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

Synthesis of π-conjugated polycyclic compounds by late-stage extrusion of chalcogen fragments

• Aissam Okba,
• Pablo Simón Marqués,
• Kyohei Matsuo,
• Naoki Aratani,
• Hiroko Yamada,
• Gwénaël Rapenne and
• Claire Kammerer

Beilstein J. Org. Chem. 2024, 20, 287–305, doi:10.3762/bjoc.20.30

• or crystals, or adsorbed on metallic substrates [9][10][11][12]. Conversion of the non-planar soluble precursor into the flat π-conjugated target compound is triggered on demand by a stimulus such as thermal activation, irradiation with light or injection of electrons, leading to the elimination of

Substitution reactions in the acenaphthene analog of quino[7,8-h]quinoline and an unusual synthesis of the corresponding acenaphthylenes by tele-elimination

• Ekaterina V. Kolupaeva,
• Narek A. Dzhangiryan,
• Alexander F. Pozharskii,
• Oleg P. Demidov and
• Valery A. Ozeryanskii

Beilstein J. Org. Chem. 2024, 20, 243–253, doi:10.3762/bjoc.20.24

• 5Н+PicO−, in the cationic part of which a similar intramolecular NHN hydrogen bond is realized [15]. To understand the structure of the resulting complex, we tried to grow its crystals from acetonitrile by co-evaporating solutions of quinoline 5 and chloranil at room temperature. Interestingly, in

• 5. As the XRD study of the crystals showed (Figure 3), the molecular and crystal structure of the isolated compound is strongly dominated, on the one hand, by intra- and intermolecular hydrogen bonds with the participation of N, Cl, and O heteroatoms (forming an endless slightly corrugated ribbon

• in a 2:1 ratio leads to the formation of co-crystals, in which, as judged by the X-ray data, the supramolecular organization is again in action (Figure 4). Two molecules of the base are almost parallel to each other (the distance between the π-systems of two molecular planes is 3.551 Å with the

Photochromic derivatives of indigo: historical overview of development, challenges and applications

• Gökhan Kaplan,
• Zeynel Seferoğlu and
• Daria V. Berdnikova

Beilstein J. Org. Chem. 2024, 20, 228–242, doi:10.3762/bjoc.20.23

• exists in two crystalline modifications, namely indigo A and indigo B. In particular, 10% of indigo B was found alongside the known form indigo A (90%), in the dye crystals grown from vapor at 10 torr. Both crystalline forms of indigo have the same symmetry and similar cell parameters with the only

Comparison of glycosyl donors: a supramer approach

• Anna V. Orlova,
• Nelly N. Malysheva,
• Maria V. Panova,
• Nikita M. Podvalnyy,
• Michael G. Medvedev and
• Leonid O. Kononov

Beilstein J. Org. Chem. 2024, 20, 181–192, doi:10.3762/bjoc.20.18

• was filtered off and washed with t-BuOMe/petroleum ether 1:1 (v/v) mixture to give 7 as white crystals (576 mg, 70%). [α]D27 −116.0 (c 2.9, acetone); Rf 0.21 (toluene/acetone 5:1); 1H NMR (600 MHz, acetone-d6, δ, ppm, J, Hz) 2.20 (dd, J3a,3e = 13.6, J3a,4 = 11.9, 1H, H-3a), 2.83 (dd, J3e,3a = 13.6

Perspectives on push–pull chromophores derived from click-type [2 + 2] cycloaddition–retroelectrocyclization reactions of electron-rich alkynes and electron-deficient alkenes

• Michio Yamada

Beilstein J. Org. Chem. 2024, 20, 125–154, doi:10.3762/bjoc.20.13

• resulted from optically active constituents. Compound 53, due to its elongated rigid structure, holds potential for use as a chiral dopant in nematic liquid crystals (LCs); however, the helical twisting powers of 53 within nematic LCs are limited. Recently, Alonso-Gómez et al. reported the synthesis and

Multi-redox indenofluorene chromophores incorporating dithiafulvene donor and ene/enediyne acceptor units

• Christina Schøttler,
• Kasper Lund-Rasmussen,
• Line Broløs,
• Philip Vinterberg,
• Ema Bazikova,
• Viktor B. R. Pedersen and
• Mogens Brøndsted Nielsen

Beilstein J. Org. Chem. 2024, 20, 59–73, doi:10.3762/bjoc.20.8

• Crystals suitable for single-crystal X-ray diffraction studies were obtained for compounds 25, 26, and 29. Their structures are shown in Figure 10, top, and their respective crystal packings below. All three compounds pack in a herringbone manner in the crystal structure, with the major difference that

Using the phospha-Michael reaction for making phosphonium phenolate zwitterions

• Matthias R. Steiner,
• Max Schmallegger,
• Larissa Donner,
• Johann A. Hlina,
• Christoph Marschner,
• Judith Baumgartner and
• Christian Slugovc

Beilstein J. Org. Chem. 2024, 20, 41–51, doi:10.3762/bjoc.20.6

• in these cases (Supporting Information File 1, Figures S54 and S74). Crystal structures The solid-state structures of 2a and 2f were determined by single-crystal X-ray diffraction. The crystals were grown from concentrated solutions in toluene. A representation of the molecular structure of 2a is

• the crystals were mounted onto the tips of glass fibres. Data collection was performed with a Bruker-AXS SMART APEX CCD diffractometer using graphite-monochromated Mo Kα radiation (0.71073 Å). The data were reduced to Fo2 and corrected for absorption effects with SAINT (Version 6.45, Bruker AXS Inc

Aldiminium and 1,2,3-triazolium dithiocarboxylate zwitterions derived from cyclic (alkyl)(amino) and mesoionic carbenes

• Nedra Touj,
• François Mazars,
• Guillermo Zaragoza and
• Lionel Delaude

Beilstein J. Org. Chem. 2023, 19, 1947–1956, doi:10.3762/bjoc.19.145

• . Crystallography Crystals of CAAC·CS2 zwitterions 4a and 4c suitable for X-ray diffraction (XRD) analysis were grown by slow diffusion of cyclohexane in a THF solution at 6 °C. Their molecular structures are depicted in Figure 3. The orange-red needles of compound 4a belonged to the trigonal space group, while

• layered with petroleum ether or n-hexane and kept at −18 °C for a few weeks. This procedure successfully afforded single crystals of products 6b and 6e suitable for XRD analysis (Figure 4). Orange prisms of zwitterion 6b belonged to the monoclinic P21/n space group, while the dark red-brown blocks of

A novel recyclable organocatalyst for the gram-scale enantioselective synthesis of (S)-baclofen

• Gyula Dargó,
• Dóra Erdélyi,
• Balázs Molnár,
• Péter Kisszékelyi,
• Zsófia Garádi and
• József Kupai

Beilstein J. Org. Chem. 2023, 19, 1811–1824, doi:10.3762/bjoc.19.133

• product was purified by preparative thin-layer chromatography (SiO2, hexane/ethyl acetate 2:1, Rf 0.36) to obtain the product (S)-14 as pale-yellow crystals. The products had the same spectroscopic data than those of reported (the absolute configuration was determined by the optical rotation of the

Selectivity control towards CO versus H₂ for photo-driven CO₂ reduction with a novel Co(II) catalyst

• Lisa-Lou Gracia,
• Philip Henkel,
• Olaf Fuhr and
• Claudia Bizzarri

Beilstein J. Org. Chem. 2023, 19, 1766–1775, doi:10.3762/bjoc.19.129

• -dissolving the powder in acetonitrile and layering on top of diethyl ether (Et2O). Slow diffusion of the antisolvent Et2O allowed the growth of magenta-colored crystals. Interestingly, two different sets of data could be solved, which is an indication that compound 1 has two polymorphs, 1a and 1b (Figure 2

• ). Efforts to selectively achieve one polymorph, through differentiated crystallization processes, were unsuccessful. When analyzing the molecular structure in both crystals, the cobalt core is hexacoordinated, as expected. The two isothiocyanate ions are oriented cis to each other and trans to the

Charge carrier transport in perylene-based and pyrene-based columnar liquid crystals

• Alessandro L. Alves,
• Simone V. Bernardino,
• Carlos H. Stadtlober,
• Edivandro Girotto,
• Giliandro Farias,
• Rodney M. do Nascimento,
• Sergio F. Curcio,
• Thiago Cazati,
• Marta E. R. Dotto,
• Juliana Eccher,
• Leonardo N. Furini,
• Hugo Gallardo,
• Harald Bock and
• Ivan H. Bechtold

Beilstein J. Org. Chem. 2023, 19, 1755–1765, doi:10.3762/bjoc.19.128

• ), organic light-emitting diodes (OLEDs) and sensors [1][2]. Columnar liquid crystals are attractive due to their solution processability and their self-organization in highly anisotropic supramolecular architectures, which favors the mainly one-dimensional migration of charge carriers with an anisotropy of

• literature [24]. It is important to emphasize that the charge carrier mobility of columnar liquid crystals can be improved by five orders of magnitude due to molecular alignment of the film in the device structure [33]. Usually, the π-system conjugation and the frontier orbitals energies dominates the charge

• of the optimized isopropyl derivatives geometry are presented in Supporting Information File 1. Conclusion The electron and hole-transporting characteristics of two columnar liquid crystals were evaluated with electron-only and hole-only devices. Compound 1 is a perylene-based molecule presenting a

Unprecedented synthesis of a 14-membered hexaazamacrocycle

• Anastasia A. Fesenko and
• Anatoly D. Shutalev

Beilstein J. Org. Chem. 2023, 19, 1728–1740, doi:10.3762/bjoc.19.126

• (1.026 g) was recrystallized from boiling DMF (255 mL). After precipitation completed, the solid was filtered, washed with cold DMF (3 × 5 mL). The filter cake was suspended in water (10 mL) for 5 min followed by suction, this procedure was repeated 3 times to remove DMF from crystals. After drying in a

• was filtered and washed with cold DMF (3 × 2 mL). The 1H NMR spectrum showed that the solid was pure macrocycle 5. The mother liquor was collected, H2O (20 mL) was added and the solution was left standing overnight at room temperature. After that, some additional violet crystals precipitated and were

Effects of the aldehyde-derived ring substituent on the properties of two new bioinspired trimethoxybenzoylhydrazones: methyl vs nitro groups

• Dayanne Martins,
• Roberta Lamosa,
• Talis Uelisson da Silva,
• Carolina B. P. Ligiero,
• Sérgio de Paula Machado,
• Daphne S. Cukierman and
• Nicolás A. Rey

Beilstein J. Org. Chem. 2023, 19, 1713–1727, doi:10.3762/bjoc.19.125

• -acylhydrazones were synthesized and fully characterized, both in solution and in the solid state. The compounds differ with respect to the carbonyl precursors, i.e., 3-substituted salicylaldehydes with either a methyl or a nitro group. Single crystals of both compounds were isolated from the respective mother

• water molecules in the network (calcd.: 9.47% for C18H20O5N2·2H2O, MW = 380.39 g mol−1). On the other hand, hdz-NO2 did not show any mass loss below 250 °C, indicating the absence of solvation molecules in the sample (C17H17O7N3, MW = 375.34 g mol−1). Single crystals of both compounds, as monohydrates

• were used to calculate the percentage decrease in concentration of the compound with respect to the first reading and data were processed using the OriginPro 21 software. X-ray diffraction Single crystals of hdz-CH3 and hdz-NO2 suitable for X-ray diffraction were obtained from the slow evaporation of

Sulfur-containing spiroketals from Breynia disticha and evaluations of their anti-inflammatory effect

• Ken-ichi Nakashima,
• Naohito Abe,
• Masayoshi Oyama,
• Hiroko Murata and
• Makoto Inoue

Beilstein J. Org. Chem. 2023, 19, 1604–1614, doi:10.3762/bjoc.19.117

• resulting dark blue crystals were dissolved in dimethyl sulfoxide, and the absorbance of the obtained solution was measured at 492 nm. ELISA The concentrations of IL-1β and IL-6 in the culture medium after 12 h of LPS treatment were measured using Quantikine ELISA kits for mouse IL-1β and IL-6 (R&D Systems

Radical chemistry in polymer science: an overview and recent advances

• Zixiao Wang,
• Feichen Cui,
• Yang Sui and
• Jiajun Yan

Beilstein J. Org. Chem. 2023, 19, 1580–1603, doi:10.3762/bjoc.19.116

• with poly(ethersulfone) [143]. Highly reactive gaseous species may also generate radicals on polymer surfaces. For example, atomic oxygen radical anions emitted from 12CaO⋅7Al2O3 crystals [144] were used to modify PVC and polystyrene [145][146]. Plasma is also a powerful gas-phase tool for polymer

Synthesis and biological evaluation of Argemone mexicana-inspired antimicrobials

• Jessica Villegas,
• Bryce C. Ball,
• Katelyn M. Shouse,
• Caleb W. VanArragon,
• Ashley N. Wasserman,
• Hannah E. Bhakta,
• Allen G. Oliver,
• Danielle A. Orozco-Nunnelly and
• Jeffrey M. Pruet

Beilstein J. Org. Chem. 2023, 19, 1511–1524, doi:10.3762/bjoc.19.108

• still unclear, and so we grew high quality crystals of B4 and B6 to unambiguously determine the structure through X-ray crystallography, which showed the oxidation was in fact occurring at position-13 (Figure 2). A potential mechanistic explanation for the formation of this oxidation byproduct can be

Organic thermally activated delayed fluorescence material with strained benzoguanidine donor

• Alexander C. Brannan,
• Elvie F. P. Beaumont,
• Nguyen Le Phuoc,
• George F. S. Whitehead,
• Mikko Linnolahti and
• Alexander S. Romanov

Beilstein J. Org. Chem. 2023, 19, 1289–1298, doi:10.3762/bjoc.19.95

• isomeric mixture of 4BGIPN. This is expectedly higher than the analogous Tg of 176 °C for the 4CzIPN material [13] due to a lower molecular mass of the latter (Figure S1, Supporting Information File 1). Single crystals for X-ray diffraction study were obtained by slow layer diffusion of hexanes into

• the pure product as a yellow powder in 70% yield (450 mg, 474 μmol). Single crystals suitable for X-ray diffraction were grown by layering a concentrated solution in DCM with hexane which was left for slow evaporation. 1H NMR (700 MHz, DMSO-d6) δ 8.46–8.35 (m), 8.23–8.22 (m), 8.16–8.06 (m), 7.94–6.86

• ppm; Anal. calcd. for C60H32N14 (948.29): C, 75.94; H, 3.40; N, 20.66; found: C, 75.59; H, 3.54; N, 20.28; HRESIMS m/z: [M + Na]+ calcd. for C60H32N14Na, 971.2827; found, 971.2854. X-ray crystallography Crystals suitable for X-ray diffraction study were obtained by slow layer diffusion of hexanes

CO₂ complexation with cyclodextrins

• Cecilie Høgfeldt Jessen,
• Jesper Bendix,
• Theis Brock Nannestad,
• Heloisa Bordallo,
• Martin Jæger Pedersen,
• Christian Marcus Pedersen and
• Mikael Bols

Beilstein J. Org. Chem. 2023, 19, 1021–1027, doi:10.3762/bjoc.19.78

• stoichioimetry and that a number of simple and modified cyclodextrins bind CO2 in water with a Kg of 0.18–1.2 bar−1 (7–35 M−1) with per-O-methyl α-cyclodextrin having the highest CO2 affinity. Keywords: carbon dioxide; crystals; cyclodextrin; gas binding; Introduction The concentration of carbon dioxide (CO2

• CO2 is captured by non-covalent binding. Henglein and Cramer showed many years ago that α-cyclodextrin (1, Figure 1), when treated with CO2 under pressure for several days gave crystals with the gas trapped inside [8]. According to Cramer only 1 was able to form crystals, while larger cyclodextrins

• bind CO2 in water with a Kg of 0.18–1.2 bar−1 (7–35 M−1). Results and Discussion When a saturated solution of 1 was treated with CO2 at a pressure from 6–20 bar in an autoclave for 1–19 days, crystals containing CO2 were obtained in 16–63% yield (Table 1). The most important factor for getting higher

Cyclodextrins as building blocks for new materials

• Miriana Kfoury and
• Sophie Fourmentin

Beilstein J. Org. Chem. 2023, 19, 889–891, doi:10.3762/bjoc.19.66

• other neurodegenerative diseases, such as Alzheimer’s, Parkinson’s, and Huntington’s diseases. Due to their ability to extract cholesterol, treatment with CDs could reduce atherogenesis and atherosclerotic plaque size by solubilizing cholesterol crystals [9]. In addition, CDs can sequester cholesterol