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

• , copies of NMR spectra, X-ray crystallographic data and refinement details. Supporting Information File 142: Analytical data of all compounds 4, 7 and 9. Acknowledgements Crystal structure determination was performed in the Department of Structural Studies of Zelinsky Institute of Organic Chemistry

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

• translated to the formation of other macrocycles as long as they share a similar reaction mechanism. (a) Control experiment testing deiodination of 2-iodoresorcinol. (b) Molecular crystal structure of chlorinated resorcin[4]arenes 1h and 1i, and carboxylic acid-containing 1s at 100 K. Thermal ellipsoids are

Synthesis and conformational analysis of pyran inter-halide analogues of ᴅ-talose

• Olivier Lessard,
• Mathilde Grosset-Magagne,
• Paul A. Johnson and
• Denis Giguère

Beilstein J. Org. Chem. 2024, 20, 2442–2454, doi:10.3762/bjoc.20.208

• results showed no qualitative difference. Entries marked – are below the 0.50 kcal/mol threshold. Supporting Information Supporting Information File 118: Experimental and analytical data, crystal structure determination and NMR spectra. Funding This work was supported by the Natural Sciences and

Evaluating the halogen bonding strength of a iodoloisoxazolium(III) salt

• Dominik L. Reinhard,
• Anna Schmidt,
• Marc Sons,
• Julian Wolf,
• Elric Engelage and
• Stefan M. Huber

Beilstein J. Org. Chem. 2024, 20, 2401–2407, doi:10.3762/bjoc.20.204

• ) Å, 84% of Σr, and C1–I1···Br1 = 176.08(9)°]. The bond distances indicate that the hydrogen bond is noticeably weaker than the two XBs and thus constitutes merely an assisting interaction. The XB interactions in this crystal structure were compared to the ones in the literature-known co-crystal of

• prototypic iodolium 1BArF with bromide (CCDC: 1145291) [5]. For the latter, such a dimeric binding motif was also found, with I–Br bond lengths of 3.1936(9) Å [83% of Σr] and 3.2299(9) Å [84% of Σr]. It can be concluded that stronger halogen bonding can be found in the crystal structure of iodoloisoxazolium

• 3Cl which resulted from crystallization of the respective cation with the abstracted chloride from the Ritter-type solvolysis of benzhydryl chloride [13]. The crystal structure of 5Br was also obtained directly from the halide-abstraction reaction (see Supporting Information File 1). These three facts

Synthesis, electrochemical properties, and antioxidant activity of sterically hindered catechols with 1,3,4-oxadiazole, 1,2,4-triazole, thiazole or pyridine fragments

• Daria A. Burmistrova,
• Andrey Galustyan,
• Nadezhda P. Pomortseva,
• Kristina D. Pashaeva,
• Maxim V. Arsenyev,
• Oleg P. Demidov,
• Mikhail A. Kiskin,
• Andrey I. Poddel’sky,
• Nadezhda T. Berberova and
• Ivan V. Smolyaninov

Beilstein J. Org. Chem. 2024, 20, 2378–2391, doi:10.3762/bjoc.20.202

• of neighboring molecules [57][58][59][60][61]. The intra- and intermolecular interactions in crystals 5, 6·0.5CH3CN, and 8 lead to different complex structural motifs in crystals of these compounds. Two intramolecular hydrogen bonds (Figure 1) are observed in the crystal structure of 5: between OH

Tandem diazotization/cyclization approach for the synthesis of a fused 1,2,3-triazinone-furazan/furoxan heterocyclic system

• Yuri A. Sidunets,
• Valeriya G. Melekhina and
• Leonid L. Fershtat

Beilstein J. Org. Chem. 2024, 20, 2342–2348, doi:10.3762/bjoc.20.200

• . Supporting Information Supporting Information File 96: Experimental procedures, characterization data of all products, copies of 1H, 13C NMR, 15N spectra of new compounds, DSC curves,X-ray crystallographic data and copies of IR spectra. Acknowledgements The crystal structure determination was performed at

Multicomponent syntheses of pyrazoles via (3 + 2)-cyclocondensation and (3 + 2)-cycloaddition key steps

• Ignaz Betcke,
• Alissa C. Götzinger,
• Maryna M. Kornet and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2024, 20, 2024–2077, doi:10.3762/bjoc.20.178

• -phenyl-3,5-substituted pyrazoles 148 (Scheme 51) [156]. Efforts to synthesize bridged pyrazoles using fumaryl chloride proved unsuccessful, with only 3,5-substituted pyrazoles isolated. Nonetheless, the crystal structure of such a pyrazole was investigated [157]. In their study, Alizadeh et al. showed

The Groebke–Blackburn–Bienaymé reaction in its maturity: innovation and improvements since its 21st birthday (2019–2023)

• Cristina Martini,
• Muhammad Idham Darussalam Mardjan and
• Andrea Basso

Beilstein J. Org. Chem. 2024, 20, 1839–1879, doi:10.3762/bjoc.20.162

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

• intermolecular Diels–Alder reactions with 34 or other dienophiles, leading to a diverse array of bisorbicillinoids. Based on the crystal structure of TropB, a homologous enzyme of SorbC, Narayan and co-workers have intensively elucidated that the detailed mechanisms of the oxidative dearomatization catalyzed by

• 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

Oxidation of benzylic alcohols to carbonyls using N-heterocyclic stabilized λ³-iodanes

• Thomas J. Kuczmera,
• Pim Puylaert and
• Boris J. Nachtsheim

Beilstein J. Org. Chem. 2024, 20, 1677–1683, doi:10.3762/bjoc.20.149

• ]. A crystal structure was additionally obtained for tetrazine 1c. Bond lengths and angles were similar to those of known five-membered NHIs [25], including a strong intramolecular interaction between the nitrogen of the tetrazine and the hypervalent iodine atom (I1–N1: 2.44(4) Å; the sum of VdW radii

• on silica. Overview of common non-iodine-based (left) and iodine-based (right) oxidizing reagents for the generation of carbonyls from the corresponding alcohols. NHIs investigated for the oxidation of benzylic alcohols and the crystal structure (ORTEP drawing) of 1c (CCDC 2321313), showing the

Methyltransferases from RiPP pathways: shaping the landscape of natural product chemistry

• Maria-Paula Schröder,
• Isabel P.-M. Pfeiffer and
• Silja Mordhorst

Beilstein J. Org. Chem. 2024, 20, 1652–1670, doi:10.3762/bjoc.20.147

• cyclised core peptide to exert its effects on the precursor peptide. Furthermore, SAM was shown to be an obligate co-substrate for OlvSA [71]. Crystallographic data of OlvSA is not yet available. The predicted three-dimensional structure displays substantial differences from the crystal structure of LahSB

• cobalamin and the [4Fe-4S] cluster (Figure 10). The structural variation among C-MTs becomes apparent when comparing the crystal structure of TsrM with the predicted structures of PoyB and PoyC. Class C rSAM MTs are enzymes with a HemN-like didomain structure, consisting of an rSAM core domain and a C

Polymer degrading marine Microbulbifer bacteria: an un(der)utilized source of chemical and biocatalytic novelty

• Weimao Zhong and
• Vinayak Agarwal

Beilstein J. Org. Chem. 2024, 20, 1635–1651, doi:10.3762/bjoc.20.146

• and cloned from deep-sea-derived Microbulbifer sp. JAMB-A94 with pH and temperature optima being 7.0 and 55 °C, respectively [26]. The recombinant enzyme was likewise produced using a B. subtilis host. The crystal structure of the catalytic domain was determined to show a β-jelly roll fold with

• structural similarity to two other β-agarases, ZgAgaA and ZgAgaB, from Zobellia galactanivorans, which is a model marine bacterium for the bioconversion of algal biomass [29][107][108][109]. The crystal structure suggested that the thermostability of rAgaA likely derives from the numerous surface salt

Regio- and stereochemical stability induced by anomeric and gauche effects in difluorinated pyrrolidines

• Ana Flávia Candida Silva,
• Francisco A. Martins and
• Matheus P. Freitas

Beilstein J. Org. Chem. 2024, 20, 1572–1579, doi:10.3762/bjoc.20.140

• (nN→σ*CF anomeric and σCH→σ*CF fluorine gauche effects) on the conformation of different stereoisomers is explored. MAE comparing the geometry parameters (bond length, bond angle, and dihedral angle) obtained from DFT calculations at the CCSD/DGTZVP level. The MAE for the crystal structure compared to

Photoswitchable glycoligands targeting Pseudomonas aeruginosa LecA

• Yu Fan,
• Ahmed El Rhaz,
• Stéphane Maisonneuve,
• Emilie Gillon,
• Maha Fatthalla,
• Franck Le Bideau,
• Guillaume Laurent,
• Samir Messaoudi,
• Anne Imberty and
• Juan Xie

Beilstein J. Org. Chem. 2024, 20, 1486–1496, doi:10.3762/bjoc.20.132

• the known crystal structure. The extended E-isomer establishes contact through galactoside and the first aryl ring only, while the bent Z-isomer has proper conformation to wrap around the central His53 residue and to establish a more extended interaction with the protein surface. This would be in

Bioinformatic prediction of the stereoselectivity of modular polyketide synthase: an update of the sequence motifs in ketoreductase domain

• Changjun Xiang,
• Shunyu Yao,
• Ruoyu Wang and
• Lihan Zhang

Beilstein J. Org. Chem. 2024, 20, 1476–1485, doi:10.3762/bjoc.20.131

• KRC, the N-terminal helix αB and the lid region αFG located at the C-terminal of KRC (Figure 2d). Indeed, this lid region exhibits a direct interaction with the DH and DH-KR linker (Figure 2c). However, such interaction was not observed between the N-terminal helix αB and DH in the crystal structure

• rings. The triangles indicate a product having α-substituents. (c) Crystal structure of DH-ER-KR tridomain (PDB ID 8G7W) [24]. DH, KRS, ER, KRC are colored in cyan, pink, yellow, and purple, respectively. The lid of KR catalytic pocket is colored in red. The co-crystallized cofactor is represented as

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

• that all tricyclic compounds have this kind of relative configuration on the basis of NMR spectra and single crystal structure. In order to develop the scope of the reaction, another kind of 5,6-unsubstituted 1,4-dihydropyridines 5 were also employed in the reaction, which were previously prepared from

A comparison of structure, bonding and non-covalent interactions of aryl halide and diarylhalonium halogen-bond donors

• Nicole Javaly,
• Theresa M. McCormick and
• David R. Stuart

Beilstein J. Org. Chem. 2024, 20, 1428–1435, doi:10.3762/bjoc.20.125

• (THF) incorporating Huber, Truhlar, and Cramer’s correction for bromine and iodine [32] using Gaussian 09 [33]. Our prior work on the orbital analysis of diarylhalonium salts [21], showed good agreement between crystal structure data and energy-minimized structures at the B3LYP/cc-pvtz level with def2

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

• File 96: Experimental procedures, characterization data of all products, copies of 1H, 13C NMR, spectra of all new compounds, and X-ray crystallographic data. Acknowledgements The crystal structure determination was performed in the Department of Structural Studies of Zelinsky Institute of Organic

Synthesis of indano[60]fullerene thioketone and its application in organic solar cells

• Yong-Chang Zhai,
• Shimon Oiwa,
• Shinobu Aoyagi,
• Shohei Ohno,
• Tsubasa Mikie,
• Jun-Zhuo Wang,
• Hirofumi Amada,
• Koki Yamanaka,
• Kazuhira Miwa,
• Naoyuki Imai,
• Takeshi Igarashi,
• Itaru Osaka and
• Yutaka Matsuo

Beilstein J. Org. Chem. 2024, 20, 1270–1277, doi:10.3762/bjoc.20.109

• time. A single crystal of t-Bu-FIDS was grown by liquid–liquid diffusion method (CS2/EtOH). The crystal structure was successfully analyzed using synchrotron radiation at SPring-8. The crystal exhibited the orthorhombic space group (No. 61) with the D2h point group, and the structure confirmed the 1,2

• -Bu-FIDS (black) and of toluene used to rinse the evaporated film of t-Bu-FIDS (red). Single-crystal structure of t-Bu-FIDS. (a) The π–π distance between two molecules. (b) Crystal packing. Cyclic voltammograms of fullerene derivatives in o-DCB solution containing Bu4N+(CF3SO2)2N− (0.1 M) as

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

• . It crystallized in a triclinic crystal system in the space group P−1. It was structurally similar to the other oxamides 3 and 9. It showed an intramolecular hydrogen bonding between the NH and the carbonyl group of the methoxy ester. A layer-by-layer packing was observed in the crystal structure

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

• ][40][41][42], except for rare examples such as 3-(hydroxydimesitylsilyl)-1,1-dimesityl-2,2-bis(trimethylsilyl)-1-silirane [43]. In contrast, we earlier reported the crystal structure of the adduct of Lu3N@Ih–C80 with silylene Dep2Si (Dep = 2,6-diethylphenyl), which was revealed to be a sila-fulleroid

Enhancing structural diversity of terpenoids by multisubstrate terpene synthases

• Min Li and
• Hui Tao

Beilstein J. Org. Chem. 2024, 20, 959–972, doi:10.3762/bjoc.20.86

• distinct primary structures with class I TSs, its crystal structure reveals a similar overall structure of BalTS to the α-domain of class I TSs and therefore was proposed as class IB, a new subclass of TSs [37]. The discovery of TSs from bacteria not only expands the diversity of terpene skeletons but also

Synthesis and properties of 6-alkynyl-5-aryluracils

• Ruben Manuel Figueira de Abreu,
• Till Brockmann,
• Alexander Villinger,
• Peter Ehlers and
• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 898–911, doi:10.3762/bjoc.20.80

• were obtained by slow evaporation of the solvent from a mixture of the compound in dichloromethane and heptane at room temperature (Figure 3). Crystal structure analysis revealed that 5a crystallizes in a base-centered monoclinic system with the P21/c space group. The structure is mostly planar, except

• ). Samples were ionized by electron impact ionization (EI) on an Agilent 6890/5973 or Agilent 7890/5977 GC–MS equipped with a HP-5 capillary column using helium carrier gas or by electron spray ionization (ESI) on an Agilent 1200/6210 time-of-flight (TOF) LC–MS. X-ray single-crystal structure analysis was

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

• suitable for X-ray diffraction [35]. The crystal structure of 13 clearly showed that the 19- and 20-methyl groups are cis-oriented in the D-ring which is consistent with that of spirograterpene A. This structural data reaffirms the revised structure of spiroviolene, and further support the unified

Skeletal rearrangement of 6,8-dioxabicyclo[3.2.1]octan-4-ols promoted by thionyl chloride or Appel conditions

• Martyn Jevric,
• Julian Klepp,
• Johannes Puschnig,
• Oscar Lamb,
• Christopher J. Sumby and
• Ben W. Greatrex

Beilstein J. Org. Chem. 2024, 20, 823–829, doi:10.3762/bjoc.20.74

• chlorosulfite 25 or the alkoxytriphenylphosphonium chloride 26, respectively. With heating, SO2 or triphenylphosphine oxide is extruded with a concerted migration of the neighbouring O8 leading to an oxocarbenium ion 27, which is then trapped with chloride giving the observed products. The crystal structure for