrocycle). For the anion-recognition experiments, the binding of selected dicarboxylate anions ((S/R)-glutamate, fumarate, and maleate) was investigated by fluorescence titrations. This revealed an impressive chiral discrimination towards (S)-Glu2− with a selectivity of K(S

• the enantioselective Michael addition with different rotaxane catalysts (S)-56a/56b/57a/57b and their non-interlocked counterparts. Synthesis of Beer´s [2]rotaxanes 64a/b for anion recognition. Association constants of different anions (used as the Bu4N+ salts) to the [2]rotaxanes (S)-64a/b and the

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

• advances in the research fields of crystal engineering [26], medicinal chemistry [27], anion recognition [28][29][30][31][32] and transport [33][34][35]. In addition, intramolecular chalcogen bonding interactions have been suggested to stabilize reactive intermediates in a range of isothiourea-catalyzed

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

• , 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

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 concepts and implementation of natural principles of anion recognition by small molecule catalysts. Review Hydrogen bonding to neutral substrates or anion binding? In the early stages of anion-binding-catalysis development, some reactions might have potentially been mistaken to be hydrogen-bond

• diastereoselective glycosylation reaction. b) Competing SN1 vs SN2 reactivity. a) Folding mechanism of oligotriazoles upon anion recognition. b) Representative tetratriazole 82 catalyzed enantioselective Reissert-type reaction of quinolines and pyridines with various nucleophiles. Switchable chiral tetratriazole

Chiral anion recognition using calix[4]arene-based ureido receptors in a 1,3-alternate conformation

• Tereza Horáčková,
• Jan Budka,
• Vaclav Eigner,
• Wen-Sheng Chung,
• Petra Cuřínová and
• Pavel Lhoták

Beilstein J. Org. Chem. 2020, 16, 2999–3007, doi:10.3762/bjoc.16.249

• for N-acetyl-ʟ-phenylalaninate. The structures of some receptors were confirmed by single crystal X-ray analysis. Keywords: anion recognition; calixarene; chiral receptor; complexation; enantiodiscrimination; Introduction The recognition and complexation of anions has become undoubtedly one of the

• anions is becoming more and more significant [12][13][14]. There are many strategies aiming at anion recognition in the literature. Most of the receptors, however, rely on electrostatic interactions. These systems are represented by positively charged molecules, such as quaternary N-, S-, and P

• for chiral anion recognition, contrary to the cone receptor, a design based on the 1,3-alternate conformer enables the introduction of chiral units into the phenolic functions of the inverted aromatic moieties nearby the ureido cavity responsible for the binding, as in C. This design can be

Optical detection of di- and triphosphate anions with mixed monolayer-protected gold nanoparticles containing zinc(II)–dipicolylamine complexes

• Lena Reinke,
• Julia Bartl,
• Marcus Koch and
• Stefan Kubik

Beilstein J. Org. Chem. 2020, 16, 2687–2700, doi:10.3762/bjoc.16.219

• of an additional component in the solution unnecessary. This approach has several advantages: one is the flexibility with respect to the receptor units that can be used to mediate the anion recognition, which makes it possible to develop probes for anions other than sulfate. The only prerequisite is

Halogen-bonding-induced diverse aggregation of 4,5-diiodo-1,2,3-triazolium salts with different anions

• Xingyu Xu,
• Shiqing Huang,
• Zengyu Zhang,
• Lei Cao and
• Xiaoyu Yan

Beilstein J. Org. Chem. 2020, 16, 78–87, doi:10.3762/bjoc.16.10

• chemistry, anion recognition, organocatalysis, materials science and tuning of biomolecular systems [17][18][19][20][21][22][23][24][25][26][27]. 1,2,3-Triazole-based XB-donors, such as 5-iodo-1,2,3-triazoles A [28][29][30][31][32][33] and 5-iodo-1,2,3-triazolium B [34][35][36][37] (Figure 1), are promising

• candidates for XB donors, which is mainly due to the ease of preparation via a copper-catalyzed click reaction between azide and alkyne [38][39]. 1,2,3-Triazoles and 1,2,3-triazolium-based XB activators have been found applications in catalytic reactions [40][41] and anion recognition [42]. Recently, we

Small anion-assisted electrochemical potential splitting in a new series of bistriarylamine derivatives: organic mixed valency across a urea bridge and zwitterionization

• Keishiro Tahara,
• Tetsufumi Nakakita,
• Alyona A. Starikova,
• Takashi Ikeda,
• Masaaki Abe and
• Jun-ichi Kikuchi

Beilstein J. Org. Chem. 2019, 15, 2277–2286, doi:10.3762/bjoc.15.220

• used for anion recognition [27][28][29]. In the oxidized state, the enhanced acidity of NH protons can increase the strength of H-bonds and give them more dynamic properties, which can be useful for refined designs of supramolecular systems [30] and proton-coupled electron-transfer systems [31][32][33

1,2,3-Triazolium macrocycles in supramolecular chemistry

• Mastaneh Safarnejad Shad,
• Pulikkal Veettil Santhini and
• Wim Dehaen

Beilstein J. Org. Chem. 2019, 15, 2142–2155, doi:10.3762/bjoc.15.211

• receptors for molecular recognition of anionic species, pH sensors, mechanically interlocked molecules, molecular machines, and molecular reactors. Keywords: anion recognition; catenane; chalcogen bonding; click reaction; molecular reactor; hydrogen bonding; pH sensor; rotaxane; supramolecular; 1,2,3

• mechanically interlocked molecules and molecular machines. We will not concern ourselves in this review with the applications of metal complexes based on N-heterocyclic carbene coordination chemistry, derived of triazoliums or with applications as ionic liquids [26][27][28]. 2. Anion recognition Due to the

• nanoscale molecular machines and switches [41] and their importance has been recognized by the 2016 Nobel prize. Anion recognition can be used as an impediment for rotary movement in the rotaxane structure. Besides, catenanes possessing a mechanically interlocked ring, have attracted considerable attention

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

• and anion recognition of phthalimide-containing corona[3]arene[3]tetrazines. Results and Discussion In the presence of diisopropylethylamine (DIPEA) as an acid scavenger, N-phenyl (1a), N-cyclohexyl (1b) and N-n-hexyl (1c)-substituted 3,6-dihydroxyphthalimides were able to react efficiently with 3,6

Silanediol versus chlorosilanol: hydrolyses and hydrogen-bonding catalyses with fenchole-based silanes

• Falco Fox,
• Jörg M. Neudörfl and
• Bernd Goldfuss

Beilstein J. Org. Chem. 2019, 15, 167–186, doi:10.3762/bjoc.15.17

• ], (thio)ureas [30][31] and phosphoric acid derivatives [27]. Cyclodiphosph(V)azanes [32][33][34][35] and silanediols [1][28][36] are two new hydrogen bonding scaffolds for anion recognition [37] and ion-pair catalysis [6][38]. Since Kondo et al. established silanediol 1 [39] as HBD for anion recognition

Creating molecular macrocycles for anion recognition

• Amar H. Flood

Beilstein J. Org. Chem. 2016, 12, 611–627, doi:10.3762/bjoc.12.60

• activity surrounding 1,2,3-triazoles made using click chemistry; and the same triazoles are responsible for anion capture. Mistakes made and lessons learnt in anion recognition provide deeper understanding that, together with theory, now provides for computer-aided receptor design. The lessons are acted

• microscopy (STM) imaging. Their shape persistence makes them ideal for the study of structure–property relationships to enable deep understanding of anion recognition phenomena. The identification of 1,2,3-triazoles as linkers, ligands and building blocks. The synthetic creation of macrocycles sets the scene

• for the group’s initial and ongoing activities in anion recognition. Triazolophanes [6] (Figure 1) were the first of these macrocycles and the origin of their design warrants description because it represents the first time we made something new. Triazolophanes were inspired by an overarching

Fluoride-driven ‘turn on’ ESPT in the binding with a novel benzimidazole-based sensor

• Kai Liu,
• Xiaojun Zhao,
• Qingxiang Liu,
• Jianzhong Huo,
• Bolin Zhu and
• Shihua Diao

Beilstein J. Org. Chem. 2015, 11, 563–567, doi:10.3762/bjoc.11.61

• recognition and sensing, was suggested to be responsible for the fluorescence enhancement with a blue shift of 35 nm in the emission spectrum. Keywords: anion recognition; deprotonation; ESPT; fluoride; ‘turn on’ fluorescence; Introduction Design and synthesis of selective and efficient sensors for various

• anions involved in biological, industrial and environmental processes have drawn a lot of attention [1][2][3]. In recent years, much effort has been devoted to the development of anion fluorescent sensors [4]. Of particular interest concerning anion recognition and sensing was fluoride [5][6][7], as it

• proton transfer (ESPT), as an extensively exploited mechanism in many biological and chemical processes, has been employed poorly in anion recognition and sensing [2][11][12][13][14][15][16]. In the ESPT molecules, a five or six-membered intramolecular hydrogen-bonded ring formed, and a proton/hydrogen

New hydrogen-bonding organocatalysts: Chiral cyclophosphazanes and phosphorus amides as catalysts for asymmetric Michael additions

• Helge Klare,
• Jörg M. Neudörfl and
• Bernd Goldfuss

Beilstein J. Org. Chem. 2014, 10, 224–236, doi:10.3762/bjoc.10.18

• but also in applications such as anion recognition. Experimental All reactions were conducted under argon atmosphere on a dual manifold Schlenk line and in oven-dried glassware, unless otherwise stated. All solvents were dried according to known methods and distilled prior to use. NMR spectra were

Synthesis and anion recognition properties of shape-persistent binaphthyl-containing chiral macrocyclic amides

• Marco Caricato,
• Nerea Jordana Leza,
• Claudia Gargiulli,
• Giuseppe Gattuso,
• Daniele Dondi and
• Dario Pasini

Beilstein J. Org. Chem. 2012, 8, 967–976, doi:10.3762/bjoc.8.109

• electronic features of the functional groups in the 2,2' positions. Keywords: amides; anion recognition; chirality; macrocycles; molecular switches; supramolecular chemistry; Introduction Macrocyclic molecules possessing a high degree of shape persistency act as molecular cages, and the scientific interest

• complexation. Several macrocyclic systems capable of effective anion recognition and discrimination have been previously reported [16][17][18]. Binol (1,1'-binaphthyl-2,2'-diol) based synthons are popular in the recent literature; given their robustness, they are frequently used to impart or transfer chiral

• difunctional carboxylates. We deemed it to be very interesting to increase the availability of hydrogen-bond donors within the macrocycle cavity, and to unlock the hydrogen-bonding capability of the amide NHs to their full potential for anion recognition. The former could in principle be achieved by unmasking

NMR studies of anion-induced conformational changes in diindolylureas and diindolylthioureas

• Damjan Makuc,
• Jennifer R. Hiscock,
• Mark E. Light,
• Philip A. Gale and
• Janez Plavec

Beilstein J. Org. Chem. 2011, 7, 1205–1214, doi:10.3762/bjoc.7.140

• along the C7–N7α bonds and the syn–syn conformer was preferred for anion–receptor complexes. The conformational changes upon anion binding are in good agreement with energetic preferences established by ab initio calculations. Keywords: anion recognition; conformation analysis; host–guest systems; NMR

Effects of anion complexation on the photoreactivity of bisureido- and bisthioureido-substituted dibenzobarrelene derivatives

• Heiko Ihmels and
• Jia Luo

Beilstein J. Org. Chem. 2011, 7, 278–289, doi:10.3762/bjoc.7.37

• by the selective preorganization of the substrates by hydrogen bonding between neutral organic functionalities with an appropriate substitution pattern or by complexation of crown-ether units to cationic guest molecules [1][2][3]. In contrast, the selective anion recognition has not been employed

Fluorometric recognition of both dihydrogen phosphate and iodide by a new flexible anthracene linked benzimidazolium-based receptor

• Kumaresh Ghosh and
• Debasis Kar

Beilstein J. Org. Chem. 2011, 7, 254–264, doi:10.3762/bjoc.7.34

• ; dihydrogenphosphate recognition; iodide recognition; Introduction The selective recognition of anionic species by artificial abiotic receptors is a rapidly growing area in supramolecular chemistry [1][2][3][4][5][6]. Anion recognition has gained significant importance as it plays an important role in a wide range of

• biological, environmental and chemical processes [7][8][9][10]. Sensors based on anion-induced changes in fluorescence appear to be particularly attractive in anion recognition due to the simplicity and high detection limit of fluorescence [11][12]. In devising such sensors, various functional sites with

• [22] groups are well established. In addition, the use of the benzimidazolium motif [23][24] in anion recognition is also known. During the course of our work on anion recognition, we used this motif along with the other functionalities for selective recognition of carboxylates, and dihydrogen

An easy assembled fluorescent sensor for dicarboxylates and acidic amino acids

• Xiao-bo Zhou,
• Yuk-Wang Yip,
• Wing-Hong Chan and
• Albert W. M. Lee

Beilstein J. Org. Chem. 2011, 7, 75–81, doi:10.3762/bjoc.7.11

• roles of anions in many chemical and biological processes [1][2][3][4][5]. Being the key structural moieties of many bioactive molecules such as amino acids and proteins, dicarboxylates are one of the most attractive targets for anion recognition and sensing. In addition, dicarboxylates are essential

A new fluorescent chemosensor for fluoride anion based on a pyrrole–isoxazole derivative

• Zhipei Yang,
• Kai Zhang,
• Fangbin Gong,
• Shayu Li,
• Jun Chen,
• Jin Shi Ma,
• Lyubov N. Sobenina,
• Albina I. Mikhaleva,
• Guoqiang Yang and
• Boris A. Trofimov

Beilstein J. Org. Chem. 2011, 7, 46–52, doi:10.3762/bjoc.7.8

• is brought about by deprotonation of the pyrrole-NH in receptor 1. Keywords: deprotonation; fluorescent chemosensor; fluoride anion recognition; Introduction The development of anion receptors has become a field of substantial interest and activity [1][2][3]. Among the various artificial receptors

• moieties which avoids the problem of multi-anion sensitivity. The common anion recognition moieties, i.e., a pyrrole NH and an amide group, present in the structure behave as proton donors. Isoxazoles and their derivatives are important intermediates in preparation of many natural products and related

• compounds, and are used as antimicrobial antifungal and herbicide agents [10][11]. Research on the mechanism of anion recognition is helpful for understanding the biological activities of pyrrole–isoxazole derivatives. From UV–vis and fluorescence titration experiments it was found that the receptor 1 could

Anion receptors containing thiazine-1,1-dioxide heterocycles as hydrogen bond donors

• Hong-Bo Wang,
• James A. Wisner and
• Michael C. Jennings

Beilstein J. Org. Chem. 2010, 6, No. 50, doi:10.3762/bjoc.6.50

• Hong-Bo Wang James A. Wisner Michael C. Jennings Department of Chemistry, University of Western Ontario, 1151 Richmond St., London, Ontario N6A 5B7, Canada 10.3762/bjoc.6.50 Abstract The synthesis, X-ray crystal structures and anion recognition properties of two receptors containing thiazine-1,1

• of their anion recognition properties is an area of research that has grown in interest over the past several years owing to the potential use of such receptors in environmental, biomedical and materials applications [1][2]. The basic design methodology for these hosts has largely focused on the use

• receptor. Results and Discussion The two receptor structures 1 and 2 (Figure 2) were chosen with the intent of evaluating their efficacy in comparison to the known anion host N,N′-diphenyl-1,3-disulfonamidobenzene 3 (Figure 2) [21]. Originally investigated for anion recognition by Crabtree and coworkers, 3

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