Nucleoside macrocycles formed by intramolecular click reaction: efficient cyclization of pyrimidine nucleosides decorated with 5'-azido residues and 5-octadiynyl side chains

• Jiang Liu,
• Peter Leonard,
• Sebastian L. Müller,
• Constantin Daniliuc and
• Frank Seela

Beilstein J. Org. Chem. 2018, 14, 2404–2410, doi:10.3762/bjoc.14.217

• reaction the use of the TBTA complex was essential for the cyclization of dC precursor 2 but not for dU precursor 7. Protection of precursor molecules is not required and only four steps are necessary to convert a nucleoside in a nucleoside macrocycle. The single crystal X-ray structure confirmed the click

Evaluation of dispersion type metal···π arene interaction in arylbismuth compounds – an experimental and theoretical study

• Ana-Maria Preda,
• Małgorzata Krasowska,
• Lydia Wrobel,
• Philipp Kitschke,
• Phil C. Andrews,
• Jonathan G. MacLellan,
• Lutz Mertens,
• Marcus Korb,
• Tobias Rüffer,
• Heinrich Lang,
• Alexander A. Auer and
• Michael Mehring

Beilstein J. Org. Chem. 2018, 14, 2125–2145, doi:10.3762/bjoc.14.187

• dispersion energy donors in previous work. Keywords: arylbismuth compounds; DFT-D; dispersion type Bi···π arene interaction; DLPNO-CCSD(T); electronic structure calculations; polymorphism; single crystal X-ray structure; Introduction Although known for more than a century, the interest on metal···π arene

• interactions in the context of structure formation in R3Bi compounds (Bi···Bi contacts vary between 4.015 and 4.059 Å) [63]. (C6H4-OMe-4)3Bi (3) (C6H4-OMe-4)3Bi (3) crystallized from CHCl3 in the form of colorless cube-shaped or block-shaped crystals which were suitable for single crystal X-ray structure

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

• SF5-diaryliodonium salts 3p, 4b, 5a and 6a were characterized spectroscopically. The single crystal X-ray structure of 3p was also analysed. The SF5-diaryliodonium salt 3p has a T-shaped geometry at the iodine centre, consistent with the general structure of diaryliodonium salts [33] (Figure 3

Stereochemical outcomes of C–F activation reactions of benzyl fluoride

• Neil S. Keddie,
• Pier Alexandre Champagne,
• Justine Desroches,
• Jean-François Paquin and
• David O'Hagan

Beilstein J. Org. Chem. 2018, 14, 106–113, doi:10.3762/bjoc.14.6

• )-diarylmethane 10 from diaryl ketone 11 and confirmation of configuration of (R)-13 by single crystal X-ray structure. Nucleophilic substitution reactions of racemic 7-[2H1]-benzyl bromide (4). Nucleophilic substitution reactions of 7-[2H1]-(R)-benzyl fluoride ((R)-1). Friedel–Crafts reactions of 7-[2H1]-(R

Electrophilic trifluoromethylselenolation of terminal alkynes with Se-(trifluoromethyl) 4-methylbenzenesulfonoselenoate

• Clément Ghiazza,
• Anis Tlili and
• Thierry Billard

Beilstein J. Org. Chem. 2017, 13, 2626–2630, doi:10.3762/bjoc.13.260

• reaction was stirred at 25 °C for 15–18 hours (conversion was checked by 19F NMR with PhOCF3 as internal standard). The crude residue was purified by chromatography to afford the desired products 3–5. Single-crystal X-ray structure of 3a. Electrophilic addition of 1a to alkynes. Yields shown are those 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

• ; H, 4.87; N, 17.80; found: C, 73.05; H, 5.09; N, 17.59. Single-crystal X-ray structure analysis A good quality single-crystal of 2 was selected for the X-ray diffraction experiments at T = 100(2) K. Diffraction data were collected on an Agilent Technologies SuperNova Dual Source diffractometer with

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

• after purification by column chromatography shows no traces of copper in the ESR spectrum (Supporting Information File 1, Figure S21). X-ray crystal structure analysis Single-crystal X-ray structure analysis was performed for all products. It provided clear identification of the novel triazole

• 5–8 suitable for single crystal X-ray structure analysis were obtained at room temperature by partial evaporation of the solvent from the mixture of dichloromethane and methanol. Data for 5–7 were collected at 295 K on a Oxford Diffraction Xcalibur2 diffractometer with a Sapphire 3 CCD detector

Mechanochemical Knoevenagel condensation investigated in situ

• Sebastian Haferkamp,
• Franziska Fischer,
• Werner Kraus and
• Franziska Emmerling

Beilstein J. Org. Chem. 2017, 13, 2010–2014, doi:10.3762/bjoc.13.197

• grinding process, whereas p-nitrobenzaldehyde remains crystalline until the onset of the product formation. The crystalline product was of sufficient quality for single crystal X-ray structure determination. Results and Discussion Scheme 1 illustrates the investigated Knoevenagel condensation of p

A speedy route to sterically encumbered, benzene-fused derivatives of privileged, naturally occurring hexahydropyrrolo[1,2-b]isoquinoline

• Olga Bakulina,
• Alexander Ivanov,
• Vitalii Suslonov,
• Dmitry Dar’in and
• Mikhail Krasavin

Beilstein J. Org. Chem. 2017, 13, 1413–1424, doi:10.3762/bjoc.13.138

• chloroform. Anti- and syn-diastereomers of 10 and 10'. Single-crystal X-ray structure of compound 10l. Typical J(H11-H11a)-values and corresponding dihedral angles for syn- and anti-diastereomers of compounds 10 derived from 2H-indolenines. The difference in the 13C NMR chemical shifts of the angular methyl

Synthesis of tetrasubstituted pyrazoles containing pyridinyl substituents

• Josef Jansa,
• Ramona Schmidt,
• Ashenafi Damtew Mamuye,
• Laura Castoldi,
• Alexander Roller,
• Vittorio Pace and
• Wolfgang Holzer

Beilstein J. Org. Chem. 2017, 13, 895–902, doi:10.3762/bjoc.13.90

• [3,4-a]quinolizin-6-ium structure 12 was established, which was confirmed by single crystal X-ray structure analysis (see Supporting Information File 1), proving also iodide as the corresponding anion [39] which acts as a leaving group in the coupling reaction and also could origin from the CuI co

Nucleophilic and electrophilic cyclization of N-alkyne-substituted pyrrole derivatives: Synthesis of pyrrolopyrazinone, pyrrolotriazinone, and pyrrolooxazinone moieties

• Işıl Yenice,
• Sinan Basceken and
• Metin Balci

Beilstein J. Org. Chem. 2017, 13, 825–834, doi:10.3762/bjoc.13.83

• and methylene protons in 13c and 16 with the relevant carbon atoms (from the HMBC spectrum). Single-crystal X-ray structure of 12c shown with 40% probability displacement ellipsoids. The structure of allene 17 formed during the reaction of 7d with a base. Single-crystal X-ray structure of 19c shown

Derivatives of the triaminoguanidinium ion, 5. Acylation of triaminoguanidines leading to symmetrical tris(acylamino)guanidines and mesoionic 1,2,4-triazolium-3-aminides

• Jan Szabo,
• Julian Greiner and
• Gerhard Maas

Beilstein J. Org. Chem. 2017, 13, 579–588, doi:10.3762/bjoc.13.57

• , indicate a static, unsymmetrical molecule around 300 K, showing for example separate signals for the three CH2 and Ccarbonyl nuclei. A single-crystal X-ray structure determination was performed for 6b, which gave suitable crystals of 6b·2C2H5OH when crystallized from ethanol. The guanidine structure could

Synthesis, dynamic NMR characterization and XRD studies of novel N,N’-substituted piperazines for bioorthogonal labeling

• Constantin Mamat,
• Marc Pretze,
• Matthew Gott and
• Martin Köckerling

Beilstein J. Org. Chem. 2016, 12, 2478–2489, doi:10.3762/bjoc.12.242

• from coalescence temperatures Tc which were determined from dynamic 1H NMR measurements. The formation of conformers resulting from the partial double bond was additionally determined and verified using single crystal X-ray structure analysis. The second coalescence point is caused by the reduced

• showed a Tc of 248 K with a ΔG# of 11.1 kJ/mol [23] whereas piperidine shows a higher ΔG# of 42.3 and N-methylpiperidine a ΔG# = 49.8 kJ/mol [21][28]. X-ray structure analyses of 3a and 4b Single crystals of 3a and 4b were obtained and their molecular structures determined using single crystal X-ray

• structure analysis. Crystals of 3a have monoclinic symmetry of the space group C2/c. Crystals of 4b have monoclinic symmetry of the space group P21/n. The C14–C15 distance of 1.188(1) Å and the C13–C14–C15 angle of 178.2(1)° clearly indicate this group to be an alkyne residue, thus enabling the use of the

A direct method for the N-tetraalkylation of azamacrocycles

• Andrew J. Counsell,
• Angus T. Jones,
• Matthew H. Todd and
• Peter J. Rutledge

Beilstein J. Org. Chem. 2016, 12, 2457–2461, doi:10.3762/bjoc.12.239

• via recrystallization or by passing the product through a short silica plug (see Table 1 and Supporting Information File 1 for details). Recrystallisation of 3 from a methanolic solution containing KClO4 yielded large, colourless, crystalline prisms. Single crystal X-ray structure determination

Scope and limitations of a DMF bio-alternative within Sonogashira cross-coupling and Cacchi-type annulation

• Kirsty L. Wilson,
• Alan R. Kennedy,
• Jane Murray,
• Ben Greatrex,
• Craig Jamieson and
• Allan J. B. Watson

Beilstein J. Org. Chem. 2016, 12, 2005–2011, doi:10.3762/bjoc.12.187

• Cyrene as a solvent, providing guidance emerging in relation to the thermal and chemical (base) stabilities of this promising green solvent. Cyrene vs. DMF – selected physical properties [31][32]. Aldol products 4a and 4b and single crystal X-ray structure of 4b. The Sonogashira reaction. Cyrene-based

Potent triazine-based dehydrocondensing reagents substituted by an amido group

• Munetaka Kunishima,
• Daiki Kato,
• Nobu Kimura,
• Masanori Kitamura,
• Kohei Yamada and
• Kazuhito Hioki

Beilstein J. Org. Chem. 2016, 12, 1897–1903, doi:10.3762/bjoc.12.179

• intermediate 7 (Scheme 2). Single-crystal X-ray structure analysis, two-dimensional NMR spectroscopy, or derivatization of I–VI was performed to unambiguously determine their structures, i.e., whether the N- or O-substituted derivative was prepared from the amido anion (Supporting Information File 1). To

• esterification of 3-phenylpropanoic acid (1a) in neat MeOH were studied (Figure 3). Although X was shown to exist as a dihydrate by elemental analysis and single-crystal X-ray structure analysis, the yield of methyl 3-phenylpropanoate was quantitative. The rate of esterification with X was faster than that with

Dinuclear thiazolylidene copper complex as highly active catalyst for azid–alkyne cycloadditions

• Anne L. Schöffler,
• Ata Makarem,
• Frank Rominger and
• Bernd F. Straub

Beilstein J. Org. Chem. 2016, 12, 1566–1572, doi:10.3762/bjoc.12.151

• (100.0) [M − 2Cu – Oac − PF6 + CH3O]+, 397.0392 (17.7), 599.0698 (69.9); calculated for [M − 2Cu – Oac − PF6 + CH3O]+: 283.0949, found: 283.0935. IR (ATR) ν = 1594 (w), 1555 (m), 1447 (m), 1397 (w), 1328 (w), 835 (s), 691 (m) cm−1; mp 175 °C dec. Ball-and-stick model [42][43] of a single crystal X-ray

• structure of hexafluorophosphate salt 1b (CCDC 1472789). Color code: black carbon, grey hydrogen, yellow sulfur, blue nitrogen, magenta phosphorus, green fluorine. Time-conversion-diagram of the CuAAC reaction of benzyl azide with either phenylacetylene or ethyl propiolate in the presence of copper complex

Simple activation by acid of latent Ru-NHC-based metathesis initiators bearing 8-quinolinolate co-ligands

• Julia Wappel,
• Roland C. Fischer,
• Luigi Cavallo,
• Christian Slugovc and
• Albert Poater

Beilstein J. Org. Chem. 2016, 12, 154–165, doi:10.3762/bjoc.12.17

• two products, 2a and 2b, were isolated. In this case both complexes featured, according to NMR analysis, two 5,7-dichloro-8-quinolinolate ligands. The overall yield amounted to 83% in this case. Single crystal X-ray structure analyses elucidated the solid state structure of 2a and 2b (see Figure 1

• readily evident from the benzylidene proton chemical shifts of 19.10 and 18.24 ppm, which are distinctly low-field shifted in comparison to the same signal in HovII (16.56 ppm). From single crystal X-ray structure analyses of 2a and 2b it became evident that, in general, bond lengths and angles are very

Pyridinoacridine alkaloids of marine origin: NMR and MS spectral data, synthesis, biosynthesis and biological activity

• Louis P. Sandjo,
• Victor Kuete and
• Maique W. Biavatti

Beilstein J. Org. Chem. 2015, 11, 1667–1699, doi:10.3762/bjoc.11.183

• in the fusion of aromatic rings, which makes this assignment a difficult task. An initial solution for structure determination might be to associate a single crystal X-ray structure to the NMR data. Unfortunately, the development of a suitable crystal for the crystallographic analysis is not an easy

Grubbs–Hoveyda type catalysts bearing a dicationic N-heterocyclic carbene for biphasic olefin metathesis reactions in ionic liquids

• Maximilian Koy,
• Hagen J. Altmann,
• Benjamin Autenrieth,
• Wolfgang Frey and
• Michael R. Buchmeiser

Beilstein J. Org. Chem. 2015, 11, 1632–1638, doi:10.3762/bjoc.11.178

• = mesitylene). Single crystal X-ray structure of Ru-2. Co-solvent and disordered triflates have been omitted for clarity. Monomers used for biphasic ROMP reactions. Improved synthesis of Ru-1 and quarternization with methyl trifluoromethanesulfonate to Ru-2. Recycling of Ru-2 for continuous ROMP reactions

Structure and conformational analysis of spiroketals from 6-O-methyl-9(E)-hydroxyiminoerythronolide A

• Ana Čikoš,
• Irena Ćaleta,
• Dinko Žiher,
• Mark B. Vine,
• Ivaylo J. Elenkov,
• Marko Dukši,
• Dubravka Gembarovski,
• Marina Ilijaš,
• Snježana Dragojević,
• Ivica Malnar and
• Sulejman Alihodžić

Beilstein J. Org. Chem. 2015, 11, 1447–1457, doi:10.3762/bjoc.11.157

• single crystal X-ray structure of erythronolide A anhydro derivative (CSDC refcode: ERYTHR [55]) and minimized with constraints of 1000 kcal on all atoms with known X-ray coordinates. The model of 3 was generated from the model of compound 2. The model of 4 was obtained by molecular modelling with NMR

Trifluoromethyl-substituted tetrathiafulvalenes

• Olivier Jeannin,
• Frédéric Barrière and
• Marc Fourmigué

Beilstein J. Org. Chem. 2015, 11, 647–658, doi:10.3762/bjoc.11.73

• strong −I inductive effect. Among the nine possible combinations 1 and 2 described above (Scheme 2), the unsymmetrically disubstituted 2ab and 2ac have not been reported to date. We describe here the syntheses of 2ac from 2bc and the single-crystal X-ray structure determinations of both 2ac and 2bc

TTFs nonsymmetrically fused with alkylthiophenic moieties

• Rafaela A. L. Silva,
• Bruno J. C. Vieira,
• Marta M. Andrade,
• Isabel C. Santos,
• Sandra Rabaça,
• Dulce Belo and
• Manuel Almeida

Beilstein J. Org. Chem. 2015, 11, 628–637, doi:10.3762/bjoc.11.71

• /AgCl, typical of TTF donors at E11/2 = 279 V and E21/2 = 680 V for 1 and E11/2 = 304 V and E21/2 = 716 V in the case of 2. The single-crystal X-ray structure of 1 and of a charge transfer salt of 2, (α-mtdt)[Au(mnt)2] (3), are reported. Keywords: cyclic voltammetry; single-crystal X-ray diffraction

Attempts to prepare an all-carbon indigoid system

• Şeref Yildizhan,
• Henning Hopf and
• Peter G. Jones

Beilstein J. Org. Chem. 2015, 11, 363–372, doi:10.3762/bjoc.11.42

• by the usual spectroscopic methods was straightforward and the obtained spectra agreed with the reported data [28]. The assignment was corroborated by a single-crystal X-ray structure determination (Figure 6); single crystals were obtained by slow evaporation of a pentane solution. The molecule of 30

(2R,1'S,2'R)- and (2S,1'S,2'R)-3-[2-Mono(di,tri)fluoromethylcyclopropyl]alanines and their incorporation into hormaomycin analogues

• Armin de Meijere,
• Sergei I. Kozhushkov,
• Dmitrii S. Yufit,
• Christian Grosse,
• Marcel Kaiser and
• Vitaly A. Raev

Beilstein J. Org. Chem. 2014, 10, 2844–2857, doi:10.3762/bjoc.10.302

• (2R,1'R,2'S)-26b were determined by a single crystal X-ray structure analysis (see Figure 3 and Supporting Information File 1) [28]. The isolated nickel complexes 26a–c were decomposed by treatment with refluxing aqueous methanolic hydrogen chloride to give, after ion-exchange chromatography, the

• by experimental tests [36]. The initially formed main product (R,R,R)-28 in the aldol reaction of acetaldehyde with 10 had the same configuration at C-2 as the proline unit in 10. The absolute configuration of this nickel(II) complex was determined by a single crystal X-ray structure analysis (see