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Search for "extrusion" in Full Text gives 95 result(s) in Beilstein Journal of Organic Chemistry.

Silica gel and microwave-promoted synthesis of dihydropyrrolizines and tetrahydroindolizines from enaminones

  • Robin Klintworth,
  • Garreth L. Morgans,
  • Stefania M. Scalzullo,
  • Charles B. de Koning,
  • Willem A. L. van Otterlo and
  • Joseph P. Michael

Beilstein J. Org. Chem. 2021, 17, 2543–2552, doi:10.3762/bjoc.17.170

Graphical Abstract
  • [57][58][59][60][61][62][63][64][65]. Results are summarized in Table 2. Triphenylphosphine and triethyl phosphite could be used interchangeably in the sulfur extrusion step. However, in most cases the co-elution of enaminones 15 with phosphorus-derived byproducts during chromatographic purification
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Published 13 Oct 2021

Visible-light-mediated copper photocatalysis for organic syntheses

  • Yajing Zhang,
  • Qian Wang,
  • Zongsheng Yan,
  • Donglai Ma and
  • Yuguang Zheng

Beilstein J. Org. Chem. 2021, 17, 2520–2542, doi:10.3762/bjoc.17.169

Graphical Abstract
  • -catalyzed trifluoromethylchlorosulfonylation of unactivated alkenes 4 under photochemical conditions. When used in place of [Cu(dap)2]Cl, ruthenium-based, iridium-based, and eosin Y catalysts promoted the trifluoromethylchlorination of alkenes with the extrusion of SO2 (e.g., product 6). Studies were
  • – is stabilized by the copper complex. The alkyl radical reacts with LnCuII-SO2Cl to deliver the target product 5. A mechanistic study demonstrated that [Cu(dap)2]Cl can coordinate with the reactive intermediate SO2Cl and suppresses the extrusion of SO2. Thus, [Cu(dap)2]Cl achieves a unique
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Published 12 Oct 2021

An initiator- and catalyst-free hydrogel coating process for 3D printed medical-grade poly(ε-caprolactone)

  • Jochen Löblein,
  • Thomas Lorson,
  • Miriam Komma,
  • Tobias Kielholz,
  • Maike Windbergs,
  • Paul D. Dalton and
  • Robert Luxenhofer

Beilstein J. Org. Chem. 2021, 17, 2095–2101, doi:10.3762/bjoc.17.136

Graphical Abstract
  • ], micro-extrusion [7] and selective laser sintering have all been used to fabricate clinical implants [6][7]. Other emerging 3D printing technologies can also fit the prerequisites described above, including melt electrowriting (MEW) [8]. This technology is based on the direct-writing of ultra-fine (800
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Published 19 Aug 2021

Methodologies for the synthesis of quaternary carbon centers via hydroalkylation of unactivated olefins: twenty years of advances

  • Thiago S. Silva and
  • Fernando Coelho

Beilstein J. Org. Chem. 2021, 17, 1565–1590, doi:10.3762/bjoc.17.112

Graphical Abstract
  • alkyl radical with formaldehyde hydrazone, which resulted in hydrazide 74 that could afford formal hydromethylated compounds 75 after the extrusion of nitrogen and sulfinic acid (Scheme 28) [95]. The hydrazone was generated in situ due its instability, and a simple exchange of the solvent from THF to
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Published 07 Jul 2021

Breaking paracyclophane: the unexpected formation of non-symmetric disubstituted nitro[2.2]metaparacyclophanes

  • Suraj Patel,
  • Tyson N. Dais,
  • Paul G. Plieger and
  • Gareth J. Rowlands

Beilstein J. Org. Chem. 2021, 17, 1518–1526, doi:10.3762/bjoc.17.109

Graphical Abstract
  • more general route to [2.2]metaparacyclophane (3) derivatives involves synthesis of 2,11-dithia[3.3]metaparacyclophane followed by the extrusion of sulfur, or more commonly sulfur dioxide, and this has become the de facto route to these molecules [25][37][38][39][40][41][42][43]. Even though this
  • but these are substrate specific [71][72]. Conclusion Currently, substituted [2.2]metaparacyclophanes are synthesized through a long sequence involving either high temperature extrusion of sulfur dioxide or photoextrusion of sulfur. We have found a serendipitous route to a disubstituted [2.2
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Published 29 Jun 2021

Antiviral therapy in shrimp through plant virus VLP containing VP28 dsRNA against WSSV

  • Santiago Ramos-Carreño,
  • Ivone Giffard-Mena,
  • Jose N. Zamudio-Ocadiz,
  • Alfredo Nuñez-Rivera,
  • Ricardo Valencia-Yañez,
  • Jaime Ruiz-Garcia,
  • Maria Teresa Viana and
  • Ruben D. Cadena-Nava

Beilstein J. Org. Chem. 2021, 17, 1360–1373, doi:10.3762/bjoc.17.95

Graphical Abstract
  • % mortality rate with DOVLP28-mix. This protection is significantly higher compared to the first results using fish oil. Both treatments using commercial binders indicate that it is possible to administer it in the pellets. However, it is crucial to state that pellets usually undergo pelleting or extrusion
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Published 01 Jun 2021

Synthetic accesses to biguanide compounds

  • Oleksandr Grytsai,
  • Cyril Ronco and
  • Rachid Benhida

Beilstein J. Org. Chem. 2021, 17, 1001–1040, doi:10.3762/bjoc.17.82

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Published 05 May 2021

[2 + 1] Cycloaddition reactions of fullerene C60 based on diazo compounds

  • Yuliya N. Biglova

Beilstein J. Org. Chem. 2021, 17, 630–670, doi:10.3762/bjoc.17.55

Graphical Abstract
  • N2 extrusion. Therein, the formed [5,6]-opened adducts are transformed into [6,6]-closed isomers, which are more thermodynamically stable. While the range of reagents used in nucleophilic cyclopropanation with stabilized carbanions is mainly limited to malonates, the range of cyclopropanating agents
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Published 05 Mar 2021

Synthesis of (Z)-3-[amino(phenyl)methylidene]-1,3-dihydro-2H-indol-2-ones using an Eschenmoser coupling reaction

  • Lukáš Marek,
  • Lukáš Kolman,
  • Jiří Váňa,
  • Jan Svoboda and
  • Jiří Hanusek

Beilstein J. Org. Chem. 2021, 17, 527–539, doi:10.3762/bjoc.17.47

Graphical Abstract
  • high amounts of the undesirable isoindigo 9a [32] (route c). In order to accelerate the Eschenmoser coupling reaction and to enhance the reaction yield (route b) an addition of a suitable thiophile assisting the sulfur extrusion should be beneficial [36]. Therefore, we tested two P(III) compounds as
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Published 23 Feb 2021

All-carbon [3 + 2] cycloaddition in natural product synthesis

  • Zhuo Wang and
  • Junyang Liu

Beilstein J. Org. Chem. 2020, 16, 3015–3031, doi:10.3762/bjoc.16.251

Graphical Abstract
  • tricyclic compound 25, which led to the synthesis of (±)-hirsutene (14) [22] (Scheme 1A). Refluxing azo compound 22 in acetonitrile generated the proposed biradical intermediate 23 through nitrogen extrusion. This intermediate underwent isomerization to 24 and intramolecular diyl trapping through a [3 + 2
  • trimethylenemethane diyl [3 + 2] cycloaddition of 40 led to the formation of angular fused triquinane 41 in 98% yield. The authors suggested that an intramolecular cycloaddition of the diazo group and allene 38 produces tetrahydrocyclopentapyrazole 39. Extrusion of nitrogen from the newly formed 39 produces diyl 40
  • natural product syntheses that feature the all-carbon [3 + 2] cyclization as the key reaction, reported before 2011. (A) TMM cycloaddition of diyl 24 resulted from dinitrogen extrusion/isomerization is used to prepare tricycle 25, which is a synthetic precursor of (±)-hirsutene (14) [22]. (B) Synthesis of
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Published 09 Dec 2020

Metal-free synthesis of biarenes via photoextrusion in di(tri)aryl phosphates

  • Hisham Qrareya,
  • Lorenzo Meazza,
  • Stefano Protti and
  • Maurizio Fagnoni

Beilstein J. Org. Chem. 2020, 16, 3008–3014, doi:10.3762/bjoc.16.250

Graphical Abstract
  • the real extrusion of CO in diaryl ketones [48][49] or of SO2 in diaryl sulfones (Scheme 1c) [50]. Nevertheless, a recent publication demonstrated that a metal-free photoextrusion was feasible when starting from benzene sulfonamides I (Scheme 1d, path a) [51]. Following the same approach, sparse
  • the route to the extrusion of the phosphate moiety. This is demonstrated by the formation of a new emission band when more than one aryl group is present in the aryl phosphate (see Figure 1). In our investigation, we likewise stated that the formation of 5* (from 1 and 3) is highly favored in highly
  • the presence of increasing amounts of TFE (up to 20% v/v, continuous line). Synthesis of biarenes via a) photogenerated triplet aryl cations and aryl radicals (PC = photocatalyst), b) intramolecular free radical ipso substitution, c) thermally catalyzed extrusion of CO and SO2, d) photoinduced
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Published 08 Dec 2020

On the mass spectrometric fragmentations of the bacterial sesterterpenes sestermobaraenes A–C

  • Anwei Hou and
  • Jeroen S. Dickschat

Beilstein J. Org. Chem. 2020, 16, 2807–2819, doi:10.3762/bjoc.16.231

Graphical Abstract
  • and Scheme 1B. The loss of the isopropyl group C20–19–21 can be achieved by an inductive cleavage of 1•+ to g1•+ followed by an α-cleavage to h1+ (Scheme 1D). Starting from c1•+, two α-cleavages with the extrusion of ethylene can lead to i1•+ that upon a third α-fragmentation with loss of the methyl
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Published 19 Nov 2020

Synthesis of purines and adenines containing the hexafluoroisopropyl group

  • Viacheslav Petrov,
  • Rebecca J. Dooley,
  • Alexander A. Marchione,
  • Elizabeth L. Diaz,
  • Brittany S. Clem and
  • William Marshall

Beilstein J. Org. Chem. 2020, 16, 2739–2748, doi:10.3762/bjoc.16.224

Graphical Abstract
  • into the final product, with extrusion of elemental sulfur) is not well understood and may be more complex, involving additional steps. The mechanism clarification of the reaction of tetrakis(trifluoromethyl)-1,3-dithietane (1) with azoles (and anilines) does require further investigation. As was
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Published 11 Nov 2020

Pauson–Khand reaction of fluorinated compounds

  • Jorge Escorihuela,
  • Daniel M. Sedgwick,
  • Alberto Llobat,
  • Mercedes Medio-Simón,
  • Pablo Barrio and
  • Santos Fustero

Beilstein J. Org. Chem. 2020, 16, 1662–1682, doi:10.3762/bjoc.16.138

Graphical Abstract
  • extrusion of two carbon monoxide ligands from the starting cobalt species, allowing the alkyne group to bind to the cobalt metal centers. The subsequent coordination of the olefin counterpart requires the extrusion of a third carbon monoxide ligand, leading to pentacarbonyl complex II. This highly
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Published 14 Jul 2020

Photocatalyzed syntheses of phenanthrenes and their aza-analogues. A review

  • Alessandra Del Tito,
  • Havall Othman Abdulla,
  • Davide Ravelli,
  • Stefano Protti and
  • Maurizio Fagnoni

Beilstein J. Org. Chem. 2020, 16, 1476–1488, doi:10.3762/bjoc.16.123

Graphical Abstract
  • involved the formation of a C(sp2)–C(sp2) bond via an aryl radical intermediate (Scheme 11). Thus, compound 11.1 was in situ converted to the corresponding diazonium salt 11.2+, which, upon reduction and nitrogen extrusion, formed the reactive aryl radical 11.3·. In turn, the latter radical smoothly
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Published 25 Jun 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
  • to the alkene, followed by the addition of SO2Cl to produce the desired product. However, when the reaction rate is slower, the SO2Cl anion decomposes to neutral SO2 and a chloride anion due to the weak nature of the Cu–SO2Cl bond. The SO2 extrusion explains the formation of the
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Published 23 Mar 2020

A golden opportunity: benzofuranone modifications of aurones and their influence on optical properties, toxicity, and potential as dyes

  • Joza Schmitt and
  • Scott T. Handy

Beilstein J. Org. Chem. 2019, 15, 1781–1785, doi:10.3762/bjoc.15.171

Graphical Abstract
  • efficiency using an extrusion method. Of equal interest was that a highly qualitative photobleaching study indicated a significant degree of stability of these aurone-based dyes, with simultaneous or pre-mordanting offering better stability. Clearly further studies of the generality of this observation as
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Published 25 Jul 2019

Synthesis of acylglycerol derivatives by mechanochemistry

  • Karen J. Ardila-Fierro,
  • Andrij Pich,
  • Marc Spehr,
  • José G. Hernández and
  • Carsten Bolm

Beilstein J. Org. Chem. 2019, 15, 811–817, doi:10.3762/bjoc.15.78

Graphical Abstract
  • loads has led to mechanoenzymatic transformations [5][6][7], and to synthesize amino acid derivatives [8][9][10] and peptides [11][12][13] by ball milling and extrusion techniques. Similarly, mechanochemical derivatizations of sugars and sugar derivatives such as cyclodextrins (CDs) have proven
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Published 29 Mar 2019

Low-budget 3D-printed equipment for continuous flow reactions

  • Jochen M. Neumaier,
  • Amiera Madani,
  • Thomas Klein and
  • Thomas Ziegler

Beilstein J. Org. Chem. 2019, 15, 558–566, doi:10.3762/bjoc.15.50

Graphical Abstract
  • extrusion, we usually obtained channels about 100 µm smaller than set in the CAD drawing. The same effect was previously also encountered by others [28]. A smaller channel resolution than 200 µm is nearly infeasible because it repeatedly led to a blockage of the channels as previously observed by others as
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Published 26 Feb 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
  • of azide to Rh2(esp)2 complex (bis[rhodium-(α,α,α’,α’-tetramethyl-1,3-benzenedipropionic acid)]) and extrusion of N2. Then, the Rh-nitrene intermediate 65 goes through an intramolecular single electron transfer (SET) to give the nitrogen-centered radical intermediate 66 [87][88][89][90]. Next, the
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Published 28 Jan 2019

Reactions of 3-(p-substituted-phenyl)-5-chloromethyl-1,2,4-oxadiazoles with KCN leading to acetonitriles and alkanes via a non-reductive decyanation pathway

  • Akın Sağırlı and
  • Yaşar Dürüst

Beilstein J. Org. Chem. 2018, 14, 3011–3017, doi:10.3762/bjoc.14.280

Graphical Abstract
  • trisubstituted acetonitriles into alkanes by the incorporation of KCN with the association of in situ-formed HCN and most likely through the extrusion of cyanogen which could not be detected or isolated. In addition, the plausible mechanisms were proposed for both transformations. The structures of the title
  • . Then, the acidic hydrogen adjacent to the nitrile group in the intermediate product is sequentially abstracted by a CN− anion with the extrusion of an HCN molecule and a carbanion alpha to the nitrile group bearing a 1,2,4-oxadiazole ring is formed. The resulted carbanion undergoes a substitution
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Published 10 Dec 2018

Functionalization of graphene: does the organic chemistry matter?

  • Artur Kasprzak,
  • Agnieszka Zuchowska and
  • Magdalena Poplawska

Beilstein J. Org. Chem. 2018, 14, 2018–2026, doi:10.3762/bjoc.14.177

Graphical Abstract
  • species (Figure 7, step a). Then (most likely) the aryl radical is obtained from the diazonium salt via the single electron transfer (SET) process and the inclusion of a graphene sheet (Figure 7, step b). This reaction step results in nitrogen extrusion. The desired functionalization route is most
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Published 02 Aug 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
  • carbene after extrusion of nitrogen and a crosslinked product after insertion reaction; X = e.g., NH, O, CH2. FimH crystal structure (pdb code 1KLF) with docked p-nitrophenyl α-D-mannopyranoside (1, pNPMan). FimH is a two-domain protein comprising a lectin domain (FimHL) with the carbohydrate binding site
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Published 24 Jul 2018

Glycosylation reactions mediated by hypervalent iodine: application to the synthesis of nucleosides and carbohydrates

  • Yuichi Yoshimura,
  • Hideaki Wakamatsu,
  • Yoshihiro Natori,
  • Yukako Saito and
  • Noriaki Minakawa

Beilstein J. Org. Chem. 2018, 14, 1595–1618, doi:10.3762/bjoc.14.137

Graphical Abstract
  • fragmentation to produce radical 132. The radical 132 could be trapped with iodine, giving iodide 133. The oxycarbenium ion 134 generated by the extrusion of iodide from 133 reacted with the acetoxy ion to furnish the resulting acetate derivatives. The acetates 130 and 131 were then treated with silylated
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Published 28 Jun 2018

[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

Graphical Abstract
  • absence of light. Depending on the temperature, a new reaction pathway involving benzylic group migration, CO2 extrusion and final cycloaddition was proposed (Scheme 4). Kinetics and mechanism of thermal cycloaddition The kinetics and reaction mechanism of the thermal cycloaddition between 4-methyl-3
  • bicyclic intermediate via a concerted [3 + 2]-cycloaddition followed by its very fast decomposition (extrusion of CO2) via a retro-Diels–Alder [4 + 2]-cycloaddition. The almost spontaneous extrusion of CO2 is caused by an energetically favorable aromatization occurring in this step leading to the formation
  • of 3-phenylsydnone and proposed formation of N-phenylnitrilimine as the main reaction product via an internal ring closure, extrusion of CO2 and ring opening (Scheme 6). This very reactive 1,3-dipole was trapped by reaction with external (14C-labelled) CO2 to give 3-phenyl-1,3,4-oxadiazol-2(3H)-one
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Published 05 Jun 2018
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