Origami with small molecules: exploiting the C–F bond as a conformational tool

• Patrick Ryan,
• Ramsha Iftikhar and
• Luke Hunter

Beilstein J. Org. Chem. 2025, 21, 680–716, doi:10.3762/bjoc.21.54

• or against the dipole of the indole moiety. A similar phenomenon occurs with the difluorinated analogue 3. The fluorinated molecules 2 and 3 can be said to have a “chameleonic” character [9][10][11][12][13][14]: they have the ability to change polarity to suit their environment. This is a potentially

• motif has been exploited in the design of bioactive molecules [22][23] such as the histone deacetylase (HDAC) inhibitors 6 and 7 (Figure 2). The presence of the 1,2-difluoro moiety in 6 leads to greater potency and selectivity for certain HDAC isoforms, attributable to the higher polarity of the

• are aligned with either σC–H orbitals (II, Figure 3), or, to a lesser extent, σC–C orbitals, will be favoured. Another factor is simple sterics: conformations in which the flanking alkyl moieties are further apart from one another will be favoured. A third factor is polarity: for example

Asymmetric synthesis of fluorinated derivatives of aromatic and γ-branched amino acids via a chiral Ni(II) complex

• Maurizio Iannuzzi,
• Thomas Hohmann,
• Michael Dyrks,
• Kilian Haoues,
• Katarzyna Salamon-Krokosz and
• Beate Koksch

Beilstein J. Org. Chem. 2025, 21, 659–669, doi:10.3762/bjoc.21.52

• identified as optimal delivering a yield of alkylated complex of 60% (Table 1, entry 4). With DBU as base different solvents differing in polarity have been tested. At room temperature, acetonitrile proved best and increased the yield to 88% (Table 1, entry 11). Lowering the temperature to 0 °C led to a

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

• the cage framework to polarize adjacent aryl–hydrogen bonds in the ligands by enough to coordinate and activate substrates (Figure 5E) [190]. Here, the use of bulky counteranions reinforces the cationic cage interior, which is enhanced further by use of lower polarity solvents, and the pKa of confined

Synthesis, structure, ionochromic and cytotoxic properties of new 2-(indolin-2-yl)-1,3-tropolones

• Yurii A. Sayapin,
• Eugeny A. Gusakov,
• Inna O. Tupaeva,
• Alexander D. Dubonosov,
• Igor V. Dorogan,
• Valery V. Tkachev,
• Anna S. Goncharova,
• Gennady V. Shilov,
• Natalia S. Kuznetsova,
• Svetlana Y. Filippova,
• Tatyana A. Krasnikova,
• Yanis A. Boumber,
• Alexey Y. Maksimov,
• Sergey M. Aldoshin and
• Vladimir I. Minkin

Beilstein J. Org. Chem. 2025, 21, 358–368, doi:10.3762/bjoc.21.26

• thermodynamically more stable than the corresponding (OH) forms. Increasing the polarity of the medium additionally enhances their stabilization. The introduction of an additional acceptor substituent to the tropolone moiety has a similar effect. In addition, compared to compounds 7a,b, compounds 8a,b show a marked

Synthesis and characterizations of highly luminescent 5-isopropoxybenzo[rst]pentaphene

• Islam S. Marae,
• Jingyun Tan,
• Rengo Yoshioka,
• Zakaria Ziadi,
• Eugene Khaskin,
• Serhii Vasylevskyi,
• Ryota Kabe,
• Xiushang Xu and
• Akimitsu Narita

Beilstein J. Org. Chem. 2025, 21, 270–276, doi:10.3762/bjoc.21.19

• reaction conditions to selectively obtain BPP-OiPr 3 in 55% yield from dialdehyde 1. Additionally, oxidation of BPP-OiPr 3 provided BPP-dione 4 in 70% yield. The photophysical properties of BPP-OiPr 3 and BPP-dione 4 were carefully studied, examining the solvent-polarity dependence of their optical spectra

• , in comparison with parent BPP 2. Notably, both BPP-OiPr 3 and BPP-dione 4 displayed enhanced PLQYs while a significant solvent-polarity dependence of the emission was observed only for the latter, suggesting the photoinduced intramolecular charge-transfer character of 4. Moreover, BPPs 2–4 formed

• -OiPr 3 and BPP-dione 4, their absorption and emission spectra were next measured in different solvents (Figure 2c and d and Supporting Information File 1, Figures S4 and S5). For BPP-OiPr 3 the well-defined vibronic structures were observed without showing any significant solvent-polarity dependence

Heteroannulations of cyanoacetamide-based MCR scaffolds utilizing formamide

• Marios Zingiridis,
• Danae Papachristodoulou,
• Despoina Menegaki,
• Konstantinos G. Froudas and
• Constantinos G. Neochoritis

Beilstein J. Org. Chem. 2025, 21, 217–225, doi:10.3762/bjoc.21.13

• be established as a C1 feedstock. [25]. Its high polarity and dielectric constant (it is miscible with water) [26], with the ability to solubilize a wide range of reagents, from salts to polymers, proteins and saccharides, renders formamide an excellent C1 building block [25][27]. Thus, our target

Hot shape transformation: the role of PSar dehydration in stomatocyte morphogenesis

• Remi Peters,
• Levy A. Charleston,
• Karinan van Eck,
• Teun van Berlo and
• Daniela A. Wilson

Beilstein J. Org. Chem. 2025, 21, 47–54, doi:10.3762/bjoc.21.5

• hydrophobicity changes [34]. Specifically, the intensity of the I1 peak at 376.6 nm responds significantly to the surrounding polarity, while the I3 peak at 387.6 nm remains relatively stable. The ratio of these peaks (I1/I3) serves as an indicator of the hydrophobicity of the environment, with a lower I1/I3

Synthesis, characterization, and photophysical properties of novel 9‑phenyl-9-phosphafluorene oxide derivatives

• Shuxian Qiu,
• Duan Dong,
• Jiahui Li,
• Huiting Wen,
• Jinpeng Li,
• Yu Yang,
• Shengxian Zhai and
• Xingyuan Gao

Beilstein J. Org. Chem. 2024, 20, 3299–3305, doi:10.3762/bjoc.20.274

• charge transfer, as indicated by the λmax value of 342 nm. In addition, the effect of solvent polarity on the UV−vis absorption was studied with 7-H (Figure 2b). The spectra show that there is no significant difference in the absorption bands in different solvents, indicating that the polar environment

• induced by the stronger electron-donating feature of the carbazole substituent located on the donor carbazole group. In addition, we tested the emission wavelength of 7-H in different solvents (Figure 3b) and found that the maximum is redshifted gradually with increasing solvent polarity, which indicates

Efficient synthesis of fluorinated triphenylenes with enhanced arene–perfluoroarene interactions in columnar mesophases

• Yang Chen,
• Jiao He,
• Hang Lin,
• Hai-Feng Wang,
• Ping Hu,
• Bi-Qin Wang,
• Ke-Qing Zhao and
• Bertrand Donnio

Beilstein J. Org. Chem. 2024, 20, 3263–3273, doi:10.3762/bjoc.20.270

• PH8), with no or little influence of the solvent polarity (Figure 6a). This may suggest that the sigma-bonded F6 and G66 have no conjugation in their ground states, the electron density being located on one triphenylene moiety (see DFT). G66 shows a stronger absorption band than F6, with expected ε

• (λem = 402 nm for PH8) and 460–500 nm for G66, with absolute quantum yields of 30% and 32%, respectively. Further, their fluorescence spectra in solutions show some solvent polarity influence, with a substantial red shift as the solvent polarity is increased. In thin film, the single luminescence

Direct trifluoroethylation of carbonyl sulfoxonium ylides using hypervalent iodine compounds

• Radell Echemendía,
• Carlee A. Montgomery,
• Fabio Cuzzucoli,
• Antonio C. B. Burtoloso and
• Graham K. Murphy

Beilstein J. Org. Chem. 2024, 20, 3182–3190, doi:10.3762/bjoc.20.263

• -containing functional groups, the 2,2,2-trifluoroethyl group (CF3CH2), is gaining significant interest from synthetic chemists. This is due to its reduced electron-withdrawing aspect compared to the CF3 group, its larger steric bulk and increased polarity. This moiety is also considered as a bioisostere of

Controlled oligomerization of [1.1.1]propellane through radical polarity matching: selective synthesis of SF₅- and CF₃SF₄-containing [2]staffanes

• Jón Atiba Buldt,
• Wang-Yeuk Kong,
• Yannick Kraemer,
• Masiel M. Belsuzarri,
• Ansh Hiten Patel,
• James C. Fettinger,
• Dean J. Tantillo and
• Cody Ross Pitts

Beilstein J. Org. Chem. 2024, 20, 3134–3143, doi:10.3762/bjoc.20.259

• truncated after incorporation of two bicyclopentane (BCP) units. Synthetic and computational studies suggest this phenomenon can be attributed to alternating radical polarity matching. In addition, single-crystal X-ray diffraction (SC-XRD) data reveal structurally interesting features of the CF3SF4

• chloropentafluorosulfanylated [2]staffane (SF5-BCP-BCP-Cl, 2), based on alternating radical polarity matching in the chain-propagation steps (Figure 1, bottom) [45][46][47]. Density functional theory (DFT) calculations provide insight into our observed selectivity, and our hypothesis is bolstered by computation of relative

• atom abstraction over continued oligomerization in the second product-determining step than in the first – in line with our experimental observations. One possible explanation for this phenomenon is rooted in better radical polarity matching after incorporation of the second BCP unit [37][38]. That is

Chemical structure metagenomics of microbial natural products: surveying nonribosomal peptides and beyond

• Thomas Ma and
• John Chu

Beilstein J. Org. Chem. 2024, 20, 3050–3060, doi:10.3762/bjoc.20.253

• The chemical structure of a molecule is defined as the arrangement of its atoms and bonds, which describes not just the size and shape of a molecule, but also encompass its stereochemistry, charges, polarity, functional groups, as well as the way these elements are spatially oriented. The chemical

Cyclodextrin-based rotaxanes for polymer materials: challenge on simultaneous realization of inexpensive production and defined structures

• Yosuke Akae

Beilstein J. Org. Chem. 2024, 20, 3026–3049, doi:10.3762/bjoc.20.252

• )rotaxane framework The rotaxane framework is often deployed as a molecular device in which the positional relationship between the axle and wheel is controlled by external stimuli [14][32]. Acid–base, photoisomerization, redox, ion recognition, solvent polarity, or heating treatment is generally used for

• tetrathiafulvalene (TTF) and a triazole ring (Figure 7A) [61]. CD was located around the TTF moiety under neutral conditions; however, it moved to the triazole ring, following TTF oxidization. Meanwhile, the structural control by exploring the solvent polarity was reported by Harada and co-workers using the α-CD

• stabilization effect could be affected by the bulkiness and polarity of the axle-end moieties. Meanwhile, the deslipping reaction of some [3]rotaxanes directly yielded the dumbbell and two wheels without any [2]rotaxane intermediate, indicating that the deslipping on [2]rotaxane proceeded faster than on [3

Tunable full-color dual-state (solution and solid) emission of push–pull molecules containing the 1-pyrindane moiety

• Anastasia I. Ershova,
• Sergey V. Fedoseev,
• Konstantin V. Lipin,
• Mikhail Yu. Ievlev,
• Oleg E. Nasakin and
• Oleg V. Ershov

Beilstein J. Org. Chem. 2024, 20, 3016–3025, doi:10.3762/bjoc.20.251

• Table S1 and Figure S1, Supporting Information File 1). The electronic absorption spectra were characterized by a pronounced maximum in the visible region centered at 431–448 nm. Emission maxima of compound 1c were more significantly affected by the change of polarity and ranged from 475 nm (blue-green

• ) in tetrachloromethane (CTC) to 588 nm (orange) in formic acid. Therefore, it was found that compound 1c was characterized by a large Stokes shift upon increasing the solvent polarity, which reached 150 nm (5824 cm−1) in formic acid. This was associated with the bathochromic shift of the emission band

• dimethylamino group, were studied (Table 1 and Figure 3). It was found that in most solvents, compound 1i was characterized by a single pronounced absorption maximum in the range of 503–525 nm that red-shifted upon increasing the solvent polarity. In formic acid, due to the protonation of the dimethylamino

4,6-Diaryl-5,5-difluoro-1,3-dioxanes as chiral dopants for liquid crystal compositions

• Maurice Médebielle,
• Peer Kirsch,
• Jérémy Merad,
• Carolina von Essen,
• Clemens Kühn and
• Andreas Ruhl

Beilstein J. Org. Chem. 2024, 20, 2940–2945, doi:10.3762/bjoc.20.246

• the two nematic host mixtures is their polarity: whereas Host 1 is only moderately polar (Δε = 4.0), the mixture Host 2 was developed for Blue Mode LCD application and is extremely polar. As compared to chiral dopants depicted in Figure 1, HTPs are lower and closest analogues for comparison could be

The charge transport properties of dicyanomethylene-functionalised violanthrone derivatives

• Sondos A. J. Almahmoud,
• Joseph Cameron,
• Dylan Wilkinson,
• Michele Cariello,
• Claire Wilson,
• Alan A. Wiles,
• Peter J. Skabara and
• Graeme Cooke

Beilstein J. Org. Chem. 2024, 20, 2921–2930, doi:10.3762/bjoc.20.244

• mobilities (μh) of 3b and 3c are calculated as 1.07 × 10−2 and 1.21 × 10−3 cm2 V−1s−1, respectively. However, the hole mobility of 3a is only 3.62 × 10−6 cm2 V−1 s−1. Side chain engineering is crucial for OFET performance since it plays an important role in determining solubility, molecular packing, polarity

C–C Coupling in sterically demanding porphyrin environments

• Liam Cribbin,
• Brendan Twamley,
• Nicolae Buga,
• John E. O’ Brien,
• Raphael Bühler,
• Roland A. Fischer and
• Mathias O. Senge

Beilstein J. Org. Chem. 2024, 20, 2784–2798, doi:10.3762/bjoc.20.234

• , borylation of a dodecasubstituted porphyrin’s meso-phenyl position was explored and a subsequent C–C coupling showed the polarity of the reaction can be reversed resulting in higher yields. X-ray analysis of the target compounds revealed the formation of supramolecular assemblies, capable of accommodating

• dodecasubstituted porphyrins A Miyaura borylation was performed on porphyrin 13, using bis(pinacolato)diboron (B2Pin2), adapting a procedure from the literature [51]. This procedure was further optimized (Table 4) by utilizing conditions in the synthesis of 29 (Table 1, entry 9). Next, a reversed polarity Suzuki

• . Furthermore, pyrene was installed on the para-phenyl position, showing large aromatic systems can also be installed through this route. Failure of the similar anthracenylboronic acid 15 to react in the presence of Cs2CO3 at 85 °C (Table 2, entry 2) shows reversing the polarity of the reaction can induce

A review of recent advances in electrochemical and photoelectrochemical late-stage functionalization classified by anodic oxidation, cathodic reduction, and paired electrolysis

• Nian Li,
• Ruzal Sitdikov,
• Ajit Prabhakar Kale,
• Joost Steverlynck,
• Bo Li and
• Magnus Rueping

Beilstein J. Org. Chem. 2024, 20, 2500–2566, doi:10.3762/bjoc.20.214

Cell-free protein synthesis with technical additives – expanding the parameter space of in vitro gene expression

• Tabea Bartsch,
• Stephan Lütz and
• Katrin Rosenthal

Beilstein J. Org. Chem. 2024, 20, 2242–2253, doi:10.3762/bjoc.20.192

• -hexane due to the low solubility of n-hexane in water, a limited interfacial area, and evaporation in the headspace. There is no clear trend for the influence of the polarity or log P of the added solvents. Among the water-miscible additives, methanol, whose dipole moment is relatively close to that of

Metal-free double azide addition to strained alkynes of an octadehydrodibenzo[12]annulene derivative with electron-withdrawing substituents

• Naoki Takeda,
• Shuichi Akasaka,
• Susumu Kawauchi and
• Tsuyoshi Michinobu

Beilstein J. Org. Chem. 2024, 20, 2234–2241, doi:10.3762/bjoc.20.191

• apparently smaller than those previously reported for the reaction between DBA-OHex and benzyl azide (Table S1 in Supporting Information File 1). However, the Ea values were previously measured in DMSO-d6 and C6D6, and it is known that there is a solvent polarity effect on the reactivity of SpAACs. In order

Understanding X-ray-induced isomerisation in photoswitchable surfactant assemblies

• Beatrice E. Jones,
• Camille Blayo,
• Jake L. Greenfield,
• Matthew J. Fuchter,
• Nathan Cowieson and
• Rachel C. Evans

Beilstein J. Org. Chem. 2024, 20, 2005–2015, doi:10.3762/bjoc.20.176

• azobenzene (Azo) or, more recently, arylazopyrazoles (AAPs), which change shape and polarity on photoisomerisation between the E and Z states, thus changing the self-assembled structure. Small-angle X-ray scattering (SAXS) is a powerful technique to probe the morphology of PS and can be used to measure the

• molecules to create photosurfactants (PS), whose molecular shape and polarity can be modified using light [4][5][6]. Of the PS studied, most use an azobenzene (Azo) photoswitch that undergoes trans-to-cis (E-to-Z) isomerization on irradiation with UV light, typically forming a photostationary state (PSS

• ) that contains mostly Z isomers. This can be reversed using blue light or heat in a process that is stable over many cycles [7]. Isomerisation of azobenzene leads to a change in its conformation and polarity which, when combined into a surfactant molecule, modifies the resulting molecular geometry and

Syntheses and medicinal chemistry of spiro heterocyclic steroids

• Laura L. Romero-Hernández,
• Ana Isabel Ahuja-Casarín,
• Penélope Merino-Montiel,
• Sara Montiel-Smith,
• José Luis Vega-Báez and
• Jesús Sandoval-Ramírez

Beilstein J. Org. Chem. 2024, 20, 1713–1745, doi:10.3762/bjoc.20.152

Chemo-enzymatic total synthesis: current approaches toward the integration of chemical and enzymatic transformations

• Ryo Tanifuji and
• Hiroki Oguri

Beilstein J. Org. Chem. 2024, 20, 1693–1712, doi:10.3762/bjoc.20.151

• experimental results, Gulder and co-workers devised a strategy to control the dimerization modes by adjusting the polarity of the organic co-solvent to establish the divergent synthesis of dimeric scaffolds. Indeed, with 20% DMF in the SorbC-catalyzed enzymatic oxidative dearomatization, the Michael addition

Regio- and stereochemical stability induced by anomeric and gauche effects in difluorinated pyrrolidines

• Ana Flávia Candida Silva,
• Francisco A. Martins and
• Matheus P. Freitas

Beilstein J. Org. Chem. 2024, 20, 1572–1579, doi:10.3762/bjoc.20.140

• stereochemical behavior. Consequently, various molecular properties, such as polarity, viscosity, and intra- and intermolecular interactions, are impacted by the C‒F bond. These features underlie the important role of selective fluorination in pharmaceuticals and agrochemicals development [1]. For instance

Benzylic C(sp³)–H fluorination

• Alexander P. Atkins,
• Alice C. Dean and
• Alastair J. J. Lennox

Beilstein J. Org. Chem. 2024, 20, 1527–1547, doi:10.3762/bjoc.20.137

• preliminary electrochemical examples [93][101]. Middleton and co-workers described an alternating polarity approach for the fluorination of simple toluene derivatives in neat pyridine·HF (Figure 42) [102][103]. Poor conductivity necessitated the use of this waveform type. The benzylic fluorination was