Evaluation of dispersion type metal···π arene interaction in arylbismuth compounds – an experimental and theoretical study

• Ana-Maria Preda,
• Małgorzata Krasowska,
• Lydia Wrobel,
• Philipp Kitschke,
• Phil C. Andrews,
• Jonathan G. MacLellan,
• Lutz Mertens,
• Marcus Korb,
• Tobias Rüffer,
• Heinrich Lang,
• Alexander A. Auer and
• Michael Mehring

Beilstein J. Org. Chem. 2018, 14, 2125–2145, doi:10.3762/bjoc.14.187

Synthesis and supramolecular self-assembly of glutamic acid-based squaramides

• Juan V. Alegre-Requena,
• Marleen Häring,
• Isaac G. Sonsona,
• Alex Abramov,
• Eugenia Marqués-López,
• Raquel P. Herrera and
• David Díaz Díaz

Beilstein J. Org. Chem. 2018, 14, 2065–2073, doi:10.3762/bjoc.14.180

• Information File 406: NMR spectra, FTIR spectra, DSS plots, and additional photographs of gels in different solvents. Acknowledgements The authors are grateful for the financial support from the University of Regensburg, the Deutsche Forschungsgemeinschaft (DFG, DI 1748/3-1; 1748/3-2), the Ministerio de

Applications of organocatalysed visible-light photoredox reactions for medicinal chemistry

• Michael K. Bogdos,
• Emmanuel Pinard and
• John A. Murphy

Beilstein J. Org. Chem. 2018, 14, 2035–2064, doi:10.3762/bjoc.14.179

• the [3 + 2]-cycloaddition of electron-poor alkynes and 2H-azirines [60]. The reaction is performed under blue LED irradiation and using acridinium salts as a photocatalyst (Scheme 15). With respect to 2H-azirine the scope of the reaction is demonstrated to be relatively broad, with aromatics

Synthesis of new p-tert-butylcalix[4]arene-based polyammonium triazolyl amphiphiles and their binding with nucleoside phosphates

• Vladimir A. Burilov,
• Guzaliya A. Fatikhova,
• Mariya N. Dokuchaeva,
• Ramil I. Nugmanov,
• Diana A. Mironova,
• Pavel V. Dorovatovskii,
• Victor N. Khrustalev,
• Svetlana E. Solovieva and
• Igor S. Antipin

Beilstein J. Org. Chem. 2018, 14, 1980–1993, doi:10.3762/bjoc.14.173

• + represent the dye and calixarene ions, respectively. By increasing the concentration to values above the CAC complexes with 3:2 stoichiometry are observed. This indicates that the interaction of forming aggregates with EY relies on both electrostatic interactions with positively charged headgroups and

An amphiphilic pseudo[1]catenane: neutral guest-induced clouding point change

• Tomoki Ogoshi,
• Tomohiro Akutsu and
• Tada-aki Yamagishi

Beilstein J. Org. Chem. 2018, 14, 1937–1943, doi:10.3762/bjoc.14.167

• compound 4 (2 mM at 25 °C in CDCl3), (b) 3 (2 mM at 25 °C in CDCl3), (c) 3 (2 mM at 10 °C in D2O), (d) 3 (2 mM) and 1,4-dicyanobutane (20 mM) at 10 °C in D2O and (e) 1,4-dicyanobutane (20 mM at 10 °C in D2O). Resonances are labeled as shown in Figure 1. Temperature dependence of light transmittance at 650

• nm of an aqueous solution of (a) 3 (2 mM) upon addition of 1,4-dicyanobutane (0–20 mM) and (b) 1 (2 mM) in the presence and absence of 1,4-dicyanobutane (20 mM) on heating. Photographs of (a) 3 and (c) a mixture of 3 (2 mM) and 1,4-dicyanobutane (20 mM) in aqueous media at 20 °C and schematic

A pyridinium/anilinium [2]catenane that operates as an acid–base driven optical switch

• Sarah J. Vella and
• Stephen J. Loeb

Beilstein J. Org. Chem. 2018, 14, 1908–1916, doi:10.3762/bjoc.14.165

• pure [2]catenane, the reaction solvent (CH3CN) was evaporated and the residue washed with toluene to remove excess crown ether. This was then followed by column chromatography on silica gel using a 5:3:2 mixture of CH3OH/2 M NH4Cl/CH3NO2 as the eluent. Fractions containing the product (Rf = 0.66) were

• added along with NaOTf (0.0330 g, 0.193 mmol) and the reaction stirred at room temperature for 21 days. The water layer was separated and the CH3NO2 evaporated. The resulting residue was washed with CH2Cl2 (3 × 10 mL) to remove excess DB24C8 and subjected to column chromatography on silica gel (5:3:2

First thia-Diels–Alder reactions of thiochalcones with 1,4-quinones

• Grzegorz Mlostoń,
• Katarzyna Urbaniak,
• Paweł Urbaniak,
• Anna Marko,
• Anthony Linden and
• Heinz Heimgartner

Beilstein J. Org. Chem. 2018, 14, 1834–1839, doi:10.3762/bjoc.14.156

• regioselective manner [16][20]. In cycloaddition chemistry, 1,4-quinones are applied widely both as dipolarophiles and dienophiles. In the case of [3 + 2] cycloadditions, reactions can occur chemoselectively with either the C=O or the C=C unit [21][22][23]. On the other hand, reactions with diverse 1,3-dienes

Synthesis of new tricyclic 5,6-dihydro-4H-benzo[b][1,2,4]triazolo[1,5-d][1,4]diazepine derivatives by [3⁺ + 2]-cycloaddition/rearrangement reactions

• Lin-bo Luan,
• Zi-jie Song,
• Zhi-ming Li and
• Quan-rui Wang

Beilstein J. Org. Chem. 2018, 14, 1826–1833, doi:10.3762/bjoc.14.155

• ][1,4]diazepinium salts 10 and the related neutral, free bases 13 were synthesized from 4-acetoxy-1-acetyl-4-phenylazo-1,2,3,4-tetrahydroquinolines 8 and nitriles 9 in the presence of aluminium chloride by the [3+ + 2]-cycloaddition reaction of the in situ generated azocarbenium intermediates 14

• ][26][27][28][29][30]. Over the past years, we have been engaged in the synthesis of novel 1,2,4-triazolo heterocycles annulated to benzoazepine or heteroazepine derivatives by a tandem [3+ + 2]-cycloaddition/rearrangement between 1-aza-2-azoniaallenium ions with nitriles [31][32][33][34]. In the [3

• , we wish to describe the synthesis of unprecedented tricyclic heterocycles, i.e., 5,6-dihydro-4H-benzo[b][1,2,4]triazolo[1,5-d][1,4]diazepinium salts 10 and the related neutral free base derivatives 13 via the cationic [3+ + 2]-cycloaddition/rearrangement reactions using the bicyclic 4-acetoxy-4-azo

Synthesis of spirocyclic scaffolds using hypervalent iodine reagents

• Fateh V. Singh,
• Priyanka B. Kole,
• Saeesh R. Mangaonkar and
• Samata E. Shetgaonkar

Beilstein J. Org. Chem. 2018, 14, 1778–1805, doi:10.3762/bjoc.14.152

• starting from substrate 147. (±)-Aculeatin and its derivatives possessing spirocyclic skeleton are known for their antibacterial and antiprotozoal properties [135]. In this report, substrate 147 was cyclized to spiroketals, i.e., (−)-aculeatin (146a) and (+)-146b in 3:2 ratio. Herein, 1.0 equivalent of

Synthesis and photophysical studies of a multivalent photoreactive Ru^II-calix[4]arene complex bearing RGD-containing cyclopentapeptides

• Sofia Kajouj,
• Lionel Marcelis,
• Alice Mattiuzzi,
• Adrien Grassin,
• Damien Dufour,
• Pierre Van Antwerpen,
• Didier Boturyn,
• Eric Defrancq,
• Mathieu Surin,
• Julien De Winter,
• Pascal Gerbaux,
• Ivan Jabin and
• Cécile Moucheron

Beilstein J. Org. Chem. 2018, 14, 1758–1768, doi:10.3762/bjoc.14.150

• ). Emission quantum yields were determined by integrating the corrected emission spectra over the frequencies. [Ru(bpy)3]2+ in water under air was chosen as the standard luminophore (quantum yield of 0.042 under argon). The luminescence lifetimes were measured by the time-correlated single photon counting (TC

Lanyamycin, a macrolide antibiotic from Sorangium cellulosum, strain Soce 481 (Myxobacteria)

• Lucky S. Mulwa,
• Rolf Jansen,
• Dimas F. Praditya,
• Kathrin I. Mohr,
• Patrick W. Okanya,
• Joachim Wink,
• Eike Steinmann and
• Marc Stadler

Beilstein J. Org. Chem. 2018, 14, 1554–1562, doi:10.3762/bjoc.14.132

• dichloromethane/acetone (3:2) and turned dark brown on treatment with vanillin/H2SO4 reagent. RP-HPLC coupled to HRESIMS showed the two compounds were isomers with the elemental formula C45H63NO12, which was derived from the ion clusters [2M + Na]+, [M + Na]+, [M − H2O + H]+, [M − 2H2O + H]+, and [M − 3H2O + H

Hypervalent organoiodine compounds: from reagents to valuable building blocks in synthesis

• Gwendal Grelier,
• Benjamin Darses and
• Philippe Dauban

Beilstein J. Org. Chem. 2018, 14, 1508–1528, doi:10.3762/bjoc.14.128

• mechanism that first involves the formation of a 2’-iodobiphenyl-2-azide promoted by the copper complex. The latter then catalyzes an intermolecular [3 + 2] cycloaddition with the alkyne. Finally, the copper-triazole moiety inserts intramolecularly into the second Ar–I bond, allowing a ring closure after

Synthesis of chiral 3-substituted 3-amino-2-oxindoles through enantioselective catalytic nucleophilic additions to isatin imines

• Hélène Pellissier

Beilstein J. Org. Chem. 2018, 14, 1349–1369, doi:10.3762/bjoc.14.114

• asymmetric formal [3 + 2] annulation reaction between N-Boc-isatin imines 3 and 1,4-dithiane-2,5-diol (53) as equal equivalent of 2-mercaptoacetaldehyde [78]. The domino reaction catalyzed by chiral tertiary amine-squaramide catalyst 54 began with the addition of 2-mercaptoacetaldehyde to isatin imine 3

[3 + 2]-Cycloaddition reaction of sydnones with alkynes

• Veronika Hladíková,
• Jiří Váňa and
• Jiří Hanusek

Beilstein J. Org. Chem. 2018, 14, 1317–1348, doi:10.3762/bjoc.14.113

• Veronika Hladikova Jiri Vana Jiri Hanusek Institute of Organic Chemistry and Technology, University of Pardubice, Studentská 573, 532 10 Pardubice, Czech Republic 10.3762/bjoc.14.113 Abstract This review covers all known examples of [3 + 2]-cycloaddition between sydnones and both terminal as well

• regioselectivity. Keywords: alkynes; Cu(I) catalysis; [3 + 2]-cycloaddition; mechanism; regioselectivity; sydnones; Review Introduction Since Huisgen’s discovery of the [3 + 2]-cycloaddition between 3-substituted sydnones and both terminal as well as internal alkynes [1][2] many researchers have tried to utilize

• examples found for [3 + 2]-cycloadditions between sydnones and symmetrical non-cyclic alkynes including conditions used for the synthesis, are presented in Table 1. Extraordinarily good dipolarophiles – e.g., cycloalkynes – containing a very reactive “bent” triple bond such as in bicyclo[6.1.0]non-4-yne-9

An overview of recent advances in duplex DNA recognition by small molecules

• Sayantan Bhaduri,
• Nihar Ranjan and
• Dev P. Arya

Beilstein J. Org. Chem. 2018, 14, 1051–1086, doi:10.3762/bjoc.14.93

• site in the H4c promoter in treated cells, thereby inhibiting tumor growth in mice. Chenoweth and Dervan showed DNA structural distortion induced by an 8-ring cyclic Py/Im polyamide (conjugate 17) bound to the central 6 bp of the sequence d(5'-CCAGGCCTGG-3')2 by using a high resolution X-ray crystal

Cross-coupling of dissimilar ketone enolates via enolonium species to afford non-symmetrical 1,4-diketones

• Keshaba N. Parida,
• Gulab K. Pathe,
• Shimon Maksymenko and
• Alex M. Szpilman

Beilstein J. Org. Chem. 2018, 14, 992–997, doi:10.3762/bjoc.14.84

• involve the coupling of amide enolates with ketone enolates. Baran reported that stoichiometric Cu(2-ethylhexanoate)2 or Fe(acac)3 (2 equiv) are able to selectively oxidize imides, including Evan’s-type chiral imides, to the corresponding radicals. The formed radical then reacts selectively with a ketone

Mechanochemistry of nucleosides, nucleotides and related materials

• Olga Eguaogie,
• Joseph S. Vyle,
• Patrick F. Conlon,
• Manuela A. Gîlea and
• Yipei Liang

Beilstein J. Org. Chem. 2018, 14, 955–970, doi:10.3762/bjoc.14.81

• (Scheme 5) [42]. In the absence of light, azobenzene derivatives were isolated as the pure E-isomers. In their original report, Sharpless and co-workers described the use of copper turnings to promote a regioselective azide–alkyne [3 + 2]-cycloaddition ("click") reaction over 24 hours [43]. High-speed

Crystal structure of the inclusion complex of cholesterol in β-cyclodextrin and molecular dynamics studies

• Elias Christoforides,
• Andreas Papaioannou and
• Kostas Bethanis

Beilstein J. Org. Chem. 2018, 14, 838–848, doi:10.3762/bjoc.14.69

• of the [FeFe]-H2ase active site, (μ-SCH2NH(C6H4SO3−)CH2S)[FeI(CO)3]2, within the cavity of a 1·2 β-CD sodium salt clathrate. 28 water molecules are also found in the asymmetric unit. The incorporation of charged functional groups into the guest molecule of cyclodextrin host/guest system provides a

Phosphodiester models for cleavage of nucleic acids

• Satu Mikkola,
• Tuomas Lönnberg and
• Harri Lönnberg

Beilstein J. Org. Chem. 2018, 14, 803–837, doi:10.3762/bjoc.14.68

• guanylyl-3´,3´-(2´-amino-2´-deoxyuridine) has been accounted for by intermediary formation of a highly reactive minor tautomer (Scheme 10) [89]. The pKa value of the amino group is surprisingly low, 4.9 at 90 °C. Both the zwitterionic (amino group protonated) and monoanionic (amino group neutral) species

Nanoreactors for green catalysis

• M. Teresa De Martino,
• Loai K. E. A. Abdelmohsen,
• Floris P. J. T. Rutjes and
• Jan C. M. van Hest

Beilstein J. Org. Chem. 2018, 14, 716–733, doi:10.3762/bjoc.14.61

• ]. In this review we will highlight some typical nanoreactors that are used to accommodate homogeneous catalysts, holding promise in green organic synthesis. A division will be made between self-assembled nanoreactors, section 2, and covalent systems, section 3. 2. Self-assembled nanoreactors Self

Enhanced quantum yields by sterically demanding aryl-substituted β-diketonate ancillary ligands

• Rebecca Pittkowski and
• Thomas Strassner

Beilstein J. Org. Chem. 2018, 14, 664–671, doi:10.3762/bjoc.14.54

• spin density on the complexes Pt(MPIM)(acac) left, Pt(MPIM)(mes) (2) middle, and Pt(MPIM)(dur) (3) right (B3LYP/6-31G(d), ECP LANL2DZ, isovalue 0.02). Synthesis of complexes 2 and 3. Photoluminescence data of complexes 2 and 3 (2 wt % in PMMA, λexc = 320 nm) and literature-known compound Pt(MPIM)(acac

High-yielding continuous-flow synthesis of antimalarial drug hydroxychloroquine

• Eric Yu,
• Hari P. R. Mangunuru,
• Nakul S. Telang,
• Caleb J. Kong,
• Jenson Verghese,
• Stanley E. Gilliland III,
• Saeed Ahmad,
• Raymond N. Dominey and
• B. Frank Gupton

Beilstein J. Org. Chem. 2018, 14, 583–592, doi:10.3762/bjoc.14.45

• was purified using flash chromatography with DCM/Et3N/MeOH 95:3:2 to give a white solid (0.263 g, 78%). 1H NMR (600 MHz, CDCl3) δ 8.48 (d, J = 5.4 Hz, 1H), 7.93 (d, J = 5.4 Hz, 1H), 7.70 (d, J = 9.2 Hz, 1H), 7.34 (dd, J = 8.8, 7.3 Hz, 1H), 6.39 (d, J = 5.4 Hz, 1H), 4.96 (d, J = 7.5 Hz, 1H), 3.70 (sx

Mannich base-connected syntheses mediated by ortho-quinone methides

• Petra Barta,
• Ferenc Fülöp and
• István Szatmári

Beilstein J. Org. Chem. 2018, 14, 560–575, doi:10.3762/bjoc.14.43

• pentoxide (P2O5) [46], silica-supported phosphorus pentoxide (P2O5-SiO2) [47], N,N,N’,N’-tetrabromobenzene-1,3-disulfonamide (TBBDA) [48], 1-methyl-3-(2-(sulfoxy)ethyl)-1H-imidazol-3-ium chloride (MSI) [49], succinic acid [50], tannic acid [49], p-nitrobenzoic acid [52], a carbon-based solid acid (CBSA) [53

Addition of dithi(ol)anylium tetrafluoroborates to α,β-unsaturated ketones

• Yu-Chieh Huang,
• An Nguyen,
• Simone Gräßle,
• Sylvia Vanderheiden,
• Nicole Jung and
• Stefan Bräse

Beilstein J. Org. Chem. 2018, 14, 515–522, doi:10.3762/bjoc.14.37

• -dithioacetals [4] are of particular interest as attractive nucleophiles for the addition to halonium ions [5][6], acyl chlorides [7] and other electrophiles [8][9][10] and are broadly used as precursors for [2 + 2]-cycloaddition [11][12], (aza)-Diels–Alder reaction [13][14], and [3 + 2]-cycloaddition reactions

Stimuli-responsive oligonucleotides in prodrug-based approaches for gene silencing

• Françoise Debart,
• Christelle Dupouy and
• Jean-Jacques Vasseur

Beilstein J. Org. Chem. 2018, 14, 436–469, doi:10.3762/bjoc.14.32