Search results

Search for "extrusion" in Full Text gives 92 result(s) in Beilstein Journal of Organic Chemistry.

CF3SO2X (X = Na, Cl) as reagents for trifluoromethylation, trifluoromethylsulfenyl-, -sulfinyl- and -sulfonylation and chlorination. Part 2: Use of CF3SO2Cl

  • Hélène Chachignon,
  • Hélène Guyon and
  • Dominique Cahard

Beilstein J. Org. Chem. 2017, 13, 2800–2818, doi:10.3762/bjoc.13.273

Graphical Abstract
  • interestingly, when the reaction was performed using an aryl or alkylsulfonyl chloride, instead of trifluoromethanesulfonyl chloride, no extrusion of the SO2 moiety was observed, and the sulfonated products were recovered. The reaction mechanism involved excitation of the iridium catalyst under visible light to
  • derivatives 9. It was found out that such compounds could take part in similar catalytic cycles, without CO extrusion, to yield trifluoromethylated isoquinolindione derivatives 10 in moderate to good yields (Scheme 9). Additionally, Zhang and co-workers reported once again that BiOBr nanosheet catalysis was
  • (dtbbpy)]PF6 or Eosin Y favoured the introduction of the CF3 group and a chlorine atom, with SO2 extrusion. This phenomenon can be explained by the presumed ability of copper to coordinate SO2Cl− (intermediate 25), preventing it from decomposing into SO2 and Cl− and consequently allowing it to be
PDF
Album
Full Research Paper
Published 19 Dec 2017

Reagent-controlled regiodivergent intermolecular cyclization of 2-aminobenzothiazoles with β-ketoesters and β-ketoamides

  • Irwan Iskandar Roslan,
  • Kian-Hong Ng,
  • Gaik-Khuan Chuah and
  • Stephan Jaenicke

Beilstein J. Org. Chem. 2017, 13, 2739–2750, doi:10.3762/bjoc.13.270

Graphical Abstract
  • abstraction, releasing the catalyst as In(OTf)2OH [102] and forming D. An intramolecular condensation reaction occurs which forms the desired product 5a with extrusion of MeOH. The In(OTf)3 is regenerated by TfOH with release of a water molecule, and the catalytic cycle is repeated. Conclusion We have
PDF
Album
Supp Info
Full Research Paper
Published 18 Dec 2017

Spatial effects in polymer chemistry

  • Helmut Ritter

Beilstein J. Org. Chem. 2017, 13, 2015–2016, doi:10.3762/bjoc.13.198

Graphical Abstract
  • the solid phase is not only influenced by external forces, for example, during extrusion, but is often also a result of chain mobility and strong intermolecular interactions. It should also be mentioned that the solubility of polymer chains is a spatial interplay between the solvent molecules and the
PDF
Editorial
Published 27 Sep 2017

Synthesis of benzannelated sultams by intramolecular Pd-catalyzed arylation of tertiary sulfonamides

  • Valentin A. Rassadin,
  • Mirko Scholz,
  • Anastasiia A. Klochkova,
  • Armin de Meijere and
  • Victor V. Sokolov

Beilstein J. Org. Chem. 2017, 13, 1932–1939, doi:10.3762/bjoc.13.187

Graphical Abstract
  • of 14 can also proceed as a cheletropic extrusion of SO2 from 13 followed by recombination of SO2 with the formed carbanionic center. Similar fragmentations of such 1,3-dihydro-2,1-benzothiazol-2,2-dioxides and related compounds are known, but usually require heating to above 200 °C to yield aza
  • -ortho-quinodimethane derivatives [44], which can rearrange into the corresponding Schiff bases by sigmatropic [1,5]-hydrogen shift [45]. In the case of 13, the extrusion of SO2 must be drastically accelerated due to its carbanionic nature, so that it can occur at 70 °C. The resulting anionic aza-ortho
PDF
Album
Supp Info
Full Research Paper
Published 12 Sep 2017

A novel application of 2-silylated 1,3-dithiolanes for the synthesis of aryl/hetaryl-substituted ethenes and dibenzofulvenes

  • Grzegorz Mlostoń,
  • Paulina Pipiak,
  • Róża Hamera-Fałdyga and
  • Heinz Heimgartner

Beilstein J. Org. Chem. 2017, 13, 1900–1906, doi:10.3762/bjoc.13.185

Graphical Abstract
  • applied [14]. Another approach, which opens access to diverse ethenes, is the ‘two-fold extrusion reaction’, which comprises the [3 + 2]-cycloaddition of a diazo compound with a thiocarbonyl dipolarophile and subsequent elimination of N2 followed by sulfur extrusion [15][16][17]. In our continuing studies
PDF
Album
Supp Info
Full Research Paper
Published 08 Sep 2017

Solvent-free sonochemistry: Sonochemical organic synthesis in the absence of a liquid medium

  • Deborah E. Crawford

Beilstein J. Org. Chem. 2017, 13, 1850–1856, doi:10.3762/bjoc.13.179

Graphical Abstract
  • include techniques such as shearing [2], microfluidics [3] and twin screw extrusion [4][5][6]. More recently, sonochemistry has been included under the umbrella term of mechanochemistry [7] as it has demonstrated excellent potential when instigating chemical activity in solutions by applying mechanical
  • ninhydrin and dimedone. Both systems were investigated in the complete absence of solvent and without the presence of any grinding media (such as inert silica beads) to help mediate the reaction. The aldol reaction was successfully carried out by twin screw extrusion, as I have reported previously [6]. The
  • indicating that a complete reaction had taken place between a hydroxy group of ninhydrin and the activated methylene of dimedone (Figure 7). This reaction has previously been carried out by twin screw extrusion in the absence of solvent [6], and it was confirmed that the same product was obtained by both
PDF
Album
Supp Info
Full Research Paper
Published 04 Sep 2017

18-Hydroxydolabella-3,7-diene synthase – a diterpene synthase from Chitinophaga pinensis

  • Jeroen S. Dickschat,
  • Jan Rinkel,
  • Patrick Rabe,
  • Arman Beyraghdar Kashkooli and
  • Harro J. Bouwmeester

Beilstein J. Org. Chem. 2017, 13, 1770–1780, doi:10.3762/bjoc.13.171

Graphical Abstract
  • diphosphate and the pyrophosphate sensor, a highly conserved arginine located 43 amino acids upstream of the NSE triad, and the RY dimer, a highly conserved motif at the C-terminus. The substrate is ionised by extrusion of diphosphate, yielding a highly reactive allyl cation that can react in a cyclisation
PDF
Album
Supp Info
Full Research Paper
Published 23 Aug 2017

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

Graphical Abstract
  • systems [98]; b) the spontaneous division of the growing systems was found difficult to achieve in a predictable way. Early experiments used extrusion methods (i.e., structures were physically pressed through filters with very small pores, a procedure that leads to structure re-sizing, thereby to the
PDF
Album
Review
Published 07 Aug 2017

Continuous-flow processes for the catalytic partial hydrogenation reaction of alkynes

  • Carmen Moreno-Marrodan,
  • Francesca Liguori and
  • Pierluigi Barbaro

Beilstein J. Org. Chem. 2017, 13, 734–754, doi:10.3762/bjoc.13.73

Graphical Abstract
  • the form of a downstream located cartridge [97]. Honeycomb (or foam) catalysts consist of inert carrier materials with millimetre size parallel channels (or cavities) obtained by extrusion, onto which a catalytically active layer is deposited, usually a porous inorganic oxide bonded to the support
PDF
Album
Review
Published 20 Apr 2017

Membrane properties of hydroxycholesterols related to the brain cholesterol metabolism

  • Malte Hilsch,
  • Ivan Haralampiev,
  • Peter Müller,
  • Daniel Huster and
  • Holger A. Scheidt

Beilstein J. Org. Chem. 2017, 13, 720–727, doi:10.3762/bjoc.13.71

Graphical Abstract
  • spectra were dePaked and smoothed order parameters were determined as described in [37]. From these order parameters, the lipid chain extent was calculated according the mean torque model [25][26]. Preparation of LUVs LUVs were prepared using the extrusion method [38]. Aliquots of lipids dissolved in
  • 7.4, final lipid concentration 1 mM) and the mixture was vortexed. To prepare LUVs, this suspension was subjected to five freeze-thaw cycles followed by extrusion of the lipid suspension 10 times through 0.1 μm polycarbonate filters at 40 °C (extruder from Lipex Biomembranes Inc., Vancouver, Canada
PDF
Album
Full Research Paper
Published 18 Apr 2017

Dimerization reactions of aryl selenophen-2-yl-substituted thiocarbonyl S-methanides as diradical processes: a computational study

  • Michael L. McKee,
  • Grzegorz Mlostoń,
  • Katarzyna Urbaniak and
  • Heinz Heimgartner

Beilstein J. Org. Chem. 2017, 13, 410–416, doi:10.3762/bjoc.13.44

Graphical Abstract
  • -methanides 1 belong to the class of S-centered 1,3-dipolar species, which were identified by Huisgen as reactive intermediates formed via nitrogen extrusion from 2,5-dihydro-1,3,4-thiadiazoles 2 [1][2]. In spite of the fact that several methods are reported for the preparation of these precursors, the most
PDF
Album
Supp Info
Full Research Paper
Published 03 Mar 2017

3D printed fluidics with embedded analytic functionality for automated reaction optimisation

  • Andrew J. Capel,
  • Andrew Wright,
  • Matthew J. Harding,
  • George W. Weaver,
  • Yuqi Li,
  • Russell A. Harris,
  • Steve Edmondson,
  • Ruth D. Goodridge and
  • Steven D. R. Christie

Beilstein J. Org. Chem. 2017, 13, 111–119, doi:10.3762/bjoc.13.14

Graphical Abstract
  • -dimensional parts, often with geometries which would be extremely complex, or in some cases impossible to manufacture using more conventional subtractive manufacturing processes [1]. In AM, parts are built layer-by-layer, using processes such as material extrusion [2], material jetting [3], vat
PDF
Album
Supp Info
Full Research Paper
Published 18 Jan 2017

Extrusion – back to the future: Using an established technique to reform automated chemical synthesis

  • Deborah E. Crawford

Beilstein J. Org. Chem. 2017, 13, 65–75, doi:10.3762/bjoc.13.9

Graphical Abstract
  • Deborah E. Crawford Queen’s University Belfast, School of Chemistry and Chemical Engineering, David Keir Building, 39–123 Stranmillis Road, Belfast, BT9 5AG, Northern Ireland, UK 10.3762/bjoc.13.9 Abstract Herein, the benefits which extrusion can provide for the automated continuous synthesis of
  • organic compounds are highlighted. Extrusion is a well-established technique that has a vital role in the manufacturing processes of polymers, pharmaceuticals and food products. Furthermore, this technique has recently been applied to the solvent-free continuous synthesis of co-crystals and coordination
  • compounds including metal-organic frameworks (MOFs). To date, a vast amount of research has already been conducted into reactive extrusion (REX), particularly in the polymer industry, which in many cases has involved organic transformations, however, it has not received significant recognition for this
PDF
Album
Review
Published 11 Jan 2017

A self-assembled cyclodextrin nanocarrier for photoreactive squaraine

  • Ulrike Kauscher and
  • Bart Jan Ravoo

Beilstein J. Org. Chem. 2016, 12, 2535–2542, doi:10.3762/bjoc.12.248

Graphical Abstract
  • side can be synthesized in a simple and straightforward three step synthesis [27][30]. Cyclodextrin vesicles (CDVs) can be easily prepared by sonication or extrusion in aqueous solution. CDVs have the unique possibility of versatile surface decoration by the simple addition of guest molecules to the
  • solution in a round bottom flask. Hydration and extrusion with a Liposofast extruder and membranes with 100 nm pore size yield bilayer vesicles of an approximate size of 100 nm. CDVs were decorated with AdSq by simple addition of the AdSq to the aqueous dispersion of the CDVs. Interestingly, the
PDF
Album
Supp Info
Full Research Paper
Published 25 Nov 2016

On the cause of low thermal stability of ethyl halodiazoacetates

  • Magnus Mortén,
  • Martin Hennum and
  • Tore Bonge-Hansen

Beilstein J. Org. Chem. 2016, 12, 1590–1597, doi:10.3762/bjoc.12.155

Graphical Abstract
  • are usually two orders of magnitude higher and the reaction times longer in comparison to the decomposition rate of 2b. There are in principle three pathways for the thermal decomposition of the halo diazoacetates [3]: 1) a unimolecular extrusion of dinitrogen giving N2 (g) and a carbene; 2) a
  • bimolecular dimerization leading to azines; and 3) a reaction of the diazo compound with the solvent or a reactant prior to nitrogen extrusion. The fact that the decomposition rate of all halodiazoacetates showed first order kinetics and that t1/2 for 2b is independent of its concentration indicates that
  • diazo compounds [3]. DFT calculations The proposed unimolecular extrusion of N2 to form the free carbene (Scheme 2) was investigated further by DFT calculations for compounds 1 and 2 and the results are summarized in Figure 3. In order to expande the calculation to fluorine, ethyl fluorodiazoacetate (2d
PDF
Album
Supp Info
Full Research Paper
Published 26 Jul 2016

Diradical reaction mechanisms in [3 + 2]-cycloadditions of hetaryl thioketones with alkyl- or trimethylsilyl-substituted diazomethanes

  • Grzegorz Mlostoń,
  • Paulina Pipiak and
  • Heinz Heimgartner

Beilstein J. Org. Chem. 2016, 12, 716–724, doi:10.3762/bjoc.12.71

Graphical Abstract
  • aryl hetaryl thioketones 1 (Table 1). As mentioned before, in some cases tri- and tetrasubstituted thiiranes partially underwent spontaneous extrusion of sulfur to form the corresponding tri- or tetrasubstituted ethene derivatives 9. In these cases, complete desulfurization was achieved by treatment of
PDF
Album
Supp Info
Full Research Paper
Published 14 Apr 2016

Three new trixane glycosides obtained from the leaves of Jungia sellowii Less. using centrifugal partition chromatography

  • Luíse Azevedo,
  • Larissa Faqueti,
  • Marina Kritsanida,
  • Antonia Efstathiou,
  • Despina Smirlis,
  • Gilberto C. Franchi Jr,
  • Grégory Genta-Jouve,
  • Sylvie Michel,
  • Louis P. Sandjo,
  • Raphaël Grougnet and
  • Maique W. Biavatti

Beilstein J. Org. Chem. 2016, 12, 674–683, doi:10.3762/bjoc.12.68

Graphical Abstract
  • volume was determined as 320 mL. The butanol fraction was injected after dissolution in 20 mL of a mixture 1:1 of the selected biphasic system. 70 fractions of 50 mL were collected in the ascending mode. After switching to descending mode, 20 additional fractions of 50 mL were collected. Extrusion
PDF
Album
Supp Info
Full Research Paper
Published 12 Apr 2016

Cross-metathesis of polynorbornene with polyoctenamer: a kinetic study

  • Yulia I. Denisova,
  • Maria L. Gringolts,
  • Alexander S. Peregudov,
  • Liya B. Krentsel,
  • Ekaterina A. Litmanovich,
  • Arkadiy D. Litmanovich,
  • Eugene Sh. Finkelshtein and
  • Yaroslav V. Kudryavtsev

Beilstein J. Org. Chem. 2015, 11, 1796–1808, doi:10.3762/bjoc.11.195

Graphical Abstract
  • Vestenamer® [17], is a semicrystalline rubber applied as a polymer processing aid for extrusion, injection molding etc. Though easily homopolymerized, NB and COE hardly enter metathesis copolymerization [18][19] because of the much higher activity of NB possessing a considerably more strained bicyclic
PDF
Album
Full Research Paper
Published 01 Oct 2015

Synthesis of 1,2-cis-2-C-branched aryl-C-glucosides via desulfurization of carbohydrate based hemithioacetals

  • Henok H. Kinfe,
  • Fanuel M. Mebrahtu,
  • Mandlenkosi M. Manana,
  • Kagiso Madumo and
  • Mokela S. Sokamisa

Beilstein J. Org. Chem. 2015, 11, 583–588, doi:10.3762/bjoc.11.64

Graphical Abstract
  • -1 Raney Nickel in acetone at ambient temperature with no evidence on the formation of glucoside 4a and ring contraction by sulfur extrusion. Consideration of the conditions required for the formation of the mixture of carbaldehydes 5a and 5a’ suggests that hydrogenolytic desulfurization of the C(sp2
PDF
Album
Supp Info
Full Research Paper
Published 29 Apr 2015

Hetero-Diels–Alder reactions of hetaryl and aryl thioketones with acetylenic dienophiles

  • Grzegorz Mlostoń,
  • Paulina Grzelak,
  • Maciej Mikina,
  • Anthony Linden and
  • Heinz Heimgartner

Beilstein J. Org. Chem. 2015, 11, 576–582, doi:10.3762/bjoc.11.63

Graphical Abstract
  • the present study were used for oxidation reactions aimed at the preparation of the corresponding sulfoxides and sulfones. As demonstrated in a recent publication [20], polycyclic sulfones are attractive substrates for the synthesis of polycyclic hydrocarbons via thermal SO2 extrusion. In our
  • treatment with mCPBA at room temperature to give the corresponding sulfones. In this reaction, even when using equimolar amounts of mCPBA, selective formation of the sulfoxide could not be achieved. The obtained sulfones are promising substrates for thermal SO2 extrusion reactions aimed at the contraction
PDF
Album
Supp Info
Full Research Paper
Published 28 Apr 2015

Thermodynamically stable [4 + 2] cycloadducts of lanthanum-encapsulated endohedral metallofullerenes

  • Yuta Takano,
  • Yuki Nagashima,
  • M. Ángeles Herranz,
  • Nazario Martín and
  • Takeshi Akasaka

Beilstein J. Org. Chem. 2014, 10, 714–721, doi:10.3762/bjoc.10.65

Graphical Abstract
  • precursors to afford [4 + 2] cycloadducts of fullerenes, the sultine 4,5-benzo-3,6-dihydro-1,2-oxathiin 2-oxide and its derivatives are useful to afford thermodynamically stable compounds because thermolysis of sultine affords highly reactive o-quinodimethanes by extrusion of sulfur dioxide without
PDF
Album
Supp Info
Full Research Paper
Published 25 Mar 2014

Substrate dependent reaction channels of the Wolff–Kishner reduction reaction: A theoretical study

  • Shinichi Yamabe,
  • Guixiang Zeng,
  • Wei Guan and
  • Shigeyoshi Sakaki

Beilstein J. Org. Chem. 2014, 10, 259–270, doi:10.3762/bjoc.10.21

Graphical Abstract
  • hydrazine (Me2C=N–NH2) was obtained. The channel involves two likely proton-transfer routes. However, it was found that the base-free reaction was unlikely at the N2 extrusion step from the isopropyl diimine intermediate (Me2C(H)–N=N–H). Two base-catalyzed reactions were investigated by models of the ketone
  • , H2N–NH2 and OH−(H2O)7. Here, ketones are acetone and acetophenone. While routes of the ketone → hydrazone → diimine are similar, those from the diimines are different. From the isopropyl diimine, the N2 extrusion and the C–H bond formation takes place concomitantly. The concomitance leads to the
  • -K reduction in the former step is the conversion of the C=O bond to the C=N–NH2 group. The latter step involves a shift of two hydrogen atoms from the terminal nitrogen atom to the carbon and the simultaneous extrusion of an N2 molecule. The Huang-Minglon modification is an alternative and
PDF
Album
Supp Info
Full Research Paper
Published 23 Jan 2014

Less reactive dipoles of diazodicarbonyl compounds in reaction with cycloaliphatic thioketones – First evidence for the 1,3-oxathiole–thiocarbonyl ylide interconversion

  • Valerij A. Nikolaev,
  • Alexey V. Ivanov,
  • Ludmila L. Rodina and
  • Grzegorz Mlostoń

Beilstein J. Org. Chem. 2013, 9, 2751–2761, doi:10.3762/bjoc.9.309

Graphical Abstract
  • obtained as the major product at 80 °С. The formation of the latter can occur via two intermediate steps, i.e. 1,3-electrocyclization of ylide 6 into the corresponding thiirane and subsequent extrusion of the sulfur atom to produce alkene 5е. An analogous ‘two-fold extrusion process’ was previously
  • . The latter undergoes decomposition to the alkene 5e upon extrusion of disulfur S2. Similar mechanisms for the spontaneous desulfurization of oxathiiranes have been reported in a recent publication [27]. In order to verify the observed reversibility of the thiocarbonyl ylide 6e' and oxathiole 3e
PDF
Album
Supp Info
Full Research Paper
Published 02 Dec 2013

The chemistry of isoindole natural products

  • Klaus Speck and
  • Thomas Magauer

Beilstein J. Org. Chem. 2013, 9, 2048–2078, doi:10.3762/bjoc.9.243

Graphical Abstract
  • starting materials, via a Staudinger–aza-Wittig reaction gave amine 237 as a mixture of four diastereoisomers. Conversion into 4-oxido-isoquinolinium betaine 238 could be achieved by an acid-catalyzed methanol extrusion and isomerization. Betaine 238 served as the substrate for the following 1,3-aza
PDF
Album
Video
Review
Published 10 Oct 2013
Graphical Abstract
  • the second to the methyl or methyne group attached to the nitrogen atom with the formation of the six-membered dithiazine ring in 14, similarly to that proposed for 1,2-dithioles prepared from isopropylamines [14]. Ultimate sulfur extrusion (cf. reference [13]) would then give stable and planar
  • formation of thiol 17 followed by the dihydropyrrole ring closure under the impact of both quinone and amine groups and the generation of the aromatic pyrrole cycle with hydrogen sulfide extrusion by the action of base (triethylamine). Although, to the best of our knowledge, the transformation of 3H-spiro
PDF
Album
Supp Info
Full Research Paper
Published 19 Mar 2013
Other Beilstein-Institut Open Science Activities