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

• dopants for liquid-crystal compositions. Keywords: chiral dopant; chirality; cholesteric phase; diols; fluorine; helical twisting power; liquid crystal; Introduction Liquid crystals for use in liquid crystal displays (LCDs) have become one of the most prominent application areas of fluoroorganic

• chemistry [1][2][3]. In particular, cholesteric, i.e., chiral nematic, liquid crystals (LCs) are attractive for many display applications due to their chiroptical characteristics as well as the selective reflection of light giving rise to Bragg interference colors [4]. Cholesteric LCs can be obtained either

• ) LCDs which need a higher HTP or increased dopant concentrations [8][9]. TN and STN displays are still based on liquid crystals in the nematic or cholesteric mesophase. Even higher concentrations of chiral dopants with extremely high HTP tend to induce a Blue Phase, which is a cubic mesophase composed

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

• enhanced push–pull effect in this molecule due to the presence of a stronger acceptor. Furthermore, the energy of the LUMO of compound 3 is comparable to reported PDI-based acceptors which have been used in OPVs with PCE > 7% [34]. Crystallographic study Needle-shape crystals of compound 3b suitable for

Access to optically active tetrafluoroethylenated amines based on [1,3]-proton shift reaction

• Yuta Kabumoto,
• Eiichiro Yoshimoto,
• Bing Xiaohuan,
• Masato Morita,
• Motohiro Yasui,
• Shigeyuki Yamada and
• Tsutomu Konno

Beilstein J. Org. Chem. 2024, 20, 2776–2783, doi:10.3762/bjoc.20.233

•  1a, 1, 2) [10][11][12], liquid crystals (Figure 1b, 3, 4) [13][14][15][16][17], fluorescence materials (Figure 1c, 5) [18][19], and so on, have been developed in recent years. In sharp contrast to the major development of such non-chiral tetrafluoroethylenated compounds, there have been only few

Applications of microscopy and small angle scattering techniques for the characterisation of supramolecular gels

• Connor R. M. MacDonald and
• Emily R. Draper

Beilstein J. Org. Chem. 2024, 20, 2608–2634, doi:10.3762/bjoc.20.220

• material in its hydrated state. Cryogenic techniques utilise a vitrification process to maximise the formation of vitreous ice to minimise the formation of ice crystals which can disrupt the material structure. The ability of cryo-EM to probe the structure of soft nanostructured materials has led to a

• area-to-volume ratio which reduces the cooling rate reached in the vitrification process. High-pressure freezing (HPF) methods are capable of fixing samples 100 times thicker than plunge freezing. HPF reduces the growth of crystals during the fixation of cryo-SEM samples by using very high pressures of

Efficient modification of peroxydisulfate oxidation reactions of nitrogen-containing heterocycles 6-methyluracil and pyridine

• Alfiya R. Gimadieva,
• Yuliya Z. Khazimullina,
• Aigiza A. Gilimkhanova and
• Akhat G. Mustafin

Beilstein J. Org. Chem. 2024, 20, 2599–2607, doi:10.3762/bjoc.20.219

• mixture to room temperature, concentrated H2SO4 was slowly added until pH 6–7 according to litmus paper and left standing for 12 h. The precipitated white crystals were filtered off, washed with water, and dried in air. Compound 2 yields are given in [13] and compound 5 yields are given in Table 1. b

• temperature, concentrated H2SO4 was slowly added until pH 6–7 according to litmus paper and left standing overnight (12 h). The precipitated crystals were filtered off, washed with water, acetone, and dried in air. The crude product was recrystallized from water with activated carbon. The yield of compound 2

• H2SO4 was added and the reaction mixture was stirred at the same temperature for 1 h and cooled. The precipitated crystals were filtered off, washed with cold distilled water to pH 6–7 (2 × 5 mL), and recrystallized from ethanol. 5-Hydroxy-6-methyluracil (3). Yield 98%. The spectral characteristics are

Anion-dependent ion-pairing assemblies of triazatriangulenium cation that interferes with stacking structures

• Yohei Haketa,
• Takuma Matsuda and
• Hiromitsu Maeda

Beilstein J. Org. Chem. 2024, 20, 2567–2576, doi:10.3762/bjoc.20.215

• orthogonal arrangement in comparison with the phenyl moieties in 1b+. Solid-state ion-pairing assemblies of the ion pairs 2+-X− (X− = Cl−, BF4−, PF6−, B(C6F5)4−, and PCCp−) were investigated by X-ray analysis of the orange rod-shaped single crystals, which were obtained by vapour diffusion using CHCl3/n

• -heptane for 2+-Cl−, 2+-BF4−, and 2+-PCCp−, CH2Cl2/n-heptane with small amounts of MeOH and toluene for 2+-PF6−, and toluene/n-hexane for 2+-B(C6F5)4− (Figure 3 and Figures S11–15 in Supporting Information File 1) [32]. In the single crystals, 2+ showed highly planar core structures with mean-plane

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

• , chlorinated species 1h and 1i, and carboxylic acid-containing 1s, developed high quality crystals from standing solutions in dimethyl sulfoxide for 1h and 1i, and methanol for 1s. Their molecular crystal structures were determined and are shown in Figure 1b displaying the classic cone conformation for both

Synthesis, electrochemical properties, and antioxidant activity of sterically hindered catechols with 1,3,4-oxadiazole, 1,2,4-triazole, thiazole or pyridine fragments

• Daria A. Burmistrova,
• Andrey Galustyan,
• Nadezhda P. Pomortseva,
• Kristina D. Pashaeva,
• Maxim V. Arsenyev,
• Oleg P. Demidov,
• Mikhail A. Kiskin,
• Andrey I. Poddel’sky,
• Nadezhda T. Berberova and
• Ivan V. Smolyaninov

Beilstein J. Org. Chem. 2024, 20, 2378–2391, doi:10.3762/bjoc.20.202

• ), HRMS, and elemental analysis. The molecular structures of compounds 5, 6 and 8 in crystal state were determined by single-crystal X-ray analysis. X-ray data The X-ray suitable crystals 5, 6·0.5CH3CN, and 8 were grown by slow recrystallization of the compounds from acetonitrile solutions. The unit cells

• of complexes 5 and 8 do not contain any solvent molecules, while the unit cell of crystals 6·0.5CH3CN contains one acetonitrile molecule per two catechol molecules. The nitro-substituted pyridine group in 5 is disordered in two positions. The X-ray structure of catechol 5 is shown in Figure 1, and

• of neighboring molecules [57][58][59][60][61]. The intra- and intermolecular interactions in crystals 5, 6·0.5CH3CN, and 8 lead to different complex structural motifs in crystals of these compounds. Two intramolecular hydrogen bonds (Figure 1) are observed in the crystal structure of 5: between OH

Natural resorcylic lactones derived from alternariol

• Joachim Podlech

Beilstein J. Org. Chem. 2024, 20, 2171–2207, doi:10.3762/bjoc.20.187

Novel truxene-based dipyrromethanes (DPMs): synthesis, spectroscopic characterization and photophysical properties

• Shakeel Alvi and
• Rashid Ali

Beilstein J. Org. Chem. 2024, 20, 2163–2170, doi:10.3762/bjoc.20.186

• ][12][13]. The most promising applications of truxene-based systems have been found in organic photovoltaics (OPVs), dye‐sensitized solar cells (DSSCs), fluorescent probes, organic thin‐film transistors (OTFTs), lasers, organic light emitting diodes (OLEDs), liquid crystals, non-linear optical (NLO

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

• Chemie, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany 10.3762/bjoc.20.176 Abstract Dynamic, responsive materials can be built using photosurfactants (PS) that self-assemble into ordered nanostructures, such as micelles or liquid crystals. These PS contain photoswitchable groups, such as

Ugi bisamides based on pyrrolyl-β-chlorovinylaldehyde and their unusual transformations

• Alexander V. Tsygankov,
• Vladyslav O. Vereshchak,
• Tetiana O. Savluk,
• Serhiy M. Desenko,
• Valeriia V. Ananieva,
• Oleksandr V. Buravov,
• Yana I. Sakhno,
• Svitlana V. Shishkina and
• Valentyn A. Chebanov

Beilstein J. Org. Chem. 2024, 20, 1773–1784, doi:10.3762/bjoc.20.156

• Alexander V. Tsygankov Vladyslav O. Vereshchak Tetiana O. Savluk Serhiy M. Desenko Valeriia V. Ananieva Oleksandr V. Buravov Yana I. Sakhno Svitlana V. Shishkina Valentyn A. Chebanov Institute of Functional Materials Chemistry, State Scientific Institution “Institute for Single Crystals” of

Synthesis and characterization of 1,2,3,4-naphthalene and anthracene diimides

• Adam D. Bass,
• Daniela Castellanos,
• Xavier A. Calicdan and
• Dennis D. Cao

Beilstein J. Org. Chem. 2024, 20, 1767–1772, doi:10.3762/bjoc.20.155

• . Crystallography Despite exhaustive efforts, we were unable to obtain single crystals of 7-Hex and 8-Hex; these compounds formed polycrystalline bundles that are fragile and insufficient for obtaining diffraction data. Fortunately, single crystals of the N-phenyl compounds were successfully grown by slow

Towards an asymmetric β-selective addition of azlactones to allenoates

• Behzad Nasiri,
• Ghaffar Pasdar,
• Paul Zebrowski,
• Katharina Röser,
• David Naderer and
• Mario Waser

Beilstein J. Org. Chem. 2024, 20, 1504–1509, doi:10.3762/bjoc.20.134

• residual water during column chromatography. Unfortunately, attempts to assign the absolute configuration of products 5 failed, as we have not been able to obtain any crystals suited for single crystal X-ray diffraction analysis. Finally, we also tested the suitability of products 5 to access acyclic α-AA

Synthesis of substituted triazole–pyrazole hybrids using triazenylpyrazole precursors

• Simone Gräßle,
• Laura Holzhauer,
• Nicolai Wippert,
• Olaf Fuhr,
• Martin Nieger,
• Nicole Jung and
• Stefan Bräse

Beilstein J. Org. Chem. 2024, 20, 1396–1404, doi:10.3762/bjoc.20.121

• aromatic and aliphatic alkynes 20a–h in a copper-catalyzed azide–alkyne cycloaddition (CuAAC). All attempted reactions could be conducted under standard conditions using copper sulfate and sodium ascorbate in THF/water (depicted in Scheme 3 and Figure 2). For selected derivatives, 21sd and 21vg, crystals

Two-fold addition reaction of silylene to C₆₀: structural and electronic properties of a bis-adduct

• Masahiro Kako,
• Masato Kai,
• Masanori Yasui,
• Michio Yamada,
• Yutaka Maeda and
• Takeshi Akasaka

Beilstein J. Org. Chem. 2024, 20, 1179–1188, doi:10.3762/bjoc.20.100

• (s, 1C), 37.59 (d, 2C), 37.35 (d, 2C), 37.24 (d, 2C), 37.11 (d, 2C), 28.55 (q, 2C), 27.86 (q, 2C), 27.57 (q, 2C), 27.44 (q, 2C), 25.61 (q, 2C), 25.25 (q, 2C), 25.10 (q, 2C), 24.11 (q, 2C); UV–vis (CH2Cl2) λmax 515 nm. X-ray crystallography of 3: Black plate crystals suitable for X-ray diffraction

Structure–property relationships in dicyanopyrazinoquinoxalines and their hydrogen-bonding-capable dihydropyrazinoquinoxalinedione derivatives

• Tural N. Akhmedov,
• Ajeet Kumar,
• Daken J. Starkenburg,
• Kyle J. Chesney,
• Khalil A. Abboud,
• Novruz G. Akhmedov,
• Jiangeng Xue and
• Ronald K. Castellano

Beilstein J. Org. Chem. 2024, 20, 1037–1052, doi:10.3762/bjoc.20.92

• moderate to excellent hole transport mobilities (1.5 × 10−3 and 1.5 cm2/Vs, respectively) [21]. In 2012, Miao et al. reported an H-bonding capable 1,4-dihydropyrazinopyrazine fragment within N-heteroacenes [22]. The X-ray analysis of single crystals revealed the formation of highly-ordered ribbons

• equiv of 1,2-aceanthrylenedione, the reaction provided pure 3a product in moderate yield (41%). Subsequent recrystallization with boiling DMSO provided pristine red-brown crystals of 3a. The synthesis of DCPQ 4a was simple and proceeded with the condensation of a 1:1 mixture of acenaphthenequinone and

• 12 under standard boiling acetic acid conditions, as reported in Scheme 1. The crude product could be collected via vacuum filtration, followed by additional purification via recrystallization from boiling DMF to afford golden crystals of 4a in moderate yields. In order to access 5a and 6a, a

Spin and charge interactions between nanographene host and ferrocene

• Akira Suzuki,
• Yuya Miyake,
• Ryoga Shibata and
• Kazuyuki Takai

Beilstein J. Org. Chem. 2024, 20, 1011–1019, doi:10.3762/bjoc.20.89

• temperatures 55 °C and 150 °C (FeCp2-ACFs-55, FeCp2-ACFs-150), for 18 to 24 hours. The vapor pressure of ferrocene corresponding to each temperature was previously reported (15 Pa for 55 °C, 5.7 × 103 Pa for 150 °C) [27]. In the case of introduction at 150 °C, excessive FeCp2 precipitated as crystals on the

• graphene crystals but becomes Raman-active by an electron-scattering process due to impurities and edges in crystallites [29]. The G and D-bands were fitted with two Lorentzian curves, as shown in Figure 4. Although characteristic peaks of FeCp2 molecules around 1100 cm−1 are not obtained in the spectrum

One-pot Ugi-azide and Heck reactions for the synthesis of heterocyclic systems containing tetrazole and 1,2,3,4-tetrahydroisoquinoline

• Jiawei Niu,
• Yuhui Wang,
• Shenghu Yan,
• Yue Zhang,
• Xiaoming Ma,
• Qiang Zhang and
• Wei Zhang

Beilstein J. Org. Chem. 2024, 20, 912–920, doi:10.3762/bjoc.20.81

• and 13C NMR, and HRMS analysis. In addition, single crystals of compound 6d and 8c were obtained for X-ray analysis to confirm the structures (Figure 2). Conclusion In conclusion, we have developed a one-pot synthesis with two or three steps for making tetrazolo-pyrazino[2,1-a]isoquinolin-6(5H)-ones

Synthesis and properties of 6-alkynyl-5-aryluracils

• Ruben Manuel Figueira de Abreu,
• Till Brockmann,
• Alexander Villinger,
• Peter Ehlers and
• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 898–911, doi:10.3762/bjoc.20.80

• ring instead of a benzene moiety. This was demonstrated by the introduction of thiophene (5r) and furan (5t) to the uracil structure. The molecules 5n and 5o could not be obtained, due to decomposition during the reaction. The structure of 5a was confirmed by X-ray crystallographic analysis. Crystals

Research progress on the pharmacological activity, biosynthetic pathways, and biosynthesis of crocins

• Zhongwei Hua,
• Nan Liu and
• Xiaohui Yan

Beilstein J. Org. Chem. 2024, 20, 741–752, doi:10.3762/bjoc.20.68

• (2b) consists of one glucose and one gentiobiose unit, crocin-III (2c) comprises two glucose molecules, crocin-IV (2d) contains only one gentiobiose moiety, and crocin-V (2e) has only one glucose moiety (Figure 1 and Table 1). Pure crocins form reddish-brown acicular crystals with a slight odor. They

Pseudallenes A and B, new sulfur-containing ovalicin sesquiterpenoid derivatives with antimicrobial activity from the deep-sea cold seep sediment-derived fungus Pseudallescheria boydii CS-793

• Zhen Ying,
• Xiao-Ming Li,
• Sui-Qun Yang,
• Hong-Lei Li,
• Xin Li,
• Bin-Gui Wang and
• Ling-Hong Meng

Beilstein J. Org. Chem. 2024, 20, 470–478, doi:10.3762/bjoc.20.42

• compound 1, crystals suitable for X-ray crystal analysis were obtained by slow evaporation of the solvent, which could be analyzed by X-ray diffraction analysis using Cu Kα radiation (Figure 4). The resulting Flack parameter, 0.019(6), allowed the assignment of the absolute configurations of all the

• –6.10). Then, compound 2 (13.7 mg) was isolated by CC on Si gel (CH2Cl2/MeOH, 250:1 to 50:1) and preparative TLC (plate: 20 × 20 cm, developing solvent: ether/acetone 2:1) from Fr. 6.3 (578 mg). Pseudallene A (1): colorless crystals (MeOH); mp 115–117 °C; [α]D25 +20.0 (c 0.4, MeOH); 1H and 13C NMR data

• , see Table 2; HRESIMS (m/z): [M + H]+ calcd for C16H29O5S, 333.1730; found: 333.1733). Pseudallene B (2): colorless crystals (MeOH); mp 171–175 °C; [α]D25 +53.3 (c 0.3, MeOH); 1H and 13C NMR data, see Table 2; HRESIMS (m/z): [M + H]+ calcd for C15H27O5S, 319.1573; found: 319.1568.. X-ray

Facile approach to N,O,S-heteropentacycles via condensation of sterically crowded 3H-phenoxazin-3-one with ortho-substituted anilines

• Eugeny Ivakhnenko,
• Vasily Malay,
• Pavel Knyazev,
• Nikita Merezhko,
• Nadezhda Makarova,
• Oleg Demidov,
• Gennady Borodkin,
• Andrey Starikov and
• Vladimir Minkin

Beilstein J. Org. Chem. 2024, 20, 336–345, doi:10.3762/bjoc.20.34

• data of 4c,d,f, 5c, and 10b were obtained at 100 K. Crystals of 5c were obtained in the form of a solvate with molecules of isopropanol and water present. The protons attached to heteroatoms were localized by difference Fourier synthesis and refined with isotropic thermal parameters. The collection of

Spatial arrangements of cyclodextrin host–guest complexes in solution studied by ¹³C NMR and molecular modelling

• Konstantin Lebedinskiy,
• Ivan Barvík,
• Zdeněk Tošner,
• Ivana Císařová,
• Jindřich Jindřich and
• Radim Hrdina

Beilstein J. Org. Chem. 2024, 20, 331–335, doi:10.3762/bjoc.20.33

• calorimetry [13]. Single crystals for many host–guest complexes have been prepared, and their structure elucidated by X-ray crystallography [14][15]. Conformations of host–guest complexes in solution have been studied by 2D NMR experiments [11] (NOESY, ROESY) or proposed computationally [16][17] based on

Elucidating the glycan-binding specificity and structure of Cucumis melo agglutinin, a new R-type lectin

• Jon Lundstrøm,
• Emilie Gillon,
• Valérie Chazalet,
• Nicole Kerekes,
• Antonio Di Maio,
• Ten Feizi,
• Yan Liu,
• Annabelle Varrot and
• Daniel Bojar

Beilstein J. Org. Chem. 2024, 20, 306–320, doi:10.3762/bjoc.20.31

• crystallography. We obtained several hits for the full-length protein after sparse screening using a crystallization robot at the HTX platform, EMBL, Grenoble. Pill-shaped crystals obtained under conditions of a high salt concentration, in particular ammonium sulfate (Figure S3, Supporting Information File 2

• ), did not give rise to any diffraction. Multiple layer plate or needles clusters were obtained in the presence of PEGs, but only showed weak diffraction (≈3.5 Å). Finally, in the presence of 20% PEG 8K, 0.2 M MgCl2, and 0.1 M Tris HCl pH 8.5, single diamond-shaped crystals were obtained after 1–2 days

• for the N-terminal domain (Figure S3, Supporting Information File 2). High-resolution diffraction of the crystals allowed us to solve the CMA1-Nter structure in complex with LacNAc at 1.3 Å and GalNAc at 1.55 Å (see data and refinement statistics in Table 1). All residues of the N-terminal construct