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

• specific MCR-based scaffolds as precursors and employing the abundant and inexpensive formamide as a C1 feedstock under neat conditions, we were able to efficiently access substituted thieno-, quinolino- and indolopyrimidones without the need of column chromatography. Further, a single-crystal X-ray

• structure was obtained, revealing certain geometrical features. Keywords: 2-amino-substituted heterocycles; cyanoacetamide; Gewald reaction; multicomponent reaction (MCR); pyrimidine; Introduction The term “net-zero carbon” is becoming increasingly common as we consider a future marked by a rising global

Hydrogen-bonded macrocycle-mediated dimerization for orthogonal supramolecular polymerization

• Wentao Yu,
• Zhiyao Yang,
• Chengkan Yu,
• Xiaowei Li and
• Lihua Yuan

Beilstein J. Org. Chem. 2025, 21, 179–188, doi:10.3762/bjoc.21.10

• 2444.3405, respectively. Stacked 1H NMR spectra (CDCl3/CD3CN 1:1, v/v, 400 MHz, 298 K) of G1 upon addition of different equiv of H1 ([G1] = 1.0⋅10−3 M). (a) 0.0 equiv, (b) 0.2 equiv, (c) 0.4 equiv, (d) 0.6 equiv, (e) 0.8 equiv, (f) 1.0 equiv, (g) 1.2 equiv, (h) 1.4 equiv, and (i) only H1. Single-crystal X

• -ray structure of the complex H2 ⊃ G1. a) Dimeric structure formed by cyclo[6]aramide H2 and cationic guest G1, with each guest molecule threading one molecule of H2 at its end. b) A portion of the dimeric structure showing an array of hydrogen bonding interactions between the amide oxygen atoms of H2

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

• the single crystal X-ray structure of 11 (Figure 5), the environment around the ortho-bromo-position is extremely sterically hindered. Figure 5, shows the Br…Br separations in the α2β2-atropsiomer of compound 11 to be 4.3–4.4 Å. While only an illustration of the situation in the solid phase this

Primary amine-catalyzed enantioselective 1,4-Michael addition reaction of pyrazolin-5-ones to α,β-unsaturated ketones

• Pooja Goyal,
• Akhil K. Dubey,
• Raghunath Chowdhury and
• Amey Wadawale

Beilstein J. Org. Chem. 2024, 20, 1518–1526, doi:10.3762/bjoc.20.136

• temperature. The crude reaction mixture was purified by silica gel (230–400 mesh) column chromatography (petroleum ether/EtOAc as the eluent) to give the product 3 or ent-3. Selected examples of drugs and bioactive molecules bearing a pyrazole core. Single crystal X-ray structure of ent-3ba (CCDC 2234286

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

• )cyclohexa-2,5-diene-1,4-dione (compound 10). Single-crystal X-ray crystallographic studies The ORTEP diagram of oxamide 3 is shown in Figure 1. Compound 3 crystallized in a monoclinic crystal system in the P21/n space group. The single-crystal X-ray structure of compound 3 was reported with the space group

• + Na]+ calcd for C54H48N6NaO18, 1091.2917; found, 1091.2885; FTIR (KBr) ν̃max: 3444, 3354, 1677, 1625, 1423, 1304, 1237, 820 cm−1. X-ray data Table 2 and Table 3 show single-crystal X-ray structure refinement data. Molecular structure of 3. Thermal ellipsoids drawn at 50% probability. Selected bond

• -crystal X-ray structure refinement data for 3, 9, and 10. Single-crystal X-ray structure refinement data for 11, 12, and 13. Supporting Information Supporting Information File 64: Spectroscopic characterization of products (1H, 13C and 77Se NMR, IR, and HRMS spectra), packing arrangements of compounds

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

• 305-8577, Japan 10.3762/bjoc.20.100 Abstract The addition reaction of C60 with silylene 1, a silicon analog of carbene, yielded the corresponding bis-adduct 3. The structure of 3 was determined by single-crystal X-ray structure analysis, representing the first example of a crystal structure of a

• ions of 3. Finally, the structure of 3 was established by single-crystal X-ray structure analysis. The ORTEP diagram of 3 is presented in Figure 5 with the selected bond lengths and angles collected in Table 1. The cage C–C bond lengths of the addition sites are C1–C9: 1.623(2) Å and C21–C40: 1.6282(19

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

• product of interest 2a. Compound 2a was identified by a combination of NMR spectroscopic methods and single-crystal X-ray structure analysis (vide infra) as the zwitterionic phospha-Michael adduct of 1 and acrylonitrile, formally stabilized by proton transfer from the phenol group to the initially formed

Light-responsive rotaxane-based materials: inducing motion in the solid state

• Adrian Saura-Sanmartin

Beilstein J. Org. Chem. 2023, 19, 873–880, doi:10.3762/bjoc.19.64

• -crystal X-ray structure of rotaxane 1a (R1 = Me, R2 = R3 = H) showing two interlocked molecules of the crystalline array [44]. Colour key of the solid structure: light blue = carbon atoms; purple = nitrogen atoms; red = oxygen atoms; and orange = iron atoms. Hydrogen atoms are omitted for clarity. (a

• materials and molecular machinery operating through light stimuli. Thus, the construction of smart materials by the rotaxane approach leads to envision a promising future in the area of photoresponsive materials incorporating molecular machines. a) Chemical structure of pseudorotaxanes 1; and (b) single

Facile access to 3-sulfonylquinolines via Knoevenagel condensation/aza-Wittig reaction cascade involving ortho-azidobenzaldehydes and β-ketosulfonamides and sulfones

• Ksenia Malkova,
• Andrey Bubyrev,
• Stanislav Kalinin and
• Dmitry Dar’in

Beilstein J. Org. Chem. 2023, 19, 800–807, doi:10.3762/bjoc.19.60

• good to excellent yields (Scheme 3). The product structures were confirmed by the standard set of characterization data as well as the single-crystal X-ray structure of the representative compound 5a. The presence of an electron-withdrawing group in the o-azidobenzaldehyde leads to decreased yields of

Solvent-free synthesis of enantioenriched β-silyl nitroalkanes under organocatalytic conditions

• Akhil K. Dubey and
• Raghunath Chowdhury

Beilstein J. Org. Chem. 2021, 17, 2642–2649, doi:10.3762/bjoc.17.177

• with respect to limiting reagent). Single crystal X-ray structure of ent-3k (CCDC 2097263). Selected methods for the synthesis of enantioenriched β-silyl nitroalkanes, synthesis of chiral organosilanes from β-silyl α,β-unsaturated carbonyl compounds, and the present work. Scope of substrates. Reaction

Synthesis and antimicrobial activity of 1H-1,2,3-triazole and carboxylate analogues of metronidazole

• Satya Kumar Avula,
• Syed Raza Shah,
• Khdija Al-Hosni,
• Muhammad U. Anwar,
• Rene Csuk,
• Biswanath Das and
• Ahmed Al-Harrasi

Beilstein J. Org. Chem. 2021, 17, 2377–2384, doi:10.3762/bjoc.17.154

• were characterized by 1H NMR, 13C NMR, HRMS, and 19F NMR (5b, 5c and 5h) spectroscopy wherever applicable. The structures of compounds 3, 5c and 7b were unambiguously confirmed by single crystal X-ray analysis diffraction method. Single crystal X-ray structure analysis supported the formation of the

Total synthesis of ent-pavettamine

• Memory Zimuwandeyi,
• Manuel A. Fernandes,
• Amanda L. Rousseau and
• Moira L. Bode

Beilstein J. Org. Chem. 2021, 17, 1440–1446, doi:10.3762/bjoc.17.99

• pavettamine, in order to obtain the enantiomer. The final deprotection step proved particularly efficient, with two protecting groups being removed simultaneously to unveil the desired target. Structure of pavettamine 1 and its enantiomer 2. Crystal structure of compound 9. Single crystal X-ray structure of

Selective and reversible 1,3-dipolar cycloaddition of 6-aryl-1,5-diazabicyclo[3.1.0]hexanes with 1,3-diphenylprop-2-en-1-ones under microwave irradiation

• Alexander P. Molchanov,
• Mariia M. Efremova,
• Mariya A. Kryukova and
• Mikhail A. Kuznetsov

Beilstein J. Org. Chem. 2020, 16, 2679–2686, doi:10.3762/bjoc.16.218

• [1,2-a]pyrazoles (Michael-type adducts). For the first time it was shown, that under heating the cycloadducts can undergo cycloreversion with the generation of new azomethine imines, which can be trapped with suitable dipolarophiles. Single-crystal X-ray structure of compound 3e. Single-crystal X-ray

• structure of compound 3g. The two types of azomethine imines (AMI). Reaction of 1,5-diazabicyclo[3.1.0]hexanes 1a–d with diarylpropenones 2a–l. Control experiments. Mechanistic hypothesis for cycloaddition and cycloreversion reactions of diazabicyclohexane 1a with propenone 2f. Experiments on the trapping

Rearrangement of o-(pivaloylaminomethyl)benzaldehydes: an experimental and computational study

• Csilla Hargitai,
• Györgyi Koványi-Lax,
• Tamás Nagy,
• Péter Ábrányi-Balogh,
• András Dancsó,
• Gábor Tóth,
• Judit Halász,
• Angéla Pandur,
• Gyula Simig and
• Balázs Volk

Beilstein J. Org. Chem. 2020, 16, 1636–1648, doi:10.3762/bjoc.16.136

• elucidation of compounds 3a [1], 3b, 8a,b, and 23a,b was based on the molecular formula obtained from HRMS, comprehensive 1H and 13C NMR study and on the single-crystal X-ray structure of compounds 3a [1], 3b, 8b, 23a, and 23b (for spectra and detailed interpretation, see Supporting Information File 1

Five-component, one-pot synthesis of an electroactive rotaxane comprising a bisferrocene macrocycle

• Natalie Lagesse,
• Luca Pisciottani,
• Maxime Douarre,
• Pascale Godard,
• Brice Kauffmann,
• Vicente Martí-Centelles and
• Nathan D. McClenaghan

Beilstein J. Org. Chem. 2020, 16, 1564–1571, doi:10.3762/bjoc.16.128

• crystal X-ray structure of a doubly ferrocene-decorated [2]rotaxane are further reported. Keywords: ferrocene; macrocycle; rotaxane; single crystal X-ray structure; template; Introduction The development of interlocked molecules with tailored properties allowed the preparation of molecular machines able

• ferrocene units were electronically decoupled and retained the reversible oxidation properties of the parent compound, while the single crystal X-ray structure of a doubly ferrocene-decorated [2]rotaxane indicated four relatively long and seemingly weak NH···CO hydrogen bonds. As the [2]rotaxane could be

• ]rotaxane is a homologue of the versatile benchmark tetraamide variant developed by Leigh and co-workers. The relative templating effect of different hydrogen-bonding motifs in rotaxane and pseudorotaxane generation is compared, with yields varying from 0 to 41%. The electrochemical properties and single

One-pot synthesis of dicyclopenta-fused peropyrene via a fourfold alkyne annulation

• Ji Ma,
• Yubin Fu,
• Junzhi Liu and
• Xinliang Feng

Beilstein J. Org. Chem. 2020, 16, 791–797, doi:10.3762/bjoc.16.72

• -fused PAHs in large π-systems. High-resolution MALDI-TOF mass spectrum of 1. Inset: isotopic distribution compared to mass spectrum simulated for C84H50. Single-crystal X-ray structure of 1. (a) Top view and (b) side view of the (P,P) isomer. c) Crystal packing of the enantiomer pairs (P,P and M,M) of 1

Towards triptycene functionalization and triptycene-linked porphyrin arrays

• Gemma M. Locke,
• Keith J. Flanagan and
• Mathias O. Senge

Beilstein J. Org. Chem. 2020, 16, 763–777, doi:10.3762/bjoc.16.70

• porphyrin/BODIPY dimers. Moreover, the synthesis of one unsymmetric porphyrin dimer 16 and a porphyrin-linked bistriptycene 18 was also achieved. A single crystal X-ray structure of the former highlighted the evident linearity in the system and arrangement of the porphyrins at a dihedral angle of 66.84

• charge from The Cambridge Crystallographic Data Centre via http://www.ccdc.cam.ac.uk/data_request/cif. Triptycene as a scaffold and selected porphyrin and BODIPY arrays. Single crystal X-ray structure of triptycene 5. (a) Molecular structure of 5 in the crystal with hydrogen atoms and minor disorder

• (iii) of another triptycene molecule. Hydrogen atoms and minor disorder omitted for clarity (thermal displacement 50%). Single crystal X-ray structure of triptycene-linked zinc-nickel porphyrin dimer 16 showing the conformation within the crystal structure; (a) top-view of zinc porphyrin; (b) top-view

Direct borylation of terrylene and quaterrylene

• Haruka Kano,
• Keiji Uehara,
• Kyohei Matsuo,
• Hironobu Hayashi,
• Hiroko Yamada and
• Naoki Aratani

Beilstein J. Org. Chem. 2020, 16, 621–627, doi:10.3762/bjoc.16.58

• tetra-borylated quaterrylene despite a low yield. The post modification of rylenes enables us to prepare their borylated products as versatile units after creating the rylene skeletons. Keywords: borylation; π-conjugation; oligorylene; single crystal X-ray structure; solubility; Introduction Compared

• -bridging oligorylenes, d) bay-alkoxy oligorylenes, and e) tetra-tert-butyl oligorylenes. (Top) Single crystal X-ray structure of TB4. The thermal ellipsoids are scaled at 50% probability. (Bottom) Packing diagram of TB4. The solvent molecules are omitted for clarity. UV–vis absorption and fluorescence

Synthesis of 4-(2-fluorophenyl)-7-methoxycoumarin: experimental and computational evidence for intramolecular and intermolecular C–F···H–C bonds

• Vuyisa Mzozoyana,
• Fanie R. van Heerden and
• Craig Grimmer

Beilstein J. Org. Chem. 2020, 16, 190–199, doi:10.3762/bjoc.16.22

• this F···H interaction. The single crystal X-ray structure and the DFT-optimized structure showed that the fluorinated phenyl ring favors the orientation with the fluorine atom closer to H5 than H3. The X-ray structure also showed the existence of the intermolecular C–F···H–C interaction. Keywords

• basis set, as implemented in Gaussian-09W (Rev. C.01) [45]. The superposition of the single-crystal X-ray structure (red) and the optimized structure (green) is shown in Figure 4. The DFT optimized geometric structure is shown in Figure 5 and has a dihedral angle, Φ (C2'–C1'–C4–C4a) of 65.3°. Following

• ) whereas C4 and C4a are not. The 2D HOESY spectrum shows the F···H5 coupling and also F···H3 coupling, seemingly weaker than F···H5 since splitting of the H3 signal is not observed in the 1H and 1H-{19F} 1D spectra. The single crystal X-ray structure showed that the fluorinated phenyl ring is orientated in

The reaction of arylmethyl isocyanides and arylmethylamines with xanthate esters: a facile and unexpected synthesis of carbamothioates

• Narasimhamurthy Rajeev,
• Toreshettahally R. Swaroop,
• Ahmad I. Alrawashdeh,
• Shofiur Rahman,
• Abdullah Alodhayb,
• Seegehalli M. Anil,
• Kuppalli R. Kiran,
• Chandra,
• Paris E. Georghiou,
• Kanchugarakoppal S. Rangappa and
• Maralinganadoddi P. Sadashiva

Beilstein J. Org. Chem. 2020, 16, 159–167, doi:10.3762/bjoc.16.18

• , however, carbamothioates 4a–l were instead obtained in 76–88% yield (Scheme 1). Herein, we report on this intriguing finding and show several examples, including a single crystal X-ray structure of one of the products so obtained. A plausible mechanism to explain the reaction using density functional

Emission solvatochromic, solid-state and aggregation-induced emissive α-pyrones and emission-tuneable 1H-pyridines by Michael addition–cyclocondensation sequences

• Natascha Breuer,
• Irina Gruber,
• Christoph Janiak and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2019, 15, 2684–2703, doi:10.3762/bjoc.15.262

• -pyridines 5 was further corroborated by a single crystal X-ray structure determination of compound 5a (Figure 1) [35]. In the single crystal the carboxyl ester group is oriented to the N–H and via a hydrogen bond. Solid-state torsional/dihedral angles between the 4- and 6-positioned aryl rings differ

A heteroditopic macrocycle as organocatalytic nanoreactor for pyrroloacridinone synthesis in water

• Piyali Sarkar,
• Sayan Sarkar and
• Pradyut Ghosh

Beilstein J. Org. Chem. 2019, 15, 1505–1514, doi:10.3762/bjoc.15.152

• different spectroscopic techniques, 1H NMR, 13C NMR, IR and HRMS. In addition, one of the compounds, 4d, was also examined by single crystal X-ray structure analysis (Figure 5). Mechanistic pathway A probable mechanism is portrayed in Scheme 3 including the role of the BATA-MC nanoreactor. The nanoreactor

Synthesis of pyrrolo[1,2-a]quinolines by formal 1,3-dipolar cycloaddition reactions of quinolinium salts

• Anthony Choi,
• Rebecca M. Morley and
• Iain Coldham

Beilstein J. Org. Chem. 2019, 15, 1480–1484, doi:10.3762/bjoc.15.149

• ). The adducts could be reduced, oxidised, or could undergo Suzuki–Miyaura coupling to give different substituted dihydro- and tetrahydroquinoline derivatives. Single crystal X-ray structure for 7c. Single crystal X-ray structure for 9. Reaction of ketone 1 with electron-deficient alkenes 2. Reactions of

Selenophene-containing heterotriacenes by a C–Se coupling/cyclization reaction

• Pierre-Olivier Schwartz,
• Sebastian Förtsch,
• Astrid Vogt,
• Elena Mena-Osteritz and
• Peter Bäuerle

Beilstein J. Org. Chem. 2019, 15, 1379–1393, doi:10.3762/bjoc.15.138

• starting material, but also ring fusion to selenophene was achieved by Cu-catalyzed C–Se cross-coupling reaction [28]. The detailed geometric structure and the packing behaviour in the solid state of triacenes 2–4 have been elucidated by single crystal X-ray structure analysis and X-ray diffraction on

• accordance with data for selenophene compared to thiophene [35]. Single crystal X-ray structure analysis Single crystals of heterotriacenes DTS 2, DST 3, and DSS 4 suitable for X-ray structure analysis were obtained and details of the refinements are summarized in Tables S1-S3 (Supporting Information File 1

• well soluble systems, which allowed for the determination of thermal, optical, and electrochemical properties. By single crystal X-ray structure analysis the geometric structure and packing motifs of selenolotriacenes 2–4 were determined. Quantum chemical calculations allowed for a deeper understanding

Catalytic asymmetric oxo-Diels–Alder reactions with chiral atropisomeric biphenyl diols

• Chi-Tung Yeung,
• Wesley Ting Kwok Chan,
• Wai-Sum Lo,
• Ga-Lai Law and
• Wing-Tak Wong

Beilstein J. Org. Chem. 2019, 15, 955–962, doi:10.3762/bjoc.15.92

• optimization with different substituents are ongoing in our group and further experiments are underway to develop the use of these diols for other catalytic reactions. (a) Single crystal X-ray structure of 3: showing intra- and intermolecular hydrogen bonds (green dashed line). Torsion angles of biphenyl rings