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

• on 13C NMR spectroscopy (see below). We suspect that deleterious hydrophilic effects caused the subsequent decomposition of the CAAC·CS2 and MIC·CS2 zwitterions when an aqueous work-up was applied. Structural analysis Several analytical techniques were employed to characterize the nine aldiminium and

Studying specificity in protein–glycosaminoglycan recognition with umbrella sampling

• Mateusz Marcisz,
• Sebastian Anila,
• Margrethe Gaardløs,
• Martin Zacharias and
• Sergey A. Samsonov

Beilstein J. Org. Chem. 2023, 19, 1933–1946, doi:10.3762/bjoc.19.144

• ][24][25][26]. The structural analysis of GAGs improves the understanding of their biological functions and helps in the development of structure–activity relationships for these important biopolymers [27][28]. Although the composition of the individual saccharide components of GAGs is simple, the

• structural analysis of GAGs is extremely difficult due to their complex pattern of modification such as epimerization and sulfation [29]. In addition, GAGs’ high flexibility and periodicity render these molecules profoundly challenging to analyze using experimental techniques only [30][31]. Thus

Controlling the reactivity of La@C₈₂ by reduction: reaction of the La@C₈₂ anion with alkyl halide with high regioselectivity

• Yutaka Maeda,
• Saeka Akita,
• Mitsuaki Suzuki,
• Michio Yamada,
• Takeshi Akasaka,
• Kaoru Kobayashi and
• Shigeru Nagase

Beilstein J. Org. Chem. 2023, 19, 1858–1866, doi:10.3762/bjoc.19.138

• afforded the corresponding single-bonded adducts 2–5 with high regioselectivity. One-electron reduction of La@C2v-C82 increased its reactivity during thermal reaction relative to that of neutral La@C2v-C82. Structural analysis of the two major products indicated that the characteristic absorption features

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

• between the two glucopyranose moieties was confirmed by the HMBC correlation of H-1′′/C-2′ and the H2BC correlation of H-1′/C-2′, giving the relative structure of 4 shown in Figure 1. Although 1D NMR and HRESIMS data for probreynin I (4) were reported in a Chinese patent in 2019 [13], no structural

• analysis based on 2D NMR spectroscopy has previously been described. He et al. reported that epibreynin D, which bears the same aglycone moiety as compounds 2 and 7, exhibits anti-inflammatory effects in mice and rat models [12]. To investigate the anti-inflammatory effects of the sulfur-containing

Selective construction of dispiro[indoline-3,2'-quinoline-3',3''-indoline] and dispiro[indoline-3,2'-pyrrole-3',3''-indoline] via three-component reaction

• Ziying Xiao,
• Fengshun Xu,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2023, 19, 1234–1242, doi:10.3762/bjoc.19.91

• the three-component reaction. To our surprise, instead of the above mentioned dispiro[indoline-3,2'-quinoline-3',3''-indolines] 3a–m, the novel dispiro[indoline-3,2'-pyrrole-3',3''-indoline] derivatives 4a–i were obtained in high yields. The results are summarized in Table 3. The structural analysis

Synthesis of imidazo[4,5-e][1,3]thiazino[2,3-c][1,2,4]triazines via a base-induced rearrangement of functionalized imidazo[4,5-e]thiazolo[2,3-c][1,2,4]triazines

• Dmitry B. Vinogradov,
• Alexei N. Izmest’ev,
• Angelina N. Kravchenko,
• Yuri A. Strelenko and
• Galina A. Gazieva

Beilstein J. Org. Chem. 2023, 19, 1047–1054, doi:10.3762/bjoc.19.80

• –spin interaction constants of other doublets (2JCH = 1.3–1.5 Hz) indicate the position of the carboxyl (for 4a, red) or carbonyl (for 5a, blue) groups through two bonds relative to the olefinic proton. The structure of compound 5a was additionally confirmed by X-ray structural analysis data (Figure 5

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

• and DSC results for each sample are available (Section 5, pp. S15 and S16 in Supporting Information File 1). Single crystal X-ray structural analysis The crystal structures of β-CD·BES, β-CD·PRO and γ-CD·PRO were solved by isomorphous replacement using as trial models the rigid host atom frameworks of

Synthesis, optical and electrochemical properties of (D–π)₂-type and (D–π)₂Ph-type fluorescent dyes

• Kosuke Takemura,
• Kazuki Ohira,
• Taiki Higashino,
• Keiichi Imato and
• Yousuke Ooyama

Beilstein J. Org. Chem. 2022, 18, 1047–1054, doi:10.3762/bjoc.18.106

• , compared with those in toluene. The Φfl-solid (0.24) of OTT-2 is higher than that (Φfl-solid = 0.15) of OTK-2, while the Φfl-solid of OTK-2 and OTT-2 are lower than those in toluene. Although single crystals of OTK-2 and OTT-2 with sufficient size for X-ray structural analysis were not obtained, the

Synthesis of bis-spirocyclic derivatives of 3-azabicyclo[3.1.0]hexane via cyclopropene cycloadditions to the stable azomethine ylide derived from Ruhemann's purple

• Alexander S. Filatov,
• Olesya V. Khoroshilova,
• Anna G. Larina,
• Vitali M. Boitsov and
• Alexander V. Stepakov

Beilstein J. Org. Chem. 2022, 18, 769–780, doi:10.3762/bjoc.18.77

• triple bonds due to ring strain. It is noteworthy that we managed to determine the relative configuration of cycloadduct 3e by carrying out the corresponding X-ray structural analysis (Figure 1 and Table S2 in Supporting Information File 1). As anticipated, the azomethine ylide 1 cycloaddition to

Structural basis for endoperoxide-forming oxygenases

• Takahiro Mori and
• Ikuro Abe

Beilstein J. Org. Chem. 2022, 18, 707–721, doi:10.3762/bjoc.18.71

• . Structure of NvfI In the structural analysis of NvfI, three different active site conformations (open, partially closed, and closed) were observed (PDB IDs: 7DE2, 7EMZ, and 7ENB) (Figure 4A–C) [28]. The conformations of the loop regions between Ser122-Gly128 and Trp199-Pro209 were altered by soaking with

The enzyme mechanism of patchoulol synthase

• Houchao Xu,
• Bernd Goldfuss,
• Gregor Schnakenburg and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2022, 18, 13–24, doi:10.3762/bjoc.18.2

• no. 1491695) [17], but these data did not allow to conclude on the absolute configuration of compound 3. We now obtained 3 as a crystalline material and performed an X-ray structural analysis through anomalous dispersion using Cu Kα irradiation (Table S2 in Supporting Information File 1), resulting

The PIFA-initiated oxidative cyclization of 2-(3-butenyl)quinazolin-4(3H)-ones – an efficient approach to 1-(hydroxymethyl)-2,3-dihydropyrrolo[1,2-a]quinazolin-5(1H)-ones

• Alla I. Vaskevych,
• Nataliia O. Savinchuk,
• Ruslan I. Vaskevych,
• Eduard B. Rusanov,
• Oleksandr O. Grygorenko and
• Mykhailo V. Vovk

Beilstein J. Org. Chem. 2021, 17, 2787–2794, doi:10.3762/bjoc.17.189

• oxidant and 24 h reaction time were necessary (Table 2, entry 10). The optimized conditions were applied to all quinazolones 7a–l, and target 1-(hydroxymethyl)-2,3-dihydropyrrolo[1,2-a]quinazolin-5(1H)-ones 6a–l were obtained in 75–83% yield (see Table 3). Their structural analysis showed that the

In-depth characterization of self-healing polymers based on π–π interactions

• Josefine Meurer,
• Julian Hniopek,
• Johannes Ahner,
• Michael Schmitt,
• Jürgen Popp,
• Stefan Zechel,
• Kalina Peneva and
• Martin D. Hager

Beilstein J. Org. Chem. 2021, 17, 2496–2504, doi:10.3762/bjoc.17.166

• P1 goes hand in hand with the structural analysis of the material before. Since the healing behavior is based on π–π interactions, a sufficient healing could only be observed at temperatures above the activation of the π–π interactions. At temperatures below the activation, the healing was incomplete

Development of N-F fluorinating agents and their fluorinations: Historical perspective

• Teruo Umemoto,
• Yuhao Yang and
• Gerald B. Hammond

Beilstein J. Org. Chem. 2021, 17, 1752–1813, doi:10.3762/bjoc.17.123

• -QN-BF4 30-3, and F-QD-BF4 30-4 in good yields (Scheme 69). Soon after in 2001, they reported the X-ray structural analysis of F-CD-BF4 30-1 [98]. The enantioselective fluorination of the sodium enolate of 2-methyl-1-tetralone was examined using these N-F alkaloid salts (Scheme 70). F-CD-BF4 30-1 gave

Amino- and polyaminophthalazin-1(2H)-ones: synthesis, coordination properties, and biological activity

• Zbigniew Malinowski,
• Emilia Fornal,
• Agata Sumara,
• Renata Kontek,
• Karol Bukowski,
• Beata Pasternak,
• Dariusz Sroczyński,
• Joachim Kusz,
• Magdalena Małecka and
• Monika Nowak

Beilstein J. Org. Chem. 2021, 17, 558–568, doi:10.3762/bjoc.17.50

• compound moiety. Based on the results of X-ray structural analysis of the Cu(II) complex with 7, it can be assumed, that also in the case of ligand 5i (L2) the nitrogen atoms of the pyridin-2-yl and azomethin moiety participate in the coordination with Cu(II) ions. Crystallography of complex 17 The copper

Menthyl esterification allows chiral resolution for the synthesis of artificial glutamate analogs

• Kenji Morokuma,
• Shuntaro Tsukamoto,
• Kyosuke Mori,
• Kei Miyako,
• Ryuichi Sakai,
• Raku Irie and
• Masato Oikawa

Beilstein J. Org. Chem. 2021, 17, 540–550, doi:10.3762/bjoc.17.48

• *) [4]. The structural analysis of the diastereomeric menthyl esters obtained after chiral resolution was conducted based on a combination of NOESY data and conformational calculation in that study [4]. In this study, the configurational analysis of the menthyl ester is reasonably justified by X-ray

1,2,3-Triazoles as leaving groups: S_NAr reactions of 2,6-bistriazolylpurines with O- and C-nucleophiles

• Dace Cīrule,
• Irina Novosjolova,
• Ērika Bizdēna and
• Māris Turks

Beilstein J. Org. Chem. 2021, 17, 410–419, doi:10.3762/bjoc.17.37

• hydrogen bond. This is supported by a smaller deviation of the C(2’’) chemical shift value (61.7 ppm) in comparison to the theoretical shifts for a Csp2 centre. Similar structural analogues are known in the literature [54][83][84][85] but their structural analysis was incomplete. As the aforementioned

¹⁹F NMR as a tool in chemical biology

• Diana Gimenez,
• Aoife Phelan,
• Cormac D. Murphy and
• Steven L. Cobb

Beilstein J. Org. Chem. 2021, 17, 293–318, doi:10.3762/bjoc.17.28

• fluorinated probes and their incorporation into macromolecules, the application of 19F NMR to monitor protein–protein interactions, protein–ligand interactions, physiologically relevant ions and in the structural analysis of proteins and nucleic acids. The continued relevance of the technique to investigate

• in this field since then. Review Structural analysis of macromolecules using 19F NMR In order to elucidate their various functions, it is essential to have a detailed understanding of both the structure of biological molecules and the way in which they interact in their environment and with one

• of which were consistent with those obtained in previous work but measured in cell membrane extracts [46]. Structural analysis of macromolecules using 19F NMR The three-dimensional (3D) structure of biomacromolecules and their conformational dynamics are often the starting point for the development

Tuning the solid-state emission of liquid crystalline nitro-cyanostilbene by halogen bonding

• Subrata Nath,
• Alexander Kappelt,
• Matthias Spengler,
• Bibhisan Roy,
• Jens Voskuhl and
• Michael Giese

Beilstein J. Org. Chem. 2021, 17, 124–131, doi:10.3762/bjoc.17.13

• behaviour of halogen-bonded liquid crystals has been reported. In 2014, Tothadi and Desiraju reported on a new supramolecular synthon based on the non-covalent interaction between 1,4-dinitrobenzene and iodobenzene [13]. Their structural analysis of a series of ternary cocrystals revealed that the nitro

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

• without THF solvent producing alkyne 9b in 82% yield (Table 4, entry 2). The structure of 9c was unambiguously proved by X-ray structural analysis (see Supporting Information File 1, Figure S34). Earlier, at the final step of a similar synthesis of the azine-fused [5]helicenes, we used trifluoroacetic

Comparative ligand structural analytics illustrated on variably glycosylated MUC1 antigen–antibody binding

• Christopher B. Barnett,
• Tharindu Senapathi and
• Kevin J. Naidoo

Beilstein J. Org. Chem. 2020, 16, 2540–2550, doi:10.3762/bjoc.16.206

• partially pre-structuring is seen prior to binding. Although the bound conformation of peptide and glycopeptide is similar, the glycopeptide fluctuates less and resides in specific conformers for more extended periods. This structural analysis which gives a high-level view of the features in the system

• for antibody binding. The results agreed with previous findings that glycosylation may affect peptide conformations near the glycosylation site and correlated with the hypothesis that glycosylation alters the conformational equilibrium of the antigen. This structural analysis which gives a high-level

Naphthalene diimide bis-guanidinio-carbonyl-pyrrole as a pH-switchable threading DNA intercalator

• Poulami Jana,
• Filip Šupljika,
• Carsten Schmuck and
• Ivo Piantanida

Beilstein J. Org. Chem. 2020, 16, 2201–2211, doi:10.3762/bjoc.16.185

• intercalators, particularly those which have substituents protruding into either the major or minor grooves (or both) [29]. For a more detailed structural analysis of the complexes, CD spectroscopy was applied [12][13]. It should be noted that due to the distance between the asymmetric atom and NDI or GCP

One-step route to tricyclic fused 1,2,3,4-tetrahydroisoquinoline systems via the Castagnoli–Cushman protocol

• Aleksandar Pashev,
• Nikola Burdzhiev and
• Elena Stanoeva

Beilstein J. Org. Chem. 2020, 16, 1456–1464, doi:10.3762/bjoc.16.121

• the structural analysis were deposited with the Cambridge Crystallographic Data Centre, CCDC 1963825 and 1963826, respectively. Copy of this information can be obtained free of charge from The Director, CCDC, 12 Union Road, Cambridge, CB2 1EZ, UK. Fax: +44 1223 336–033, e-mail: deposit@ccdc.cam.ac.uk

• (Laboratory of Molecular Spectroscopy and Structural Analysis) for the acquisition and refinement of the X-ray crystallographic data. Funding The financial support of Sofia University “St. Kliment Ohridski” (projects 028/28.04.2014 and 80-10-221/24.04.2017, as well as Grants BG051PO001-3.3.06-0048/04.10.2012

Efficient synthesis of dipeptide analogues of α-fluorinated β-aminophosphonates

• Marcin Kaźmierczak and
• Henryk Koroniak

Beilstein J. Org. Chem. 2020, 16, 756–762, doi:10.3762/bjoc.16.69

• difference between refinements with H2O and D2O could be found). The correct absolute configuration was determined on the basis of Flack and Parson’s parameters, as well as of slightly better R factors for the correct model. The crystallographic data for the structural analysis has been deposited with the

Absolute configurations of talaromycones A and B, α-diversonolic ester, and aspergillusone B from endophytic Talaromyces sp. ECN211

• Ken-ichi Nakashima,
• Junko Tomida,
• Takao Hirai,
• Yoshiaki Kawamura and
• Makoto Inoue

Beilstein J. Org. Chem. 2020, 16, 290–296, doi:10.3762/bjoc.16.28

• . Supporting Information File 266: Crystal structure information files for 1, 3, and 5. Acknowledgements The authors thank the Rigaku Corporation for the single-crystal X-ray structural analysis of talaromycone A. The authors are also grateful to Dr. Hiromi Ota at the Division of Instrumental Analysis for the