First thia-Diels–Alder reactions of thiochalcones with 1,4-quinones

• Grzegorz Mlostoń,
• Katarzyna Urbaniak,
• Paweł Urbaniak,
• Anna Marko,
• Anthony Linden and
• Heinz Heimgartner

Beilstein J. Org. Chem. 2018, 14, 1834–1839, doi:10.3762/bjoc.14.156

• (for C26H20O2S): 395 (100, [M − 1]−). ORTEP plot [29] of the molecular structure of 4k showing the major conformation of the disordered thiophene ring (50% probability ellipsoids; arbitrary numbering of the atoms). Products of the reactions of thiochalcones 1a and 1b with 1,4-benzoquinone (2a) and of

Synthesis of new tricyclic 5,6-dihydro-4H-benzo[b][1,2,4]triazolo[1,5-d][1,4]diazepine derivatives by [3⁺ + 2]-cycloaddition/rearrangement reactions

• Lin-bo Luan,
• Zi-jie Song,
• Zhi-ming Li and
• Quan-rui Wang

Beilstein J. Org. Chem. 2018, 14, 1826–1833, doi:10.3762/bjoc.14.155

• present synthetic protocol paves the way for further applications in drug-discovery research. Examples of marketed pharmaceutical 1,2,4-triazolobenzodiazepines. Crystal structure of salt 10k. The displacement ellipsoids are drawn at the 30% probability level. Crystal structure of the free base 13e. The

• displacement ellipsoids are drawn at the 30% probability level. Preparation of N-acylated 2,3-dihydro-4(1H)-quinolones 6. Synthesis of α-acetoxyazo compounds 8a–g. Reaction conditions: for synthesis of 8a: 7a (10.42 mmol), PhI(OAc)2 (12.50 mmol), AcOH (10 mL); for synthesis of 8b–g: 7b–g (0.71 mmol), PhI(OAc)2

Synthesis of pyrimido[1,6-a]quinoxalines via intermolecular trapping of thermally generated acyl(quinoxalin-2-yl)ketenes by Schiff bases

• Svetlana O. Kasatkina,
• Ekaterina E. Stepanova,
• Maksim V. Dmitriev,
• Ivan G. Mokrushin and
• Andrey N. Maslivets

Beilstein J. Org. Chem. 2018, 14, 1734–1742, doi:10.3762/bjoc.14.147

• under solvent-free conditions. ORTEP drawing of compound 3g (CCDC 1834011) showing thermal ellipsoids at the 30% probability level. ORTEP drawing of compound 3j (CCDC 1834012) showing thermal ellipsoids at the 30% probability level. Thermolysis of five-membered 2,3-dioxoheterocycles resulting in acyl

Synthesis of pyrazolopyrimidinones using a “one-pot” approach under microwave irradiation

• Mark Kelada,
• John M. D. Walsh,
• Robert W. Devine,
• Patrick McArdle and
• John C. Stephens

Beilstein J. Org. Chem. 2018, 14, 1222–1228, doi:10.3762/bjoc.14.104

• of versatile 5-aminopyrazoles is reported. Bioactive pyrazolo[1,5-a]pyrimidinones. X-ray crystal structure of pyrazolo[1,5-a]pyrimidinone 3m with ellipsoids at 50% probability. Synthesis of 5-aminopyrazoles. Reaction conditions: ketonitrile (2.0 mmol, 1.0 equiv), hydrazine (2.6 mmol, 1.3 equiv), MeOH

Preparation, structure, and reactivity of bicyclic benziodazole: a new hypervalent iodine heterocycle

• Akira Yoshimura,
• Michael T. Shea,
• Cody L. Makitalo,
• Melissa E. Jarvi,
• Gregory T. Rohde,
• Akio Saito,
• Mekhman S. Yusubov and
• Viktor V. Zhdankin

Beilstein J. Org. Chem. 2018, 14, 1016–1020, doi:10.3762/bjoc.14.87

• assisted coupling of carboxylic acids with alcohols or amines to afford the corresponding esters or amides in moderate to good yields. X-ray crystal structure of compound 7a. Ellipsoids are drawn to the 50% probability level. Selected bond lengths and angles: I(1)–C(1) 2.040 (4) Å; I(1)–N(1) 2.184 (4) Å; I

Nanoreactors for green catalysis

• M. Teresa De Martino,
• Loai K. E. A. Abdelmohsen,
• Floris P. J. T. Rutjes and
• Jan C. M. van Hest

Beilstein J. Org. Chem. 2018, 14, 716–733, doi:10.3762/bjoc.14.61

• substrates through the hydrogels and increased the probability of the reactant to be in contact with the catalyst (Ag NPs). Conclusion In this review we have discussed the utility of supramolecular polymersomes, micelles, dendrimers and nanogels in catalysis. Over the past decades, many groups have

Enhanced quantum yields by sterically demanding aryl-substituted β-diketonate ancillary ligands

• Rebecca Pittkowski and
• Thomas Strassner

Beilstein J. Org. Chem. 2018, 14, 664–671, doi:10.3762/bjoc.14.54

• ); 195Pt NMR (CDCl3, 64.52 MHz) δ (ppm) −3383; ESIMS m/z = 688.4 [M + H]+; anal. calcd for C33H36N2O2Pt: C, 57.63; H, 5.28; N, 4.07; found: C, 57.93; H, 5.46; N, 3.82. ORTEP representation of 3. Thermal ellipsoids are drawn at the 50% probability level. Selected bond lengths (Å) and angles (deg): C(1)–Pt(1

Sequential Ugi reaction/base-induced ring closing/IAAC protocol toward triazolobenzodiazepine-fused diketopiperazines and hydantoins

• Robby Vroemans,
• Fante Bamba,
• Jonas Winters,
• Joice Thomas,
• Jeroen Jacobs,
• Luc Van Meervelt,
• Jubi John and
• Wim Dehaen

Beilstein J. Org. Chem. 2018, 14, 626–633, doi:10.3762/bjoc.14.49

• examples. X-ray crystal structure of hydantoin-fused triazolobenzodiazepine 10a. (Displacement ellipsoids are drawn at the 30% probability level.) Retrosynthetic analysis towards 2,5-diketopiperazine fused triazolobenzodiazepine. Ugi 4-CR reaction. Synthesis of diketopiperazine-fused triazolobenzodiazepine

An air-stable bisboron complex: a practical bidentate Lewis acid catalyst

• Longcheng Hong,
• Sebastian Ahles,
• Andreas H. Heindl,
• Gastelle Tiétcha,
• Andrey Petrov,
• Zhenpin Lu,
• Christian Logemann and
• Hermann A. Wegner

Beilstein J. Org. Chem. 2018, 14, 618–625, doi:10.3762/bjoc.14.48

• distilled off from the resulting mixture in vacuo. The residue was purified by column chromatography over SiO2 (ethyl acetate/cyclohexane 1:1) to obtain the product. Time-dependent 1H NMR spectra of the air-exposed complex B. ORTEP drawing (50% probability) of complex B. UV–vis spectrum of complex B was

Carbohydrate inhibitors of cholera toxin

• Vajinder Kumar and
• W. Bruce Turnbull

Beilstein J. Org. Chem. 2018, 14, 484–498, doi:10.3762/bjoc.14.34

• ligand group dissociates from the protein, then the others will continue to make contact between the protein and the inhibitor, thus maintaining a high effective concentration of the dissociated ligand group in the vicinity of the binding site and increasing the probability of rebinding occurring. The

Preparation of trinucleotide phosphoramidites as synthons for the synthesis of gene libraries

• Ruth Suchsland,
• Bettina Appel and
• Sabine Müller

Beilstein J. Org. Chem. 2018, 14, 397–406, doi:10.3762/bjoc.14.28

• trinucleotide mixture, to ensure that each of the trinucleotides is coupled with identical statistical probability, or alternatively, to adjust the trinucleotide mixture to a desired amino acid distribution at the respective position. Thus, the application of trinucleotide building blocks for the synthesis of

Synthesis of fluoro-functionalized diaryl-λ³-iodonium salts and their cytotoxicity against human lymphoma U937 cells

• Prajwalita Das,
• Etsuko Tokunaga,
• Hidehiko Akiyama,
• Hiroki Doi,
• Norimichi Saito and
• Norio Shibata

Beilstein J. Org. Chem. 2018, 14, 364–372, doi:10.3762/bjoc.14.24

• . Briefly, U937 cells (1 × 104 cells/mL) were incubated with each test compound at 1 μM and 5 μM for 24 h. Cells were stained with annexin V and propidium iodide (PI). The data shown is the mean ± SD (n = 3). X-ray crystallographic structure of 3p drawn at 50% probability (CCDC 1573953). Ortho-SF5 phenyl

Recent advances on organic blue thermally activated delayed fluorescence (TADF) emitters for organic light-emitting diodes (OLEDs)

• Thanh-Tuân Bui,
• Fabrice Goubard,
• Malika Ibrahim-Ouali,
• Didier Gigmes and
• Frédéric Dumur

Beilstein J. Org. Chem. 2018, 14, 282–308, doi:10.3762/bjoc.14.18

• operated at high voltages [17]. Second, and still related to their wide bandgaps, the probability to transfer an electron from the ground to the excited stable state is considerably reduced, providing materials displaying PLQY greatly reduced compared to that observed for the other colors [18][19]. To end

Nucleophilic dearomatization of 4-aza-6-nitrobenzofuroxan by CH acids in the synthesis of pharmacology-oriented compounds

• Alexey M. Starosotnikov,
• Dmitry V. Shkaev,
• Maxim A. Bastrakov,
• Ivan V. Fedyanin,
• Svyatoslav A. Shevelev and
• Igor L. Dalinger

Beilstein J. Org. Chem. 2017, 13, 2854–2861, doi:10.3762/bjoc.13.277

• drawn at 50% probability; a DMF molecule is omitted for clarity. Partial 1H NMR spectrum of compound 15 in DMSO-d6. General view of molecule 15 in crystal. Anisotropic displacement parameters for non-hydrogen atoms are drawn at 50% probability; a DMSO molecule and the minor component of the disordered

The use of 4,4,4-trifluorothreonine to stabilize extended peptide structures and mimic β-strands

• Yaochun Xu,
• Isabelle Correia,
• Tap Ha-Duong,
• Nadjib Kihal,
• Jean-Louis Soulier,
• Julia Kaffy,
• Benoît Crousse,
• Olivier Lequin and
• Sandrine Ongeri

Beilstein J. Org. Chem. 2017, 13, 2842–2853, doi:10.3762/bjoc.13.276

• the aforementioned extended conformations. More specifically, the probability of each residue to be in α- or β-conformation can be quantified by calculating the area under the peaks of the ψ distribution functions centered around −30° or +140°, respectively. The probability of the three central

• CSDs and 3JHN-Hα coupling constant values. The probability of each peptide to have all its three central residues in β-conformation (which is equal to the product of the three central residue probabilities) is a good indication of its propensity to adopt a global extended structure. According to this

• -protected pentapeptides 1a–4a and free amine pentapeptides 1b–4b. Probability distribution of the peptide conformations as a function of end-to-end distance (defined as the distance between the nitrogen of residue Ala1 and the carbon of the C-terminal carbonyl). Probability distribution of the peptide

Ring-size-selective construction of fluorine-containing carbocycles via intramolecular iodoarylation of 1,1-difluoro-1-alkenes

• Takeshi Fujita,
• Ryo Kinoshita,
• Tsuyoshi Takanohashi,
• Naoto Suzuki and
• Junji Ichikawa

Beilstein J. Org. Chem. 2017, 13, 2682–2689, doi:10.3762/bjoc.13.266

• probability. ORTEP diagram of 6a with 50% ellipsoid probability. Intramolecular site-selective iodoarylation of 1,1-difluoro-1-alkenes bearing a biaryl group. Mechanism for formation of 3a. Transformation of a CF2I group of 2a into a CHF2 group. Construction of seven-membered carbocycles via iodoarylation of

A Brønsted base-promoted diastereoselective dimerization of azlactones

• Danielle L. J. Pinheiro,
• Gabriel M. F. Batista,
• Pedro P. de Castro,
• Leonã S. Flores,
• Gustavo F. S. Andrade and
• Giovanni W. Amarante

Beilstein J. Org. Chem. 2017, 13, 2663–2670, doi:10.3762/bjoc.13.264

• dimer. X-ray crystallographic structure of 2a (30% ellipsoids probability). Plausible mechanism for the dimerization of azlactone. Plot of vs time for the dimerization of azlactone 1a. X-ray crystallographic structure of 6 (30% ellipsoids probability). Diastereoselective dimerization of azlactones

Regioselective decarboxylative addition of malonic acid and its mono(thio)esters to 4-trifluoromethylpyrimidin-2(1H)-ones

• Sergii V. Melnykov,
• Andrii S. Pataman,
• Yurii V. Dmytriv,
• Svitlana V. Shishkina,
• Mykhailo V. Vovk and
• Volodymyr A. Sukach

Beilstein J. Org. Chem. 2017, 13, 2617–2625, doi:10.3762/bjoc.13.259

• heterochiral dimer in the crystal state. Intermolecular hydrogen bonds in the dimer are shown as dashed lines. Thermal ellipsoids are defined at 50% probability. Hydrogenation of compounds 4–6 and preparation of N1(3)-unsubstituted compounds 9–11d. Screening of the reaction conditions for organic base

Rh(II)-mediated domino [4 + 1]-annulation of α-cyanothioacetamides using diazoesters: A new entry for the synthesis of multisubstituted thiophenes

• Jury J. Medvedev,
• Ilya V. Efimov,
• Yuri M. Shafran,
• Vitaliy V. Suslonov,
• Vasiliy A. Bakulev and
• Valerij A. Nikolaev

Beilstein J. Org. Chem. 2017, 13, 2569–2576, doi:10.3762/bjoc.13.253

• structure of thiophene 5c according to the data of X-ray analysis (Olex2 plot with 50% probability level of ellipsoids). The structure of the complex 6e according to the data of X-ray analysis (Olex2 plot with 50% probability level of ellipsoids). General scheme for intramolecular heterocylization of

Pyrene–nucleobase conjugates: synthesis, oligonucleotide binding and confocal bioimaging studies

• Artur Jabłoński,
• Yannic Fritz,
• Hans-Achim Wagenknecht,
• Rafał Czerwieniec,
• Tytus Bernaś,
• Damian Trzybiński,
• Krzysztof Woźniak and
• Konrad Kowalski

Beilstein J. Org. Chem. 2017, 13, 2521–2534, doi:10.3762/bjoc.13.249

• –nucleobase conjugates A1–A3. ORTEP diagram of 2 at 50% probability level. The hydrogen and halogen bonds are represented by dashed lines. Selected bond lengths (Å) and angles (°): O26–C17, 1.223(2); O27–C21, 1.233(2); O28–C23, 1.225(2); N20–C25, 1.380(2); N22–C21, 1.372(2); N22–C23, 1.389(2); C1–C17, 1.501(2

Synthesis and supramolecular properties of regioisomers of mononaphthylallyl derivatives of γ-cyclodextrin

• Markéta Bláhová,
• Sergey K. Filippov,
• Lubomír Kováčik,
• Jiří Horský,
• Simona Hybelbauerová,
• Zdenka Syrová,
• Tomáš Křížek and
• Jindřich Jindřich

Beilstein J. Org. Chem. 2017, 13, 2509–2520, doi:10.3762/bjoc.13.248

• consequently, longer oligomers can be expected for it. The fraction of suprapolymer with polymerization degree n is then given for negligible cyclisation as where θ is the degree of occupation, i.e., the probability that the particular group, either naphthyl or CD, is in a bound state. θ is determined by the

Syntheses, structures, and stabilities of aliphatic and aromatic fluorous iodine(I) and iodine(III) compounds: the role of iodine Lewis basicity

• Tathagata Mukherjee,
• Soumik Biswas,
• Andreas Ehnbom,
• Subrata K. Ghosh,
• Ibrahim El-Zoghbi,
• Nattamai Bhuvanesh,
• Hassan S. Bazzi and
• John A. Gladysz

Beilstein J. Org. Chem. 2017, 13, 2486–2501, doi:10.3762/bjoc.13.246

• para and ortho to the iodine atoms are denoted ° and ◊ (red = ArI; blue = ArICl2). Two views of the molecular structure of 1,3,5-(Rf6)2C6H3I with thermal ellipsoids at the 50% probability level. Key bond lengths (Å) and angles (°): C1–I1 2.099(3), C1–C2 1.391(4), C2–C3 1.386(4), C3–C4 1.393(4), C4–C5

Synthesis, effect of substituents on the regiochemistry and equilibrium studies of tetrazolo[1,5-a]pyrimidine/2-azidopyrimidines

• Elisandra Scapin,
• Paulo R. S. Salbego,
• Caroline R. Bender,
• Alexandre R. Meyer,
• Anderson B. Pagliari,
• Tainára Orlando,
• Geórgia C. Zimmer,
• Clarissa P. Frizzo,
• Helio G. Bonacorso,
• Nilo Zanatta and
• Marcos A. P. Martins

Beilstein J. Org. Chem. 2017, 13, 2396–2407, doi:10.3762/bjoc.13.237

• (3JH-H) of (a) H6–H7 for 3a and (b) H5–H6 for 5h. LUMO coefficients for (a) β-enaminones 1a,h, and their (b) conjugated acids. (a) 1H and (b) 13C NMR spectra demonstrating the 3d4d equilibrium in DMSO-d6 at 25 °C. ORTEP® [45] plot of 7a with thermal ellipsoids drawn at 50% probability level. Tetrazolo

• [1,5-a]pyrimidine observed in solution (CDCl3 and DMSO-d6) and 2-azidopyrimidine observed in the solid state based on equilibrium. ORTEP® [45] plot of 8i with thermal ellipsoids drawn at 50% probability level. Representation of the possible equilibrium existing between 6i, 7i, and 8i. Reaction

Solvent-free copper-catalyzed click chemistry for the synthesis of N-heterocyclic hybrids based on quinoline and 1,2,3-triazole

• Martina Tireli,
• Silvija Maračić,
• Stipe Lukin,
• Marina Juribašić Kulcsár,
• Dijana Žilić,
• Mario Cetina,
• Ivan Halasz,
• Silvana Raić-Malić and
• Krunoslav Užarević

Beilstein J. Org. Chem. 2017, 13, 2352–2363, doi:10.3762/bjoc.13.232

• the atom-numbering scheme. Displacement ellipsoids for non-hydrogen atoms are drawn at the 30% probability level. Only the major component of disordered fluorine atoms is presented. (b) Overlap of molecules 5–8 showing almost identical molecular conformation. Color code: 5 green, 6 orange, 7 purple, 8

One-pot syntheses of blue-luminescent 4-aryl-1H-benzo[f]isoindole-1,3(2H)-diones by T3P^® activation of 3-arylpropiolic acids

• Melanie Denißen,
• Alexander Kraus,
• Guido J. Reiss and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2017, 13, 2340–2351, doi:10.3762/bjoc.13.231

• and non-conjugated bichromophores in a rapid fashion. Studies directed towards the one-pot synthesis of more complex polycyclic emitters are currently underway. The ORTEP-style plot of crystal structure 4b (ellipsoids are draw at the 40% probability level). The ORTEP-type plot of the crystal structure

• 5 (left) and a centrosymmetric dimer formation by π–π interactions (right) (ellipsoids are drawn at the 40% probability level). The ORTEP-type plot of the asymmetric unit of the crystal structure 6 (top) and π-stacking interactions (bottom) (ellipsoids are drawn at the 40% probability level