Trifluoromethyl-substituted tetrathiafulvalenes

• Olivier Jeannin,
• Frédéric Barrière and
• Marc Fourmigué

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

• < CO2Me < CF3 < CN, as discussed above (Table 1 and Table 2). X-ray crystal structures of the neutral donor molecules As mentioned in the Introduction, the substitution of one hydrogen atom on the TTF core by one EWG such as ester or cyano group is known to distort the dithiole ring, as illustrated in

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

• , respectively. These electrochemical studies show that α-tbtdt and α-mtdt are easier to oxidise than the related unsubstituted extended TTFs, with higher electron donor ability compared to related TTF-type donors with the exception of BET-TTF. Crystal structures Ketone I Compound I crystallises in the

Azirinium ylides from α-diazoketones and 2H-azirines on the route to 2H-1,4-oxazines: three-membered ring opening vs 1,5-cyclization

• Nikolai V. Rostovskii,
• Mikhail S. Novikov,
• Alexander F. Khlebnikov,
• Galina L. Starova and
• Margarita S. Avdontseva

Beilstein J. Org. Chem. 2015, 11, 302–312, doi:10.3762/bjoc.11.35

• -azabuta-1,3-dienes which transform back to the oxazines in the dark at room temperature. The rate of the reverse cyclization reaction increases with increasing electron-withdrawing ability of C1-substituent in 2-azabuta-1,3-diene. X-ray crystal structure of azadiene 3e. X-ray crystal structures of

Molecular cleft or tweezer compounds derived from trioxabicyclo[3.3.1]nonadiene diisocyanate and diacid dichloride

• Gert Kollenz,
• Ralf Smounig,
• Ferdinand Belaj,
• David Kvaskoff and
• Curt Wentrup

Beilstein J. Org. Chem. 2015, 11, 1–8, doi:10.3762/bjoc.11.1

• minima [1]. Optimization of the endo,exo structure leads to ring opening to a new diisocyanate (Scheme 1). Therefore, it is of some importance to ascertain the actual molecular structures of compounds of this type by X-ray crystallography. Here we report the X-ray crystal structures of two derivatives of

• in Supporting Information File 1). It is seen in the crystal structures depicted in Figures 3–5 that compounds 4 and 5 (and therefore also 1) exist in the endo,endo structures, and each functional group is surrounded by three tert-butyl groups, which direct these functional groups away from the ether

• close proximity. Calculations The structures of 4 and 5 were calculated at the B3LYP/6-31G** level, which reproduces the crystal structures very well, as demonstrated in Figure 6 and Figure 7 and in Figure S2 and Figure S3 (Supporting Information File 1). While there are several possible conformations

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

• solid-state inclusion complexes between RSV and CDs, despite the fact that such complexes have strong potential for incorporation into tablets or capsules when formulated for medicinal use. A search of the Cambridge Crystallographic Database [10] revealed that no CD·RSV crystal structures have been

• occurring in two of the three complex crystal structures investigated. Finally, as far as further new insights from the X-ray studies are concerned, we conclude that CD-RSV inclusion in the more flexible hosts TMA and TMB involves a mutual induced fit. The evidence for this is the flexibility displayed by

• the RSV molecule, reflected in the wide range observed for the interplanar angle between the phenyl rings [17.7(1)–51.6(3)°] in the respective complex crystal structures, coupled with significant host distortions to accommodate the RSV molecule. In contrast, with the host DMB, whose round structure is

Synthesis and characterization of a new photoinduced switchable β-cyclodextrin dimer

• Florian Hamon,
• Claire Blaszkiewicz,
• Marie Buchotte,
• Estelle Banaszak-Léonard,
• Hervé Bricout,
• Sébastien Tilloy,
• Eric Monflier,
• Christine Cézard,
• Laurent Bouteiller,
• Christophe Len and
• Florence Djedaini-Pilard

Beilstein J. Org. Chem. 2014, 10, 2874–2885, doi:10.3762/bjoc.10.304

• were 9.1 and 6.6 Å for the trans and cis configurations, respectively, and the C–N=N–C dihedral angles were 180° and −10°, respectively. These results are comparable to those obtained by Koshima et al. [33][34] on crystal structures where intermolecular packing effects might be important. From these

Gold(I)-catalysed synthesis of a furan analogue of thiamine pyrophosphate

• Amjid Iqbal,
• El-Habib Sahraoui and
• Finian J. Leeper

Beilstein J. Org. Chem. 2014, 10, 2580–2585, doi:10.3762/bjoc.10.270

• base that deprotonates C-2 to form the ylid [7][8]. Although many crystal structures of ThDP dependent enzymes exist, there still are some unanswered questions regarding mechanistic processes of these enzymes (e.g., how the substrate binds, what is the role of important catalytic groups, how are

De novo macrolide–glycolipid macrolactone hybrids: Synthesis, structure and antibiotic activity of carbohydrate-fused macrocycles

• Richard T. Desmond,
• Anniefer N. Magpusao,
• Chris Lorenc,
• Jeremy B. Alverson,
• Nigel Priestley and
• Mark W. Peczuh

Beilstein J. Org. Chem. 2014, 10, 2215–2221, doi:10.3762/bjoc.10.229

• macrocycle through the C1’ (glycosidic) and C6’ oxygens. The new macrolides bear a resemblance to sophorolipid lactone 2 and to polyketide macrocycles that contain a tetrahydropyran moiety [20][21][22]. We report on the synthesis, X-ray crystal structures and antibiotic activities of the new compounds

A new approach for the synthesis of bisindoles through AgOTf as catalyst

• Jorge Beltrá,
• M. Concepción Gimeno and
• Raquel P. Herrera

Beilstein J. Org. Chem. 2014, 10, 2206–2214, doi:10.3762/bjoc.10.228

• the values previously reported in [59]. 13C APT-NMR (100 MHz, CDCl3) δ 135.3 (2C), 128.7 (2C), 121.9 (2C), 121.6 (2C), 119.4 (2C), 119.2 (2C), 119.1 (2C), 110.7 (2C), 43.1 (1C), 35.8 (1C), 29.0 (3C). Bisindolyl based important targets: 1 [21], 2 [22] and 3 [23]. Crystal structures for compounds 6ad

Scalable synthesis of 5,11-diethynylated indeno[1,2-b]fluorene-6,12-diones and exploration of their solid state packing

• Bradley D. Rose,
• Peter J. Santa Maria,
• Aaron G. Fix,
• Chris L. Vonnegut,
• Lev N. Zakharov,
• Sean R. Parkin and
• Michael M. Haley

Beilstein J. Org. Chem. 2014, 10, 2122–2130, doi:10.3762/bjoc.10.219

• row – 8f, 8f, 8g; 4th row 8h, 8i, 8j. Hydrogen atoms omitted for clarity; ellipsoids drawn at the 30% probability; individual molecules were colored the same to identify overlap easier. Schematic of the parameters used for comparing X-ray crystal structures, view is parallel to the molecular plane

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

• dimethylformamide (DMF) and act as complexing agents towards a series of anions (Cl−, Br−, I−, NO3−, HSO4−). The crystal structures of 3, 2·2DMSO, 2·2DMF, and of the complex NEt4[Br·2] have been determined. Quantitative investigations of the complexation equilibria were performed via 1H NMR titrations. While 1 is a

• positioned protons may arise from the interaction with the carbonyl oxygen atom of the urea groups. This interaction is sensitive on the conformation of the flexible macrocyclic ring system. Comparing the crystal structures of 2·2DMSO/DMF with [Br·2]− shows a slight decrease of the mean O···H(ortho) distance

Selective allylic hydroxylation of acyclic terpenoids by CYP154E1 from Thermobifida fusca YX

• Anna M. Bogazkaya,
• Clemens J. von Bühler,
• Sebastian Kriening,
• Alexandrine Busch,
• Alexander Seifert,
• Jürgen Pleiss,
• Sabine Laschat and
• Vlada B. Urlacher

Beilstein J. Org. Chem. 2014, 10, 1347–1353, doi:10.3762/bjoc.10.137

• smenochromene D [21], pseudopteranes, furanocembranes [22], indole alkaloids [23], and antitumor cembrane lactones crassin and isolobophytolide [24][25]. Obviously, there is a need for P450s with changed chemoselectivity. Previously a systematic analysis of 31 P450 crystal structures and more than 6300 P450

Palladium-catalysed cross-coupling reaction of ultra-stabilised 2-aryl-1,3-dihydro-1H-benzo[d]1,3,2-diazaborole compounds with aryl bromides: A direct protocol for the preparation of unsymmetrical biaryls

• Siphamandla Sithebe and
• Ross S. Robinson

Beilstein J. Org. Chem. 2014, 10, 1107–1113, doi:10.3762/bjoc.10.109

• syntheses, crystal structures, fluorescence and theoretical characteristics of 1,3,2-diazaborolane functionalised organic molecules, which is reported in details elsewhere [17], we were encouraged by the high yields of 2-aryl-1,3-dihydro-1H-benzo[d]1,3,2-diazaborole compounds (Scheme 1), their solubility in

Columnar/herringbone dual crystal packing of pyrenylsumanene and its photophysical properties

• Binod Babu Shrestha,
• Shuhei Higashibayashi and
• Hidehiro Sakurai

Beilstein J. Org. Chem. 2014, 10, 841–847, doi:10.3762/bjoc.10.80

• columnar structure of buckybowl crystals resulting from convex–concave intermolecular π–π interactions is expected to be quite predictable and to serve as a directing force to provide specific crystal structures [16][17]. The present study demonstrates the promising possibility of utilizing the sumanene

• moiety as a directing group to obtain specific crystal structures. Experimental General UV–visible absorption spectra were recorded on a JASCO V-670 spectrometer. Fluorescence spectra were recorded on a JASCO FP6500 spectrometer. Melting points were determined on a Standford Research Systems MPA 100 and

Intermediates in monensin biosynthesis: A late step in biosynthesis of the polyether ionophore monensin is crucial for the integrity of cation binding

• Wolfgang Hüttel,
• Jonathan B. Spencer and
• Peter F. Leadlay

Beilstein J. Org. Chem. 2014, 10, 361–368, doi:10.3762/bjoc.10.34

• improved therapeutic properties. We report here fresh insight into the order of the final steps of monensin biosynthesis, facilitated by genetic manipulation of an industrial strain of S. cinnamonensis. Further, the crystal structures of two of the monensin analogues obtained reveal the structural basis

• hydrogen bonds for the stability of the complex is underlined by the conservation of this feature in the crystal structures of the polyether ionophores nigericin [30][31] and dianemycin (nanchangmycin) [32], where a carboxylic acid oxygen atom likewise form hydrogen bonds to the distal hydroxy groups

• was set to record positive and negative ion scans between m/z 300 to 1000. Crystal structure data: The crystal structures have been deposited at the Cambridge Crystallographic Data Centre and allocated the deposition numbers CCDC-793152(sp0601) for 4 and CCDC-793153(sp0602) for 5. These

Tanzawaic acids I–L: Four new polyketides from Penicillium sp. IBWF104-06

• Louis P. Sandjo,
• Eckhard Thines,
• Till Opatz and
• Anja Schüffler

Beilstein J. Org. Chem. 2014, 10, 251–258, doi:10.3762/bjoc.10.20

• . Crystal structures (ORTEP plot) of arohynapene A (5, left) and tanzawaic acid E (8, right). Thermal ellipsoids are drawn at the 50% probability level. 1H NMR data of compounds 1–4 (CD3OD, 600 MHz). 13C NMR data of compounds 1–4 (CD3OD, 150 MHz). Inhibition of germination in Magnaporthe oryzae (IC90

The difluoromethylene (CF₂) group in aliphatic chains: Synthesis and conformational preference of palmitic acids and nonadecane containing CF₂ groups

• Yi Wang,
• Ricardo Callejo,
• Alexandra M. Z. Slawin and
• David O’Hagan

Beilstein J. Org. Chem. 2014, 10, 18–25, doi:10.3762/bjoc.10.4

• groups locate at the corners, even for 5 which gives rise to a distorted ring conformation [6][7]. Synthesis targets: Palmitic acid analogues 6a–c. DSC traces for the three palmitic acid analogues 6a–c. The X-ray crystal structures of 8,8-difluorohexadecanoic acid (6a). The X-ray structure of 8,8,11,11

Studies toward bivalent κ opioids derived from salvinorin A: heteromethylation of the furan ring reduces affinity

• Thomas A. Munro,
• Wei Xu,
• Douglas M. Ho,
• Lee-Yuan Liu-Chen and
• Bruce M. Cohen

Beilstein J. Org. Chem. 2013, 9, 2916–2924, doi:10.3762/bjoc.9.328

• sites. Immediately adjacent to these residues is Asp1383.32, a critical residue for binding of morphinans and related opioids. Asp3.32 forms strong ionic H-bonds (‘salt bridges’) to the basic nitrogen atoms found in almost all opioids, as in the crystal structures of JDTic (red in Figure 2A

• ), naltrindole [10], β-funaltrexamine [11], and the NOP antagonist C-24 [16]. Beyond opioids, ionic H-bonds to Asp3.32 are conserved across biogenic amine receptors; indeed, this residue3.32 interacts with the ligand in almost all GPCR crystal structures reported to date [17]. In summary, 1 appears to bind

Modulating NHC catalysis with fluorine

• Yannick P. Rey and
• Ryan Gilmour

Beilstein J. Org. Chem. 2013, 9, 2812–2820, doi:10.3762/bjoc.9.316

• catalyst 10 (Scheme 3; lower) was prepared in a short synthesis starting from the primary bromide 23 [22]. Hydrogenolysis (24, 67%) [41] and subsequent conversion to the triazolium salt completed the short synthesis (52% over 3 steps). X-Ray structural analysis of 5, 6 and 7 The X-ray crystal structures of

• respective C-carboxyazlactones (3→4). Target triazolium salts 5–10 for this study. The synclinal-endo conformation of 5 is shown [18]. Only the synclinal-exo arrangement of 6 and 7 is shown [22]. X-ray crystal structures of triazolium salts 5·BF4−, 6·BF4− and 7·BF4− [42]. The tetrafluoroborate counterions

Synthesis of axially chiral gold complexes and their applications in asymmetric catalyses

• Yin-wei Sun,
• Qin Xu and
• Min Shi

Beilstein J. Org. Chem. 2013, 9, 2224–2232, doi:10.3762/bjoc.9.261

•  3). The distance between the center of the aromatic ring in one naphthyl moiety (C20–C25) and the Au atom in (S)-15a was only 3.7 Å (Figure 2). The distance from the Au atom to the center of the bis(trifluoromethyl)phenyl ring (C29–C34) in (S)-15b was 3.5 Å (Figure 3). Thus, their X-ray crystal

• structures clearly revealed the presence of a weak gold–π interaction between the Au atom and the aromatic rings in these gold complexes. Because of the gold–π interaction, the C–N bond could not rotate freely, giving two diastereomeric rotamers (S)-15a and (S)-15b. Slaughter and co-workers have also found

Synthesis, characterization and luminescence studies of gold(I)–NHC amide complexes

• Adrián Gómez-Suárez,
• David J. Nelson,
• David G. Thompson,
• David B. Cordes,
• Duncan Graham,
• Alexandra M. Z. Slawin and
• Steven P. Nolan

Beilstein J. Org. Chem. 2013, 9, 2216–2223, doi:10.3762/bjoc.9.260

• wider range of gold(I)–amide complexes, including those prepared using designed aromatic amines. Further work is underway in our group to explore both the potential of gold(I)–NHC amide complexes, and further applications of gold(I) hydroxides as building blocks and catalysts. X-ray crystal structures

The first example of the Fischer–Hepp type rearrangement in pyrimidines

• Inga Cikotiene,
• Mantas Jonusis and
• Virginija Jakubkiene

Beilstein J. Org. Chem. 2013, 9, 1819–1825, doi:10.3762/bjoc.9.212

• preparation of condensed pyrimidine derivatives [27][28], have an interesting crystal structures [29][30][31], can be useful as bidentate ligands [32][33][34], and represent a class of biologically active compounds [35][36][37][38][39]. Results and Discussion The starting compounds 1 were prepared by the

Selective copper(II) acetate and potassium iodide catalyzed oxidation of aminals to dihydroquinazoline and quinazolinone alkaloids

• Matthew T. Richers,
• Chenfei Zhao and
• Daniel Seidel

Beilstein J. Org. Chem. 2013, 9, 1194–1201, doi:10.3762/bjoc.9.135

• resulted in a lower yield than the corresponding pyrrolidine and azepane products (2 and 12, respectively). While differences in conformation may in part account for the observed differences in reactivity (X-ray crystal structures of aminals containing pyrrolidine and piperidine revealed that the

Enhancement of efficiency in organic photovoltaic devices containing self-complementary hydrogen-bonding domains

• Rohan J. Kumar,
• Jegadesan Subbiah and
• Andrew B. Holmes

Beilstein J. Org. Chem. 2013, 9, 1102–1110, doi:10.3762/bjoc.9.122

• cases are indistinguishable using this model [30]. Crystal structures and scanning tunnelling microscopy studies of related compounds show that both dimers [29], higher order n-mers [31], and chains of hydrogen-bonded molecules are possible [32]. An additional observation from the 1H NMR experiments was

Synthesis of functionalized spiro[indoline-3,4’-pyridines] and spiro[indoline-3,4’-pyridinones] via one-pot four-component reactions

• Li-Juan Zhang,
• Qun Wu,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2013, 9, 846–851, doi:10.3762/bjoc.9.97

• structures of the prepared spiro[indoline-3,4’-pyridines] 1a–1p were fully characterized by spectroscopic methods and were further confirmed by the determination of the single crystal structures of the spiro compounds 1c (Figure 1) and 1h (Figure 2). When ethyl cyanoacetate was utilized in the domino

• spectroscopic methods. The single-crystal structures of spiro compounds 2b (Figure 3) and 3b (Figure 4) were successfully determined by X-ray diffraction methods. It should be pointed out that the 1H NMR spectra of compounds 2a–2h showed some distinguishing features. The characteristic resonance of the NH2