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Search for "insertion" in Full Text gives 342 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.

Insertion of [1.1.1]propellane into aromatic disulfides

  • Robin M. Bär,
  • Gregor Heinrich,
  • Martin Nieger,
  • Olaf Fuhr and
  • Stefan Bräse

Beilstein J. Org. Chem. 2019, 15, 1172–1180, doi:10.3762/bjoc.15.114

Graphical Abstract
  • as bioisosters of para-substituted benzene and alkyne moieties. The most promising precursor for BCPs is [1.1.1]propellane (1). The available methods to synthesize BCPs are quite limited and many groups contribute to the development of novel methods. The insertion of 1 into disulfide bonds is known
  • of the thiol addition [24]. In analogy to this reaction, the insertion of 1 into disulfide bonds has been discovered early, but only very few examples can be found in the literature [10][11][25][26][27][28]. In this work, the insertion of [1.1.1]propellane (1) into disulfide bonds was investigated
  • the first to use UV irradiation in this reaction, but did not report detailed conditions [28]. They used diacetyldithiol and 1 to obtain bisacetylthio[n]staffanes. To find feasible conditions for the insertion of 1 into disulfide bonds, a screening with irradiations of different wavelengths and other
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Published 28 May 2019

Multicomponent reactions (MCRs): a useful access to the synthesis of benzo-fused γ-lactams

  • Edorta Martínez de Marigorta,
  • Jesús M. de Los Santos,
  • Ana M. Ochoa de Retana,
  • Javier Vicario and
  • Francisco Palacios

Beilstein J. Org. Chem. 2019, 15, 1065–1085, doi:10.3762/bjoc.15.104

Graphical Abstract
  • experiments allowed the authors to propose the mechanism as follows (Scheme 20). First, cyclocondensation of 2-aminobenzamide (59) with 2-bromobenzaldehyde (62) to form intermediate 63 is followed by oxidative addition of Pd(0) to provide palladium complex 64. Then, insertion of CO (23) in the C–Pd bond
  • the authors to propose that the first stage of the reaction would be the insertion of carbon monoxide into the Ar–I bond to produce aryl iodide 107, followed by the reaction with the nitrogen nucleophile to form amide intermediate 108. Finally, intramolecular Michael addition would furnish lactam unit
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Published 08 May 2019

Synthesis of functionalized diazocines for application as building blocks in photo- and mechanoresponsive materials

  • Widukind Moormann,
  • Daniel Langbehn and
  • Rainer Herges

Beilstein J. Org. Chem. 2019, 15, 727–732, doi:10.3762/bjoc.15.68

Graphical Abstract
  • photostationary states (PSS (385 nm): 25–30% trans). The electronic decoupling of the azobenzene unit and the oxygen and nitrogen containing functional groups (OH, OR, N3, NH2) was achieved by insertion of one or two CH2 groups. Thereby, the switching efficiencies were increased by about a factor of two (PSS (385
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Published 20 Mar 2019

Design, synthesis and spectroscopic properties of crown ether-capped dibenzotetraaza[14]annulenes

  • Krzysztof M. Zwoliński and
  • Julita Eilmes

Beilstein J. Org. Chem. 2019, 15, 617–622, doi:10.3762/bjoc.15.57

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  • differentiated Lewis-basic binding sites, however, from a broader perspective, the nature of the DBTAA binding site can be easily switched into a Lewis-acidic one after appropriate metal insertion (e.g., with zinc(II) ions) [33]. The crown-capped DBTAA’s were synthesized by refluxing 1,4,10-trioxa-7,13
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Published 11 Mar 2019

Intramolecular cascade annulation triggered by rhodium(III)-catalyzed sequential C(sp2)–H activation and C(sp3)–H amination

  • Liangliang Song,
  • Guilong Tian,
  • Johan Van der Eycken and
  • Erik V. Van der Eycken

Beilstein J. Org. Chem. 2019, 15, 571–576, doi:10.3762/bjoc.15.52

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  • intramolecular migratory insertion affords intermediate C. Reductive elimination and subsequent oxidative addition give intermediate D. Then two pathways are involved in the following steps. In the main pathway (path a), intermediate D undergoes β-H elimination and tandem cyclization to give product 3a and Rh–H
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Published 27 Feb 2019

Design of indole- and MCR-based macrocycles as p53-MDM2 antagonists

  • Constantinos G. Neochoritis,
  • Maryam Kazemi Miraki,
  • Eman M. M. Abdelraheem,
  • Ewa Surmiak,
  • Tryfon Zarganes-Tzitzikas,
  • Beata Łabuzek,
  • Tad A. Holak and
  • Alexander Dömling

Beilstein J. Org. Chem. 2019, 15, 513–520, doi:10.3762/bjoc.15.45

Graphical Abstract
  • -pot procedure with one purification step), much better yields, no need of expensive catalysts as in ring-closing metathesis (RCM) reaction and higher complexity/diversity on the macrocyclic ring, e.g., insertion of heteroatoms that could improve the ADMET properties (Scheme 1) [4]. Results and
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Published 20 Feb 2019

Synthesis of C3-symmetric star-shaped molecules containing α-amino acids and dipeptides via Negishi coupling as a key step

  • Sambasivarao Kotha and
  • Saidulu Todeti

Beilstein J. Org. Chem. 2019, 15, 371–377, doi:10.3762/bjoc.15.33

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  • . Results and Discussion The required zinc insertion compound 7 was prepared from L-serine (3). Thus, commercially available L-serine (3) was treated with acetyl chloride in methanol to give methyl ester 4, which was subjected to N-Boc protection with di-tert-butyl dicarbonate (Boc2O) and triethylamine in
  • iodo compound 6 was treated with freshly activated Zn in DMF at room temperature to afford the zinc insertion product 7 (Scheme 1) [43]. With the organozinc compound 7 at hand we turned to the synthesis of the halide component for the attempted Negishi coupling. For this 4-iodoacetophenone (8) was
  • of Zn insertion reaction, stirring was stopped and the solid was allowed to settle down. The supernatant was carefully transferred to a suspension of triiodo derivative 9 (500 mg, 0.73 mmol) in DMF (10 mL) at room temperature. Five mol % tetrakis(triphenylphosphane)palladium (Pd(PPh3)4) was added to
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Published 08 Feb 2019

A novel and efficient synthesis of phenanthrene derivatives via palladium/norbornadiene-catalyzed domino one-pot reaction

  • Yue Zhong,
  • Wen-Yu Wu,
  • Shao-Peng Yu,
  • Tian-Yuan Fan,
  • Hai-Tao Yu,
  • Nian-Guang Li,
  • Zhi-Hao Shi,
  • Yu-Ping Tang and
  • Jin-Ao Duan

Beilstein J. Org. Chem. 2019, 15, 291–298, doi:10.3762/bjoc.15.26

Graphical Abstract
  • is presented in Scheme 5. As is commonly considered, the aryl-PdII complex A is formed by oxidative addition of aryl iodide to the Pd0 complex, which is followed by the insertion of norbornadiene to the C–Pd bond of A to produce B. Then, an ortho-C–H activation reaction occurs to B, which offers
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Published 31 Jan 2019

Oxidative radical ring-opening/cyclization of cyclopropane derivatives

  • Yu Liu,
  • Qiao-Lin Wang,
  • Zan Chen,
  • Cong-Shan Zhou,
  • Bi-Quan Xiong,
  • Pan-Liang Zhang,
  • Chang-An Yang and
  • Quan Zhou

Beilstein J. Org. Chem. 2019, 15, 256–278, doi:10.3762/bjoc.15.23

Graphical Abstract
  • intermediate 15, which undergoes a ring-opening process to form the radical intermediate 16 [52][53]. Then, the radical 16 reacts with copper(II) acetate to produce organocopper intermediate 17. Finally, the intramolecular insertion of C–Cu in compounds 17 to the carbon–carbon double bond takes place to
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Published 28 Jan 2019

Olefin metathesis in multiblock copolymer synthesis

  • Maria L. Gringolts,
  • Yulia I. Denisova,
  • Eugene Sh. Finkelshtein and
  • Yaroslav V. Kudryavtsev

Beilstein J. Org. Chem. 2019, 15, 218–235, doi:10.3762/bjoc.15.21

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  • the initiator efficiency. The sacrificial approach also helps to describe the multiblock copolymer structure: owing to the acid-labile acetal group, polymer scission takes place at the point of the dioxepin insertion thus providing an indirect way to detect the monomer location [73]. Supramolecular
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Published 24 Jan 2019

Synthesis, biophysical properties, and RNase H activity of 6’-difluoro[4.3.0]bicyclo-DNA

  • Sibylle Frei,
  • Adam K. Katolik and
  • Christian J. Leumann

Beilstein J. Org. Chem. 2019, 15, 79–88, doi:10.3762/bjoc.15.9

Graphical Abstract
  • oligonucleotides (AONs) [6]. An effective way to tune the properties of antisense oligonucleotides is by the insertion of the fluorine atom in the sugar moiety of the nucleoside. In this way, the sugar pucker can be controlled which ideally results in an increased affinity towards complementary RNA [7]. An
  • oligonucleotides towards complementary DNA and RNA (Table 3). A single insertion of a 6’-diF-bc4,3-T into DNA strands led to a remarkable duplex destabilization versus both complements (ΔTm/mod = −1.6 to −5.5 °C) in a sequence specific manner but with a slight lesser degree of destabilization towards complementary
  • (ΔTm/mod = −5.4 °C and −4.5 °C for complementary DNA and RNA, respectively). Interestingly, the DNA/RNA hybrid structure better accommodated multiple 6’-diF-bc4,3-Ts than a single insertion. Additionally, the hybrid structure also better tolerated multiple 6’-diF-bc4,3-T units than the DNA/DNA duplex
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Published 08 Jan 2019

Gold-catalyzed ethylene cyclopropanation

  • Silvia G. Rull,
  • Andrea Olmos and
  • Pedro J. Pérez

Beilstein J. Org. Chem. 2019, 15, 67–71, doi:10.3762/bjoc.15.7

Graphical Abstract
  • the insertion of the carbene CHCO2Et group into the C–Cl of the solvent was the major one, accordingly with previous work from this and other laboratories using silver-based catalysts [20][21]. Therefore, we moved onto gold-based catalysts that had already been validated for EDA decomposition and
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Published 07 Jan 2019

Ruthenium-based olefin metathesis catalysts with monodentate unsymmetrical NHC ligands

  • Veronica Paradiso,
  • Chiara Costabile and
  • Fabia Grisi

Beilstein J. Org. Chem. 2018, 14, 3122–3149, doi:10.3762/bjoc.14.292

Graphical Abstract
  • , Figure 6), developed by Grubbs and co-workers, is based on a chelating NHC ligand that is derived from an intramolecular carboxylate-driven C–H bond insertion of the adamantyl N-substituent of the same NHC ligand in complex 22 [20]. Unsymmetrical complexes bearing smaller N-alkyl groups (Figure 7) were
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Published 28 Dec 2018

6’-Fluoro[4.3.0]bicyclo nucleic acid: synthesis, biophysical properties and molecular dynamics simulations

  • Sibylle Frei,
  • Andrei Istrate and
  • Christian J. Leumann

Beilstein J. Org. Chem. 2018, 14, 3088–3097, doi:10.3762/bjoc.14.288

Graphical Abstract
  • , Figure 1) [23]. Another strategy to overcome some of the limitations deals with the insertion of one or several fluorine atom(s) in the sugar moiety of the nucleic acid analog. The polar hydrophobic nature [24] of the fluorine atom can positively alter the furanose conformation, basicity and/or
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Published 20 Dec 2018

Degenerative xanthate transfer to olefins under visible-light photocatalysis

  • Atsushi Kaga,
  • Xiangyang Wu,
  • Joel Yi Jie Lim,
  • Hirohito Hayashi,
  • Yunpeng Lu,
  • Edwin K. L. Yeow and
  • Shunsuke Chiba

Beilstein J. Org. Chem. 2018, 14, 3047–3058, doi:10.3762/bjoc.14.283

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  • absorption [28][29][30][31][32][33][34][35][36][37]. In the area of polymer synthesis, visible-light-induced RAFT polymerization of xanthates with vinyl monomers under blue LED (light-emitting diode) irradiation has been reported [38][39][40][41]. Visible-light-induced single unit monomer insertion of the
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Published 13 Dec 2018

Stereodivergent approach in the protected glycal synthesis of L-vancosamine, L-saccharosamine, L-daunosamine and L-ristosamine involving a ring-closing metathesis step

  • Pierre-Antoine Nocquet,
  • Aurélie Macé,
  • Frédéric Legros,
  • Jacques Lebreton,
  • Gilles Dujardin,
  • Sylvain Collet,
  • Arnaud Martel,
  • Bertrand Carboni and
  • François Carreaux

Beilstein J. Org. Chem. 2018, 14, 2949–2955, doi:10.3762/bjoc.14.274

Graphical Abstract
  • introduction of nitrogen in the convenient position (C3) could be performed by a stereopecific nitrene insertion reaction catalyzed by rhodium(II) complexes [24][25]. Herein, we describe our outcomes related to the implementation of this strategy for the synthesis of L-vancosamine derivative 1, as well as its
  • data [9]. As an example, the expected protected glycal of L-daunosamine 3 [9][47] was obtained by regioselective rhodium nitrene insertion thus demonstrating the usefulness of this strategy for the synthesis of such compounds. Conclusion We developed an alternative route to 3-aminoglycals through ring
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Published 29 Nov 2018

1,8-Bis(dimethylamino)naphthyl-2-ketimines: Inside vs outside protonation

  • A. S. Antonov,
  • A. F. Pozharskii,
  • P. M. Tolstoy,
  • A. Filarowski and
  • O. V. Khoroshilova

Beilstein J. Org. Chem. 2018, 14, 2940–2948, doi:10.3762/bjoc.14.273

Graphical Abstract
  • (Figure S13 in Supporting Information File 1). The addition of a second OMe group in the case of 6 leads to the formation of 25% 6b’. Upon the insertion of a third OMe group in 7, the amount of 7b’ expectedly increases to 33%. Switching of the solvent to acetone-d6 facilitates the proton transfer away
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Published 28 Nov 2018

Enhanced single-isomer separation and pseudoenantiomer resolution of new primary rim heterobifunctionalized α-cyclodextrin derivatives

  • Iveta Tichá,
  • Gábor Benkovics,
  • Milo Malanga and
  • Jindřich Jindřich

Beilstein J. Org. Chem. 2018, 14, 2829–2837, doi:10.3762/bjoc.14.261

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  • prepared the target 6A,6X-heterobifunctionalized α-CDs. Mesitylenesulfonyl was chosen as the appropriate functional group for insertion in the α-CD skeleton because it is sufficiently stable for reverse column chromatography and more sterically hindered than a tosyl group. The idea of attaching the
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Published 13 Nov 2018

Cobalt- and rhodium-catalyzed carboxylation using carbon dioxide as the C1 source

  • Tetsuaki Fujihara and
  • Yasushi Tsuji

Beilstein J. Org. Chem. 2018, 14, 2435–2460, doi:10.3762/bjoc.14.221

Graphical Abstract
  • formed (step a) [42]. Then, the insertion of CO2 into the Co–C(sp3) bond occurs, and the seven-membered Co intermediate C is obtained (step b). The transmetalation of C with the Zn(II) species proceeds then to afford the alkenylzinc species D (step c). The subsequent two-electron reduction of D with Zn
  • corresponding pyrone and the Rh(I) species A (step c). Alternatively, the oxidative cyclization of A proceeds as one of the C–C triple bonds of the diyne and CO2 react regioselectively, and rhodacycle D is subsequently formed (step d). Then, the insertion of the alkyne into the Rh–C bond occurs to give
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Published 19 Sep 2018

Practical tetrafluoroethylene fragment installation through a coupling reaction of (1,1,2,2-tetrafluorobut-3-en-1-yl)zinc bromide with various electrophiles

  • Ken Tamamoto,
  • Shigeyuki Yamada and
  • Tsutomu Konno

Beilstein J. Org. Chem. 2018, 14, 2375–2383, doi:10.3762/bjoc.14.213

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  • Ken Tamamoto Shigeyuki Yamada Tsutomu Konno Faculty of Molecular Chemistry and Engineering, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan 10.3762/bjoc.14.213 Abstract (1,1,2,2-Tetrafluorobut-3-en-1-yl)zinc bromide was prepared by insertion of the zinc–silver couple
  • variety of CF2CF2-containing molecules, and the results are described in this article (Scheme 1). Results and Discussion We carried out the optimization of the reaction conditions for the preparation of 2-Zn by direct zinc insertion into the CF2–Br bond of commercially available fluorinated substance 1
  • . The results are summarized in Table 1. Initially, we attempted zinc insertion using a typical protocol [33], i.e., treating 1 with 2.0 equiv of zinc powder, pre-activated with dilute HCl solution, in DMF at 0 °C for 0.5 h. Unfortunately, no desired zinc insertion occurred and substrate 1 was
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Published 11 Sep 2018

Hydroarylations by cobalt-catalyzed C–H activation

  • Rajagopal Santhoshkumar and
  • Chien-Hong Cheng

Beilstein J. Org. Chem. 2018, 14, 2266–2288, doi:10.3762/bjoc.14.202

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  • or a C–H activation with high-valent cobalt to give A2 via deprotonation, followed by migratory insertion and reductive elimination or protonation (Scheme 3). We believe that this review will be helpful to the researchers for their future research on hydroarylation using earth-abundant metal
  • found intermolecular kinetic isotope effect (KIE) of kH/kD = 2.1 and H/D crossover studies strongly suggest that the reaction proceeds through an oxidative addition of a C–H bond to low-valent cobalt followed by alkyne insertion and reductive elimination. Furthermore, the new C–C bond formation occurred
  • -products. Then, coordination of the alkyne with the cobalt catalyst afforded B1 and the oxidative addition of C–H gave the cobalt complex B2. Intramolecular insertion of the Co–H bond into the alkyne and subsequent reductive elimination of the less-hindered alkenyl carbon with aryl group in B3 provides the
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Published 29 Aug 2018

Novel photochemical reactions of carbocyclic diazodiketones without elimination of nitrogen – a suitable way to N-hydrazonation of C–H-bonds

  • Liudmila L. Rodina,
  • Xenia V. Azarova,
  • Jury J. Medvedev,
  • Dmitrij V. Semenok and
  • Valerij A. Nikolaev

Beilstein J. Org. Chem. 2018, 14, 2250–2258, doi:10.3762/bjoc.14.200

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  • , 3 Nobel st., Russia 10.3762/bjoc.14.200 Abstract The sensitized photoexcitation of 2-diazocyclopentane-1,3-diones in the presence of THF leads to the insertion of the terminal N-atom of the diazo group into the α-С–Н bond of THF, producing the associated N-alkylhydrazones in yields of up to 63–71
  • with up to 90–97% yield. Keywords: C–H insertion; diazo compounds; excited state; photochemistry; Wolff rearrangement; Introduction Photochemical reactions of diazocarbonyl compounds are well-known transformations in the synthesis of the diversified acyclic, carbo- and heterocyclic structures [1][2
  • ][30]. This photochemical process is assumed to proceed through the triplet excited states of diazoketones via ‘insertion’ of the terminal nitrogen atom of the diazo group into the С–Н bond of the organic substrates [27][30]. Hence it was principally demonstrated that by carefully varying the
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Published 28 Aug 2018

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

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  • performed by the dye micellization method using pyrene and eosin Y (EY) as fluorescent and spectrophotometric probes, respectively (Table 1). The nonpolar pyrene can be incorporated into hydrophobic domains of the aggregates due to hydrophobic interactions. Pyrene insertion is measured by analyzing the
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Published 31 Jul 2018

Synthesis and characterization of π–extended “earring” subporphyrins

  • Haiyan Guan,
  • Mingbo Zhou,
  • Bangshao Yin,
  • Ling Xu and
  • Jianxin Song

Beilstein J. Org. Chem. 2018, 14, 1956–1960, doi:10.3762/bjoc.14.170

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  • detected in the very low field region. This indicates that the Pd is inserted in the cavity of 3 with the deprotonation of both N-H and meso-H. Meanwhile all signals belong to aromatic hydrogens shifted to a slightly higher field region after the complexation with Pd, which reveals that the insertion of
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Published 30 Jul 2018

Diazirine-functionalized mannosides for photoaffinity labeling: trouble with FimH

  • Femke Beiroth,
  • Tomas Koudelka,
  • Thorsten Overath,
  • Stefan D. Knight,
  • Andreas Tholey and
  • Thisbe K. Lindhorst

Beilstein J. Org. Chem. 2018, 14, 1890–1900, doi:10.3762/bjoc.14.163

Graphical Abstract
  • insert into OH, NH, or CH groups of a protein in a fast reaction [5][6]. Further advantages of the diazirine group are its robustness at different pH values and its stability against nucleophiles. However, besides desired insertion reactions, carbenes can undergo unwanted side reactions, in particular
  • diazirine 3, with scoring values of −34.7 (open gate) and −36.2 (closed gate), is predicted as suitable FimH ligand with high affinity. Additionally, docking suggests that the diazirine function of 3 is positioned in close proximity to the protein surface, making a specific insertion reaction of the carbene
  • . However, purification of the photolabile mannosides is problematic due to their poor solubility and the light sensitivity of the diazirine moiety. Therefore, the products often contain minor impurities after chromatography resulting from light-induced activation of the diazirine and insertion reaction
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Published 24 Jul 2018
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