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

• least-squares technique using SHELXH [22]. With only a single complex unit DIMEB·2ME in the crystal asymmetric unit, structure solution was fairly straightforward. However, the structure determination and refinement of the TRIMEB inclusion complex proved to be considerably more challenging due to the

Bromotyrosine-derived alkaloids from the Caribbean sponge Aplysina lacunosa

• Qun Göthel,
• Thanchanok Sirirak and
• Matthias Köck

Beilstein J. Org. Chem. 2015, 11, 2334–2342, doi:10.3762/bjoc.11.254

• ), 113.1 (C-2), 120.9 (C-4), 131.1 (C-5), 147.1 (C-3), 154.3 (C-8), and 159.0 (C-9) together with 1H,13C-HMBC correlations revealed that 2 consist of only one spirocyclohexadienylisoxazoline moiety in comparison with 1. The structure determination of 2 was accomplished based on 1H,1H-COSY and 1H,13C-HMBC

Hexacoordinate Ru-based olefin metathesis catalysts with pH-responsive N-heterocyclic carbene (NHC) and N-donor ligands for ROMP reactions in non-aqueous, aqueous and emulsion conditions

• Shawna L. Balof,
• K. Owen Nix,
• Matthew S. Olliff,
• Sarah E. Roessler,
• Arpita Saha,
• Kevin B. Müller,
• Ulrich Behrens,
• Edward J. Valente and
• Hans-Jörg Schanz

Beilstein J. Org. Chem. 2015, 11, 1960–1972, doi:10.3762/bjoc.11.212

• ; N, 12.41; found: C, 58.26; H, 6.49, N, 11.74. Crystal structure determination of complex 12. Crystals suitable for X-ray diffraction were obtained by layer diffusion of heptane into a THF solution of complex 12 at ambient temperatures over a period of 3 d to yield dark brown prisms. The crystals do

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

The chemical behavior of terminally tert-butylated polyolefins

• Dagmar Klein,
• Henning Hopf,
• Peter G. Jones,
• Ina Dix and
• Ralf Hänel

Beilstein J. Org. Chem. 2015, 11, 1246–1258, doi:10.3762/bjoc.11.139

• investigation was carried out. Although the quality of the structure determination was disappointing because of high residual electron density, it sufficed to determine the connectivity of the atoms in the compound and to demonstrate that the double bond configuration was E (Figure 1). The molecule possesses no

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

• electrolyte. Crystal structure determination X-ray diffraction studies were performed with a Bruker APEX-II CCD detector diffractometer using graphite-monochromated Mo Kα radiation (λ = 0.71073 Å), in the φ and ω scans mode. A semi empirical absorption correction was carried out using SADABS [25]. Data

Hetero-Diels–Alder reactions of hetaryl and aryl thioketones with acetylenic dienophiles

• Grzegorz Mlostoń,
• Paulina Grzelak,
• Maciej Mikina,
• Anthony Linden and
• Heinz Heimgartner

Beilstein J. Org. Chem. 2015, 11, 576–582, doi:10.3762/bjoc.11.63

• sulfoxide. No attempts were made to isolate this product. The same oxidation protocol was applied to convert thiopyranes 5a, 4b, and 5b into the corresponding sulfones 6b–6d in 94, 70, and 80% yield, respectively. The structure of 6d was established by X-ray single crystal structure determination (Figure 2

• , details of the crystal structure determination, and the original 1H and 13C NMR spectra for all products. CCDC-1038599 and 1038600 contain the supplementary crystallographic data for this paper. These data can be obtained free of charge from The Cambridge Crystallographic Data Centre via http

• polycyclic thiopyran derivatives 4b and 4c, respectively, were obtained in 90 and 46% yield (Scheme 2). In the 1H NMR spectra of both compounds the low-field shifted CHS signal appeared at 5.82 and 4.49 ppm. Finally, the 2H-thiopyran structure of 4b was established by X-ray single crystal structure

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

• not the hoped-for diene 22, but an isomer, the hydrocarbon 23 (Scheme 5). The structure of hydrocarbon 23 was established by the usual spectroscopic data (see experimental section) and also by an X-ray crystal structure determination (Figure 3). The molecule of 23 is planar (mean deviation 0.03 Å) and

• structure determination had to await X-ray crystallographic analysis. The required single crystals were obtained from the different chromatographic fractions (which contained either isomer in enriched form only) by recrystallization from chloroform and dichloromethane/chloroform, respectively. As can be

• observed (H5···π 2.76 Å, H9A···π 2.83 Å). The structure determination of 25 was of limited accuracy because of twinning and disorder problems (indeed, there may be a small amount of contamination by 24) and we therefore do not discuss it in detail. Both independent molecules display non-crystallographic

Synthesis of dinucleoside acylphosphonites by phosphonodiamidite chemistry and investigation of phosphorus epimerization

• William H. Hersh

Beilstein J. Org. Chem. 2015, 11, 184–191, doi:10.3762/bjoc.11.19

• barriers. Supporting Information Supporting Information contains the experimental procedures, characterization of new compounds, copies of 1H, 13C and 31P NMR spectra, IR spectra, details of the X-ray structure determination, and details of the DFT calculations. Supporting Information File 189

Efficient deprotection of F-BODIPY derivatives: removal of BF₂ using Brønsted acids

• Mingfeng Yu,
• Joseph K.-H. Wong,
• Cyril Tang,
• Peter Turner,
• Matthew H. Todd and
• Peter J. Rutledge

Beilstein J. Org. Chem. 2015, 11, 37–41, doi:10.3762/bjoc.11.6

• structure determination is available as Supporting Information File 2 and is also available on request from the Cambridge Crystallographic Data Centre as deposition 1018518. Conversion of F-BODIPYs 1 to the parent dipyrrins 2. Synthesis of the triazolyl-cyclam/F-BODIPY conjugates 3 (A) and 4 (B). Reagents

Inclusion of trans-resveratrol in methylated cyclodextrins: synthesis and solid-state structures

• Lee Trollope,
• Dyanne L. Cruickshank,
• Terence Noonan,
• Susan A. Bourne,
• Milena Sorrenti,
• Laura Catenacci and
• Mino R. Caira

Beilstein J. Org. Chem. 2014, 10, 3136–3151, doi:10.3762/bjoc.10.331

• , permethylated β-CD and 2,6-dimethylated β-CD) are described. Isolation of the corresponding crystalline 1:1 inclusion compounds enabled their full structure determination by X-ray analysis for the first time, revealing a variety of guest inclusion modes and unique supramolecular crystal packing motifs. The

Reversibly locked thionucleobase pairs in DNA to study base flipping enzymes

• Christine Beuck and
• Elmar Weinhold

Beilstein J. Org. Chem. 2014, 10, 2293–2306, doi:10.3762/bjoc.10.239

• , as we demonstrated for the DNA MTase M.TaqI, but could also be used to determine their site and mechanism of action by introducing cross-linked base pairs at different positions within the DNA, or stall proteins on the DNA in a pre-flipped complex for structure determination to reveal the initial

A new charge-tagged proline-based organocatalyst for mechanistic studies using electrospray mass spectrometry

• J. Alexander Willms,
• Rita Beel,
• Martin L. Schmidt,
• Christian Mundt and
• Marianne Engeser

Beilstein J. Org. Chem. 2014, 10, 2027–2037, doi:10.3762/bjoc.10.211

• to the reported procedure [54] and obtained as orange oil (using L-proline: 83%, using 1: 80%). Crystal structure determination: X-ray crystallographic analysis of 7 was performed on a Nonius KappaCCD diffractometer using graphite monochromated Mo Kα radiation (λ = 0.71073 Å). Intensities were

• X-ray structure determination and Prof. A. C. Filippou for providing X-ray infrastructure.

Five-membered ring annelation in [2.2]paracyclophanes by aldol condensation

• Henning Hopf,
• Swaminathan Vijay Narayanan and
• Peter G. Jones

Beilstein J. Org. Chem. 2014, 10, 2021–2026, doi:10.3762/bjoc.10.210

• were obtained by recrystallization from pentane/chloroform to allow their X-ray structure determination in the solid state. The results are shown in Figure 2. The molecule displays crystallographic inversion symmetry (which precludes the use of standard cyclophane numbering to some extent). It shows

Macrocyclic bis(ureas) as ligands for anion complexation

• Claudia Kretschmer,
• Gertrud Dittmann and
• Johannes Beck

Beilstein J. Org. Chem. 2014, 10, 1834–1839, doi:10.3762/bjoc.10.193

• planar ligand, as was shown by indole-based macrocycles [9]. This ligand system represents a stiff ring of two bis(indole) units connected via two ethynylene groups as linkers. As proven by a crystal structure determination, a chloride ion fits into the cavity bound via four N−H∙∙∙Cl bonds and strong

• in good yields. The quest for the molecular conformation is challenging for both molecules. Since the bis(triazenide) congeners of 1 and 2 are planar, one can presume an analogous molecular shape for the bis(ureas). All attempts to obtain single crystals of 1 for a structure determination failed

A tandem Mannich addition–palladium catalyzed ring-closing route toward 4-substituted-3(2H)-furanones

• Jubi John,
• Eliza Târcoveanu,
• Peter G. Jones and
• Henning Hopf

Beilstein J. Org. Chem. 2014, 10, 1462–1470, doi:10.3762/bjoc.10.150

• the usual spectroscopic methods (see Supporting Information File 1) and also by X-ray structure determination [43] for furanones 7 (product formed by the reaction of 1b with 2b) and 10 (product formed by the reaction of 1d with 2a) (Figure 3). We believe that the mechanism of the present furanone

Tandem Cu-catalyzed ketenimine formation and intramolecular nucleophile capture: Synthesis of 1,2-dihydro-2-iminoquinolines from 1-(o-acetamidophenyl)propargyl alcohols

• Gadi Ranjith Kumar,
• Yalla Kiran Kumar,
• Ruchir Kant and
• Maddi Sridhar Reddy

Beilstein J. Org. Chem. 2014, 10, 1255–1260, doi:10.3762/bjoc.10.125

• for supervising the X-ray data collection and structure determination of 9j reported in this paper. We gratefully acknowledge the financial support by CSIR-Network project 'BSC0102' (CSIR-CDRI-THUNDER) and by DST under the 'Fast Track Proposal Scheme for Young Scientists'. CDRI Communication No. 8678.

Copper–phenanthroline catalysts for regioselective synthesis of pyrrolo[3′,4′:3,4]pyrrolo[1,2-a]furoquinolines/phenanthrolines and of pyrrolo[1,2-a]phenanthrolines under mild conditions

• Rupankar Paira,
• Tarique Anwar,
• Maitreyee Banerjee,
• Yogesh P. Bharitkar,
• Shyamal Mondal,
• Sandip Kundu,
• Abhijit Hazra,
• Prakas R. Maulik and
• Nirup B. Mondal

Beilstein J. Org. Chem. 2014, 10, 692–700, doi:10.3762/bjoc.10.62

• -least-squares methods on F2. Programs: APEX2 (Bruker AXS Inc., Madison, Wisconsin, USA) for data collection, SAINT (Bruker AXS Inc., Madison, Wisconsin, USA) for cell refinement and data reduction, SHELXTL (Bruker AXS Inc., Madison, Wisconsin, USA) for structure determination, refinements and molecular

Self-assembly of metallosupramolecular rhombi from chiral concave 9,9’-spirobifluorene-derived bis(pyridine) ligands

• Rainer Hovorka,
• Sophie Hytteballe,
• Torsten Piehler,
• Georg Meyer-Eppler,
• Filip Topić,
• Kari Rissanen,
• Marianne Engeser and
• Arne Lützen

Beilstein J. Org. Chem. 2014, 10, 432–441, doi:10.3762/bjoc.10.40

• {[(dppp)2Pd2{(S)-6}2](OTf)2}2+, 2482.5 {[(dppp)2Pd2{(S)-6}2](OTf)3}+ and {[(dppp)4Pd4{(S)-6}4](OTf)6}2+. Crystal structure determination: Data for the X-ray crystallographic analysis of [(dppp)2Pd2{(R)-3}2][(dppp)2Pd2{(S)-3}2](OTf)8 derived from (rac)-3 and [(dppp)Pd(OTf)2] were collected on a SuperNova

Four-component reaction of cyclic amines, 2-aminobenzothiazole, aromatic aldehydes and acetylenedicarboxylate

• Hong Gao,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2013, 9, 2934–2939, doi:10.3762/bjoc.9.330

• the different reactivity of piperidine, pyrrolidine and morpholine in this reaction is not very clear. The structures of the prepared 2-pyrrolidinones 1a–1n were fully characterized by 1H and 13C NMR, HRMS, IR spectra, and were further confirmed by single crystal structure determination of compound 1f

• -olates 2f–2h in good yields (Table 2, entries 6–8). The prepared piperidinium and morpholinium 2-pyrrolidinon-3-olates 2a–2h are very stable compounds. Their structures were fully characterized by 1H and 13C NMR, HRMS, IR spectra, and were also confirmed by single crystal structure determination of

Less reactive dipoles of diazodicarbonyl compounds in reaction with cycloaliphatic thioketones – First evidence for the 1,3-oxathiole–thiocarbonyl ylide interconversion

• Valerij A. Nikolaev,
• Alexey V. Ivanov,
• Ludmila L. Rodina and
• Grzegorz Mlostoń

Beilstein J. Org. Chem. 2013, 9, 2751–2761, doi:10.3762/bjoc.9.309

• precipitate was separated by filtration and washed with dichloromethane (2 × 1–2 mL). The solvents from the filtrate were evaporated and the reaction products from the residue were isolated by recrystallization or chromatography. X-ray crystal-structure determination of 3a. All measurements were performed on

Synthesis and characterization of novel bioactive 1,2,4-oxadiazole natural product analogs bearing the N-phenylmaleimide and N-phenylsuccinimide moieties

• Catalin V. Maftei,
• Elena Fodor,
• Peter G. Jones,
• M. Heiko Franz,
• Gerhard Kelter,
• Heiner Fiebig and
• Ion Neda

Beilstein J. Org. Chem. 2013, 9, 2202–2215, doi:10.3762/bjoc.9.259

• underwent a cyclodehydration reaction, delivering aniline 1 with 59% yield after purification. The structure of compound 1 was confirmed by X-ray structure determination (Figure 3 and Figure 4). It crystallizes with two molecules in the asymmetric unit, which differ in the relative orientation of the rings

• -butylamidoxime and 4-nitrobenzonitrile under mild conditions. The results are summarized in Table 1. The optimized yield was 93% (Scheme 3) which makes this route more practical than the amidoxime route presented in Scheme 2 with a yield of only 59%. The structure of compound 2 was confirmed by X-ray structure

• determination (Figure 5 and Figure 6). The interplanar angle in compound 2 is only 3° and the molecules are linked to ribbons parallel to the b axis by two C–H···O interactions. Imide derivatives have been found to possess a broad spectrum of biological activities. A variety of methods have been reported for

Sequential Diels–Alder/[3,3]-sigmatropic rearrangement reactions of β-nitrostyrene with 3-methyl-1,3-pentadiene

• Peter A. Wade,
• Alma Pipic,
• Matthias Zeller and
• Panagiota Tsetsakos

Beilstein J. Org. Chem. 2013, 9, 2137–2146, doi:10.3762/bjoc.9.251

• where ternary adduct 12a,b is formed. Consistent with the presence of these zwitterions, the related open-chain adduct 13 was a minor product obtained from the reaction of Z-diene 1b and β-nitrostyrene in dichloromethane solution. Nitronic ester structure determination Structure assignments for nitronic

Synthesis of enantiomerically pure (2S,3S)-5,5,5-trifluoroisoleucine and (2R,3S)-5,5,5-trifluoro-allo-isoleucine

• Holger Erdbrink,
• Elisabeth K. Nyakatura,
• Susanne Huhmann,
• Ulla I. M. Gerling,
• Dieter Lentz,
• Beate Koksch and
• Constantin Czekelius

Beilstein J. Org. Chem. 2013, 9, 2009–2014, doi:10.3762/bjoc.9.236

• confirmed by crystal structure determination of intermediate 6, based on the known auxiliary configuration (see Supporting Information File 1). Hydrophobicity of L-5-F3-Ile We investigated the relationship between side chain volume and hydrophobicity of L-5-F3Ile. Since size and hydrophobicity are known to

Synthesis of the reported structure of piperazirum using a nitro-Mannich reaction as the key stereochemical determining step

• James C. Anderson,
• Andreas S. Kalogirou,
• Michael J. Porter and
• Graham J. Tizzard

Beilstein J. Org. Chem. 2013, 9, 1737–1744, doi:10.3762/bjoc.9.200

• [56]. Further stereochemical proof was provided by a single crystal X-ray structure determination of 2·HCl (vide infra). We presumed again that the primary amine of 21 would be more nucleophilic towards a keto acid derivative 5. In order to obtain a piperazinone of the desired connectivity (23) a keto

• recording of NMR spectra in D2O, but again the chemical shifts were inconsistent with those reported. Single crystal X-ray structure determination of 2 proved unambiguously the assigned structure obtained from spectroscopic data (Figure 1) [59]. Conclusion The rapid synthesis of r-3,c-5-diisobutyl-c-6