Latest development in the synthesis of ursodeoxycholic acid (UDCA): a critical review

• Fabio Tonin and
• Isabel W. C. E. Arends

Beilstein J. Org. Chem. 2018, 14, 470–483, doi:10.3762/bjoc.14.33

• dehydroxylation reactions are highlighted with a red, blue and green arrow, respectively. Names of compounds are indicated in the box. The general stereoinformation of steroid scaffold is shown in Figure 2. R = 4-pentanoic acid. Schematic representation of the flow reactor for the continuous conversion of CDCA to

Terahertz spectroscopy of 2,4,6-trinitrotoluene molecular solids from first principles

• Ido Azuri,
• Anna Hirsch,
• Anthony M. Reilly,
• Alexandre Tkatchenko,
• Shai Kendler,
• Oded Hod and
• Leeor Kronik

Beilstein J. Org. Chem. 2018, 14, 381–388, doi:10.3762/bjoc.14.26

• experimental and computed peaks denote peak assignment. Schematic representation of typical TNT vibrational modes, demonstrated using modes of the orthorhombic polymorph at frequencies of (a) ca. 1.0 THz, (b) ca. 2.3 THz. Purple and orange arrows denote the direction of primary inter- and intramolecular

Continuous-flow retro-Diels–Alder reaction: an efficient method for the preparation of pyrimidinone derivatives

• Imane Nekkaa,
• Márta Palkó,
• István M. Mándity and
• Ferenc Fülöp

Beilstein J. Org. Chem. 2018, 14, 318–324, doi:10.3762/bjoc.14.20

• were selected on the basis of the solubility of the starting materials. A schematic representation of the flow reactor setup is illustrated in Figure 1. Products 9–14 thus prepared were identified by means of HPLC–MS and NMR spectroscopic analysis. All physical and spectroscopic data of pyrimidinones 9

Polarization spectroscopy methods in the determination of interactions of small molecules with nucleic acids – tutorial

• Tamara Šmidlehner,
• Ivo Piantanida and
• Gennaro Pescitelli

Beilstein J. Org. Chem. 2018, 14, 84–105, doi:10.3762/bjoc.14.5

Aminosugar-based immunomodulator lipid A: synthetic approaches

• Alla Zamyatina

Beilstein J. Org. Chem. 2018, 14, 25–53, doi:10.3762/bjoc.14.3

Recent applications of click chemistry for the functionalization of gold nanoparticles and their conversion to glyco-gold nanoparticles

• Vivek Poonthiyil,
• Thisbe K. Lindhorst,
• Vladimir B. Golovko and
• Antony J. Fairbanks

Beilstein J. Org. Chem. 2018, 14, 11–24, doi:10.3762/bjoc.14.2

• derivatives, DCM, 11000 atm, 25 °C, 15–24 h [48]. The synthesis of AuNPs functionalized with strained alkyne derivatives. HBTU = O-benzotriazole-N,N,N',N'-tetramethyluroniumhexafluorophosphate; DIPEA = N,N-diisopropylethylamine [57]. A schematic representation of the SPAAC between azide-functionalized

Halogen-containing thiazole orange analogues – new fluorogenic DNA stains

• Aleksey A. Vasilev,
• Meglena I. Kandinska,
• Stanimir S. Stoyanov,
• Stanislava B. Yordanova,
• David Sucunza,
• Juan J. Vaquero,
• Obis D. Castaño,
• Stanislav Baluschev and
• Silvia E. Angelova

Beilstein J. Org. Chem. 2017, 13, 2902–2914, doi:10.3762/bjoc.13.283

• and in the presence of increasing concentrations of dsDNA (c = 0–1.4 × 10−4 M). Photostability of dyes TO-7Cl and 5a–d in acetonitrile in the concentration range of 1 × 10−5 M. B3LYP optimized structures. Graphical representation of the frontier orbitals (isodensity plot, isovalue = 0.02 a.u

Synthetic mRNA capping

• Fabian Muttach,
• Nils Muthmann and
• Andrea Rentmeister

Beilstein J. Org. Chem. 2017, 13, 2819–2832, doi:10.3762/bjoc.13.274

• mRNA caps which conferred specific properties such as eIF4E binding and turned non-modified RNAs into strongly eIF4E-binding RNAs. Schematic representation of enzymatic 5′-cap formation in eukaryotic mRNA. The 5′-triphosphate-end of the pre-mRNA is hydrolyzed to a diphosphate by an RNA 5

• nucleotide results in formation of the cap1 structure. Nucleotide analogues 1–11 were converted by Paramecium bursaria Chlorella virus-1 capping enzyme instead of GTP to generate RNAs with the respective caps [45]. Schematic representation of co-transcriptional capping with different cap analogues. A DNA

Metal-mediated base pairs in parallel-stranded DNA

• Jens Müller

Beilstein J. Org. Chem. 2017, 13, 2671–2681, doi:10.3762/bjoc.13.265

• ) Reversed Hoogsteen-type A:T and G:CH+ base pairs. R, R’, R’’ = DNA backbone. Representation of a β-dA:α-dT base pair. Representation of mononuclear metal-mediated base pairs involving canonical pyrimidine nucleobases. Base pairs within an antiparallel-stranded context are displayed in grey, whereas base

Synthesis, effect of substituents on the regiochemistry and equilibrium studies of tetrazolo[1,5-a]pyrimidine/2-azidopyrimidines

• Elisandra Scapin,
• Paulo R. S. Salbego,
• Caroline R. Bender,
• Alexandre R. Meyer,
• Anderson B. Pagliari,
• Tainára Orlando,
• Geórgia C. Zimmer,
• Clarissa P. Frizzo,
• Helio G. Bonacorso,
• Nilo Zanatta and
• Marcos A. P. Martins

Beilstein J. Org. Chem. 2017, 13, 2396–2407, doi:10.3762/bjoc.13.237

• [1,5-a]pyrimidine observed in solution (CDCl3 and DMSO-d6) and 2-azidopyrimidine observed in the solid state based on equilibrium. ORTEP® [45] plot of 8i with thermal ellipsoids drawn at 50% probability level. Representation of the possible equilibrium existing between 6i, 7i, and 8i. Reaction

Solvent-free copper-catalyzed click chemistry for the synthesis of N-heterocyclic hybrids based on quinoline and 1,2,3-triazole

• Martina Tireli,
• Silvija Maračić,
• Stipe Lukin,
• Marina Juribašić Kulcsár,
• Dijana Žilić,
• Mario Cetina,
• Ivan Halasz,
• Silvana Raić-Malić and
• Krunoslav Užarević

Beilstein J. Org. Chem. 2017, 13, 2352–2363, doi:10.3762/bjoc.13.232

• gray. c) Capped-stick representation of 5, showing the dimer formed by C–H∙∙∙N hydrogen bond (orange stippled lines). Synthetic procedures for preparation of p-halogen-substituted and non-substituted phenyl-1,2,3-triazole 6-phenyl-2-(trifluoromethyl)quinolines. Reaction conditions and yields for the

Solid-state studies and antioxidant properties of the γ-cyclodextrin·fisetin inclusion compound

• Joana M. Pais,
• Maria João Barroca,
• Maria Paula M. Marques,
• Filipe A. Almeida Paz and
• Susana S. Braga

Beilstein J. Org. Chem. 2017, 13, 2138–2145, doi:10.3762/bjoc.13.212

• . Measurements were conducted at the steady-state of inhibition, occurring at 20 min of incubation. Structural representation of fisetin as guest (a) and γ-CD as host (b) used in the present study, depicting the herein adopted labeling for atoms and rings of fisetin. Selected FTIR bands for fisetin and its

Novel approach to hydroxy-group-containing porous organic polymers from bisphenol A

• Tao Wang,
• Yan-Chao Zhao,
• Li-Min Zhang,
• Yi Cui,
• Chang-Shan Zhang and
• Bao-Hang Han

Beilstein J. Org. Chem. 2017, 13, 2131–2137, doi:10.3762/bjoc.13.211

• (downtriangle), PPOP-2 (circle), and PPOP-3 (square) (a) hydrogen at 77 K, (b) carbon dioxide at 273 K, (c) carbon dioxide at 298 K, and (d) methane at 273 K. Variation of isosteric heat of adsorption with amount of adsorbed CO2 in PPOP-1, PPOP-2, and PPOP-3. Schematic representation of the possible structures

β-Cyclodextrin- and adamantyl-substituted poly(acrylate) self-assembling aqueous networks designed for controlled complexation and release of small molecules

• Liang Yan,
• Duc-Truc Pham,
• Philip Clements,
• Stephen F. Lincoln,
• Jie Wang,
• Xuhong Guo and
• Christopher J. Easton

Beilstein J. Org. Chem. 2017, 13, 1879–1892, doi:10.3762/bjoc.13.183

• = 100%. Representation of ditopic complexation of an ADddn substituent of PAAADddn, by two β-CDen substituents of PAAβ-CDen through initial complexation of the adamantyl group followed by complexation of the dodecyl linker in the sequence (a) to (b) to (c). 2D NOESY 1H NMR spectrum of 0.44 wt % PAAβ

• MR, MO, or EO at 298.2 K in aqueous Na2HPO4/KH2PO4 buffer at pH 7.0 and I = 0.10 mol dm−3. In each system, the concentrations of the β-CDen and adamantyl substituents were 3.60 × 10−3 mol dm−3 and 1.20 × 10−3 mol dm−3, respectively, and the dye concentration was 2.00 × 10−3 mol dm−3. Representation

Selective enzymatic esterification of lignin model compounds in the ball mill

• Ulla Weißbach,
• Saumya Dabral,
• Laure Konnert,
• Carsten Bolm and
• José G. Hernández

Beilstein J. Org. Chem. 2017, 13, 1788–1795, doi:10.3762/bjoc.13.173

• mixture was recovered from the milling jar, supported on silica gel and the product was purified by silica column chromatography. (a) Molecular representation of lignin. (b) Lignin model compound erythro-1a. Enzymatic reactions under ball milling conditions. Chemical and enzymatic esterification of

Molecular recognition of N-acetyltryptophan enantiomers by β-cyclodextrin

• Spyros D. Chatziefthimiou,
• Mario Inclán,
• Petros Giastas,
• Athanasios Papakyriakou,
• Konstantina Yannakopoulou and
• Irene M. Mavridis

Beilstein J. Org. Chem. 2017, 13, 1572–1582, doi:10.3762/bjoc.13.157

• H8; (b) the few differences observed in the intermolecular interactions have been magnified and reflect somewhat different binding modes of the two enantiomers revealed by intermolecular interactions of guest protons H8 and H4 only; (c) schematic representation of the respective solution models for

Chemical systems, chemical contiguity and the emergence of life

• Terrence P. Kee and
• Pierre-Alain Monnard

Beilstein J. Org. Chem. 2017, 13, 1551–1563, doi:10.3762/bjoc.13.155

• then be able to perform an increasingly more complex chemistry. These systems are precursors of protocells that preceded the emergence of ancestral cells. (B) Putative representation of a protocell (adapted from [3]). Independently of the type of chemicals involved, e.g., pure RNA catalysts/”genetic

Grip on complexity in chemical reaction networks

• Albert S. Y. Wong and
• Wilhelm T. S. Huck

Beilstein J. Org. Chem. 2017, 13, 1486–1497, doi:10.3762/bjoc.13.147

• network motif based on autocatalytic production and delayed inhibition of an enzyme that was kept out-of-equilibrium. (d) Schematic representation of the flow reactor that is used to implement flow. (e) The output of the reactor was measured using an enzymatic activity in an offline analysis. The response

Mechanochemistry-assisted synthesis of hierarchical porous carbons applied as supercapacitors

• Desirée Leistenschneider,
• Nicolas Jäckel,
• Felix Hippauf,
• Volker Presser and
• Lars Borchardt

Beilstein J. Org. Chem. 2017, 13, 1332–1341, doi:10.3762/bjoc.13.130

• . For the graphical representation of the cyclic voltammograms, the specific capacitances were calculated with Equation 3. For the calculation of the specific energy of the carbon electrodes in two different electrolytes, Equation 4 was applied with discharge data after the iR drop. Synthesis of

One-pot synthesis of block-copolyrotaxanes through controlled rotaxa-polymerization

• Jessica Hilschmann,
• Gerhard Wenz and
• Gergely Kali

Beilstein J. Org. Chem. 2017, 13, 1310–1315, doi:10.3762/bjoc.13.127

• ) polyrotaxane 6 (dashed line), and (b) 500 MHz, 1H NMR and DOSY spectra of polyHEMA-b-polyisoprene-b-polyHEMA polyrotaxane 4 in DMSO-d6. Synthesis route of RAMEB based statistical polyrotaxane. Schematic representation of the synthetic procedure for the preparation of randomly methylated β-CD based block

Biomimetic molecular design tools that learn, evolve, and adapt

• David A Winkler

Beilstein J. Org. Chem. 2017, 13, 1288–1302, doi:10.3762/bjoc.13.125

• . This is a mathematical object usually consisting of three layers, each of which contains a variable number of nodes (see Figure 4). A mathematical representation of an object (such as a molecule) is applied to the input layer nodes. The representations are distributed via a set of weights to the hidden

Strategies in megasynthase engineering – fatty acid synthases (FAS) as model proteins

• Manuel Fischer and
• Martin Grininger

Beilstein J. Org. Chem. 2017, 13, 1204–1211, doi:10.3762/bjoc.13.119

• transferase (AT) and malonyl-/palmitoyl-transferase (MPT). Two linkers, abstracted as grey lines, flexibly bind the acyl carrier protein (ACP) domain. The reaction volume was calculated as indicated by dashed lines. b) Cartoon representation of X-shaped animal FAS I (PDB-code: 2vz8) with one of overall two

Towards open-ended evolution in self-replicating molecular systems

• Herman Duim and
• Sijbren Otto

Beilstein J. Org. Chem. 2017, 13, 1189–1203, doi:10.3762/bjoc.13.118

• system. One strand of the double helix acts as a template for the formation of the other complementary strand and vice versa. Figure 3 shows a schematic representation of a reciprocal replicating system. It consists of two catalytic cycles which both lead to the same template duplex [TCD∙TEF]. Instead of

Kinetic analysis of mechanoradical formation during the mechanolysis of dextran and glycogen

• Naoki Doi,
• Yasushi Sasai,
• Yukinori Yamauchi,
• Tetsuo Adachi,
• Masayuki Kuzuya and
• Shin-ichi Kondo

Beilstein J. Org. Chem. 2017, 13, 1174–1183, doi:10.3762/bjoc.13.116

• ). Schematic representation of bond cleavage at α-1,4- and α-1,6-bonds. ESR spectrum of fractured sample of Dx and TCNE (a) before and (b) after visible-light irradiation. Component spectra of the simulated ESR spectra. Progressive changes in the intensity of component spectra corresponding to the simulated

Glycoscience@Synchrotron: Synchrotron radiation applied to structural glycoscience

• Serge Pérez and
• Daniele de Sanctis

Beilstein J. Org. Chem. 2017, 13, 1145–1167, doi:10.3762/bjoc.13.114