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Search for "intermolecular" in Full Text gives 763 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.

Constrained thermoresponsive polymers – new insights into fundamentals and applications

  • Patricia Flemming,
  • Alexander S. Münch,
  • Andreas Fery and
  • Petra Uhlmann

Beilstein J. Org. Chem. 2021, 17, 2123–2163, doi:10.3762/bjoc.17.138

Graphical Abstract
  • polymer chains and with the solvent molecules. For a polymer to dissolve well in a solvent, the intermolecular forces between the polymer chains on one side and between the solvent molecules on the other side must be smaller than the effective forces between polymer and solvent molecules among each other
  • intra- and intermolecular interactions between polymer segments are favored and the polymer begins to precipitate. A comparison of the calorimetrically determined enthalpies of mixture ∆mH for PNAGA and PNIPAAm reveals the different mechanisms. The entropically driven LCST phase transition of PNIPAAm
  • polymer chains can form superstructures that have a direct influence on the physical properties, such as mobility and intermolecular interactions, and thus also on the position and width of the phase transition. A topologically simple way to restrict the mobility of the polymer chains is the radial
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Published 20 Aug 2021

Recent advances in the syntheses of anthracene derivatives

  • Giovanni S. Baviera and
  • Paulo M. Donate

Beilstein J. Org. Chem. 2021, 17, 2028–2050, doi:10.3762/bjoc.17.131

Graphical Abstract
  • methodology, they synthesized 2,3,6,7-anthracenetetracarbonitrile (90) in a good yield (84%) by double intermolecular Wittig reaction of the protected benzenetetracarbaldehyde 87 with reagent 88, followed by deprotection and double ring-closing reaction of intermediate 89; they used a mixture of triflic acid
  • different arenes [71]. Recently, Satyanarayana and Suchand developed a one-pot strategy to synthesize substituted anthraquinones 170 via palladium-catalyzed intermolecular direct acylation of aromatic aldehydes 169 and o-iodoesters 168 (Scheme 38) [72]. The overall process involved sequential Pd-catalyzed
  • intermolecular acylation/H2SO4-promoted intramolecular Friedel–Crafts cyclization. The authors prepared substituted anthraquinones bearing Me, OMe, OH, Br, F, or other groups, such as anthraquinones 170a–g, in moderate to good yields (55–69%). The reaction proved efficient mainly with electron-donating
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Published 10 Aug 2021

Progress and challenges in the synthesis of sequence controlled polysaccharides

  • Giulio Fittolani,
  • Theodore Tyrikos-Ergas,
  • Denisa Vargová,
  • Manishkumar A. Chaube and
  • Martina Delbianco

Beilstein J. Org. Chem. 2021, 17, 1981–2025, doi:10.3762/bjoc.17.129

Graphical Abstract
  • are ideal probes to study polysaccharides at the molecular level and identify structure–property correlations. Access to synthetic polysaccharides facilitated the correlation of chemical structure with molecular conformations [5][6], intermolecular interactions [7][8], and biological response [9
  • pattern by chemical synthesis, albeit in low yields. Selective disruption of intra- and intermolecular hydrogen bonds suggested that modifications can be designed to prevent precipitation and guide cellulose assembly. Xyloglucans Xyloglucans (XGs) are based on a β(1–4)-Glc backbone decorated with
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Published 05 Aug 2021

On the application of 3d metals for C–H activation toward bioactive compounds: The key step for the synthesis of silver bullets

  • Renato L. Carvalho,
  • Amanda S. de Miranda,
  • Mateus P. Nunes,
  • Roberto S. Gomes,
  • Guilherme A. M. Jardim and
  • Eufrânio N. da Silva Júnior

Beilstein J. Org. Chem. 2021, 17, 1849–1938, doi:10.3762/bjoc.17.126

Graphical Abstract
  • (Scheme 17C). The White group also reported a series of manganese-catalyzed intermolecular benzylic C(sp3)–H amination reactions using 2,2,2-trichloroethyl sulfamate (TcesNH2) and PhI(OPiv)2 as the oxidant (Scheme 18A and 18B) [131]. The manganese perchlorophthalocyanine [MnIII(ClPc)Cl] catalyst enabled a
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Published 30 Jul 2021

Development of N-F fluorinating agents and their fluorinations: Historical perspective

  • Teruo Umemoto,
  • Yuhao Yang and
  • Gerald B. Hammond

Beilstein J. Org. Chem. 2021, 17, 1752–1813, doi:10.3762/bjoc.17.123

Graphical Abstract
  • -dicarbonyl compounds using Selectfluor (16-3a) [61]. In 1995, the same group reported that Selectfluor reacted with quinuclidine to form N-fluoroquinuclidinium tetrafluoroborate in quantitative yield [62] (Scheme 35). They described this as a “transfer fluorination” since there was an intermolecular transfer
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Published 27 Jul 2021

Sustainable manganese catalysis for late-stage C–H functionalization of bioactive structural motifs

  • Jongwoo Son

Beilstein J. Org. Chem. 2021, 17, 1733–1751, doi:10.3762/bjoc.17.122

Graphical Abstract
  • [49]. To date, there are several examples of late-stage C–H amination methods that utilize iron and manganese as 3d transition metal catalysts [50][51][52]. However, intermolecular benzylic C–H amination has rarely been explored due to the challenges associated with selectivity and reactivity. In 2018
  • [104]. The manganese(I)-catalyzed intermolecular alkenylation of tryptophan-containing peptides 32 was performed under basic conditions, yielding hybrid peptides 34 without racemization, containing a trans-alkene linker bearing biologically active motifs in chemo- and site-selective manners assisted by
  • -NH tryptophan. Notably, alkenylative ligation of tryptophan-containing peptides and alkynes containing biomolecular motifs including sugar, menthol, or coumarin units was successful, delivering unprecedented hybrid complex peptides 34d–f in good yield. Based on the developed intermolecular process
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Published 26 Jul 2021

Cerium-photocatalyzed aerobic oxidation of benzylic alcohols to aldehydes and ketones

  • Girish Suresh Yedase,
  • Sumit Kumar,
  • Jessica Stahl,
  • Burkhard König and
  • Veera Reddy Yatham

Beilstein J. Org. Chem. 2021, 17, 1727–1732, doi:10.3762/bjoc.17.121

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  • generating oxygen-centered radicals, that lead to carbon-centered radicals through intra/intermolecular hydrogen atom transfer (HAT) processes, radical decarboxylative or radical deformylation [57][58][59]. In continuation of our research interest on visible-light-driven cerium photocatalysis [59][65], we
  • involvement of possible intermolecular HAT or 1,2-HAT from the intermediate III to generate the product 2. Conclusion In summary, we have developed a catalytic aerobic oxidation of benzylic alcohols to the corresponding aldehydes without further oxidation and formation of benzoic acids. A variety of primary
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Published 23 Jul 2021

2,4-Bis(arylethynyl)-9-chloro-5,6,7,8-tetrahydroacridines: synthesis and photophysical properties

  • Najeh Tka,
  • Mohamed Adnene Hadj Ayed,
  • Mourad Ben Braiek,
  • Mahjoub Jabli,
  • Noureddine Chaaben,
  • Kamel Alimi,
  • Stefan Jopp and
  • Peter Langer

Beilstein J. Org. Chem. 2021, 17, 1629–1640, doi:10.3762/bjoc.17.115

Graphical Abstract
  • attributed to intermolecular charge transfer between the oxygen lone pair electrons and the quinoline core. The unsubstituted derivative 4a presents an onset of absorption (λonset) at 389 nm and its optical band gap was deduced to be around 3.18 eV. Tetrahydroacridines 4e and 4f showed approximately the same
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Published 16 Jul 2021

A recent overview on the synthesis of 1,4,5-trisubstituted 1,2,3-triazoles

  • Pezhman Shiri,
  • Ali Mohammad Amani and
  • Thomas Mayer-Gall

Beilstein J. Org. Chem. 2021, 17, 1600–1628, doi:10.3762/bjoc.17.114

Graphical Abstract
  • is imine–enamine-tautomerized to afford the intermediate 27. Then, the final triazole compound, as major isomer, is achieved through an intermolecular cyclization process and elimination of one unit of TsNH2 [23]. A general strategy was described for the synthesis of 1,4,5-trisubstituted glycosyl
  • catalyst with the corresponding acetylide by using LiOt-Bu. Further intermolecular [3 + 2]-cycloadditions of azide 67 with intermediate 70 affords a 5-copper(I)-substituted triazolide intermediate 71. The oxidative addition of 1-bromoalkyne 68 forms an alkyne–Cu(III)Br–triazole complex intermediate 72
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Published 13 Jul 2021

Copper-mediated oxidative C−H/N−H activations with alkynes by removable hydrazides

  • Feng Xiong,
  • Bo Li,
  • Chenrui Yang,
  • Liang Zou,
  • Wenbo Ma,
  • Linghui Gu,
  • Ruhuai Mei and
  • Lutz Ackermann

Beilstein J. Org. Chem. 2021, 17, 1591–1599, doi:10.3762/bjoc.17.113

Graphical Abstract
  • remarkable robustness of the copper-promoted C−H activations with alkynes, we became interested to explore the working mode by a set of experiments. To this end, electron-poor arenes inherently reacted preferentially in intermolecular competition experiments (Scheme 4a). This observation could be explained
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Published 08 Jul 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
  • ), and notably, hydroalkylation products were produced from α-aryl ketones, from more acidic substrates like 4a, and from α-alkyl ketones, including the less activated methyl ketone 4c. Examples of intermolecular hydroalkylations of olefins using Pd were much scarcer than their intramolecular
  • counterparts, and so therefore are examples of quaternary centers generated by this means. The tendency of σ-alkylpalladium complexes to undergo a β-hydride elimination process is the major obstacle associated with the development of successful methodologies to promote intermolecular hydroalkylation of
  • after the nucleophilic addition as a stable bis-5,5-palladacycle (A), thereby preventing the β-hydride elimination step and allowing its further reaction with a proton to yield intermolecular hydroalkylation products (Scheme 5) [35]. In that work, the authors considerably expanded the scope of suitable
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Published 07 Jul 2021

Photoinduced post-modification of graphitic carbon nitride-embedded hydrogels: synthesis of 'hydrophobic hydrogels' and pore substructuring

  • Cansu Esen and
  • Baris Kumru

Beilstein J. Org. Chem. 2021, 17, 1323–1334, doi:10.3762/bjoc.17.92

Graphical Abstract
  • physical adsorption/releasing performance being under the control of intermolecular interactions. Hydrophobization might enhance the hydrophobic interactions between the dye core and the polymer network, thus releasing can be achieved in a longer term. As a last simulative experiment, cation (K+, Ca2+, Mg2
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Published 21 May 2021

Structural effects of meso-halogenation on porphyrins

  • Keith J. Flanagan,
  • Maximilian Paradiz Dominguez,
  • Zoi Melissari,
  • Hans-Georg Eckhardt,
  • René M. Williams,
  • Dáire Gibbons,
  • Caroline Prior,
  • Gemma M. Locke,
  • Alina Meindl,
  • Aoife A. Ryan and
  • Mathias O. Senge

Beilstein J. Org. Chem. 2021, 17, 1149–1170, doi:10.3762/bjoc.17.88

Graphical Abstract
  • CSD. In this study we have used the Hirshfeld fingerprint plots together with normal-coordinate structural decomposition and determined crystal structures to elucidate the conformation, present intermolecular interactions, and compare respective contacts within the crystalline architectures
  • -substituted porphyrins were investigated. Hirshfeld fingerprints [26] were obtained to elucidate the intermolecular interactions and compare the respective contacts. Hirshfeld surface analysis (HSA) displayed that H···H, X···C, and X···H (where X is a halogen atom) interactions vastly contribute to the
  • in the NSD where the overall profiles are similar to compound 6, in the IP with only a small difference observed in the OOP due to a shift from the Eg(x) to the Eg(y) closer aligned to compound 4. To elucidate the intermolecular interactions, the Hirshfeld surface analyses were obtained (Supporting
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Published 14 May 2021

Synthesis of multiply fluorinated N-acetyl-D-glucosamine and D-galactosamine analogs via the corresponding deoxyfluorinated glucosazide and galactosazide phenyl thioglycosides

  • Vojtěch Hamala,
  • Lucie Červenková Šťastná,
  • Martin Kurfiřt,
  • Petra Cuřínová,
  • Martin Dračínský and
  • Jindřich Karban

Beilstein J. Org. Chem. 2021, 17, 1086–1095, doi:10.3762/bjoc.17.85

Graphical Abstract
  • desolvation penalty associated with binding of hydrophilic natural carbohydrates [8], and (2) create additional contacts with the binding cavity via electrostatic and dipolar interactions with C–F bonds [9][10], new intermolecular hydrogen bonds [11], or rearrangement of hydrogen bond-mediating water
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Published 11 May 2021

Microwave-assisted multicomponent reactions in heterocyclic chemistry and mechanistic aspects

  • Shivani Gulati,
  • Stephy Elza John and
  • Nagula Shankaraiah

Beilstein J. Org. Chem. 2021, 17, 819–865, doi:10.3762/bjoc.17.71

Graphical Abstract
  • the involvement of an elementary formation of Knoevenagel adduct A from the reaction between the aldehyde and 11. This adduct undergoes an intermolecular Michael addition to naphthylamine resulting in the formation of B. A subsequent intramolecular nucleophilic cyclization leads C followed by
  • that employing indanedione as the cyclic diketone directed the formation of an aromatized molecule 139a instead of the expected spiro product. The authors rationalized 139a formation through a competitive intramolecular cyclo condensation over intermolecular cyclo condensation reaction with loss of
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Published 19 Apr 2021

Synthetic reactions driven by electron-donor–acceptor (EDA) complexes

  • Zhonglie Yang,
  • Yutong Liu,
  • Kun Cao,
  • Xiaobin Zhang,
  • Hezhong Jiang and
  • Jiahong Li

Beilstein J. Org. Chem. 2021, 17, 771–799, doi:10.3762/bjoc.17.67

Graphical Abstract
  • spectroscopy shows that phosphono radicals could proceed throughout the reaction. A halogen bond (XB) is a noncovalent interaction formed between a halogen atom and a neutral or negatively charged Lewis base. It is a kind of weak intermolecular interaction analogous to a hydrogen bond and basically can be
  • substrates under 23 W CFL (compact fluorescent lamp) irradiation, affording the desired imidazole derivative 10 by utilizing DMSO as the solvent at room temperature (Scheme 4). It is worth noting that, unlike most reported intermolecular electron-transfer via an EDA complex pathway, this approach transfers
  • -alkyl moiety in 31 or N,N-dimethylaniline (30). This approach utilizes N,N-dimethylaniline (30) as electron donor and N-methylmaleimide (31) as electron acceptor to form an EDA complex, so that single-electron transfer occurs under ultraviolet-light irradiation. Subsequently, intermolecular proton
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Published 06 Apr 2021

Effective microwave-assisted approach to 1,2,3-triazolobenzodiazepinones via tandem Ugi reaction/catalyst-free intramolecular azide–alkyne cycloaddition

  • Maryna O. Mazur,
  • Oleksii S. Zhelavskyi,
  • Eugene M. Zviagin,
  • Svitlana V. Shishkina,
  • Vladimir I. Musatov,
  • Maksim A. Kolosov,
  • Elena H. Shvets,
  • Anna Yu. Andryushchenko and
  • Valentyn A. Chebanov

Beilstein J. Org. Chem. 2021, 17, 678–687, doi:10.3762/bjoc.17.57

Graphical Abstract
  • . Synthesis of Ugi products 6, their structures and yields. Cyclization of Ugi-product 6aab with terminal alkyne fragment. The substrate scope of intermolecular cycloaddition. Optimizing the reaction conditions for IAAC on internal alkynes. Supporting Information Supporting Information File 68: General
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Published 08 Mar 2021

Amino- and polyaminophthalazin-1(2H)-ones: synthesis, coordination properties, and biological activity

  • Zbigniew Malinowski,
  • Emilia Fornal,
  • Agata Sumara,
  • Renata Kontek,
  • Karol Bukowski,
  • Beata Pasternak,
  • Dariusz Sroczyński,
  • Joachim Kusz,
  • Magdalena Małecka and
  • Monika Nowak

Beilstein J. Org. Chem. 2021, 17, 558–568, doi:10.3762/bjoc.17.50

Graphical Abstract
  • angles equal to 27.61 and 28.71°, respectively, and moreover, the methyl groups of the methoxy substituents are directed opposite and towards to the pyridin-2-yl substituents, respectively. The crystal structure of complex 17 is stabilized with a 3D intermolecular hydrogen bond network (Figure S1a
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Published 25 Feb 2021

Metal-free visible-light-enabled vicinal trifluoromethyl dithiolation of unactivated alkenes

  • Xiaojuan Li,
  • Qiang Zhang,
  • Weigang Zhang,
  • Jinzhu Ma,
  • Yi Wang and
  • Yi Pan

Beilstein J. Org. Chem. 2021, 17, 551–557, doi:10.3762/bjoc.17.49

Graphical Abstract
  • under irradiation of visible light [38]. In 2017, the photoredox-catalyzed intermolecular trifluoromethylthio–trifluoromethylation and thiosulfonylation reaction of unactivated alkenes have been respectively developed by Liu [34] and Xu [42]. Recently, Qing [43] and co-workers reported an efficient anti
  • substrate scope of the disulfides (Scheme 2). Using borate-substituted olefins, the intermolecular trifluoromethylthio–thiolation induced by the sequential radical difunctionalization proceeded smoothly in a chemoselective fashion. Both, with electron-withdrawing and electron-donating groups substituted
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Published 24 Feb 2021

Menthyl esterification allows chiral resolution for the synthesis of artificial glutamate analogs

  • Kenji Morokuma,
  • Shuntaro Tsukamoto,
  • Kyosuke Mori,
  • Kei Miyako,
  • Ryuichi Sakai,
  • Raku Irie and
  • Masato Oikawa

Beilstein J. Org. Chem. 2021, 17, 540–550, doi:10.3762/bjoc.17.48

Graphical Abstract
  • in small molecules and biomacromolecule due to intermolecular or intramolecular H-bonds and/or hydrophobic interactions [13]. Hydrolytic deprotections were finally examined to complete the synthesis. The previously employed alkaline hydrolysis (1 M aq LiOH, MeOH or THF, rt→45 °C) [4], however, gave
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Published 24 Feb 2021

Biochemistry of fluoroprolines: the prospect of making fluorine a bioelement

  • Vladimir Kubyshkin,
  • Rebecca Davis and
  • Nediljko Budisa

Beilstein J. Org. Chem. 2021, 17, 439–460, doi:10.3762/bjoc.17.40

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Published 15 Feb 2021

Helicene synthesis by Brønsted acid-catalyzed cycloaromatization in HFIP [(CF3)2CHOH]

  • Takeshi Fujita,
  • Noriaki Shoji,
  • Nao Yoshikawa and
  • Junji Ichikawa

Beilstein J. Org. Chem. 2021, 17, 396–403, doi:10.3762/bjoc.17.35

Graphical Abstract
  • specific problems in conducting these synthetic reactions for large scale production (Scheme 1). For example, the Mallory reaction [12], which is a widely used photocyclization in helicene synthesis [13][14], requires high dilution or excess amounts of oxidizing agents to suppress intermolecular side
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Published 09 Feb 2021

Regioselective chemoenzymatic syntheses of ferulate conjugates as chromogenic substrates for feruloyl esterases

  • Olga Gherbovet,
  • Fernando Ferreira,
  • Apolline Clément,
  • Mélanie Ragon,
  • Julien Durand,
  • Sophie Bozonnet,
  • Michael J. O'Donohue and
  • Régis Fauré

Beilstein J. Org. Chem. 2021, 17, 325–333, doi:10.3762/bjoc.17.30

Graphical Abstract
  • -based polysaccharides, such as arabinoxylans and arabinans. In this respect, Faes are important components of plant-cell-wall-degrading enzymatic arsenals since the hydrolysis of trans-ferulate–polysaccharide linkages contributes to the breakdown of intermolecular bonds that structure the
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Published 01 Feb 2021

19F NMR as a tool in chemical biology

  • Diana Gimenez,
  • Aoife Phelan,
  • Cormac D. Murphy and
  • Steven L. Cobb

Beilstein J. Org. Chem. 2021, 17, 293–318, doi:10.3762/bjoc.17.28

Graphical Abstract
  • characterization of intermolecular dynamic processes such as protein dimerization, oligomerization and fibrillation, even within large and especially complex systems [62][63]. In a recent study, Aramini et al. employed 19F NMR to investigate the conformational dynamics within the interacting interface of non
  • state that is apt to stabilize further intermolecular interactions and progress to the fibril state. The C-terminus non-amyloid component region, as monitored at position 133, was in comparison found to keep largely dynamically disordered in all species formed. Moreover, results from these studies
  • boosted the overall spectral sensitivity even when minimal protein concentrations were employed. The structural dynamics of the Myc-Max dimer formation were then evaluated by using intermolecular PREs between 19F‐Myc and three differently paramagnetic spin labelled MTSL ([(1-oxyl-2,2,5,5-tetramethyl-Δ3
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Published 28 Jan 2021
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  • element between S1 and T1 and ρFCWD is the Franck–Condon-weighted density of states, which can be expressed as [16]: where λ is the Marcus reorganization energy associated with the intermolecular and intramolecular low-frequency vibrations; kB is Boltzmann’s constant; and T is temperature. Combing
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Published 21 Jan 2021
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