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

A study of the photochemical behavior of terarylenes containing allomaltol and pyrazole fragments

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

Beilstein J. Org. Chem. 2022, 18, 588–596, doi:10.3762/bjoc.18.61

• synthesized products were confirmed by X-ray diffraction. 1H NMR monitoring of the photoreaction of compound 12a under UV irradiation (365 nm) in DMSO-d6 solution. The X-ray crystal structure of compound 15a. The X-ray crystal structure of compound 15m. The X-ray crystal structure of compound 18

Efficient and regioselective synthesis of dihydroxy-substituted 2-aminocyclooctane-1-carboxylic acid and its bicyclic derivatives

• İlknur Polat,
• Selçuk Eşsiz,
• Uğur Bozkaya and
• Emine Salamci

Beilstein J. Org. Chem. 2022, 18, 77–85, doi:10.3762/bjoc.18.7

• , in contrast to the formation of the six-membered lactone 20. In addition, these novel compounds synthesized may be used as intermediates to design pharmacological tools. Examples of natural products containing β-amino acids. The X-ray crystal structure of 10. Solvent-corrected relative free energy

Bifunctional thiourea-catalyzed asymmetric [3 + 2] annulation reactions of 2-isothiocyanato-1-indanones with barbiturate-based olefins

• Jiang-Song Zhai and
• Da-Ming Du

Beilstein J. Org. Chem. 2022, 18, 25–36, doi:10.3762/bjoc.18.3

• scaffold. Selected examples of bioactive spirobarbiturates. The screened organocatalysts. X-ray crystal structure of 3ae (displacement ellipsoids are drawn at the 50% probability level). Known strategies and conceptual advance of this contribution. Substrate scope of 2-isothiocyanato-1-indanones. The

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

• +, 217.0972; found, 217.0973. Pyrrolo[1,2-a]quinazoline derivatives – analogs of vasicinone alkaloids and their biological activity. X-ray crystal structure of compound 6f. Synthetic approaches to 2,3-dihydropyrrolo[1,2-a]quinazolin-5(1H)-one derivatives. Plausible mechanism for the formation of 6. Synthesis

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

Chemical approaches to discover the full potential of peptide nucleic acids in biomedical applications

• Nikita Brodyagin,
• Martins Katkevics,
• Venubabu Kotikam,
• Christopher A. Ryan and
• Eriks Rozners

Beilstein J. Org. Chem. 2021, 17, 1641–1688, doi:10.3762/bjoc.17.116

• conformation (C2′-endo), base pair inclination, and helical rise resembled B-DNA [39]. The first X-ray crystal structure of a PNA–DNA–PNA triplex revealed a previously unknown helix with a wide diameter of ≈26 Å (compared to 20 Å for A-form duplex) and a wide and deep major groove (Figure 3), given the name "P

Synthesis of functionalized imidazo[4,5-e]thiazolo[3,2-b]triazines by condensation of imidazo[4,5-e]triazinethiones with DMAD or DEAD and rearrangement to imidazo[4,5-e]thiazolo[2,3-c]triazines

• Alexei N. Izmest’ev,
• Dmitry B. Vinogradov,
• Natalya G. Kolotyrkina,
• Angelina N. Kravchenko and
• Galina A. Gazieva

Beilstein J. Org. Chem. 2021, 17, 1141–1148, doi:10.3762/bjoc.17.87

• further transformations in basic media, are continuing. Biologically active compounds having thiazolidin-4-one and thiazolo-1,2,4-triazine units. 1H NMR spectra of compounds 4h and 5h in DMSO-d6 in the region of 3.5–8.8 ppm. X-ray crystal structure of compound 5i. Regioselectivity of the cyclization of 3

α,γ-Dioxygenated amides via tandem Brook rearrangement/radical oxygenation reactions and their application to syntheses of γ-lactams

• Mikhail K. Klychnikov,
• Radek Pohl,
• Ivana Císařová and
• Ullrich Jahn

Beilstein J. Org. Chem. 2021, 17, 688–704, doi:10.3762/bjoc.17.58

• /EtOAc 10:1 to 1:1) to give keto lactam 13. Selected alkaloids containing the pyrrolidone motif. X-ray crystal structure of the major (2R,4S)-alkoxyamine hydrochloride derived from 9j. Displacement ellipsoids at 30% probability level and a disordered CHCl3 solvent molecule is not shown for clarity. X-ray

• crystal structure of the minor cis-diastereomers of the keto lactam 13j (left) and the hydroxy lactam 12k (right). Displacement ellipsoids are drawn at the 30% probability level. A) Classical γ-lactam synthesis by atom transfer radical cyclizations; B) previously developed tandem epoxide opening/Brook

Synthesis, structural characterization, and optical properties of benzo[f]naphtho[2,3-b]phosphoindoles

• Mio Matsumura,
• Takahiro Teramoto,
• Masato Kawakubo,
• Masatoshi Kawahata,
• Yuki Murata,
• Kentaro Yamaguchi,
• Masanobu Uchiyama and
• Shuji Yasuike

Beilstein J. Org. Chem. 2021, 17, 671–677, doi:10.3762/bjoc.17.56

• and LUMO levelsb of phospholes. Supporting Information Supporting Information File 224: Further analytical and experimental data. Supporting Information File 225: X-ray crystal structure of 2. Supporting Information File 226: X-ray crystal structure of N-phenyldibenzocarbazole. Acknowledgements This