Spin state switching in iron coordination compounds

• Philipp Gütlich,
• Ana B. Gaspar and
• Yann Garcia

Beilstein J. Org. Chem. 2013, 9, 342–391, doi:10.3762/bjoc.9.39

Synthesis and testing of the first azobenzene mannobioside as photoswitchable ligand for the bacterial lectin FimH

• Vijayanand Chandrasekaran,
• Katharina Kolbe,
• Femke Beiroth and
• Thisbe K. Lindhorst

Beilstein J. Org. Chem. 2013, 9, 223–233, doi:10.3762/bjoc.9.26

• -coated surface. The inhibitory potencies of (E)- and (Z)-2 are compared to the standard inhibitors MeMan and pNPMan. a FlexX scoring values for the (E)- and the (Z)-isomer of 2 based on two different crystal structures in comparison to MeMan and pNPMan. Supporting Information Supporting Information File

Asymmetric synthesis of host-directed inhibitors of myxoviruses

• Terry W. Moore,
• Kasinath Sana,
• Dan Yan,
• Pahk Thepchatri,
• John M. Ndungu,
• Manohar T. Saindane,
• Mark A. Lockwood,
• Michael G. Natchus,
• Dennis C. Liotta,
• Richard K. Plemper,
• James P. Snyder and
• Aiming Sun

Beilstein J. Org. Chem. 2013, 9, 197–203, doi:10.3762/bjoc.9.23

• acid (17). However, the enantiomeric (D)-lactic acid is substantially more expensive, and as seen below, the products arising from (L)-lactic acid are less active, making this route less attractive than the route utilizing chiral α-bromopropionamides 12. Crystal structures of (R)- and (S)-1 obtained by

• benzimidazole nitrogen in these crystal structures results in pseudo seven-membered rings. Whether this conformation is biologically relevant is unknown. Structure–activity relationships A small set of compounds was synthesized based on variations of 1 by replacing the p-methoxyphenyl group with other

• discussed and have unequivocally demonstrated that the (S)-enantiomer is more active in this series than the (R)-enantiomer. Further work from our laboratories regarding the in vivo efficacy of these compounds is underway. Structure of first-generation lead compound 1. Renderings of crystal structures of (S

Inclusion of the insecticide fenitrothion in dimethylated-β-cyclodextrin: unusual guest disorder in the solid state and efficient retardation of the hydrolysis rate of the complexed guest in alkaline solution

• Dyanne L. Cruickshank,
• Natalia M. Rougier,
• Raquel V. Vico,
• Susan A. Bourne,
• Elba I. Buján,
• Mino R. Caira and
• Rita H. de Rossi

Beilstein J. Org. Chem. 2013, 9, 106–117, doi:10.3762/bjoc.9.14

• ]. In our recent reports on the interaction between CDs and the organophosphorus insecticide 1 we gave an account of the X-ray crystal structures and thermal decomposition profiles of two solid inclusion complexes between permethylated α- and β-cyclodextrins, hexakis(2,3,6-tri-O-methyl)-α-CD (TRIMEA

• crystal structures of the CD complexes of fenitrothion with TRIMEB [6] and DIMEB (see above), it is clear that the major components of the fenitrothion molecules have their reactive phosphorothioate moieties positioned at the narrower primary rims of the cyclodextrin cavities. The stronger inhibition of

Chemical–biological characterization of a cruzain inhibitor reveals a second target and a mammalian off-target

• Jonathan W. Choy,
• Clifford Bryant,
• Claudia M. Calvet,
• Patricia S. Doyle,
• Shamila S. Gunatilleke,
• Siegfried S. F. Leung,
• Kenny K. H. Ang,
• Steven Chen,
• Jiri Gut,
• Juan A. Oses-Prieto,
• Jonathan B. Johnston,
• Michelle R. Arkin,
• Alma L. Burlingame,
• Jack Taunton,
• Matthew P. Jacobson,
• James M. McKerrow,
• Larissa M. Podust and
• Adam R. Renslo

Beilstein J. Org. Chem. 2013, 9, 15–25, doi:10.3762/bjoc.9.3

• ) predicted to interact with the tryptophan ring of (R)-5 (Figure 2A). This same hydrophobic site in TcCYP51 binds the fluoroaryl rings of fluconazole and posaconazole in co-crystal structures [14]. The predicted binding mode of the enantiomer (S)-5 was described previously [16] and is distinct from that

Amino-substituted diazocines as pincer-type photochromic switches

• Hanno Sell,
• Christian Näther and
• Rainer Herges

Beilstein J. Org. Chem. 2013, 9, 1–7, doi:10.3762/bjoc.9.1

• yield a centred multiplet. This symmetry of the fine structure shows that they divide into two chemically unequal groups of two chemically equal protons. Hence, there is no boat inversion at room temperature on the NMR time scale. According to the X-ray crystal structures the amino nitrogen lone pairs

• (isobutane): m/z (% relative intensity) 323 (100) [M + H]+. Configurations and conformations of 5,6-dihydrodibenzo[c,g][1,2]diazocine (1), and DFT (B3LYP/6-31G*) calculated energies (kcal mol−1) relative to the most stable cis boat form. Dipol moments are given in Debye. Crystal structures of the cis isomers

• derivative 5. Half-life and photostationary states of EBAB 1 and derivatives. Supporting Information 1H NMR spectra of 4 and 5 before and after the irradiation with 405 nm, and 1H NMR binding study of 3,3-acetamido-EBAB (5) with ethylenediamine. cif-Files of X-ray crystal structures of cis-4 and cis-5, and

Synthesis of a derivative of α-D-Glcp(1->2)-D-Galf suitable for further glycosylation and of α-D-Glcp(1->2)-D-Gal, a disaccharide fragment obtained from varianose

• Carla Marino,
• Carlos Lima,
• Karina Mariño and
• Rosa M. de Lederkremer

Beilstein J. Org. Chem. 2012, 8, 2142–2148, doi:10.3762/bjoc.8.241

• )Galf and β-Galf(1→6)Galf [12][13][14]. Synthetic oligosaccharides have been used to characterize these GalfTs and it was demonstrated that a single active site in GalfT2 is responsible for both activities [15]. The crystal structures of both, free and UDP-bound GalfT2 have been recently determined [16

Peptides presenting the binding site of human CD4 for the HIV-1 envelope glycoprotein gp120

• Julia Meier,
• Kristin Kassler,
• Heinrich Sticht and
• Jutta Eichler

Beilstein J. Org. Chem. 2012, 8, 1858–1866, doi:10.3762/bjoc.8.214

• entry of the virus HIV-1 into its host cell. A range of crystal structures of the gp120–CD4 complex [2][3][4][5][6] have provided information on the structural details of the gp120–CD4 interaction and, thus, the basis for a rational design of inhibitors. Later on, it was found that the epitopes of a

Highly enantioselective access to cannabinoid-type tricyles by organocatalytic Diels–Alder reactions

• Stefan Bräse,
• Nicole Volz,
• Franziska Gläser and
• Martin Nieger

Beilstein J. Org. Chem. 2012, 8, 1385–1392, doi:10.3762/bjoc.8.160

• experiments and X-ray crystal structures of two imidazolidinones 15d and 15f. Synthesis of thiourea catalysts 9a–l. Organocatalytic Diels–Alder reaction with thiourea-catalysis. Synthesis of electron poor imidazolidinone catalysts. Co-catalyst screening. Screening of imidazolidinone catalysts 15. Yields of

Restructuring polymers via nanoconfinement and subsequent release

• Alan E. Tonelli

Beilstein J. Org. Chem. 2012, 8, 1318–1332, doi:10.3762/bjoc.8.151

• ][8][17][20]. The presence of both guest polymer and host CD can be confirmed by FTIR and NMR spectroscopy, while solid-state 13C NMR and X-ray diffraction can confirm the columnar IC structure. For example, in Figure 2 the crystal structures of as-received cage and columnar IC γ-CDs are easily

• cyclodextrin inclusion complex [2]. Crystal structures and wide-angle X-ray diffractograms of neat (a) cage and (b) columnar IC γ-CD [20]. DSC cooling scans of as-received (upper) and coalesced N-6 (lower) [58]. DSC heating scans for asr-PVAc (upper) and c-PVAc coalesced from its γ-CD IC (lower) [72]. Melt

The preferred conformation of erythro- and threo-1,2-difluorocyclododecanes

• Yi Wang,
• Peer Kirsch,
• Tomas Lebl,
• Alexandra M. Z. Slawin and
• David O'Hagan

Beilstein J. Org. Chem. 2012, 8, 1271–1278, doi:10.3762/bjoc.8.143

• ][2]. There are four endo hydrogens above and four below the plane of the ring, which are tensioned as they are within van der Waals contact distances. Thus the ring adopts a [3333] square-type structure. (Reproduced with permission from [1]; Copyright © 1960 Verlag GmbH & Co KGaA, Weinheim). Crystal

• structures of (a) 1,1,4,4- (b) 1,1,7,7- and (c) 1,1,6,6-tetrafluorocyclododecanes (2–4) , illustrating the corner preference of the CF2 groups. Structures 2 and 3 adopt a [3333] conformation, whereas 4 adopts a distorted [4332] conformation. Fluorine atoms are presented in green [7]. Erythro- and threo-1,2

Synthesis and structure of tricarbonyl(η⁶-arene)chromium complexes of phenyl and benzyl D-glycopyranosides

• Thomas Ziegler and
• Ulrich Heber

Beilstein J. Org. Chem. 2012, 8, 1059–1070, doi:10.3762/bjoc.8.118

• nonclassical H-bonds. Figure 9 and Figure 10 show the crystal structures of the two diastereomers 2m. The isomer with (pR)-configuration of the tricarbonyl(η6-benzene)chromium group (Figure 9) shows one intramolecular nonclassical hydrogen bond between carbonyl oxygen O11 and H22B of the 2-O-acetyl group and

• revealed crystal structures that contain numerous nonclassical hydrogen bonds. Experimental General details. All solvents were dried and distilled prior to their use. Reactions were performed under Ar and monitored by TLC on Polygram Sil G/UV silica gel plates from Machery & Nagel. Detection was effected

Synthesis of new pyrrole–pyridine-based ligands using an in situ Suzuki coupling method

• Matthias Böttger,
• Björn Wiegmann,
• Steffen Schaumburg,
• Peter G. Jones,
• Wolfgang Kowalsky and
• Hans-Hermann Johannes

Beilstein J. Org. Chem. 2012, 8, 1037–1047, doi:10.3762/bjoc.8.116

• target structures 1–3 were successfully synthesized in good to acceptable yields by applying an in situ variation of the Suzuki coupling as the main reaction step. The crystal structures of these compounds could be obtained by X-ray analysis. They exhibit interesting, but very different structural

High-affinity multivalent wheat germ agglutinin ligands by one-pot click reaction

• Henning S. G. Beckmann,
• Heiko M. Möller and
• Valentin Wittmann

Beilstein J. Org. Chem. 2012, 8, 819–826, doi:10.3762/bjoc.8.91

• were determined by an enzyme-linked lectin assay (ELLA), resulting in IC50 values in the low-micromolar/high-nanomolar range. A trivalent ligand has a remarkable IC50 value of 220 nM. Molecular dynamics calculations based on published X-ray crystal structures of WGA-ligand complexes provide an

• . Combining information from the crystal structures of WGA3 in complex with N,N’-diacetylchitobiose (PDB ID: 1K7U) [60] and WGA3 binding to a divalent ligand presenting two GlcNAc residues (PDB ID: 2X52) [36], two N,N’-diacetylchitobiose residues were placed in a pair of adjacent primary binding sites of WGA

Stereoselective, nitro-Mannich/lactamisation cascades for the direct synthesis of heavily decorated 5-nitropiperidin-2-ones and related heterocycles

• Pavol Jakubec,
• Dane M. Cockfield,
• Madeleine Helliwell,
• James Raftery and
• Darren J. Dixon

Beilstein J. Org. Chem. 2012, 8, 567–578, doi:10.3762/bjoc.8.64

• ). Supporting Information File 153: X-ray crystal structure of compound 2m’. Supporting Information File 154: X-ray crystal structures of compounds 1g, 2, 2a’’, 6e and 11c. Acknowledgements We gratefully acknowledge Merck, Sharp and Dohme (Hoddesdon, U.K.) for a studentship (to D.M.C.); the EPSRC for a

Fifty years of oxacalix[3]arenes: A review

• Kevin Cottet,
• Paula M. Marcos and
• Peter J. Cragg

Beilstein J. Org. Chem. 2012, 8, 201–226, doi:10.3762/bjoc.8.22

• has been expanded to include numerous derivatives and complexes. This review describes the syntheses of the parent compounds, their derivatives, and their complexation behaviour towards cations. Extraction data are presented, as are crystal structures of the macrocycles and their complexes with guest

• cleaved to give an acyclic surface-bound product with free methyl and aldehyde termini (Scheme 20). Klufers prepared complexes of 3b, 3d and 3k through reaction of the macrocycles with (Et3N)2[Re(CO)3Br3] in acetonitrile [49]. The X-ray crystal structures of the complexes with 3b and 3d showed binding by

Computational evidence for intramolecular hydrogen bonding and nonbonding X···O interactions in 2'-haloflavonols

• Tânia A. O. Fonseca,
• Matheus P. Freitas,
• Rodrigo A. Cormanich,
• Teodorico C. Ramalho,
• Cláudio F. Tormena and
• Roberto Rittner

Beilstein J. Org. Chem. 2012, 8, 112–117, doi:10.3762/bjoc.8.12

• ubiquitous than one imagines and can determine crystal structures [10] and the binding of biological molecules [11] and may possibly be the main forces in determining conformational preferences in molecular systems. 2'-Haloflavonols are important compounds with widespread use as bioactive molecules

(How) does 1,3,5-triethylbenzene scaffolding work? Analyzing the abilities of 1,3,5-triethylbenzene- and 1,3,5-trimethylbenzene-based scaffolds to preorganize the binding elements of supramolecular hosts and to improve binding of targets

• Xing Wang and
• Fraser Hof

Beilstein J. Org. Chem. 2012, 8, 1–10, doi:10.3762/bjoc.8.1

• were predetermined by macrocyclizations (and that therefore were not under the control of steric gearing). In total, 126 such crystal structures of tripodal triethylbenzene-based hosts were found in the database. Among these, 86 (68.3%) were in the up–down alternating conformation in which all ethyl

• crystal structures, showing that the bound metal did not perturb the predicted up–down alternating conformation [6]. The coordination of the larger Cr(CO)2PPh3 fragment produced instead a crystal structure in which the highly unfavorable all-up conformation of hexaethylbenzene dominated, and it was

• confirmed by NMR that this conformation persisted in solution [6]. The CSD was also mined for structures of 1,3,5-trimethylbenzene-based hosts, by using a similar search methodology and selection criteria to those described above. Of the total 194 crystal structures of such hosts found in the database, 88

A simple and convenient one-pot synthesis of substituted isoindolin-1-ones via lithiation, substitution and cyclization of N'-benzyl-N,N-dimethylureas

• Keith Smith,
• Gamal A. El-Hiti,
• Amany S. Hegazy and
• Benson Kariuki

Beilstein J. Org. Chem. 2011, 7, 1219–1227, doi:10.3762/bjoc.7.142

• crystalline products were therefore subjected to X-ray crystallography. The structures found are illustrated in Figure 2. The X-ray crystal structures of the isolated crystals of products 15, 17 and 18 showed that they were α-(R*)-3-(S*)-diastereoisomers, while that of 16 showed that it was the α-(R*)-3-(R

• of a molecular ion or pseudo molecular ion confirmed the formula. Structures of 4–6. X-Ray crystal structures of crystallized compounds 12 and 15–18. Structures of compounds 41–44. X-ray crystal structures of compounds 38 and 39. Lithiation and substitution of isoindolin-1-ones [43]. Lithiation and

NMR studies of anion-induced conformational changes in diindolylureas and diindolylthioureas

• Damjan Makuc,
• Jennifer R. Hiscock,
• Mark E. Light,
• Philip A. Gale and
• Janez Plavec

Beilstein J. Org. Chem. 2011, 7, 1205–1214, doi:10.3762/bjoc.7.140

• phosphate and sulfate for neutral receptors in DMSO-d6/0.5% water and have been shown to perturb the pKa of bound guests (Table 1) [38][39]. X-ray crystal structures of a variety of complexes with anions revealed the adoption of the syn–syn conformation in the solid state upon anion complexation. With the

Triazole–Au(I) complex as chemoselective catalyst in promoting propargyl ester rearrangements

• Dawei Wang,
• Yanwei Zhang,
• Rong Cai and
• Xiaodong Shi

Beilstein J. Org. Chem. 2011, 7, 1014–1020, doi:10.3762/bjoc.7.115

• significant challenge in gold catalysis. Results and Discussions Recently, our group reported the synthesis and characterization of the 1,2,3-triazole [36][37][38][39][40] coordinated gold(I) complexes. As revealed by the X-ray crystal structures (Scheme 3), both neutral and anionic triazoles can coordinate

• the synthesis of allenes through gold activated alkynes. X-ray crystal structures of the two different types of 1,2,3-triazole–Au complexes. Synthesis of α-iodoenone compounds from propargyl esters. The reaction substrate scope.a Different migrating groups.a Supporting Information Supporting

• –Au-2 was prepared either from the addition of HOTf to TA–Au-1 or by the reaction between PPh3Au–OTf (prepared from PPh3–Au–Cl and AgOTf) and benzotriazole. Both complexes were stable and could be further purified by recrystallization to ensure no extra Ag+ or acid in the catalysts. The crystal

An overview of the key routes to the best selling 5-membered ring heterocyclic pharmaceuticals

• Marcus Baumann,
• Ian R. Baxendale,
• Steven V. Ley and
• Nikzad Nikbin

Beilstein J. Org. Chem. 2011, 7, 442–495, doi:10.3762/bjoc.7.57

SbCl₃-catalyzed one-pot synthesis of 4,4′-diaminotriarylmethanes under solvent-free conditions: Synthesis, characterization, and DFT studies

• Ghasem Rezanejade Bardajee

Beilstein J. Org. Chem. 2011, 7, 135–144, doi:10.3762/bjoc.7.19

• compound 11, calculated by HF and DFT levels with the HF/6-31G*, 6-31G*/B3LYP, and B3LYP/cc-pVDZ methods, are listed in Table 2. The optimized configuration is shown in Figure 2. Because of unavailability of X-ray crystal structures for these compounds, the optimized structure is compared with X-ray

Tandem catalysis of ring-closing metathesis/atom transfer radical reactions with homobimetallic ruthenium–arene complexes

• Yannick Borguet,
• Xavier Sauvage,
• Guillermo Zaragoza,
• Albert Demonceau and
• Lionel Delaude

Beilstein J. Org. Chem. 2010, 6, 1167–1173, doi:10.3762/bjoc.6.133

• obtained by the Swiss team and our group indicate that complex 7 can adopt various crystalline structures (see Supporting Information File 2 for more details on crystal structures and Supporting Information File 3 for X-ray crystal data). The clean transformation of catalyst precursor 1 into compound 7

Backbone tuning in indenylidene–ruthenium complexes bearing an unsaturated N-heterocyclic carbene

• César A. Urbina-Blanco,
• Xavier Bantreil,
• Hervé Clavier,
• Alexandra M. Z. Slawin and
• Steven P. Nolan

Beilstein J. Org. Chem. 2010, 6, 1120–1126, doi:10.3762/bjoc.6.128

• ), which quantifies the volume of a sphere centred around the metal (with a specific radius distance) occupied by the ligand. The more sterically demanding ligands will correspond to larger %Vbur values [36][39]. Analysis of the crystal structures of 5a–d, in conjunction with the aforementioned

• are available in the supporting information. The CIF files of crystal structures 5a–d have been deposited with the CCDC, No. 793640–793643, respectively. Copies of the data can be obtained free of charge on applications to CCDC, 12 Union Road, Cambridge CB2 1EZ, UK, fax: +44 1223 336 033; http