Iridium-catalyzed hydroacylation reactions of C1-substituted oxabenzonorbornadienes with salicylaldehyde: an experimental and computational study

• Angel Ho,
• Austin Pounder,
• Krish Valluru,
• Leanne D. Chen and
• William Tam

Beilstein J. Org. Chem. 2022, 18, 251–261, doi:10.3762/bjoc.18.30

• optimizations of all the intermediates and transition states were carried out with the Minnesota functional M06 [69] with the double-ζ basis set def2SVP [70] and Grimme’s dispersion (GD3) [71]. Harmonic vibrational frequencies were computed to verify the nature of the stationary points. The normal modes of all

The enzyme mechanism of patchoulol synthase

• Houchao Xu,
• Bernd Goldfuss,
• Gregor Schnakenburg and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2022, 18, 13–24, doi:10.3762/bjoc.18.2

• no. 1491695) [17], but these data did not allow to conclude on the absolute configuration of compound 3. We now obtained 3 as a crystalline material and performed an X-ray structural analysis through anomalous dispersion using Cu Kα irradiation (Table S2 in Supporting Information File 1), resulting

N-Sulfinylpyrrolidine-containing ureas and thioureas as bifunctional organocatalysts

• Viera Poláčková,
• Dominika Krištofíková,
• Boglárka Némethová,
• Renata Górová,
• Mária Mečiarová and
• Radovan Šebesta

Beilstein J. Org. Chem. 2021, 17, 2629–2641, doi:10.3762/bjoc.17.176

• -range London dispersion interactions. Geometrical optimizations were performed with the Karlsruhe split-valence def2-SV(P) basis set [41]. Energies were refined using the Minnesota M06-2X functional [42] and valence triple-zeta def2-TZVP basis set [43]. The lowest energy conformers of both catalyst (S,R

Exfoliated black phosphorous-mediated CuAAC chemistry for organic and macromolecular synthesis under white LED and near-IR irradiation

• Azra Kocaarslan,
• Zafer Eroglu,
• Önder Metin and
• Yusuf Yagci

Beilstein J. Org. Chem. 2021, 17, 2477–2487, doi:10.3762/bjoc.17.164

• of BP was dispersed thoroughly in DMSO by a sonication bath (200 W) for 10 h at 6 °C. The resulting BP nanosheets dispersion was kept under an inert atmosphere for the further use. Preparation of azide and alkyne derivatives Synthesis of benzyl azide (Az-1) A literature procedure was used [44

Progress and challenges in the synthesis of sequence controlled polysaccharides

• Giulio Fittolani,
• Theodore Tyrikos-Ergas,
• Denisa Vargová,
• Manishkumar A. Chaube and
• Martina Delbianco

Beilstein J. Org. Chem. 2021, 17, 1981–2025, doi:10.3762/bjoc.17.129

• enzymatic synthesis of cellulose was reported by Kobayashi in 1991 [61]. Since then, a plethora of enzymes [62] and substrates [63] were developed, aiming to narrow the dispersion of molecular weight (MW), increase the DP, or control the molecular organization of the resulting material (Scheme 1). Enzymatic

Electron-rich triarylphosphines as nucleophilic catalysts for oxa-Michael reactions

• Susanne M. Fischer,
• Simon Renner,
• A. Daniel Boese and
• Christian Slugovc

Beilstein J. Org. Chem. 2021, 17, 1689–1697, doi:10.3762/bjoc.17.117

• TURBOMOLE program (version 7.4.1) [43]. Geometries were pre-optimized using the PBE [44] functional, the def2-SVPD [45][46] basis set and D3 [47] dispersion correction. All structures were then re-optimized using the hybrid functional B3LYP [48][49][50][51] D3 with the def2-TZVPPD basis set. For gas-phase

Photoinduced post-modification of graphitic carbon nitride-embedded hydrogels: synthesis of 'hydrophobic hydrogels' and pore substructuring

• Cansu Esen and
• Baris Kumru

Beilstein J. Org. Chem. 2021, 17, 1323–1334, doi:10.3762/bjoc.17.92

• yellow powder was ultrasonicated in water to obtain a g-CN aqueous colloidal dispersion. The freshly prepared CM/water colloidal dispersion was mixed with water-soluble monomer (N,N-dimethylacrylamide, DMA) and crosslinker (N,N’-methylenebisacrylamide, MBA) followed by the addition of the redox couple

Heterogeneous photocatalytic cyanomethylarylation of alkenes with acetonitrile: synthesis of diverse nitrogenous heterocyclic compounds

• Guanglong Pan,
• Qian Yang,
• Wentao Wang,
• Yurong Tang and
• Yunfei Cai

Beilstein J. Org. Chem. 2021, 17, 1171–1180, doi:10.3762/bjoc.17.89

• , thus leading to an enhanced optical absorption, improved electron-hole separation and easy dispersion in polar solvents [32]. CN-K, which can be easily prepared by the direct KCl-induced structure remodeling of bulk g-C3N4 [33][34][35][36], showed great potentials for future industrial applications

Synthesis and physicochemical evaluation of fluorinated lipopeptide precursors of ligands for microbubble targeting

• Masayori Hagimori,
• Estefanía E. Mendoza-Ortega and
• Marie Pierre Krafft

Beilstein J. Org. Chem. 2021, 17, 511–518, doi:10.3762/bjoc.17.45

• phospholipid dispersion and subjected to agitation/amalgamation using a Vialmix® device (2 cycles of 45 s, Lantheus Medical Imaging N. Billerica, MA) at room temperature and under F-hexane-saturated N2 at room temperature (for details, see [39]). The resulting foam was immediately diluted with 5 mL of HEPES

• buffer. Size fractionation of the microbubbles was achieved by flotation for 60 min. Reference microbubbles shelled with DPPC/DPPE-PEG2000 were prepared using the same protocol. Two to three droplets of the bubble dispersion were placed into a concave glass slide, covered with a glass slide and observed

Synthesis of trifluoromethyl ketones by nucleophilic trifluoromethylation of esters under a fluoroform/KHMDS/triglyme system

• Yamato Fujihira,
• Yumeng Liang,
• Makoto Ono,
• Kazuki Hirano,
• Takumi Kagawa and
• Norio Shibata

Beilstein J. Org. Chem. 2021, 17, 431–438, doi:10.3762/bjoc.17.39

• HCF3 at −60 °C (Scheme 2d) [44]. However, the preparation of NaDA was rather complicated and required pre-mixing of diisopropylamine, tetramethylethylenediamine (TMEDA), isoprene, and even more tedious “dispersion sodium” in n-heptane at 25 °C for 4 h, before the reaction of esters with HCF3 at −60 °C

¹⁹F NMR as a tool in chemical biology

• Diana Gimenez,
• Aoife Phelan,
• Cormac D. Murphy and
• Steven L. Cobb

Beilstein J. Org. Chem. 2021, 17, 293–318, doi:10.3762/bjoc.17.28

• additional 1D 19F T1, T2, and CPMG relaxation dispersion experiments and solvent-induced isotope shift effects. This study also highlighted the particular advantages of employing 19F NMR fluorine probes strategically labelled in the second ring of the Trp indole moiety to directly measure conformational

• innate flexibility of IDPs imposes tremendous technical challenges to standard NMR analysis, as pronounced conformational averaging gives rise to narrow signal dispersion and low signal-to-noise ratios. Indeed, unless more sophisticated NMR techniques are employed, the combination of these two effects

• Granqvist et al. [101], the 19F NMR signals observed when employing these probes to evaluate the thermal denaturation of a range of RNA hairpins were indeed found to be sensitive enough to allow the monitoring of their secondary structural changes with relatively wide shift dispersion. It also enabled to

Diels–Alder reaction of β-fluoro-β-nitrostyrenes with cyclic dienes

• Savva A. Ponomarev,
• Roman V. Larkovich,
• Alexander S. Aldoshin,
• Andrey A. Tabolin,
• Sema L. Ioffe,
• Jonathan Groß,
• Till Opatz and
• Valentine G. Nenajdenko

Beilstein J. Org. Chem. 2021, 17, 283–292, doi:10.3762/bjoc.17.27

• dispersion effects are not included, whereas M062X includes nonlocal effects of electronic dispersion [70][75]. We also demonstrate the preparation of norbornene structures substituted at the methylene bridge. The reaction of model nitrostyrene 1h with spiro[2.4]hepta-4,6-diene was carried out (Scheme 2). As

Tuning the solid-state emission of liquid crystalline nitro-cyanostilbene by halogen bonding

• Subrata Nath,
• Alexander Kappelt,
• Matthias Spengler,
• Bibhisan Roy,
• Jens Voskuhl and
• Michael Giese

Beilstein J. Org. Chem. 2021, 17, 124–131, doi:10.3762/bjoc.17.13

• temperature, which indicates that the strength of the halogen bond is not the only contributor to the mesomorphic behaviour of the halogen-bonded materials. The change in the electronic anisotropy by unsymmetrical substitution with fluorine as present in F3Az will also have an impact on the dispersion

Direct synthesis of anomeric tetrazolyl iminosugars from sugar-derived lactams

• Michał M. Więcław and
• Bartłomiej Furman

Beilstein J. Org. Chem. 2021, 17, 115–123, doi:10.3762/bjoc.17.12

• calculations were performed on a simplified model to provisionally validate this proposed mechanism. The geometry of the intermediate species were optimized with Gaussian 09 software [44], using the B3LYP/LANL2DZ theory level for Zr and B3LYP/6-31G(d,p) for other atoms, with GD3 empirical dispersion correction

Secondary metabolites of Bacillus subtilis impact the assembly of soil-derived semisynthetic bacterial communities

• Heiko T. Kiesewalter,
• Carlos N. Lozano-Andrade,
• Mikael L. Strube and
• Ákos T. Kovács

Beilstein J. Org. Chem. 2020, 16, 2983–2998, doi:10.3762/bjoc.16.248

• dispersion, likely owing to a low number of reads in two of the replicates. We fitted the most correlating (R2 > 0.6) amplicon sequence variants (ASVs) to the nMDS ordination and plotted them as vectors to investigate the differences between the mock communities. The analysis indicated that three ASVs

Fluorine effect in nucleophilic fluorination at C4 of 1,6-anhydro-2,3-dideoxy-2,3-difluoro-β-D-hexopyranose

• Danny Lainé,
• Vincent Denavit,
• Olivier Lessard,
• Laurie Carrier,
• Charles-Émile Fecteau,
• Paul A. Johnson and
• Denis Giguère

Beilstein J. Org. Chem. 2020, 16, 2880–2887, doi:10.3762/bjoc.16.237

• , DFT calculations were performed with Gaussian 09, revision E.01 [44] to evaluate the hypothesis for the formation of oxiranium ion A. Calculations were performed with the CAM-B3LYP functional [45][46][47] using Grimme’s D3 dispersion correction [48] and the 6-31+G(d,p) basis set. The results of our

Dirhamnolipid ester – formation of reverse wormlike micelles in a binary (primerless) system

• David Liese,
• Hans Henning Wenk,
• Xin Lu,
• Jochen Kleinen and
• Gebhard Haberhauer

Beilstein J. Org. Chem. 2020, 16, 2820–2830, doi:10.3762/bjoc.16.232

• anisotropic at an elevated temperature. Differential scanning calorimetry analysis yielded a transition enthalpy of about ΔHSG/GS = ±7.2 kJ/mol. This value corresponds to a strong dispersion energy and explains the formation of the highly viscous gels by the entanglement of wormlike micelles through the

• Information File 1). Both values are identical and amount to ΔHGS,SG = ±7.2 kJ/mol, which is in the order of strong dispersion energies. This further proves the formation of network-like structures by the entanglement of RWLM due to attractive dispersion interactions between the alkyl chains of neighboring

Particle size effect in the mechanically assisted synthesis of β-cyclodextrin mesitylene sulfonate

• Stéphane Menuel,
• Sébastien Saitzek,
• Eric Monflier and
• Frédéric Hapiot

Beilstein J. Org. Chem. 2020, 16, 2598–2606, doi:10.3762/bjoc.16.211

• bioavailability [11][12][13]. In our previous studies, CDs acted either as reactants [14][15], or as additives [16][17], and were shown to display supramolecular interactions with the other reaction partners. We demonstrated that the formation of CD/substrate supramolecular complexes favored the dispersion of the

Comparative ligand structural analytics illustrated on variably glycosylated MUC1 antigen–antibody binding

• Christopher B. Barnett,
• Tharindu Senapathi and
• Kevin J. Naidoo

Beilstein J. Org. Chem. 2020, 16, 2540–2550, doi:10.3762/bjoc.16.206

• dispersion interactions would be insufficient to explain a 20-fold increase in affinity. It is unlikely that this hydrogen bond explains a 20-fold increase in affinity yet note that the mobility of the glycan moiety allows the hydrogen-bond interaction to occur. The hydrogen-bonding preferences and

NMR Spectroscopy of supramolecular chemistry on protein surfaces

• Peter Bayer,
• Anja Matena and
• Christine Beuck

Beilstein J. Org. Chem. 2020, 16, 2505–2522, doi:10.3762/bjoc.16.203

• -solvent can induce unfolding of the protein, which is reflected by a collapse of signal dispersion in the HSQC spectrum, resulting in most amide signals moving into the random coil region between ≈7.5–8.5 ppm (in the 1H dimension). We found that a maximum of ≈5% of DMSO-d6 seems to be a good rule of thumb

• dispersion and more favorable relaxation properties compared to CH2 groups, so they are mostly used to observe the interactions of a protein with its binding partners. Especially methyl groups bound to a hetero atom like sulfur (in methionine) or nitrogen (e.g., in methylated lysine) have unique chemical

• only is signal overlap reduced compared to the 1H,13C-HSQC because less signals appear in the spectrum, but also the observed signal dispersion is superior due to a larger dispersion in the 15N dimension. The H2(C)N spectra have proven to be very sensitive to tweezer and calixarene binding. Similar to

The B & B approach: Ball-milling conjugation of dextran with phenylboronic acid (PBA)-functionalized BODIPY

• Patrizia Andreozzi,
• Lorenza Tamberi,
• Elisamaria Tasca,
• Gina Elena Giacomazzo,
• Marta Martinez,
• Mirko Severi,
• Marco Marradi,
• Stefano Cicchi,
• Sergio Moya,
• Giacomo Biagiotti and
• Barbara Richichi

Beilstein J. Org. Chem. 2020, 16, 2272–2281, doi:10.3762/bjoc.16.188

• spectra of pyrene could be used to estimate the polarity of the environment of the dye in an empirical way. The ratio of the two bands in an environment of unknown polarity can be compared with the values of this ratio in solvents of known polarity. The spectrum of pyrene dissolved in a water dispersion

• min at 59 kHz. The dispersion was filtered over a 0.2 µm nylon membrane recovering both solid and solution. This protocol was repeated and then the solid was washed over the filter with ethanol (2 × 30 mL) and dried under vacuum to obtain 250 mg of Dex-1a as orange solid. FTIR data are shown in Figure

• was recovered, dissolved in DMSO (6.6 mL) and the product precipitated from cold ethanol (50 mL) and filtered over a 0.2 µm nylon membrane. The powder was recovered and dispersed (6.8 mg/mL) in ethanol and sonicated for 5 min at 59 kHz. The dispersion was filtered over a 0.2 µm nylon membrane

Natural dolomitic limestone-catalyzed synthesis of benzimidazoles, dihydropyrimidinones, and highly substituted pyridines under ultrasound irradiation

• Kumar Godugu,
• Venkata Divya Sri Yadala,
• Mohammad Khaja Mohinuddin Pinjari,
• Trivikram Reddy Gundala,
• Lakshmi Reddy Sanapareddy and
• Chinna Gangi Reddy Nallagondu

Beilstein J. Org. Chem. 2020, 16, 1881–1900, doi:10.3762/bjoc.16.156

• positions might be due to the presence of trace metal contents and impurities. The morphology of the NDL catalyst was analyzed by scanning electron microscopy (Figure 5). The SEM images revealed that the morphology of the NDL catalyst consists of irregular shapes and sizes with a random dispersion. Further

One-pot synthesis of isosorbide from cellulose or lignocellulosic biomass: a challenge?

• Isaline Bonnin,
• Raphaël Mereau,
• Thierry Tassaing and
• Karine De Oliveira Vigier

Beilstein J. Org. Chem. 2020, 16, 1713–1721, doi:10.3762/bjoc.16.143

• cellulose were also investigated. An optimum amount of 0.2 g of 4 wt % Ru/C led to 56% of isosorbide whereas 0.4 g of 2% Ru/C led to a lower isosorbide yield (24%) despite the same amount of Ru atoms on these catalysts. The metal dispersion of these two catalysts was almost identical but the particle size

Models of necessity

• Timothy Clark and
• Martin G. Hicks

Beilstein J. Org. Chem. 2020, 16, 1649–1661, doi:10.3762/bjoc.16.137

• . Descriptions of directional non-covalent interactions, for instance, are necessary for any applications involving crystal engineering. These can be treated adequately using anisotropic electrostatics [102] and dispersion [103]. It is, however, important to limit these extensions to models that are as

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

• ) spectrometer equipped with a Prodigy cryo-probehead. The pulse programs were taken from the Bruker software library (TopSpin 3.5) and full 1H and 13C assignments were achieved with widely accepted strategies [34][35]. 1H NMR assignments were accomplished using general knowledge of chemical shift dispersion