Biomimetic synthesis and HPLC–ECD analysis of the isomers of dracocephins A and B

• Viktor Ilkei,
• András Spaits,
• Anita Prechl,
• Áron Szigetvári,
• Zoltán Béni,
• Miklós Dékány,
• Csaba Szántay Jr,
• Judit Müller,
• Árpád Könczöl,
• Ádám Szappanos,
• Attila Mándi,
• Sándor Antus,
• Ana Martins,
• Attila Hunyadi,
• György Tibor Balogh,
• György Kalaus (†),
• Hedvig Bölcskei,
• László Hazai and
• Tibor Kurtán

Beilstein J. Org. Chem. 2016, 12, 2523–2534, doi:10.3762/bjoc.12.247

• racemates (2a, 2c/2b, 2d; 3a, 3c/3b, 3d) by HPLC–ECD analysis (Figure 1). The planar structure and absolute configuration of the first-eluted stereoisomer of dracocephins A (±)-2a–d was determined by single-crystal X-ray diffraction analysis as (2R,5”S)-2a [2]. The biosynthesis of these flavonoid

Et₃B-mediated and palladium-catalyzed direct allylation of β-dicarbonyl compounds with Morita–Baylis–Hillman alcohols

• Ahlem Abidi,
• Yosra Oueslati and
• Farhat Rezgui

Beilstein J. Org. Chem. 2016, 12, 2402–2409, doi:10.3762/bjoc.12.234

• conjugate addition of the β-keto ester carbanion onto the enone moiety (Scheme 2) [50][51]. The structure of the tricyclic compound 6j was elucidated on the basis of X-ray diffraction analysis (Figure 2). In a previous report, Alexakis and co-workers have demonstrated that copper-catalyzed conjugate

An effective one-pot access to polynuclear dispiroheterocyclic structures comprising pyrrolidinyloxindole and imidazothiazolotriazine moieties via a 1,3-dipolar cycloaddition strategy

• Alexei N. Izmest’ev,
• Galina A. Gazieva,
• Natalya V. Sigay,
• Sergei A. Serkov,
• Valentina A. Karnoukhova,
• Vadim V. Kachala,
• Alexander S. Shashkov,
• Igor E. Zanin,
• Angelina N. Kravchenko and
• Nina N. Makhova

Beilstein J. Org. Chem. 2016, 12, 2240–2249, doi:10.3762/bjoc.12.216

• Supporting Information File 1 for full experimental data). Finally, the regio- and stereochemistry of the cycloaddition were confirmed by single crystal X-ray diffraction analysis of compounds 4c (Figure 5), 4e (Figure 6), and 4r (Figure 7) (see Supporting Information Files 2–4). The relative configurations

Synthesis and characterization of fluorinated azadipyrromethene complexes as acceptors for organic photovoltaics

• Forrest S. Etheridge,
• Roshan J. Fernando,
• Sandra Pejić,
• Matthias Zeller and
• Geneviève Sauvé

Beilstein J. Org. Chem. 2016, 12, 1925–1938, doi:10.3762/bjoc.12.182

• counter and pseudoreference electrodes. Crystals suitable for X-ray diffraction analysis were obtained by the slow diffusion of methanol into a dichloromethane solution. The crystals obtained were dark blue-black in appearance. Single-crystal X-ray diffraction studies were carried out using a Rigaku Rapid

Bridgehead vicinal diallylation of norbornene derivatives and extension to propellane derivatives via ring-closing metathesis

• Sambasivarao Kotha and
• Rama Gunta

Beilstein J. Org. Chem. 2016, 12, 1877–1883, doi:10.3762/bjoc.12.177

• propellanes via ring-closing metathesis. Single-crystal X-ray diffraction analysis of four compounds led to the realization of configurational correction of earlier reported molecules. Keywords: norbornene; propellane derivatives; ring-closing metathesis; single-crystal X-ray diffraction; vicinal

• supported by HRMS data. In addition, the configuration of 1b and 2b were unambiguously determined via single-crystal X-ray diffraction analysis (Figure 4). Based on this data it is clear that the bridgehead allyl groups in the RCM precursor 2b are in endo configuration. Subsequent RCM of diallyl compound 2b

• X-ray diffraction analysis. A control experiment with propyl bromide provided an insight into the reaction mechanism that the bridgehead allylation proceeds through enolization, O-allylation followed by CR and not via carbanion chemistry. This alternative strategy is useful to introduce vicinal

Cross-linked cyclodextrin-based material for treatment of metals and organic substances present in industrial discharge waters

• Élise Euvrard,
• Nadia Morin-Crini,
• Coline Druart,
• Justine Bugnet,
• Bernard Martel,
• Cesare Cosentino,
• Virginie Moutarlier and
• Grégorio Crini

Beilstein J. Org. Chem. 2016, 12, 1826–1838, doi:10.3762/bjoc.12.172

• then the resulting pH (pHf) was measured. The difference between the initial and final pH values (ΔpH) was plotted against the initial pH. The PZC was represented by the point ΔpH = 0 [32]. X-ray diffraction analysis (XRD) was performed on a Bruker D8 Advance diffractometer using Cu Kα radiation with a

Experimental and theoretical insights in the alkene–arene intramolecular π-stacking interaction

• Valeria Corne,
• Ariel M. Sarotti,
• Carmen Ramirez de Arellano,
• Rolando A. Spanevello and
• Alejandra G. Suárez

Beilstein J. Org. Chem. 2016, 12, 1616–1623, doi:10.3762/bjoc.12.158

• the π-stacking interaction also affects the equilibrium kinetics. In order to better understand the conformational studies, a crystal of acrylate 6a suitable for X-ray diffraction analysis was obtained (for further information, see Supporting Information File 1). The crystal structure shows the vinyl

A T-shape diphosphinoborane palladium(0) complex

• Patrick Steinhoff and
• Michael E. Tauchert

Beilstein J. Org. Chem. 2016, 12, 1573–1576, doi:10.3762/bjoc.12.152

• the ligand pointing towards the formation of a bisligand complex (DPB)2Pd [7]. Unlike complex 2 we were unable to form a pyridine adduct complex by treatment of 9 with 10 equiv of pyridine. Single crystals of complex 9 suitable for X-ray diffraction analysis were grown from hexane (Figure 2). The

One-pot synthesis of tetracyclic fused imidazo[1,2-a]pyridines via a three-component reaction

• Bo Yang,
• Chuanye Tao,
• Taofeng Shao,
• Jianxian Gong and
• Chao Che

Beilstein J. Org. Chem. 2016, 12, 1487–1492, doi:10.3762/bjoc.12.145

• products were characterized by 1H NMR, 13C NMR, HRMS spectra and the structure of 1o was further confirmed by X-ray diffraction analysis (see Supporting Information File 1 for details). A possible mechanism for the MCR is proposed in Figure 2. The MCR proceeds through the formation of a protonated imine

Bi- and trinuclear copper(I) complexes of 1,2,3-triazole-tethered NHC ligands: synthesis, structure, and catalytic properties

• Shaojin Gu,
• Jiehao Du,
• Jingjing Huang,
• Huan Xia,
• Ling Yang,
• Weilin Xu and
• Chunxin Lu

Beilstein J. Org. Chem. 2016, 12, 863–873, doi:10.3762/bjoc.12.85

• range of 157.6–216 ppm [34][35]. Single crystal X-ray diffraction studies To obtain additional insight into the coordination and supramolecular properties, suitable single crystals of all the copper complexes were obtained for single-crystal X-ray diffraction analysis. Crystals were grown by slow

• desired product X-ray diffraction analysis Analogously as described in [27], single-crystal X-ray diffraction data were collected at 298(2) K on a Siemens Smart/CCD area-detector or Oxford Diffraction Gemini A Ultra diffractometer with a Mo Kα radiation (λ = 0.71073 Å) by using an ω-2θ scan mode. Unit

• route: imidazolium salt (0.2 mmol) and an excess of copper powder (64 mg, 1.0 mmol) were placed in 3 mL of MeCN to form a heterogeneous mixture solution. After the mixture was stirred at 50 °C for 10 h under air, the solution was filtered through Celite. Single crystals suitable for X-ray diffraction

A modular approach to neutral P,N-ligands: synthesis and coordination chemistry

• Vladislav Vasilenko,
• Torsten Roth,
• Clemens K. Blasius,
• Sebastian N. Intorp,
• Hubert Wadepohl and
• Lutz H. Gade

Beilstein J. Org. Chem. 2016, 12, 846–853, doi:10.3762/bjoc.12.83

• crystals of [2a-PdCl2] and [5-Pd(2-Me-allyl)]OTf suitable for X-ray diffraction analysis (Figure 6). For an overview of metric parameters of all palladium complexes see Table 3. The solid-state structures of [2a-PdCl2] (Figure 6, left) and its cationic congener [2a-PdCl]2(BF4)2 (Figure 5) show distinct

Synthesis and in vitro cytotoxicity of acetylated 3-fluoro, 4-fluoro and 3,4-difluoro analogs of D-glucosamine and D-galactosamine

• Štěpán Horník,
• Lucie Červenková Šťastná,
• Petra Cuřínová,
• Jan Sýkora,
• Kateřina Káňová,
• Roman Hrstka,
• Ivana Císařová,
• Martin Dračínský and
• Jindřich Karban

Beilstein J. Org. Chem. 2016, 12, 750–759, doi:10.3762/bjoc.12.75

• acetal with acetic anhydride gave a mixture containing 1,2-oxazoline 41 as the main product (Scheme 5). The structure of oxazoline 41 was confirmed by single crystal X-ray diffraction analysis which also confirmed the retention of configuration during the preceding fluorine introduction. To prevent

Strecker degradation of amino acids promoted by a camphor-derived sulfonamide

• M. Fernanda N. N. Carvalho,
• M. João Ferreira,
• Ana S. O. Knittel,
• Maria da Conceição Oliveira,
• João Costa Pessoa,
• Rudolf Herrmann and
• Gabriele Wagner

Beilstein J. Org. Chem. 2016, 12, 732–744, doi:10.3762/bjoc.12.73

• concerning the analytical formulation of 2, its structure remained unclear. In the absence of crystals suitable for single crystal X-ray diffraction analysis, this point was fully clarified by NMR (Supporting Information File 1, Figure S2–S6) and further supported by calculations. The assignment of all

Pyridylidene ligand facilitates gold-catalyzed oxidative C–H arylation of heterocycles

• Kazuhiro Hata,
• Hideto Ito,
• Yasutomo Segawa and
• Kenichiro Itami

Beilstein J. Org. Chem. 2015, 11, 2737–2746, doi:10.3762/bjoc.11.295

• -ray diffraction analysis was obtained by recrystallization from nitrobenzene and pentane. 1H NMR (CDCl3, 600 MHz) δ 8.17 (d, J = 2.1 Hz, 1H), 7.90 (d, J = 2.1 Hz, 1H), 7.29 (td, J = 7.6, 2.7 Hz, 2H), 7.19 (d, J = 7.6 Hz, 2H), 7.16 (d, J = 7.6 Hz, 2H), 7.07 (s, 2H), 2.36 (s, 3H), 2.28 (s, 12H), 2.15 (s

• atmosphere. After stirring at room temperature for 19 h, the reaction mixture was filtered through a pad of Celite®. The filtrate was poured into hexane and the resulting precipitate was collected by filtration to obtain pure AuCl3(PyC) as a white solid (140 mg, 99%). The colorless single crystal used for X

Inclusion complexes of 2-methoxyestradiol with dimethylated and permethylated β-cyclodextrins: models for cyclodextrin–steroid interaction

• Mino R. Caira,
• Susan A. Bourne,
• Halima Samsodien and
• Vincent J. Smith

Beilstein J. Org. Chem. 2015, 11, 2616–2630, doi:10.3762/bjoc.11.281

• (λmax = 198.5 nm) in methanol/water (1:1 v/v) solution. This instrument was also used for solubility and dissolution rate assays (details below). Single crystal X-ray diffraction analysis Intensity data were collected on a Nonius Kappa CCD diffractometer using graphite-monochromated Mo Kα-radiation (λ

Friedel–Crafts-type reaction of pyrene with diethyl 1-(isothiocyanato)alkylphosphonates. Efficient synthesis of highly fluorescent diethyl 1-(pyrene-1-carboxamido)alkylphosphonates and 1-(pyrene-1-carboxamido)methylphosphonic acid

• Anna Wrona-Piotrowicz,
• Janusz Zakrzewski,
• Anna Gajda,
• Tadeusz Gajda,
• Anna Makal,
• Arnaud Brosseau and
• Rémi Métivier

Beilstein J. Org. Chem. 2015, 11, 2451–2458, doi:10.3762/bjoc.11.266

• = 0.25) was assigned to π–π aggregates, the presence of which was revealed by single-crystal X-ray diffraction analysis. Keywords: amide; fluorescence; isothiocyanate; phosphonate; pyrene; thioamide; X-ray structure; Introduction Friedel–Crafts-type reaction of arenes with isothiocyanates constitutes a

A concise and efficient synthesis of benzimidazo[1,2-c]quinazolines through CuI-catalyzed intramolecular N-arylations

• Xinlong Pang,
• Chao Chen,
• Ming Li and
• Chanjuan Xi

Beilstein J. Org. Chem. 2015, 11, 2365–2369, doi:10.3762/bjoc.11.258

• (Scheme 2). It is worth mentioning that during the course of our study, we observed that products 4 were not stable to acid. For example, treatment of 4c with aqueous HCl solution led to ring-opening product 5 (Scheme 3). The structure of 5 was confirmed by X-ray diffraction analysis (Figure 1), clearly

New aryloxybenzylidene ruthenium chelates – synthesis, reactivity and catalytic performance in ROMP

• Patrycja Żak,
• Szymon Rogalski,
• Mariusz Majchrzak,
• Maciej Kubicki and
• Cezary Pietraszuk

Beilstein J. Org. Chem. 2015, 11, 1910–1916, doi:10.3762/bjoc.11.206

• of CuCl at 60 °C. After 24 h of the reaction course, the formation of a green precipitate was observed. X-ray diffraction analysis of single crystals obtained by slow evaporation of the post-reaction mixture revealed the formation of dimeric complex 16, in which the phenoxybenzylidene ring was

Synthesis and structures of ruthenium–NHC complexes and their catalysis in hydrogen transfer reaction

• Chao Chen,
• Chunxin Lu,
• Qing Zheng,
• Shengliang Ni,
• Min Zhang and
• Wanzhi Chen

Beilstein J. Org. Chem. 2015, 11, 1786–1795, doi:10.3762/bjoc.11.194

• molecular structures of the complexes 4 and 5 were also studied by X-ray diffraction analysis. These ruthenium complexes have proven to be efficient catalysts for transfer hydrogenation of various ketones. Keywords: N-heterocyclic carbene; ruthenium; transfer hydrogenation; Introduction N-Heterocyclic

• , the carbene carbons of complexes 4 and 5 are found at 190 and 200 ppm, respectively. The structures of 4 and 5 determined by X-ray diffraction analysis are shown in Figure 4 and Figure 5. In the cationic structure of 4, the acetonitrile ligand at the trans-position of the NHC is substituted by a

• catalyst solution (0.01 mmol, 0.001 mmol, or 0.0001 mol of ruthenium complexes in iPrOH (1 mL) was injected. Aliquots (0.2 mL) were taken at fixed time intervals, quenched with 1 mL of H2O and extracted with 3 mL of Et2O. The product yields were determined by GC analysis. X-ray diffraction analysis Single

Latent ruthenium–indenylidene catalysts bearing a N-heterocyclic carbene and a bidentate picolinate ligand

• Thibault E. Schmid,
• Florian Modicom,
• Adrien Dumas,
• Etienne Borré,
• Loic Toupet,
• Olivier Baslé and
• Marc Mauduit

Beilstein J. Org. Chem. 2015, 11, 1541–1546, doi:10.3762/bjoc.11.169

• , under these modified conditions the desired complex 4a could be prepared in a clean manner with an improved 62% isolated yield. Given the importance of the substitution pattern of the chelating [N–O] ligand, X-ray diffraction analysis unambiguously confirmed the structure of complex 4a, which displayed

Ruthenium indenylidene “1^st generation” olefin metathesis catalysts containing triisopropyl phosphite

• Stefano Guidone,
• Fady Nahra,
• Alexandra M. Z. Slawin and
• Catherine S. J. Cazin

Beilstein J. Org. Chem. 2015, 11, 1520–1527, doi:10.3762/bjoc.11.166

• with a cis-disposition of the phosphorus donor ligands. This geometry was confirmed by X-ray diffraction analysis on a single crystal (Figure 2). Synthesis of [RuCl2(Ind){P(OiPr)3}2] (2) The synthesis of the bis-phosphite species 2 was first attempted by the reaction of Ind-I with 2.5 equivalents of P

A new and efficient procedure for the synthesis of hexahydropyrimidine-fused 1,4-naphthoquinones

• Marcelo Isidoro P. Reis,
• Vinícius R. Campos,
• Jackson A. L. C. Resende,
• Fernando C. Silva and
• Vitor F. Ferreira

Beilstein J. Org. Chem. 2015, 11, 1235–1240, doi:10.3762/bjoc.11.137

• mass spectrometry. The synthesis of compounds 14 [43] and 17 [44] has been previously reported in the literature. The structure of compound 18 was confirmed by X-ray diffraction analysis and Figure 2 shows the ORTEP diagram of this compound. The details of the crystal data and refinements are collected

• ]+ of 395.1715. The structure of compound 23 was further elucidated by X-ray diffraction analysis (Figure 3). It confirmed the insertion of two imines to form a hexahydropyrimidine ring which is coupled to a 1,4-naphthoquinone moiety. Figure 3 shows the ORTEP diagram of compound 23 and the details of

• 1,3,5-triazinanes and products were confirmed by spectroscopical methods and X-ray diffraction analysis. General template for heterocycle-fused 1,4-naphthoquinones. ORTEP diagram of compound 18 depicted with ellipsoids drawn at the 50% probability level and the atom-numbering scheme. ORTEP diagram of

Regioselective synthesis of chiral dimethyl-bis(ethylenedithio)tetrathiafulvalene sulfones

• Flavia Pop and
• Narcis Avarvari

Beilstein J. Org. Chem. 2015, 11, 1105–1111, doi:10.3762/bjoc.11.124

• elemental analysis, which are all concordant, the definite proof for the sulfone structure of 1 has been provided by single crystal X-ray diffraction analysis. Single crystals of the two enantiomers (S,S)-1 and (R,R)-1 were obtained by slow evaporation from dichloromethane/pentane or dichloromethane

A new and convenient synthetic way to 2-substituted thieno[2,3-b]indoles

• Roman A. Irgashev,
• Arseny A. Karmatsky,
• Gennady L. Rusinov and
• Valery N. Charushin

Beilstein J. Org. Chem. 2015, 11, 1000–1007, doi:10.3762/bjoc.11.112

• reflectance attachment (DRA). X-ray diffraction analysis was performed on an automated X-ray diffractometer “Xcalibur E” on standard procedure. General procedure for the synthesis of 3-(2-oxo-2-(hetero)arylethylidene)indolin-2-one 10a−10o The solution of 1-alkylisatin 7 (3 mmol), corresponding methyl ketone 8

The reactions of 2-ethoxymethylidene-3-oxo esters and their analogues with 5-aminotetrazole as a way to novel azaheterocycles

• Marina V. Goryaeva,
• Yanina V. Burgart,
• Marina A. Ezhikova,
• Mikhail I. Kodess and
• Viktor I. Saloutin

Beilstein J. Org. Chem. 2015, 11, 385–391, doi:10.3762/bjoc.11.44

• good nucleofuge [28]. Indeed, the reaction of azidopyrimidine 2a with 5-AT made it possible to obtain 2-(tetrazolylamino)pyrimidine 5 in good yield (Scheme 2). The structure of pyrimidine 5 was confirmed by X-ray diffraction analysis (Figure 1). Further in this reaction we used 2