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Search for "pyrrole" in Full Text gives 258 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.

The B & B approach: Ball-milling conjugation of dextran with phenylboronic acid (PBA)-functionalized BODIPY

  • Patrizia Andreozzi,
  • Lorenza Tamberi,
  • Elisamaria Tasca,
  • Gina Elena Giacomazzo,
  • Marta Martinez,
  • Mirko Severi,
  • Marco Marradi,
  • Stefano Cicchi,
  • Sergio Moya,
  • Giacomo Biagiotti and
  • Barbara Richichi

Beilstein J. Org. Chem. 2020, 16, 2272–2281, doi:10.3762/bjoc.16.188

Graphical Abstract
  • with small molecules, in a green and scalable process. Results and Discussion The boron dipyrromethene dye 1 bearing a phenylboronic acid moiety (PBA) at the meso position of the BODIPY core (Scheme 1) was prepared in four synthetic steps starting from 4-formylbenzeneboronic acid (2) and pyrrole (3
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Published 11 Sep 2020

Naphthalene diimide bis-guanidinio-carbonyl-pyrrole as a pH-switchable threading DNA intercalator

  • Poulami Jana,
  • Filip Šupljika,
  • Carsten Schmuck and
  • Ivo Piantanida

Beilstein J. Org. Chem. 2020, 16, 2201–2211, doi:10.3762/bjoc.16.185

Graphical Abstract
  • naphthalene diimde analogue (NDI) equipped at the imide positions with two guanidinio-carbonyl-pyrrole (GCP) pendant arms interacted significantly stronger with ds-DNA at pH 5 than at pH 7, due to reversible protonation of the GCP arms. This was consequence of a pH-switchable threading intercalation into ds
  • the DNA/RNA conjugate NDI-GCP2 showed also aggregation along the ds-polynucleotide and AFM and DLS demonstrated that NDI-GCP2 has pronounced ds-DNA condensation ability. Keywords: AFM; circular dichroism; DNA/RNA recognition; fluorescence; guanidinio-carbonyl-pyrrole; naphthalene diimide
  • spectroscopy methods (FDCD, CPL), the sensitivity of response is approaching the classical fluorimetric probes [14]. Our systematic work on aryl-guanidiniocarbonyl-pyrrole (GCP) derivatives characterised the GCP moiety as very useful building block in the design of new small molecules targeting DNA/RNA. The
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Published 08 Sep 2020

Azo-dimethylaminopyridine-functionalized Ni(II)-porphyrin as a photoswitchable nucleophilic catalyst

  • Jannis Ludwig,
  • Julian Helberg,
  • Hendrik Zipse and
  • Rainer Herges

Beilstein J. Org. Chem. 2020, 16, 2119–2126, doi:10.3762/bjoc.16.179

Graphical Abstract
  • coordination. On this account, isomerization and coordination were investigated separately by 1H NMR spectroscopy. The protons meta to the azo group in the azopyridine unit (H-11) are responsive to the configuration of the azo group (cis or trans) and the chemical shifts of the pyrrole protons of the porphyrin
  • signals (1H NMR, 600 MHz, THF-d8, 300 K) of the pyrrole protons in the PSS at 530 nm and 435 nm. Coordination/decoordination is fast on the NMR timescale and signal averages for the pyrrole protons are observed. 50.40 ppm corresponds to 100% coordinated (paramagnetic) Ni-porphyrin and 10.83 ppm is the
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Published 31 Aug 2020

Automated high-content imaging for cellular uptake, from the Schmuck cation to the latest cyclic oligochalcogenides

  • Rémi Martinent,
  • Javier López-Andarias,
  • Dimitri Moreau,
  • Yangyang Cheng,
  • Naomi Sakai and
  • Stefan Matile

Beilstein J. Org. Chem. 2020, 16, 2007–2016, doi:10.3762/bjoc.16.167

Graphical Abstract
  • )pyrrole (GCP) cation 1 as a synthetic analogue of the guanidinium cations, somehow a “super-guanidinium” conceived to drive “arginine magic” [20][21] to the extreme (Figure 1) [23]. The power of the Schmuck cation to bind carboxylate and phosphate anions in competitive water has several origins [22
  • binding is further enhanced by the addition of hydrogen-bonding interactions between the amide NH moiety in position 5 of the pyrrole ring or the pyrrole NH group and the oxoanion (Figure 1, blue part). Thirdly, the rigid and planar conformation of the GCP moiety is beneficial to bind planar anions such
  • cations (6: KD = 20 mM, Figure 2). The amide NH unit in position 5 of the pyrrole ring is crucial for this binding affinity, which even exceeds the effect of the pyrrole NH moiety (4 and 5 vs 7: KD = 7.7 mM). In addition, the size and electronic structure of the pyrrole core are also important for this
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Published 14 Aug 2020

Design, synthesis and application of carbazole macrocycles in anion sensors

  • Alo Rüütel,
  • Ville Yrjänä,
  • Sandip A. Kadam,
  • Indrek Saar,
  • Mihkel Ilisson,
  • Astrid Darnell,
  • Kristjan Haav,
  • Tõiv Haljasorg,
  • Lauri Toom,
  • Johan Bobacka and
  • Ivo Leito

Beilstein J. Org. Chem. 2020, 16, 1901–1914, doi:10.3762/bjoc.16.157

Graphical Abstract
  • superstructures [11]. The rings should be of remarkable size for accommodating even small anions, such as acetate. In many cases the receptor is formally a macrocycle, but the anion is bound on its “surface”, not inside the ring [10][12]. A well-known example is the calix[4]pyrrole family, which emerged as an
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Published 04 Aug 2020

Rearrangement of o-(pivaloylaminomethyl)benzaldehydes: an experimental and computational study

  • Csilla Hargitai,
  • Györgyi Koványi-Lax,
  • Tamás Nagy,
  • Péter Ábrányi-Balogh,
  • András Dancsó,
  • Gábor Tóth,
  • Judit Halász,
  • Angéla Pandur,
  • Gyula Simig and
  • Balázs Volk

Beilstein J. Org. Chem. 2020, 16, 1636–1648, doi:10.3762/bjoc.16.136

Graphical Abstract
  • to afford intermediate isoindole 4a [2][3][4][5][6]. Then, the addition of water to the sterically less-hindered site of the latter compound followed by ring opening resulted in the rearranged aldehyde 2a [1]. As regards the formation of dimer-like product 3a, the tendency of pyrrole [7][8], indole
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Published 13 Jul 2020

Highly selective Diels–Alder and Heck arylation reactions in a divergent synthesis of isoindolo- and pyrrolo-fused polycyclic indoles from 2-formylpyrrole

  • Carlos H. Escalante,
  • Eder I. Martínez-Mora,
  • Carlos Espinoza-Hicks,
  • Alejandro A. Camacho-Dávila,
  • Fernando R. Ramos-Morales,
  • Francisco Delgado and
  • Joaquín Tamariz

Beilstein J. Org. Chem. 2020, 16, 1320–1334, doi:10.3762/bjoc.16.113

Graphical Abstract
  • simplest pyrrole-fused heterocyclic aza-bridged compounds. The numerous series of pyrrolizine-containing polycycles include pyrrolo[2,1-a]isoindoles [6], pyrrolo[1,2-a]indoles [7][8][9][10] and isoindolo[2,1-a]indoles [11] (Figure 1). These three series constitute the core of natural occurring alkaloids
  • 5–16). None of the series of mixtures 9a–p/10a–p corresponds to the direct products of the Diels–Alder cycloadditions, since they are derivatives resulting from the double bond isomerization of adducts 17 (i.e., migration from the pyrrole-fused exo cyclic position to the endo cyclic aromatic
  • reactivity of 2-vinylpyrroles substituted by electron-withdrawing groups [34][35]. Interestingly, all the 2-vinylpyrroles, including the N-unsubstituted 16a,b or the N-substituted ones 8a and 8c–j, furnished a high endo stereoselectivity with dienophile 7c, except the N-substituted 2-acrylonitrile pyrrole 8b
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Published 17 Jun 2020

Activated carbon as catalyst support: precursors, preparation, modification and characterization

  • Melanie Iwanow,
  • Tobias Gärtner,
  • Volker Sieber and
  • Burkhard König

Beilstein J. Org. Chem. 2020, 16, 1188–1202, doi:10.3762/bjoc.16.104

Graphical Abstract
  • amines, imines, amides, pyridine nitrogen and pyrrole nitrogen or as oxidized nitrogen species, e.g., pyridine-N-oxides [10]. Díaz-Terán et al. examined the surface of the samples (surface groups, chemical state of the elements, metal content and distribution) during the activation process of
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Published 02 Jun 2020

Photocatalysis with organic dyes: facile access to reactive intermediates for synthesis

  • Stephanie G. E. Amos,
  • Marion Garreau,
  • Luca Buzzetti and
  • Jerome Waser

Beilstein J. Org. Chem. 2020, 16, 1163–1187, doi:10.3762/bjoc.16.103

Graphical Abstract
  • the substrate 15.1 using dibenzothiophene S-oxide (DBTSO, 15.2). Then, under visible-light irradiation, 15.3 could be reduced with PHTH (OD16) to generate an aryl radical that could further be trapped by a heteroarene 15.4, such as pyrrole or thiophene, furnishing the arylation product 15.5. Acyl
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Published 29 May 2020

Recent applications of porphyrins as photocatalysts in organic synthesis: batch and continuous flow approaches

  • Rodrigo Costa e Silva,
  • Luely Oliveira da Silva,
  • Aloisio de Andrade Bartolomeu,
  • Timothy John Brocksom and
  • Kleber Thiago de Oliveira

Beilstein J. Org. Chem. 2020, 16, 917–955, doi:10.3762/bjoc.16.83

Graphical Abstract
  • continuous-flow photochemistry a sustainable alternative approach being applied already by the chemical and pharmaceutical industries. Porphyrinoid is the term given for a class of organic compounds containing four pyrrole rings connected by four methylene bridges, and include porphyrin, chlorin
  • reported a metal-free photoarylation of five-membered heteroarenes with aryldiazonium salts and meso-arylated porphyrin derivatives as photoredox catalyst [11]. Compounds such as furan, thiophene, and N-Boc-pyrrole derivatives were obtained by this methodology in 29–81% yields (Scheme 3). The key-step of
  • to regular N4-porphyrins (with four pyrrole units), but also can occur with other porphyrinoid compounds. Porphyrins containing other heteroatoms present physicochemical and electronic properties that are quite different from regular N4-porphyrins. These structures absorb and emit light at lower
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Published 06 May 2020

Bipyrrole boomerangs via Pd-mediated tandem cyclization–oxygenation. Controlling reaction selectivity and electronic properties

  • Liliia Moshniaha,
  • Marika Żyła-Karwowska,
  • Joanna Cybińska,
  • Piotr J. Chmielewski,
  • Ludovic Favereau and
  • Marcin Stępień

Beilstein J. Org. Chem. 2020, 16, 895–903, doi:10.3762/bjoc.16.81

Graphical Abstract
  • into boomerang-shaped N,N'-bridged α,α'-bipyrroles that are not accessible by means of conventional oxidative coupling methods (Scheme 1) [32]. Our approach is applicable to electron-deficient and sterically encumbered systems, notably those based on pyrrole derivatives fused with naphthalenediamide
  • system more evenly. In the cNMInH series (n = 2, 3), the HOMO and LUMO are formed by superposition of the corresponding MOs of the monomeric NMI pyrrole (Supporting Information File 1, Figures S23 and S24). However, the LUMO has observably lower amplitudes on the bipyrrole part of the molecule, whereas a
  • V (Table 3). The boomerangs with unsubstituted pyrrole α-positions (cNMI3H and cNMI2H) are characterized by significantly lower oxidation and reduction potentials than the corresponding dilactam analogues. The electrochemical data obtained for cNMI3O and cNMI2O indicate a destabilization of their
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Published 04 May 2020

Towards triptycene functionalization and triptycene-linked porphyrin arrays

  • Gemma M. Locke,
  • Keith J. Flanagan and
  • Mathias O. Senge

Beilstein J. Org. Chem. 2020, 16, 763–777, doi:10.3762/bjoc.16.70

Graphical Abstract
  • /v). Recrystallization (CHCl3/n-hexane) gave red crystals (12.5 mg, 30%). Mp >350 °C. Rf = 0.75 (SiO2, CH2Cl2/n-hexane 3:1, v/v); 1H NMR (600 MHz, CDCl3) δ 8.03–7.99 (m, 8H, α-pyrrole-H and phenyl-H), 7.88 (dd, J = 5.2, 3.0 Hz, 6H, triptycene-H), 7.72 (d, 4H, phenyl-H), 7.19 (dd, J = 5.2, 3.0 Hz, 6H
  • , triptycene-H), 7.03 (d, 4H, pyrrole-H), 6.62 ppm (s, 4H, pyrrole-H); 13C NMR (151 MHz, CDCl3) δ 146.4, 144.7, 143.5, 135.0, 134.3, 132.3, 131.6, 130.9, 126.3, 126.2, 125.6, 122.5, 119.0, 92.3, 86.4, 29.8; 11B NMR (128 MHz, CDCl3) δ 0.32 (t, J = 28.7 Hz); 19F NMR (377 MHz, CDCl3) δ −145.04 (dd, J = 57.5, 28.7
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Published 17 Apr 2020

Recent advances in Cu-catalyzed C(sp3)–Si and C(sp3)–B bond formation

  • Balaram S. Takale,
  • Ruchita R. Thakore,
  • Elham Etemadi-Davan and
  • Bruce H. Lipshutz

Beilstein J. Org. Chem. 2020, 16, 691–737, doi:10.3762/bjoc.16.67

Graphical Abstract
  • authors demonstrated a wide substrate scope, including an example of benzimidazole and pyrrole, although with varying chemical yields [69]. Recently Zhang et al. [70] explored various L22-containing (NHC)Cu catalysts by means of generating interesting nonracemic aminosilanes. In this case, they performed
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Published 15 Apr 2020

Regioselectively α- and β-alkynylated BODIPY dyes via gold(I)-catalyzed direct C–H functionalization and their photophysical properties

  • Takahide Shimada,
  • Shigeki Mori,
  • Masatoshi Ishida and
  • Hiroyuki Furuta

Beilstein J. Org. Chem. 2020, 16, 587–595, doi:10.3762/bjoc.16.53

Graphical Abstract
  • ppm), and the β-CH resonances are in the range of 6.5 to 6.7 ppm (Figure 3). The disappearance of the α-pyrrole proton signals of 4a is notable. In the case of 3a, only a singlet signal appeared at 7.95 ppm for the α-pyrrole CH. In contrast, 6a revealed two singlet signals at 7.99 and 6.70 ppm
  • , assignable to the α- and β-pyrrole CHs, respectively. The 1H NMR spectrum of the mono-substituted compound 5a represents an unsymmetrical resonance pattern similar to that of 3a with two α-CH signals at 7.97 and 7.96 ppm. The proposed structures of all BODIPY compounds were elucidated based on the
  • -EBX reagents. This atom-economical method for the late-stage alkynylation of BODIPY dyes could be an alternate approach for functionalized fluorescent dyes without the need of preparing unstable halogenated pyrrole precursors. The resulting α- and β-ethynyl-substituted BODIPYs displayed distinct
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Published 01 Apr 2020

Recent advances in photocatalyzed reactions using well-defined copper(I) complexes

  • Mingbing Zhong,
  • Xavier Pannecoucke,
  • Philippe Jubault and
  • Thomas Poisson

Beilstein J. Org. Chem. 2020, 16, 451–481, doi:10.3762/bjoc.16.42

Graphical Abstract
  • vinyl azide sensitization to allow the formation of the corresponding 2,5-disubstituted pyrrole (Scheme 34) [39]. The reaction was promoted by a visible-light irradiation (450 nm) using the complex [Cu(I)(dmp)(BINAP)]BF4, and the desired pyrrole was obtained in quantitative yield. Conclusion Over the
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Published 23 Mar 2020

Room-temperature Pd/Ag direct arylation enabled by a radical pathway

  • Amy L. Mayhugh and
  • Christine K. Luscombe

Beilstein J. Org. Chem. 2020, 16, 384–390, doi:10.3762/bjoc.16.36

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  • . Results and Discussion Initial attempts to polymerize iodoindole monomer 1 using the reported conditions (Scheme 1) produced oligomers with an unanticipated coupling pattern in good yield (87%, Figure 1, Supporting Information File 1, Figure S3). The 1H NMR signals from the C2-H, C3-H on the pyrrole ring
  • and the N-CH2-R on the alkyl chain indicate the product is highly branched [15]. Comparing the monomer’s spectrum to the polymer’s shows large peaks from unfunctionalized pyrrole rings at the chain ends with a ratio of interior to end groups of 1:0.57. While low molecular weight also contributes to
  • the large signals from the chain ends, there are a few factors that indicate branching is occurring: firstly, the large variety in C3-H signals; secondly, the relative integration of the C2-H/C3-H signals to the N-CH2-R signals show that for every indole unit, there is less than one H on the pyrrole
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Published 13 Mar 2020

Architecture and synthesis of P,N-heterocyclic phosphine ligands

  • Wisdom A. Munzeiwa,
  • Bernard Omondi and
  • Vincent O. Nyamori

Beilstein J. Org. Chem. 2020, 16, 362–383, doi:10.3762/bjoc.16.35

Graphical Abstract
  • pyrrolylphosphine ligands 40 and 43 was reported by Kumar et al. [68] (Scheme 7). The condensation of pyrrole (38) with formaldehyde and the amine gave the bis(diaminomethyl)pyrrole 39, which on reaction with Ph2PH gave diphosphine pyrrole ligand 40 in good yield (90%). Following a different route, condensation of
  • pyrrole (38) with diphenylketone gave diphenyl(dipyrrolyl)methane 41. Subsequent Mannich condensation reaction resulted in the pyrrole diamine 42. Refluxing a toluene solution of intermediate 42 and diphenylphosphine gave dipyrrolyldiphosphine ligand 43 in very good yield (92%). Generally, high
  • ligands. Synthesis of diphosphine pyrrole ligands. Synthesis of 4,5-diazafluorenylphosphine ligands. Synthesis of thioether-containing pyridyldiphosphine ligands starting from ethylene sulfide and diphenylphosphine. Synthesis of monoterpene-derived phosphine pyridine ligands. Synthesis of N
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Published 12 Mar 2020

Photocontrolled DNA minor groove interactions of imidazole/pyrrole polyamides

  • Sabrina Müller,
  • Jannik Paulus,
  • Jochen Mattay,
  • Heiko Ihmels,
  • Veronica I. Dodero and
  • Norbert Sewald

Beilstein J. Org. Chem. 2020, 16, 60–70, doi:10.3762/bjoc.16.8

Graphical Abstract
  • compounds have frequently been employed as modules, e.g., to control protein–DNA interactions. However, their use in conjunction with minor groove-binding imidazole/pyrrole (Im/Py) polyamides is yet unprecedented. Dervan-type Im/Py polyamides were equipped with an azobenzene unit, i.e., 3-(3-(aminomethyl
  • acted as a building block inducing a reverse turn, which favored hydrogen bonds between the pyrrole/imidazole amide and the DNA bases. In contrast, the E-configured polyamides did not induce any ICD characteristic for minor groove binding. The incorporation of the photoswitchable azobenzene unit is a
  • . A major breakthrough concerning selective small DNA-targeting molecules was the use of pyrrole/imidazole hairpin polyamides. They are conceptually derived from the natural products netropsin and distamycin A, which selectively bind to particular sequences of the DNA duplex [2][3][4]. Covalent
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Published 09 Jan 2020

Facile regiodivergent synthesis of spiro pyrrole-substituted pseudothiohydantoins and thiohydantoins via reaction of [e]-fused 1H-pyrrole-2,3-diones with thiourea

  • Aleksandr I. Kobelev,
  • Nikita A. Tretyakov,
  • Ekaterina E. Stepanova,
  • Maksim V. Dmitriev,
  • Michael Rubin and
  • Andrey N. Maslivets

Beilstein J. Org. Chem. 2019, 15, 2864–2871, doi:10.3762/bjoc.15.280

Graphical Abstract
  • pyrrole-2-one fragment involving the reaction of [e]-fused 1H-pyrrole-2,3-diones with thioureas was developed. The obtained spiro pseudothiohydantoin derivatives were found to undergo a pseudothiohydantoin–thiohydantoin rearrangement. The reactions were shown to proceed under catalyst-free conditions in
  • spiro-fused to a pharmacologically valuable pyrrole-2-one fragment and to investigate the scope and conditions of their PTR behavior (Scheme 2). Results and Discussion 1H-Pyrrole-2,3-diones fused at [e]-side (FPDs) 1 can be viewed as a versatile polyelectrophilic synthetic platform (Figure 2), enabling
  • ] heterocycles bearing a pharmacophoric pyrrole-2-one moiety (Scheme 3) [28][29]. We employed this feature as a key step in the development of a straightforward and concise synthetic approach towards regioisomeric thiohydantoins and pseudothiohydantoins spiro-fused to a pyrrole-2-one fragment. To test the
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Published 27 Nov 2019

A review of asymmetric synthetic organic electrochemistry and electrocatalysis: concepts, applications, recent developments and future directions

  • Munmun Ghosh,
  • Valmik S. Shinde and
  • Magnus Rueping

Beilstein J. Org. Chem. 2019, 15, 2710–2746, doi:10.3762/bjoc.15.264

Graphical Abstract
  • a long gap, in 2006, Takano and Seki prepared a PLPy(Pd) electrode coated with a chiral poly-(N-substituted pyrrole) film having ʟ-(+)-lactic acid moieties as the optically active groups and further incorporated with palladium metal [27]. Thus prepared electrodes 21 were used for the
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Published 13 Nov 2019

Synthesis of aryl-substituted thieno[3,2-b]thiophene derivatives and their use for N,S-heterotetracene construction

  • Nadezhda S. Demina,
  • Nikita A. Kazin,
  • Nikolay A. Rasputin,
  • Roman A. Irgashev and
  • Gennady L. Rusinov

Beilstein J. Org. Chem. 2019, 15, 2678–2683, doi:10.3762/bjoc.15.261

Graphical Abstract
  • -heteroacenes, which can limit the effectiveness of semiconducting films in the case of solution-processable electronics [11]. Introducing the NH-containing moieties, e.g., pyrrole rings, followed by attaching solubilizing substituents is one of the ways to solve this problem. Thus, different types of N,S
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Published 12 Nov 2019

AgNTf2-catalyzed formal [3 + 2] cycloaddition of ynamides with unprotected isoxazol-5-amines: efficient access to functionalized 5-amino-1H-pyrrole-3-carboxamide derivatives

  • Ziping Cao,
  • Jiekun Zhu,
  • Li Liu,
  • Yuanling Pang,
  • Laijin Tian,
  • Xuejun Sun and
  • Xin Meng

Beilstein J. Org. Chem. 2019, 15, 2623–2630, doi:10.3762/bjoc.15.255

Graphical Abstract
  • Analysis, Qufu 273165, P. R. China 10.3762/bjoc.15.255 Abstract A formal [3 + 2] cycloaddition between ynamides and unprotected isoxazol-5-amines has been developed in the presence of catalytic AgNTf2 in an open flask. By the protocol, a variety of functionalized 5-amino-1H-pyrrole-3-carboxamide
  • derivatives can be obtained in up to 99% yield. The reaction mechanism might involve the generation of an unusual α-imino silver carbene intermediate (or a silver-stabilized carbocation) and subsequent cyclization/isomerization to build the significant pyrrole-3-carboxamide motif. The reaction features the
  • use of an inexpensive catalyst, simple reaction conditions, simple work-up without column chromatographic purification for most of products and high yields. Keywords: [3 + 2] cycloaddition; isoxazole; pyrrole; silver catalysis; ynamide; Introduction Silver-catalyzed transformations of alkynes have
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Published 04 Nov 2019

In search of visible-light photoresponsive peptide nucleic acids (PNAs) for reversible control of DNA hybridization

  • Lei Zhang,
  • Greta Linden and
  • Olalla Vázquez

Beilstein J. Org. Chem. 2019, 15, 2500–2508, doi:10.3762/bjoc.15.243

Graphical Abstract
  • cis-form did not show any decomposition under these conditions (Figure S27C, Supporting Information File 1), unlike when the oF4Azo was grafted onto a pyrrole scaffold [48]. Next, we explored if the inclusion of oF4Azo as monomer surrogate within the PNA sequence could affect its hybridization to a
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Published 22 Oct 2019

Self-assembled coordination thioether silver(I) macrocyclic complexes for homogeneous catalysis

  • Zhen Cao,
  • Aline Lacoudre,
  • Cybille Rossy and
  • Brigitte Bibal

Beilstein J. Org. Chem. 2019, 15, 2465–2472, doi:10.3762/bjoc.15.239

Graphical Abstract
  • of silver(I) complexes 1a–d, we investigated their performance in the cyclization [63] of alkynone 3 [63][64][65] in the presence of benzylamine, as a nucleophile (Table 2) that lead to substituted pyrrole 5. This tandem condensation/cycloisomerization was previously reported in 78% yield using AgOTf
  • % were employed (Table 2, entries 2–6). Interestingly, a lower catalytic loading of 0.5 mol % allowed the isolation of 73% of pyrrole 5 in the presence of catalysts 1a and 1b (Table 2, entries 7 and 8). Under the same conditions, the catalytic efficiency of 1c and 1d was slightly lower (64–67 % yield
  • acetate 70:1) to obtain pyrrole 5. X-ray structures of complex 1a, as two diastereoisomeric macrocycles (R,S-1)2·(AgOTf)2 with ligands assembled in: (a) a head-to-head fashion and, (b) a head-to-tail mode. Hydrogen atoms are omitted for clarity. X-ray structure of complex 1c, as a (R,S-1)4·(AgNO3)6 cage
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Published 17 Oct 2019

Combining the Ugi-azide multicomponent reaction and rhodium(III)-catalyzed annulation for the synthesis of tetrazole-isoquinolone/pyridone hybrids

  • Gerardo M. Ojeda,
  • Prabhat Ranjan,
  • Pavel Fedoseev,
  • Lisandra Amable,
  • Upendra K. Sharma,
  • Daniel G. Rivera and
  • Erik V. Van der Eycken

Beilstein J. Org. Chem. 2019, 15, 2447–2457, doi:10.3762/bjoc.15.237

Graphical Abstract
  • isoquinolones is very wide and may be extended to the preparation of complex compounds having heterocyclic moieties such as pyridone, furan, thiophene and pyrrole, as well as the corresponding benzo-fused derivatives. The developed procedure is simple, reproducible and does not require inert conditions
  • rings, such as furan, benzofuran, pyrrole, benzopyrrole, thiophene, benzothiophene and naphthalene were also successfully synthesized (5d–l) in moderate to very good yields. The exceptions were the cases of indolopyridone 5i and thiazolopyridone 5k, the latter one could not be obtained even after many
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Published 16 Oct 2019
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