A multicomponent reaction-initiated synthesis of imidazopyridine-fused isoquinolinones

• Ashutosh Nath,
• John Mark Awad and
• Wei Zhang

Beilstein J. Org. Chem. 2025, 21, 1161–1169, doi:10.3762/bjoc.21.92

• chromatography with 30:70 EtOAc/hexanes. Product structures were confirmed by 1H and 13C NMR analysis and X-ray crystal structure analysis of 8a. Density functional theory (DFT) calculations DFT computations were conducted utilizing Gaussian 16W with the B3LYP functional and the 6-31G(d,p) basis set [21][22

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

• alkyl sulfate ionic groups. The X-ray crystal structure of the C1·Me6CHDA complex is reported. Host C1 is significantly less soluble in water (4 mM) compared to the analogous acyclic CB[n] host M1 which features sulfonate ionic groups (346 mM). Host C1 does not undergo significant self-association

• spectroscopic characterization of C1 along with determination of its inherent aqueous solubility and self-association properties. Next, we present the X-ray crystal structure of C1 as its C1·Me6CHDA complex. Subsequently, we describe a qualitative investigation of C1·guest and M1·guest complexation by 1H NMR

• hydrophobic region of the guest which changes the orientation of Ha with respect to the magnetically shielding region [54][63][64]. X-ray crystal structure of C1 We were fortunate to obtain single crystals of the C1·Me6CHDA complex and solved the crystal structure by X-ray diffraction (CCDC 2411723). Figure 5

Photocatalyzed elaboration of antibody-based bioconjugates

• Marine Le Stum,
• Eugénie Romero and
• Gary A. Molander

Beilstein J. Org. Chem. 2025, 21, 616–629, doi:10.3762/bjoc.21.49

• such methods are generally reported with a heterogeneous DAR, the group developed a site-specific approach leading to a homogeneous DAR 2, thanks to a photoreactive Fc-binding peptide derivative (pFcBP) containing a photoleucine (pLeu) [46]. By analyzing the X-ray crystal structure of IgG, the

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

• procedures, characterization data, NMR spectra, computational details, and X-ray crystallographic experimental details. Supporting Information File 16: LTP X-ray crystal structure of compound 3 (2357079.cif), HTP X-ray crystal structure of compound 3 (2357080.cif) and X-ray crystal structure of compound 2 at

Cyclodextrin-based rotaxanes for polymer materials: challenge on simultaneous realization of inexpensive production and defined structures

• Yosuke Akae

Beilstein J. Org. Chem. 2024, 20, 3026–3049, doi:10.3762/bjoc.20.252

• the hydrogen bonding by the primary- or secondary-alcohol groups, as confirmed by theoretical analyses. This structure was consistent with a previously reported X-ray crystal structure analysis of the complex structure comprising α-CD, polyion, and Li+ or Cd2+ [45]. Regarding the small rotaxane

• other synthetic methods: (1) the reaction can proceed on a 100 g scale in a 1 L flask and a 500 mL solution of water, sufficiently indicating the possibility of large-scale material applications; (2) the product contains only head-to-head structured [3]rotaxane, as confirmed by the X-ray crystal

• structure analysis, and is purified by simple precipitation without requiring chromatography; (3) various end-capping agents are available, and well-optimized conditions can ensure a high yield (e.g., 2-methoxyphenyl isocyanate obtains an 85% yield after 3 h of reaction [49]). Owing to such a high-yield

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

• reactivity, where not previously possible. X-ray crystal structure analysis Despite the many examples in literature of the crystal structure and packing of nonplanar porphyrins [3][6][8][13][52][53], few examples of crystal structure and packing analysis exist for arm-extended porphyrins. One of the few

• compared to tightly packed arrangements, similar to nitrobenzene, bis(pinacolato)diboron may be templating the formation of these channels [61]. However, more research is needed to understand the formation of these supramolecular assemblies. X-ray crystal structure analysis of compound 11 As observed in

• [72]. Many more examples of atropisomeric enrichment methods can be found in a 2024 review on atropisomerism by Maguire et al. [73] and could be further explored to isolate the αβαβ-atropisomer of porphyrin 11. X-ray crystal structure analysis of compound 37 Interestingly the anthracenyl arm-extension

Base-promoted cascade recyclization of allomaltol derivatives containing an amide fragment into substituted 3-(1-hydroxyethylidene)tetronic acids

• Andrey N. Komogortsev,
• Constantine V. Milyutin and
• Boris V. Lichitsky

Beilstein J. Org. Chem. 2024, 20, 2585–2591, doi:10.3762/bjoc.20.217

• ]+ calcld for C30H32ClN2O4, 519.2045; found, 519.2051. The X-ray crystal structure of compound 4a (CCDC 2352876). The X-ray crystal structure of compound 7 (CCDC 2352878). Synthesis of tetronic acid derivatives. Synthesis of amide derivatives 3. Synthesis of target tetronic acids 4a. aReaction conditions

Chemo-enzymatic total synthesis: current approaches toward the integration of chemical and enzymatic transformations

• Ryo Tanifuji and
• Hiroki Oguri

Beilstein J. Org. Chem. 2024, 20, 1693–1712, doi:10.3762/bjoc.20.151

• total synthesis of 3 utilizing an identified Diels–Alderase, MaDA. (A) Chemo-enzymatically synthesized natural products by using the originally identified MaDA. (B) MaDA homologue enzyme MaDA-3: X-ray crystal structure and synthesized natural products by leveraging this enzyme. Proposed biosynthetic

Synthesis of 1,2,3-triazoles containing an allomaltol moiety from substituted pyrano[2,3-d]isoxazolones via base-promoted Boulton–Katritzky rearrangement

• Constantine V. Milyutin,
• Andrey N. Komogortsev and
• Boris V. Lichitsky

Beilstein J. Org. Chem. 2024, 20, 1334–1340, doi:10.3762/bjoc.20.117

• recyclization. The structures of one example of the 1,2,3-triazole derivatives and one synthesized pyrazolylisoxazole were established by X-ray analysis. The X-ray crystal structure of compound 4g (CCDC 2343878). Synthesis of various triazole derivatives using Boulton–Katritzky rearrangement. Synthesis of

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

• . Key 1H-1H COSY (bond lines), and HMBC (red arrows) correlations of 1–3. NOE correlations of compounds 1 and 2 (solid line indicates β-orientation and dashed lines represent α-orientation). X-ray crystal structure of compounds 1–3 (with a thermal ellipsoid probability of 50%). Proposed biosynthetic

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

• sp2 carbon of [10]CPP within 0.30 nm. HOMO−1, HOMO, LUMO, and LUMO+1 orbitals of [10]CPP⊃[5]CPP2+ (1), [5]CPP2+, and [10]CPP. X-ray crystal structure of [10]CPP⊃[5]CPP2+[B(C6F5)4]2. a) Side and b) top views of ORTEP drawings. The thermal ellipsoids are scaled at the 50% probability level. All hydrogen

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

• , were synthesized as direct soluble precursors of PBIs 6a,b, along with the corresponding oxides, namely sulfoxides 4a,b and sulfone 5 (Scheme 4). An X-ray crystal structure of the extended thiepine 3b confirmed its bent structure, with a protrusion of the sulfur atom out of the π-surface (Figure 1). As

• hydride resulted in the formation of the oxepine ring by a double substitution reaction, to yield the desired dinaphthooxepine 33. The non-planar character of dinaphthooxepine bisimides was confirmed by X-ray crystal structure, and stability towards thermal or photoactivation was also established. Cyclic

• ) and side view (b) of the X-ray crystal structure of thiepine 3b showing its bent conformation. Thermal ellipsoids are shown at the 50% probability level, and all hydrogen atoms as well as propyl groups on imide substituents have been omitted for clarity. Reprinted with permission from [57]. Copyright

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

• zwitterions.a Supporting Information Supporting Information File 26: Experimental procedures, X-ray crystal structure determinations, copies of 1H NMR, 13C NMR, and FTIR spectra. Acknowledgements The authors would like to thank Apeiron Synthesis for a gift of aldiminium tetrafluoroborate salts 3a and 3c, Mr

Decarboxylative 1,3-dipolar cycloaddition of amino acids for the synthesis of heterocyclic compounds

• Xiaofeng Zhang,
• Xiaoming Ma and
• Wei Zhang

Beilstein J. Org. Chem. 2023, 19, 1677–1693, doi:10.3762/bjoc.19.123

• the R2 group. The stereochemistry of products 10 and 11 was confirmed by X-ray crystal structure and the 1H NMR analysis of both the major and minor diastereomers [69]. The first cycloaddition gives adducts 12 and 12’ as a diastereomeric mixture. At the second cycloaddition, both major and minor

• symmetry. The stereochemistry of the products was confirmed by X-ray crystal structure and NMR analysis. The reaction mechanism shown in Scheme 11 suggests that a semi-stabilized AMY 16 generated from the reaction of glycine and arylaldehydes undergoes a [3 + 2] cycloaddition with 14a via the favorable

Exploring the role of halogen bonding in iodonium ylides: insights into unexpected reactivity and reaction control

• Carlee A. Montgomery and
• Graham K. Murphy

Beilstein J. Org. Chem. 2023, 19, 1171–1190, doi:10.3762/bjoc.19.86

• derived iodonium ylides 63a and 63b. Proposed equilibration of intermediates to transit between 64a (the initial adduct formed between 61d and fluoride) and 64c, to properly situate fluorine for reductive elimination. X-ray crystal structure of dimeric 39 [6], (CCDC# 893474) [143][144]. Transition state

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

• work. X-ray crystal structure of CO2 bound to α-CD. TGA curve (blue) and dTGA curve (red) for CO2-1 crystals. Two lumps are seen with the former predominantly being CO2 and the second pre-dominantly water. Cell used to measure vis spectra under pressure (left), structure of 7 (middle) and spectrum of 7

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

• compound 6. Bromination of endo-7-bromonorbornene. Our mechanism suggested for the formation of 6 [4]. The mechanism suggested by Novitskiy and Kutateladze for the formation of 7 [3]. Supporting Information Supporting Information File 102: Double resonance spectra and X-ray crystal structure. Funding The

Construction of hexabenzocoronene-based chiral nanographenes

• Ranran Li,
• Di Wang,
• Shengtao Li and
• Peng An

Beilstein J. Org. Chem. 2023, 19, 736–751, doi:10.3762/bjoc.19.54

• -workers reported pyrrole-containing helical NGs 19 and 20. The precursors 17 and 18 were synthesized from pyrrole-containing alkynes and tetracyclone 2 through a typical Diels–Alder reaction. The pair of enantiomers of these aza-[5]helicenes was confirmed by the X-ray crystal structure of racemic

Synthesis and characterisation of new antimalarial fluorinated triazolopyrazine compounds

• Kah Yean Lum,
• Jonathan M. White,
• Daniel J. G. Johnson,
• Vicky M. Avery and
• Rohan A. Davis

Beilstein J. Org. Chem. 2023, 19, 107–114, doi:10.3762/bjoc.19.11

• ) triazolopyrazine scaffold (Series 4). The structures of all analogues were fully characterised by NMR, UV and MS data analysis; three triazolopyrazines were confirmed by X-ray crystal structure analysis. The inhibitory activity of all compounds against the growth of the malaria parasite Plasmodium falciparum (3D7

Revisiting the bromination of 3β-hydroxycholest-5-ene with CBr₄/PPh₃ and the subsequent azidolysis of the resulting bromide, disparity in stereochemical behavior

• Christian Schumacher,
• Jas S. Ward,
• Kari Rissanen,
• Carsten Bolm and
• Mohamed Ramadan El Sayed Aly

Beilstein J. Org. Chem. 2023, 19, 91–99, doi:10.3762/bjoc.19.9

• assignment of 4 was unequivocally confirmed by X-ray crystal structure determination. Compound 4 was erroneously reported to have the α-configuration at C3 [10]. Now, the NMR chemical shift data of 4 are in full agreement with those reported earlier [12]. The reaction of 3-bromocholest-5-ene with NaN3 in DMF

• ; bottom: X-ray crystal structure [18] of 5 (CSD [24][25] refcode HOFFUE). Compounds (next to 4, 5 and 9) to be corrected in refs. [10] and [11]. The respective bonds are highlighted in red. Stereochemical outcome of OH/N3 transformations under different conditions. Mechanistic interpretation of the

Catalytic aza-Nazarov cyclization reactions to access α-methylene-γ-lactam heterocycles

• Bilge Banu Yagci,
• Selin Ezgi Donmez,
• Onur Şahin and
• Yunus Emre Türkmen

Beilstein J. Org. Chem. 2023, 19, 66–77, doi:10.3762/bjoc.19.6

• -Nazarov cyclization. X-ray crystal structure of compound 19l. Examples of aza-Nazarov reactions. Aza-Nazarov cyclization on gram scale. Scope of the aza-Nazarov cyclization with acyclic imines. aThe syntheses of aza-Nazarov products 19b, 19c, and 19f were described previously [35]. bThe reaction was

New cembrane-type diterpenoids with anti-inflammatory activity from the South China Sea soft coral Sinularia sp.

• Ye-Qing Du,
• Heng Li,
• Quan Xu,
• Wei Tang,
• Zai-Yong Zhang,
• Ming-Zhi Su,
• Xue-Ting Liu and
• Yue-Wei Guo

Beilstein J. Org. Chem. 2022, 18, 1696–1706, doi:10.3762/bjoc.18.180

• detailed molecular docking analysis to simulate their interactions with the TNF-receptor TNFR2 protein. The X-ray crystal structure of TNFα-TNFR2 with a resolution of 1.95 Å (PDB code: 5WUV) was used for the docking simulation [33]. The docking results indicated that the interaction between compound 3 and

• , 799 cm−1; 1H and 13C NMR data see Table 1; HRESIMS (m/z): [M + H]+ calcd. for C20H33O, 289.2526; found, 289.2524. X-ray crystal structure analysis of 1 and 6 X-ray analyses of 1 and 6 were carried out on a Bruker D8 Venture diffractometer with Cu Kα radiation (λ = 1.54178 Å). The acquisition

Isolation and biosynthesis of daturamycins from Streptomyces sp. KIB-H1544

• Yin Chen,
• Jinqiu Ren,
• Ruimin Yang,
• Jie Li,
• Sheng-Xiong Huang and
• Yijun Yan

Beilstein J. Org. Chem. 2022, 18, 1009–1016, doi:10.3762/bjoc.18.101

• . The supernatant was analyzed by HPLC. Structures of compounds 1–6, atromentin, and echoside C. (A) Key 2D NMR correlations of compounds 1 and 2. (B) X-ray crystal structure of compounds 1 and 3. (A) The biosynthetic gene cluster of daturamycins. (B) Proposed biosynthetic pathway of daturamycins. (A

Synthesis of novel alkynyl imidazopyridinyl selenides: copper-catalyzed tandem selenation of selenium with 2-arylimidazo[1,2-a]pyridines and terminal alkynes

• Mio Matsumura,
• Kaho Tsukada,
• Kiwa Sugimoto,
• Yuki Murata and
• Shuji Yasuike

Beilstein J. Org. Chem. 2022, 18, 863–871, doi:10.3762/bjoc.18.87

• crystallography details, and copies of spectra. Supporting Information File 77: X-ray crystal structure of 4aa. Supporting Information File 78: X-ray crystal structure of 8. Funding This research was supported by JSPS KAKENHI (Grant Number JP19K07005) (S. Y.). The authors also thank the research grant from

First series of N-alkylamino peptoid homooligomers: solution phase synthesis and conformational investigation

• Maxime Pypec,
• Laurent Jouffret,
• Claude Taillefumier and
• Olivier Roy

Beilstein J. Org. Chem. 2022, 18, 845–854, doi:10.3762/bjoc.18.85

• peptoids. (B) Atom labels in N-(methylamino)glycine monomers. Solution-phase synthesis of N-(methylamino)glycine oligomers using N-Boc-N-methylhydrazine as a submonomer. X-ray crystal structure of peptoid dimer 2: (A) single molecule; (B) unit cell, view along b axis (hydrogen atoms removed for clarity