4-(1-Methylamino)ethylidene-1,5-disubstituted pyrrolidine-2,3-diones: synthesis, anti-inflammatory effect and in silico approaches

• Nguyen Tran Nguyen,
• Vo Viet Dai,
• Luc Van Meervelt,
• Do Thi Thao and
• Nguyen Minh Thong

Beilstein J. Org. Chem. 2025, 21, 817–829, doi:10.3762/bjoc.21.65

• π–π stacking is observed in the crystal packing of the complexes, but only C–H···π interactions are present. Two C–H···O hydrogen bonds complete the interactions stabilizing the crystal packing (Figure S1 and Table S2 in Supporting Information File 1). Inhibitory activity of NO production It is

Acyclic cucurbit[n]uril bearing alkyl sulfate ionic groups

• Christian Akakpo,
• Peter Y. Zavalij and
• Lyle Isaacs

Beilstein J. Org. Chem. 2025, 21, 717–726, doi:10.3762/bjoc.21.55

• ), b) a mixture of C1 (0.5 mM) and Me6PXDA (1.0 mM), c) a mixture of C1 (0.5 mM) and Me6PXDA (0.5 mM), and d) C1 (0.5 mM). Cross-eyed stereoview of the C1·Me6CHDA complex in the crystal. Color code: C, gray; H, white; N, blue; O, red; S, yellow. Cross-eyed stereoview of the crystal packing observed in

Photochemically assisted synthesis of phenacenes fluorinated at the terminal benzene rings and their electronic spectra

• Yuuki Ishii,
• Minoru Yamaji,
• Fumito Tani,
• Kenta Goto,
• Yoshihiro Kubozono and
• Hideki Okamoto

Beilstein J. Org. Chem. 2025, 21, 670–679, doi:10.3762/bjoc.21.53

• macrocyclic picenophadiene [51]. As the solid-state fluorescence bands of the F8-phenacenes were observed in the similar wavelength region of the picenophadiene, the solid-state F8-phenacene molecules have excimeric character in the fluorescing state. It is critical to know the crystal packing of the F8

Unprecedented visible light-initiated topochemical [2 + 2] cycloaddition in a functionalized bimane dye

• Metodej Dvoracek,
• Brendan Twamley,
• Mathias O. Senge and
• Mikhail A. Filatov

Beilstein J. Org. Chem. 2025, 21, 500–509, doi:10.3762/bjoc.21.37

• ] cycloaddition reactions, states that for the reaction to occur, the distance between the centers of the double bonds must be less than 4.2 Å, and the double bonds must be coplanar and parallel [11]. Designing topochemically active compounds is a challenging task, as the crystal packing mode must first be

• optimized, which can only be predicted computationally – a process that becomes increasingly complex with more intricate structures [12]. Since these reactions depend on both crystal packing and specific intermolecular distances, another key challenge lies in designing novel structures capable of undergoing

• ). Further details on this are available in the experimental section. This suggests that the reaction is topochemical, with the bimane’s reactivity dependent on its crystal packing, since no [2 + 2] cycloaddition product was seen in the spectrum. While the reaction may also depend on the reactivities of the

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

• . This may also be due to crystal packing effects or the Ni(II) metal center [56][57], as well as the crystallization solvent [43]. It is not possible to ascertain whether steric effects of the β-ethyl and the anthracenyl carbons are causing the ruffling observed, and a full statistical model of a large

• a magnitude of ≈0.3 Å less ruffling when compared to that of the meta-substituted porphyrin 37. In terms of meta-phenyl-substituted porphyrin 36 a contribution of ruffling is observed, but no ruffling is observed in the planar analogue. Crystal packing analysis of arm-extended para-substituted

• interesting crystal packing features were that observed in the structures of compound 27 and borylated porphyrin 46. In the case of porphyrin 27, when crystallized by slow evaporation from CDCl3, a crystal structure with a void diameter of approximately 5.8 Å was obtained (Figure 4). The void was measured

Synthesis and conformational analysis of pyran inter-halide analogues of ᴅ-talose

• Olivier Lessard,
• Mathilde Grosset-Magagne,
• Paul A. Johnson and
• Denis Giguère

Beilstein J. Org. Chem. 2024, 20, 2442–2454, doi:10.3762/bjoc.20.208

• halogenated pyrans reveals deviation in the intra-annular torsion angles arising from repulsion between the axial fluorine at C2 and the axial halogen at C4, which increases with the size of the halogen at C4 (F < Cl < Br < I). Crystal packing arrangements of pyran inter-halides show hydrogen bond acceptor

• °). The solid-state conformation of each of the pyran inter-halides 13–15 is unique. One would expect that compounds 13–15 would have distinct crystal packing arrangements based on the nature of the halogen. On the contrary, all analogues adopt a similar stacking pattern. Figure 4 shows the packing

• arrangement for compound 15 and the crystal packing of compound 13 and 14 can be found in the Supporting Information File 1. The halogens are on the same side of the pyran ring, thus increasing the overall molecular dipole moment (see Supporting Information File 1). This allows intermolecular C–X···H–C

Synthesis of indano[60]fullerene thioketone and its application in organic solar cells

• Yong-Chang Zhai,
• Shimon Oiwa,
• Shinobu Aoyagi,
• Shohei Ohno,
• Tsubasa Mikie,
• Jun-Zhuo Wang,
• Hirofumi Amada,
• Koki Yamanaka,
• Kazuhira Miwa,
• Naoyuki Imai,
• Takeshi Igarashi,
• Itaru Osaka and
• Yutaka Matsuo

Beilstein J. Org. Chem. 2024, 20, 1270–1277, doi:10.3762/bjoc.20.109

• -Bu-FIDS (black) and of toluene used to rinse the evaporated film of t-Bu-FIDS (red). Single-crystal structure of t-Bu-FIDS. (a) The π–π distance between two molecules. (b) Crystal packing. Cyclic voltammograms of fullerene derivatives in o-DCB solution containing Bu4N+(CF3SO2)2N− (0.1 M) as

Competing electrophilic substitution and oxidative polymerization of arylamines with selenium dioxide

• Vishnu Selladurai and
• Selvakumar Karuthapandi

Beilstein J. Org. Chem. 2024, 20, 1221–1235, doi:10.3762/bjoc.20.105

• (Figure S37, Supporting Information File 1). The dipolar characteristics of the ester group appeared to assist the molecular layer-by-layer stacking seen in the crystal packing. The molecular structure of the quinone derivative 10 is shown in Figure 4. It crystallized in a monoclinic crystal system in the

Synthesis of 2,2-difluoro-1,3-diketone and 2,2-difluoro-1,3-ketoester derivatives using fluorine gas

• Alexander S. Hampton,
• David R. W. Hodgson,
• Graham McDougald,
• Linhua Wang and
• Graham Sandford

Beilstein J. Org. Chem. 2024, 20, 460–469, doi:10.3762/bjoc.20.41

• rotated to maximize the distances between the lone pairs of the electron-rich fluorine and oxygen atoms. Usually, one of the fluorine atoms lies in a syn orientation to an oxygen (e.g., 3f has an F–C–C–O dihedral angle of 15.6°) creating a dipole. This dipole appears to aid crystal packing by forming weak

• -generated N-fluoroammonium ion 7 to form 2-fluoro- and 2,2-difluoro-1,3-dicarbonyl products. Molecular structure of 2,2-difluoro-1,3-diphenylpropane-1,3-dione (3a). Crystal packing structure of 3f as determined by SXRC. Molecular structure and crystal packing of 5e as determined by SXRC. Monofluorination of

Enhanced host–guest interaction between [10]cycloparaphenylene ([10]CPP) and [5]CPP by cationic charges

• Eiichi Kayahara,
• Yoshiyuki Mizuhata and
• Shigeru Yamago

Beilstein J. Org. Chem. 2024, 20, 436–444, doi:10.3762/bjoc.20.38

• between the most stable calculated structure 1 and the crystalline structure is likely due to crystal packing forces, the presence of the counterion, and the inclusion of solvent molecules. The interfacial distances between the nearest neighbor centroid of a paraphenylene unit of [10]CPP and [5]CPP were

• between the Hirshfeld surface and the contacting atoms, most sp2-hybridzed carbon atoms of the [10]CPP host have short contact with the Hirshfeld surface, as shown in green, despite the tilting of [10]CPP and [5]CPP. In the crystal packing, there were two orientations, as highlighted in blue and red in

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

• (Å) and angles: N(1)–C(11) 1.3061(19), N(1)–C(14) 1.3836(18), O(23)–C(4) 1.2314(19), N(15)–C(3) 1.3765(19), N(15)–C(16) 1.383(2), C(11)–N(1)–C(14) 117.55(12), C(3)–N(15)–C(16) 131.12(14). b) Crystal packing of 4f. Important crystallographic parameters and bond distances are given in Tables S2 and S5

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

• increase in the series 3 → 5 → 8 (“clothespin” effect) [30]. The crystal packing patterns in salts 5·HBF4 and 8·HBF4 are quite similar. The main factor here continues to be the tendency of almost flat disk-shaped heterocyclic cations to π-stacking, leading to the formation of dense columns with anions in

• overlap (с). Again, π-stacking and H-bonding (blue dotted lines) strongly dominate in this structure. Fragment of the crystal packing of neutral dipyridoacenaphthene 5 showing self-association via multiple C–H…N contacts (blue dotted lines) between three independent molecules. Structure of

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

• used in the synthesis of indigo [4]. a) Intramolecular (a = 2.26 Å) and intermolecular (b = 2.11 Å) hydrogen bonds in indigo, b) crystal packing of indigo in the solid state obtained from the single-crystal X-ray diffraction data, CCDC 796873 [12], c) photos of indigo in the solid state and solutions

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

• compound 29 is perpendicular with respect to the herringbone pattern and the related structures (see Figure 10, bottom). Compound 25 packs with an intramolecular distance of 3.41 Å between the planes of the π-systems. Neither compound 26 nor 29 shows π–π interactions in the crystal packing. The large

• orbitals), the dianion has an additional 6π-aromatic cyclopentadienyl anion (highlighted in green), while the cation has a 6π-aromatic 1,3-dithiolium ring (highlighted in red). ORTEP plots (50% probability) and crystal packing of compounds a) 25, b) 26, and c) 29. The respective crystal packing of each

Bromination of endo-7-norbornene derivatives revisited: failure of a computational NMR method in elucidating the configuration of an organic structure

• Demet Demirci Gültekin,
• Arif Daştan,
• Yavuz Taşkesenligil,
• Cavit Kazaz,
• Yunus Zorlu and
• Metin Balci

Beilstein J. Org. Chem. 2023, 19, 764–770, doi:10.3762/bjoc.19.56

• ppm). NOE-Diff experiment. Irradiation at the resonance frequency of proton H7 (4.23 ppm). A) Molecular structure of the compound 6 with displacement ellipsoids drawn at the 30% probability level. H-atoms are shown as small spheres of arbitrary radii. B) Perspective view of the crystal packing of

Synthesis, structure, and properties of switchable cross-conjugated 1,4-diaryl-1,3-butadiynes based on 1,8-bis(dimethylamino)naphthalene

• Semyon V. Tsybulin,
• Ekaterina A. Filatova,
• Alexander F. Pozharskii,
• Valery A. Ozeryanskii and
• Anna V. Gulevskaya

Beilstein J. Org. Chem. 2023, 19, 674–686, doi:10.3762/bjoc.19.49

• standard value of 180° by 3–10°. Deviations of bond angles in acetylene bridges are ≈1–7°. The methoxy derivative 5b has the most complex crystal packing with a large number of different nonvalent interactions (see Supporting Information File 1, Figures S62 and S63). The molecule of cyano derivative 5d is

• characterized by the least distortion of the DMAN fragments in the series (twisting Θ = 9.45 and 12.83°, torsions φA = 20.9° and φB = 8.4°, bond angle deviations in both butadiyne and acetylene linkers do not exceed 6°). In the crystal packing of 5d (see Supporting Information File 1, Figures S64 and S65), the

• molecule 5b. In the crystal packing (Figure S66 in Supporting Information File 1), molecules 5e tend to approach π-donor DMAN and π-acceptor p-nitrophenyl fragments, and the shortest distance between the two molecules is 2.810 Å (Figure S67 in Supporting Information File 1). The alternation of the C–C bond

Inclusion complexes of the steroid hormones 17β-estradiol and progesterone with β- and γ-cyclodextrin hosts: syntheses, X-ray structures, thermal analyses and API solubility enhancements

• Alexios I. Vicatos,
• Zakiena Hoossen and
• Mino R. Caira

Beilstein J. Org. Chem. 2022, 18, 1749–1762, doi:10.3762/bjoc.18.184

• to prepare complexes by spray-drying, freeze-drying, co-grinding, kneading and solution-based crystallization; however, this modest type of ‘fingerprinting’ has not generally been pursued further to deduce important features of CD complexes such as the crystal packing of the CD host molecules

Comparison of crystal structure and DFT calculations of triferrocenyl trithiophosphite’s conformance

• Ruslan P. Shekurov,
• Mikhail N. Khrizanforov,
• Ilya A. Bezkishko,
• Tatiana P. Gerasimova,
• Almaz A. Zagidullin,
• Daut R. Islamov and
• Vasili A. Miluykov

Beilstein J. Org. Chem. 2022, 18, 1499–1504, doi:10.3762/bjoc.18.157

• that in these cases crystal packing influences the conformation. A comparison of the crystal packings for the PLEP, P=O, and P=S containing compounds clearly confirms this conclusion experimentally (Figure 4). We compared the crystal packings of three similar compounds: (FcS)3P, (FcS)3PO [19], and (FcS

Experimental and theoretical studies on the synthesis of 1,4,5-trisubstituted pyrrolidine-2,3-diones

• Nguyen Tran Nguyen,
• Vo Viet Dai,
• Nguyen Ngoc Tri,
• Luc Van Meervelt,
• Nguyen Tien Trung and
• Wim Dehaen

Beilstein J. Org. Chem. 2022, 18, 1140–1153, doi:10.3762/bjoc.18.118

• ) Å, N15–H15···O13: 145(3)˚]. The pyrrolidine-2,3-dione ring is planar (rms deviation: 0.003 Å) and makes an angle of 40.39(14)˚ with the phenyl ring C6–C11 and of 82.23(15)˚ with the phenyl ring C26–C31. The dihedral angle between these phenyl rings is 74.87(14)˚. The crystal packing of product 10aa

Thiophene/selenophene-based S-shaped double helicenes: regioselective synthesis and structures

• Mengjie Wang,
• Lanping Dang,
• Wan Xu,
• Zhiying Ma,
• Liuliu Shao,
• Guangxia Wang,
• Chunli Li and
• Hua Wang

Beilstein J. Org. Chem. 2022, 18, 809–817, doi:10.3762/bjoc.18.81

• arrangement in the crystal packing structures of DH-1 and DH-2 indicate that these compounds may be used as supramolecular self-assembly units. Changes in molecular structure may substantially modulate the optical band gap of heteroacenes, and the replacement of heteroatoms from S to Se could fine-tune their

• , and double oxidative photocyclization. The photocyclization was a highly regioselective process. The molecular structures of DH-1 and DH-2 were confirmed by X-ray single-crystal analysis. Multiple intermolecular interactions, such as C–S, C–Se, S–S, S–Se, and Se–Se, were observed in the crystal

• packing structures of these compounds. Spectroscopic results and our previous work showed that the combination of molecular structure change and heteroatom replacement from S to Se could precisely modulate molecular energy levels. Keywords: crystal structure; double helicene; regioselective synthesis

Co-crystallization of an organic solid and a tetraaryladamantane at room temperature

• Fabian Rami,
• Jan Nowak,
• Felix Krupp,
• Wolfgang Frey and
• Clemens Richert

Beilstein J. Org. Chem. 2021, 17, 1476–1480, doi:10.3762/bjoc.17.103

• of the TDA/phenol co-crystal (space group P-1). b) Portion of the asymmetric unit of the TEO/phenol co-crystal (space group Cc). c) Crystal packing in the TDA/phenol system, and d) crystal packing in the TEO/phenol system. Possible states of two organic compounds capable of crystallizing at room

Structural effects of meso-halogenation on porphyrins

• Keith J. Flanagan,
• Maximilian Paradiz Dominguez,
• Zoi Melissari,
• Hans-Georg Eckhardt,
• René M. Williams,
• Dáire Gibbons,
• Caroline Prior,
• Gemma M. Locke,
• Alina Meindl,
• Aoife A. Ryan and
• Mathias O. Senge

Beilstein J. Org. Chem. 2021, 17, 1149–1170, doi:10.3762/bjoc.17.88

• alternative substitution types. The labelled displacement ellipsoid plot and packing diagrams for compounds 1 and 2A are available in Supporting Information File 1 (Figures S1–S4). The first feature which is of interest is the crystal packing of each of the 5-halo-substituted compounds which appears to be

• which is not seen in the other two structures (Figure 4B). While this may be difficult to visualize in the crystal packing (Supporting Information File 1, Figure S6), it is clear from the Hirshfeld surface analysis that there are marked decreases in the X···H contacts and an increase in the X···C (where

• porphyrin layers compared to the packing of compounds 13 and 13A (Supporting Information File 1, Figure S37). However, these deviations are in line with crystal packing and minor steric effects to be expected for this class of compounds with little to no deviations seen in the bond lengths, angles, and atom

Synthesis, crystal structures and properties of carbazole-based [6]helicenes fused with an azine ring

• Daria I. Tonkoglazova,
• Anna V. Gulevskaya,
• Konstantin A. Chistyakov and
• Olga I. Askalepova

Beilstein J. Org. Chem. 2021, 17, 11–21, doi:10.3762/bjoc.17.2

• helicene 10b, the enantiomeric molecules are aggregated into pairs differently: the pyrazine ring of one enantiomer is located over the E ring of another enantiomer and the distance between the layers is ca. 3.4 Å (Figure 2c and Figure 2d). The crystal packing of helicene 10c (Figure 2e) is peculiar: the

• [6]helicenes 10a (a), 10b (b) and 10c (c) (X-ray data). Crystal packing of carbazole-based [6]helicenes 10a (a, b), 10b (c,d) and 10c (e). Hydrogen atoms are hidden. Overview of the synthetic methods for the carbazole-based heterohelicenes. i) Pd2dba3, xantphos, K3PO4, xylene, 100 °C, 123 h, 64–88

Ultrasound-assisted Strecker synthesis of novel 2-(hetero)aryl-2-(arylamino)acetonitrile derivatives

• Emese Gal,
• Luiza Gaina,
• Hermina Petkes,
• Alexandra Pop,
• Castelia Cristea,
• Gabriel Barta,
• Dan Cristian Vodnar and
• Luminiţa Silaghi-Dumitrescu

Beilstein J. Org. Chem. 2020, 16, 2929–2936, doi:10.3762/bjoc.16.242

• Crystallographic Data Centre as supplementary publication (CCDC 2018198) (deposit@ccdc.cam.ac.uk). The molecular structure for the representative compound 2a is depicted in Figure 1. As revealed from the crystal packing structure shown in Figure 1, compound 2a forms a single crystalline phase containing both

NMR Spectroscopy of supramolecular chemistry on protein surfaces

• Peter Bayer,
• Anja Matena and
• Christine Beuck

Beilstein J. Org. Chem. 2020, 16, 2505–2522, doi:10.3762/bjoc.16.203

• challenging due to their often moderate (µM) binding affinities. If crystal contacts between proteins are favored, this can lead to exclusion of the ligand from the crystal. On the contrary, ligands binding tightly to the protein surface can in some cases compete with crystal packing and thus inhibit

• site is observed by one method but not the other, are likely due to crystal packing effects. If crystal contacts between a ligand and additional copies of the protein are formed, this site might be favored in the crystal but not in solution. Conversely, a site that might be sampled in solution can be