Regioselective (thio)carbamoylation of 2,7-di-tert-butylpyrene at the 1-position with iso(thio)cyanates

• Anna Wrona-Piotrowicz,
• Marzena Witalewska,
• Janusz Zakrzewski and
• Anna Makal

Beilstein J. Org. Chem. 2017, 13, 1032–1038, doi:10.3762/bjoc.13.102

• was confirmed by single-crystal X-ray diffraction, which revealed a cisoidal conformation of this molecule in the crystal (Figure 2, for details, see Supporting Information File 1 and Supporting Information File 2). However, the 1H NMR spectrum of 4 at room temperature was more complex than expected

Inclusion complexes of β-cyclodextrin with tricyclic drugs: an X-ray diffraction, NMR and molecular dynamics study

• Franca Castiglione,
• Fabio Ganazzoli,
• Luciana Malpezzi,
• Andrea Mele,
• Walter Panzeri and
• Giuseppina Raffaini

Beilstein J. Org. Chem. 2017, 13, 714–719, doi:10.3762/bjoc.13.70

• in the solid state from single-crystal X-ray diffraction of 1/β-CD and 2/β-CD complexes. The latter complex was found in a single conformation in the solid state, whilst the MD simulations in explicit water reproduced the conformational transitions observed experimentally for the free molecule

• . Keywords: amitriptyline; β-cyclodextrin; crystal structure; cyclobenzaprine; molecular dynamics simulations; NOE; Introduction The present paper reports on a multidisciplinary approach [1][2] based on single crystal X-ray diffraction, solution NMR spectroscopy and molecular dynamics (MD) simulations with

• NOEs within the 2/β-CD complex points out that the overall geometry is very much similar to that described for 1/β-CD. The approximate and qualitative picture derived from NOE restraints is in good agreement with the solid state structure of the two complexes obtained from single crystal X-ray

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

• were confirmed by single-crystal X-ray diffraction (vide infra). Catalytic hydrogenation of 1,2,4-triazolium-3-aminides 7 with H2 and Pd/C in methanol selectively cleaves the N1–Cbenzyl bond and yields the neutral N-benzyl-N’-(4-benzylamino-4H-1,2,4-triazol-3-yl)benzohydrazides 10 in high yields

Brønsted acid-mediated cyclization–dehydrosulfonylation/reduction sequences: An easy access to pyrazinoisoquinolines and pyridopyrazines

• Ramana Sreenivasa Rao and
• Chinnasamy Ramaraj Ramanathan

Beilstein J. Org. Chem. 2017, 13, 428–440, doi:10.3762/bjoc.13.46

• evidence for cyclized compounds 9b and 10a was supported by single-crystal X-ray diffraction analysis (Figure 3) in addition to IR, NMR and HRMS data. To show the synthetic utility of substituted pyrazinones, we introduce a phenyl group at the C-3 position in pyrazinone derivative 10a. To begin with, the

Multicomponent synthesis of spiropyrrolidine analogues derived from vinylindole/indazole by a 1,3-dipolar cycloaddition reaction

• Manjunatha Narayanarao,
• Lokesh Koodlur,
• Vijayakumar G. Revanasiddappa,
• Subramanya Gopal and
• Susmita Kamila

Beilstein J. Org. Chem. 2016, 12, 2893–2897, doi:10.3762/bjoc.12.288

• appeared as a triplet of doublets (δ 3.42 ppm) and multiplet (δ 3.59 ppm), and the N–CH3 of the pyrrolidine ring as a singlet at δ 2.36 ppm. Further, the structures of 7a and 7f were confirmed by single crystal X-ray diffraction studies and the corresponding ORTEP representations are given in Figure 2

New approaches to organocatalysis based on C–H and C–X bonding for electrophilic substrate activation

• Pavel Nagorny and
• Zhankui Sun

Beilstein J. Org. Chem. 2016, 12, 2834–2848, doi:10.3762/bjoc.12.283

• (−)-sparteine hydrobromide in chloroform was treated with racemic 1,2-dibromohexafluoropropane, a yellow co-crystal was isolated. The structure of the co-crystal was confirmed by single-crystal X-ray diffraction, and it showed that the co-crystal was made up from one molecule of (−)-sparteine hydrobromide and

Organofluorine chemistry: Difluoromethylene motifs spaced 1,3 to each other imparts facial polarity to a cyclohexane ring

• Mathew J. Jones,
• Ricardo Callejo,
• Alexandra M. Z. Slawin,
• Michael Bühl and
• David O'Hagan

Beilstein J. Org. Chem. 2016, 12, 2823–2827, doi:10.3762/bjoc.12.281

• , showing a characteristic AB system in 19F NMR for axial/equatorial fluorines, and a triplet (1JCF = 250 Hz) in 13C NMR for the CF2 group. In addition, single crystal X-ray diffraction data were obtained for 4c which confirmed the structure (Figure 2). The C–CF2–C angles in the cyclohexane ring are

• interaction of the positive non-fluorous face with the π-system of an aromatic ring by single crystal X-ray diffraction and NMR experiments. Additionally, the polarity of 4c has been calculated by computational optimisations. It follows that functionalised cyclohexanes containing the 1,3-di-CF2 motif would

From betaines to anionic N-heterocyclic carbenes. Borane, gold, rhodium, and nickel complexes starting from an imidazoliumphenolate and its carbene tautomer

• Ming Liu,
• Jan C. Namyslo,
• Martin Nieger,
• Mika Polamo and
• Andreas Schmidt

Beilstein J. Org. Chem. 2016, 12, 2673–2681, doi:10.3762/bjoc.12.264

• mass spectrometer with electrospray ionisation. The single-crystal X-ray diffraction studies were carried out on a Bruker D8 Venture diffractometer with Photon100 detector at 123(2) K using Cu Kα (8) and Mo Kα radiation (9, 11, 12) (λ = 1.54178 Å and 0.71073 Å). Dual space methods (8, SHELXT) [53] and

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

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

• diastereoselectivity of the cycloaddition were elucidated by spectroscopic methods and single crystal X-ray diffraction. The cycloadducts 4a–t were characterized by IR, NMR, and HRMS analytical methods. The IR spectra of compounds 4 showed three intense absorption bands at 1728–1697, 1709–1680 (in some cases instead

• 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

Determination of the absolute stereostructure of a cyclic azobenzene from the crystal structure of the precursor containing a heavy element

• Reji Thomas and
• Nobuyuki Tamaoki

Beilstein J. Org. Chem. 2016, 12, 2211–2215, doi:10.3762/bjoc.12.212

• Single crystal X-ray diffraction has been used as one of the common methods for the unambiguous determination of the absolute stereostructure of chiral molecules. However, this method is limited to molecules containing heavy atoms or to molecules with the possibility of functionalization with heavy

New furoisocoumarins and isocoumarins from the mangrove endophytic fungus Aspergillus sp. 085242

• Ze’en Xiao,
• Senhua Chen,
• Runlin Cai,
• Shao’e Lin,
• Kui Hong and
• Zhigang She

Beilstein J. Org. Chem. 2016, 12, 2077–2085, doi:10.3762/bjoc.12.196

• ): 268 (4.64), 299 (3.36) nm; IR (KBr) νmax: 3476, 2998, 1670, 1581, 1369, 1283, 1125 cm−1; EIMS (m/z): 430; HRMS–ESI (m/z): [M − H]− calcd for C15H18O4, 429.1186; found, 429.1186; 1H NMR (CDCl3, 400 MHz) and 13C NMR (CDCl3, 100 MHz), see Table 2. X-ray crystallographic analysis. Single crystal X-ray

• diffraction data were collected at 123 K on an Agilent Gemini Ultra diffractometer with CuKα radiation (λ = 1.54178 Å). The structures were solved by direct methods (SHELXS-97) and refined using full-matrix least-squares difference Fourier techniques. Hydrogen atoms bonded to carbons were placed on the

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

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

• restrained to an equilateral triangle. The Cu–Cu distances are around 2.4887 Å and are shorten than that of complexe 6, which may be attributed to more rigid ligand. Complex 6 has also been characterized by single crystal X-ray diffraction (Figure 5). Complex 6 crystallizes in the hexagonal space group R3c

• 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

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

• the Rh(III) and Ir(III) complexes of 2a, respectively). The structures of [2a-Cp*IrI]BF4, and [5-Cp*IrI]BF4 were confirmed unambiguously by single-crystal X-ray diffraction. The solid-state structure of [2a-Cp*IrI]BF4 confirms the tetrahedral environment of the iridium center, rendering the two faces

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

Spiro-fused carbohydrate oxazoline ligands: Synthesis and application as enantio-discrimination agents in asymmetric allylic alkylation

• Jochen Kraft,
• Martin Golkowski and
• Thomas Ziegler

Beilstein J. Org. Chem. 2016, 12, 166–171, doi:10.3762/bjoc.12.18

• with Pd(cod)Cl2 (Figure 1). Single crystal X-ray diffraction of these Pd complexes revealed some interesting structural features in terms of ligand–metal bite angles and shielding of the palladium center by the carbohydrate scaffold from one specific side [17]. For example, we concluded from the

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

• calculations. Solid state structure of complexes 2a and 2b as retrieved from single crystal X-ray diffraction. Time/conversion plot for the polymerization of 5 by preinitiators 1–4 in the presence of HCl ([5]:[HCl]:[I] = 50:25:1; [5] = 0.1 mol/L; solvent:CDCl3). 1H NMR spectrum in the low-field region of the

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

• approximate unit cell dimensions (a ≈ 19.2, b ≈ 24.4, c ≈ 32.8 Å), results which were subsequently confirmed by a single crystal X-ray diffraction study of the same phase obtained via the co-precipitation method. (Relevant PXRD traces and single crystal data are provided in Supporting Information File 1

• . All of these preparations displayed superior dissolution characteristics to those of untreated 2ME, only 30% of which dissolved in the same medium within 20 minutes. Conclusion Single crystal X-ray diffraction has revealed the modes of inclusion of the potent anticancer agent 2-methoxyestradiol (2ME

• (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

• reaction conditions. The structures of 2a–d were confirmed by spectroscopic and elemental analysis data and (for 3a) by a single-crystal X-ray diffraction study (vide infra). Thioamidophoshonates 2a–d readily reacted with Oxone® in acetonitrile–water at room temperature to afford the corresponding

Half-sandwich nickel(II) complexes bearing 1,3-di(cycloalkyl)imidazol-2-ylidene ligands

• Johnathon Yau,
• Kaarel E. Hunt,
• Laura McDougall,
• Alan R. Kennedy and
• David J. Nelson

Beilstein J. Org. Chem. 2015, 11, 2171–2178, doi:10.3762/bjoc.11.235

• versus sealed tubes. Molecular structures of complexes [NiCl(Cp)(ICy)] (3) (left) and [NiCl(Cp)(IDD)] (4) (right) as determined by single crystal X-ray diffraction. Displacement ellipsoids are drawn at 50% probability. Most H atoms are excluded for clarity. Synthesis of [Ni(η1-Cp)(η5-Cp)(IMes)] (1) and

• -crystal X-ray diffraction analyses of [NiCl(Cp)(ICy)] and [NiCl(Cp)(IDD)]. Selected bond distances (units Å). Results of test reactions with 4’-bromo- and 4’-chloroacetophenone, conducted using the conditions detailed in Scheme 4.a Supporting Information Supporting Information File 463: Crystal structure

• [NiCl(Cp)(IMes)] (2). Synthesis of [NiCl(Cp)(ICy)] using conventional heating. Synthesis of (a) [NiCl(Cp)(ICy)] (3) and (b) [NiCl(Cp)(IDD)] (4) with microwave heating. Model Suzuki–Miyaura reaction for the evaluation of the new complexes as cross-coupling pre-catalysts. Experimental data for single

A convenient four-component one-pot strategy toward the synthesis of pyrazolo[3,4-d]pyrimidines

• Mingxing Liu,
• Jiarong Li,
• Hongxin Chai,
• Kai Zhang,
• Deli Yang,
• Qi Zhang and
• Daxin Shi

Beilstein J. Org. Chem. 2015, 11, 2125–2131, doi:10.3762/bjoc.11.229

• -6-(2-nitrophenyl)-1-phenyl-1H-pyrazolo[3,4-d]pyrimidine was determined by single crystal X-ray diffraction. Keywords: four-component; one-pot; pyrazolo[3,4-d]pyrimidine; sodium alkoxide; Introduction Heterocycles containing a pyrimidine ring are extensively present in natural products and are very

Effective ascorbate-free and photolatent click reactions in water using a photoreducible copper(II)-ethylenediamine precatalyst

• Redouane Beniazza,
• Natalia Bayo,
• Florian Molton,
• Carole Duboc,
• Stéphane Massip,
• Nathan McClenaghan,
• Dominique Lastécouères and
• Jean-Marc Vincent

Beilstein J. Org. Chem. 2015, 11, 1950–1959, doi:10.3762/bjoc.11.211

• , has been synthesized and characterized by different techniques including single crystal X-ray diffraction. Highly efficient photoreduction was demonstrated when solutions of 1 in hydrogen atom donating solvents, such as THF or MeOH, were exposed to UVA radiation (350–400 nm) provided by a low pressure

• vapour into the THF solution led to the crystallization of 1 as blue needles, which were recovered by filtration (71% yield). The proposed dinuclear and mononuclear structures of 4 and 1 were confirmed by single crystal X-ray diffraction (Figure 1). The crystal structure of 4 displays the typical “paddle