Studies on the syntheses of β-carboline alkaloids brevicarine and brevicolline

• Benedek Batizi,
• Patrik Pollák,
• András Dancsó,
• Péter Keglevich,
• Gyula Simig,
• Balázs Volk and
• Mátyás Milen

Beilstein J. Org. Chem. 2025, 21, 955–963, doi:10.3762/bjoc.21.79

• catalyst, overreduced product 31, i.e., the tetrahydro derivative of racemic brevicolline ((±)-1) was obtained in 91% yield. Structure determination of 31 was supported by single-crystal X-ray diffraction, as well (Figure 2). Changing the catalyst [Pd(OH)2, Ru, Rh], did not alter the course of the reaction

A convergent synthetic approach to the tetracyclic core framework of khayanolide-type limonoids

• Zhiyang Zhang,
• Jialei Hu,
• Hanfeng Ding,
• Li Zhang and
• Peirong Rao

Beilstein J. Org. Chem. 2025, 21, 926–934, doi:10.3762/bjoc.21.75

• tricyclo[4.2.110,30.11,4]decane ring system. Additionally, krishnolides A and C contain 9–11 stereogenic centers and exhibit diverse oxidation patterns. Their relative and absolute configurations were determined through NMR, HRESIMS and ECD experiments, as well as single crystal X-ray diffraction analysis

Silver(I) triflate-catalyzed post-Ugi synthesis of pyrazolodiazepines

• Muhammad Hasan,
• Anatoly A. Peshkov,
• Syed Anis Ali Shah,
• Andrey Belyaev,
• Chang-Keun Lim,
• Shunyi Wang and
• Vsevolod A. Peshkov

Beilstein J. Org. Chem. 2025, 21, 915–925, doi:10.3762/bjoc.21.74

• trifluoromethyl and nitro groups. Furthermore, substrates 15m–o derived from aliphatic amines, also performed well, furnishing pyrazolodiazepines 16m–o in up to 89% yield. The structure of 16m, a representative compound of this series, was confirmed through single-crystal X-ray diffraction (scXRD) analysis

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

• spectroscopy, the structure of 4-(1-methylamino)ethylidene-1,5-diphenylpyrrolidine-2,3-dione (5a) was also verified through single-crystal X-ray diffraction. Furthermore, the synthesized molecules were evaluated for compliance with established drug-likeness rules (Lipinski, Veber, Ghose, Egan, and Muegge), as

• single-crystal X-ray diffraction [19]. According to a previous publication, the condensation between pyrrolidine-2,3-diones and an amine as nucleophile normally occurred at the 3-position of nitrogen-containing heterocyclic ring which results in the corresponding enamine product [18]. However, the

• -disubstituted pyrrolidine-2,3-diones were successfully synthesized via reversible transimination reaction. The structure of all compounds was evaluated using nuclear magnetic resonance (NMR) spectroscopy and, especially, with the molecular structure of compound 5a further confirmed through single-crystal X-ray

Cryptophycin unit B analogues

• Thomas Schachtsiek,
• Jona Voss,
• Maren Hamsen,
• Beate Neumann,
• Hans-Georg Stammler and
• Norbert Sewald

Beilstein J. Org. Chem. 2025, 21, 526–532, doi:10.3762/bjoc.21.40

• control of equivalents and pH, or Leuckart–Wallach-like reaction with ammonium formate and Pd/C [25] provided monomethylaniline 7 in 37% and 35% yield, respectively. The absolute structure of monomethylaniline 7 was confirmed by single-crystal X-ray diffraction measurements (Figure 2). Compound 7

• conjugation handles in unit B. IC50 values given against (a) CCRF-CEM [20] and (b) KB-3-1 [21] cell lines. C: Cryptophycin-52 derivatives synthesised in this work. Molecular structure of Boc-ᴅ-Phe(4-NHMe)-OMe 7 as determined by single-crystal X-ray diffraction measurements. Thermal ellipsoids depicted at 50

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

• Figure 2b. We hypothesized that this reaction occurred in the solid state, and further investigations confirmed this. To validate our findings, we employed single-crystal X-ray diffraction, which revealed the packing mode in the crystal and identified any photoproducts formed. Two additional compounds

• included two additional bimane samples, Me2B and Me4B. These samples were crystallized from a MeOH–DCM 1:1 (v/v) mixture which was left to slowly evaporate over the course of several days at room temperature, followed by single-crystal X-ray diffraction to determine their structure (Figure 4) and crystal

• fluorescence spectrum and η is the refractive index of the solvent. Single crystal X-ray diffraction studies Crystals of Me4B, Cl2B (A), (B), (C), and Me2B were mounted on a MiTeGen micromount with NVH immersion oil. Data were collected from a shock-cooled single crystal at 100(2) K on a Bruker Apex Kappa Duo

Synthesis and characterizations of highly luminescent 5-isopropoxybenzo[rst]pentaphene

• Islam S. Marae,
• Jingyun Tan,
• Rengo Yoshioka,
• Zakaria Ziadi,
• Eugene Khaskin,
• Serhii Vasylevskyi,
• Ryota Kabe,
• Xiushang Xu and
• Akimitsu Narita

Beilstein J. Org. Chem. 2025, 21, 270–276, doi:10.3762/bjoc.21.19

• analysis was obtained by slow evaporation of a diethyl ether/n-hexane solution, enabling its unambiguous structural determination by single-crystal X-ray diffraction (Figure 1). The planar BPP core and the isopropyloxy group on the zigzag edge are clearly visualized (Figure 1a and b). In a unit cell

Synthesis, characterization, and photophysical properties of novel 9‑phenyl-9-phosphafluorene oxide derivatives

• Shuxian Qiu,
• Duan Dong,
• Jiahui Li,
• Huiting Wen,
• Jinpeng Li,
• Yu Yang,
• Shengxian Zhai and
• Xingyuan Gao

Beilstein J. Org. Chem. 2024, 20, 3299–3305, doi:10.3762/bjoc.20.274

• HRMS spectrometry were in full agreement with the expected structures, and single-crystal X-ray diffraction analysis was conducted to confirm the structure of compound 7-H. Moreover, the photophysical properties of these PhFlOP derivatives were determined by UV–vis absorption and photoluminescence

• simple. The structure of 7-H was confirmed by single-crystal X-ray diffraction. Furthermore, UV–vis absorption and PL studies were carried out to explore the photophysical properties of these PhFlOP derivatives. Investigations for further applications of the PhFlOP-based emitters 7 are still ongoing. An

Reactivity of hypervalent iodine(III) reagents bearing a benzylamine with sulfenate salts

• Beatriz Dedeiras,
• Catarina S. Caldeira,
• José C. Cunha,
• Clara S. B. Gomes and
• M. Manuel B. Marques

Beilstein J. Org. Chem. 2024, 20, 3281–3289, doi:10.3762/bjoc.20.272

• benziodoxolone, 2d) were obtained with quantitative yields, as white solids on the gram-scale, easy to manipulate and long-term stable below 0 °C. Crystals of compound 2d were successfully obtained and its molecular structure was confirmed through single-crystal X-ray diffraction. The X-ray analysis revealed a

Synthesis of 2H-azirine-2,2-dicarboxylic acids and their derivatives

• Anastasiya V. Agafonova,
• Mikhail S. Novikov and
• Alexander F. Khlebnikov

Beilstein J. Org. Chem. 2024, 20, 3191–3197, doi:10.3762/bjoc.20.264

• single-crystal X-ray diffraction analysis. The reaction of azetidine with diacyl chloride 2a gave a complex mixture of products, and O-methyl hydroxylamine did not react. Diacyl chloride 2a reacts with methanol and ethanol to give diesters 11a,b (Scheme 5). An experiment with isoxazole 1a and methanol on

Controlled oligomerization of [1.1.1]propellane through radical polarity matching: selective synthesis of SF₅- and CF₃SF₄-containing [2]staffanes

• Jón Atiba Buldt,
• Wang-Yeuk Kong,
• Yannick Kraemer,
• Masiel M. Belsuzarri,
• Ansh Hiten Patel,
• James C. Fettinger,
• Dean J. Tantillo and
• Cody Ross Pitts

Beilstein J. Org. Chem. 2024, 20, 3134–3143, doi:10.3762/bjoc.20.259

• truncated after incorporation of two bicyclopentane (BCP) units. Synthetic and computational studies suggest this phenomenon can be attributed to alternating radical polarity matching. In addition, single-crystal X-ray diffraction (SC-XRD) data reveal structurally interesting features of the CF3SF4

• for the first time created an opportunity for structural analysis. We previously reported and contextualized single-crystal X-ray diffraction (SC-XRD) data on 2 [36]; thus, we proceeded to grow crystals of 3 suitable for X-ray analysis through slow evaporation of ethyl acetate. To our surprise, an

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

• otherwise. The absence of transition states was confirmed by the absence of imaginary frequencies in vibrational frequency calculations. The long side chains were replaced by methyl units to aid the convergence of the geometry optimisations. Crystallography Single crystal X-ray diffraction data for 3b were

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

• (100), 595.3 (40), 596.3 (10), [M − BF4]+ calcd for C43H36N3, 594.29; (negative) 86.0 (20), 87.0 (100); [M – C43H36N3]− calcd for BF4, 87.00. This compound was further characterized by single-crystal X-ray diffraction analysis. 4,8,12-Tris(2,6-dimethylphenyl)-4,8,12-triazatriangulenium as a PF6− ion

• (0.21); MALDI–TOF MS (m/z) (% intensity): (positive) 594.3 (100), 595.3 (40), 596.3 (10), [M − F6P]+ calcd for C43H36N3, 594.29; (negative) 145.1 (100), [M − C49H30N3]− calcd for F6P, 144.96. This compound was further characterized by single-crystal X-ray diffraction analysis. 4,8,12-Tris(2,6

• –TOF MS (m/z) (% intensity): (positive) 594.3 (100), 595.3 (40), 596.3 (10), [M − C24BF20]+ calcd for C43H36N3, 594.29; (negative) 678.0 (20), 679.0 (100), 680.0 (20), [M – C43H36N3]– calcd for C24BF20, 678.98. This compound was further characterized by single-crystal X-ray diffraction analysis. 4,8,12

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

• compounds. Acknowledgements This research was supported through instrumentation made available through the Shared Instrumentation Authority at Rice University. We thank Dr. Christopher L. Pennington for assistance with HRMS data collection and Dr. Hong-Lei Xu for help with single-crystal X-ray diffraction

Harnessing unprotected deactivated amines and arylglyoxals in the Ugi reaction for the synthesis of fused complex nitrogen heterocycles

• Javier Gómez-Ayuso,
• Pablo Pertejo,
• Tomás Hermosilla,
• Israel Carreira-Barral,
• Roberto Quesada and
• María García-Valverde

Beilstein J. Org. Chem. 2024, 20, 1758–1766, doi:10.3762/bjoc.20.154

• single diastereomer (Scheme 5, Table 3), while N-phenylglycine afforded the enamine derivative 10 (Scheme 6, Table 4). Both structures were confirmed by single-crystal X-ray diffraction of compounds 9a and 10a (Figure 2). The diastereoselectivity observed in the hemiaminals and their stability can be

• further confirmed by single-crystal X-ray diffraction of compound 12c (Figure 3). Conclusion In this work, we have demonstrated the straightforward access to a variety of complex nitrogen heterocycles by using unprotected deactivated amines tethered to carboxylic acids combined with arylglyoxals in the

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

Rapid construction of tricyclic tetrahydrocyclopenta[4,5]pyrrolo[2,3-b]pyridine via isocyanide-based multicomponent reaction

• Xiu-Yu Chen,
• Ying Han,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2024, 20, 1436–1443, doi:10.3762/bjoc.20.126

• produced in the reaction, while the other diastereomers were not detected. In order to elucidate the relative configuration of the obtained compounds, the molecular structure of the compound 4a was determined by single crystal X-ray diffraction (Figure 1). From Figure 1, it can be seen that the fused

• can be performed with a wide variety of substrates. The molecular structure of the compound 6g was determined by single crystal X-ray diffraction method (Figure 2). The o-methoxyphenyl group exists on the trans-position of the fused pyrrolidine unit. The methoxycarbonyl group also exists on the cis

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

• suitable for single-crystal X-ray diffraction could be obtained and confirmed the product structure with the presumed regioisomer (Scheme 3). A library of over 50 triazole products 21aa–vg was successfully synthesized with yields ranging from 28% to quantitative, combining four different pyrazole-carbon

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

• electrons over the adjacent carboxylate function, which prompted the selenation pathway, leading to the formation of two of the isomeric diorganyl selenides of methyl anthranilate. The diaryl selenides were structurally characterized using single-crystal X-ray diffraction. Density functional theory

• in Hz. The calibration was done with respect to the signal of residual undeuterated solvent or in relationship to TMS (CDCl3: 1H 7.26 ppm, 13C 77.34 ppm). Single-crystal X–ray diffraction was recorded on a Bruker D8 Quest system. HRESIMS spectra were recorded on a Waters Xevo G2-XS QTof device. UV

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

• were obtained using the liquid–liquid bilayer diffusion method with solutions of 3 in CS2 using hexane as a poor solvent at 0 °C. Single-crystal X-ray diffraction data of 3 were collected on a Rigaku Oxford Diffraction XtaLAB Synergy R DW system with a HyPix detector equipped with a nitrogen-gas flow

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

• ). Single crystal X-ray diffraction data could be obtained for three DPQDs. One reveals pairwise hydrogen bonding in the solid state as well as a herringbone packing arrangement rendering it a promising candidate for additional studies in the context of organic optoelectronic devices. Keywords: conjugated

• exhibits a noteworthy impact on the thermal stabilities (analyzed by TGA) of the compounds. The single-crystal X-ray diffraction of DPQD 2b exhibits a desirable herringbone solid-state arrangement for a potential OFET application. Complementary gas-phase computational analysis has provided insight into the

• ). Cyclic voltammetric measurements of DCPQs, specifically 4a and 6a, and DPQDs 4b and 6b, support the overall trends observed through the electronic structure calculations. X-ray crystallography Single crystal X-ray diffraction data could be obtained for 2b, 5b, and 6b. Figure 6 illustrates the single

Confirmation of the stereochemistry of spiroviolene

• Yao Kong,
• Yuanning Liu,
• Kaibiao Wang,
• Tao Wang,
• Chen Wang,
• Ben Ai,
• Hongli Jia,
• Guohui Pan,
• Min Yin and
• Zhengren Xu

Beilstein J. Org. Chem. 2024, 20, 852–858, doi:10.3762/bjoc.20.77

• , direct evidences such as single-crystal X-ray diffraction results were not reported in their study. The reassignment of the stereochemistry at C3 has resulted in the revision of the proposed cyclization mechanism [12][13][14]. The revised mechanism resembled the cyclization process for the formation of

• obtaining a suitable crystal of the hydrazone derivative of 9-oxospiroviolane, which was synthesized by hydroboration/oxidation of spiroviolene followed by converting the resultant hydroxy group to a keto group, for single-crystal X-ray diffraction. The similar skeleton and conserved stereochemistry of

• process. Derivatization of spiroviolene for X-ray crystallography. A) Hydroboration/oxidation reaction of spiroviolene involving a borane migration process. B) Synthesis of the hydrazone derivative of spiroviolene for single-crystal X-ray diffraction. Supporting Information Supporting Information File 19

Production of non-natural 5-methylorsellinate-derived meroterpenoids in Aspergillus oryzae

• Jia Tang,
• Yixiang Zhang and
• Yudai Matsuda

Beilstein J. Org. Chem. 2024, 20, 638–644, doi:10.3762/bjoc.20.56

• . Finally, the A. oryzae strain expressing insA7 produced two major metabolites 7 and 8. Compound 7 was determined to be the C-5′ desmethyl form of insuetusin A1 [19] using NMR and single-crystal X-ray diffraction analyses (Figure 2C and Figure S1 in Supporting Information File 1; CCDC: 2300695) and was

A laterally-fused N-heterocyclic carbene framework from polysubstituted aminoimidazo[5,1-b]oxazol-6-ium salts

• Andrew D. Gillie,
• Matthew G. Wakeling,
• Bethan L. Greene,
• Louise Male and
• Paul W. Davies

Beilstein J. Org. Chem. 2024, 20, 621–627, doi:10.3762/bjoc.20.54

• the C(oxazole)–N(sulfonamide) bond. No coalescence is observed at up to 110 °C indicating that these motifs might be useful as a robust atropisomeric system. The molecular structure of 13 and 14 have been unambiguously determined by single crystal X-ray diffraction (Scheme 2) [28]. The N–metal

• complexes from 6a. The single crystal X-ray diffraction structures of 13 and 14 have ellipsoids drawn at 50% probability, with hydrogens and solvent omitted for clarity. Selected bond angles and distances: 13: C1–Au: 1.98 Å, Au–Cl: 2.28 Å, N2–Au: 3.65 Å. N1–C1–N3: 102.7°, N3–C1–Au: 129.5°, N1–C1–Au: 127.1

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

• data for compound 3 was conducted (Table 1) and its absolute configurations were assigned as 1R, 2S, 6R, 7R, 8S by single-crystal X-ray diffraction analysis with a Flack parameter of 0.024(6) (Figure 4). A plausible biosynthetic pathway for compounds 1–5 is proposed as shown in Scheme 1. In this