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Search for "heating" in Full Text gives 1035 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.

Direct trifluoroethylation of carbonyl sulfoxonium ylides using hypervalent iodine compounds

  • Radell Echemendía,
  • Carlee A. Montgomery,
  • Fabio Cuzzucoli,
  • Antonio C. B. Burtoloso and
  • Graham K. Murphy

Beilstein J. Org. Chem. 2024, 20, 3182–3190, doi:10.3762/bjoc.20.263

Graphical Abstract
  •  1, entries 9–12). We attempted to decrease the reaction time by increasing the temperature, but these changes resulted in decreased yields of 3a (Table 1, entries 13 and 14). Surprisingly, when using microwave (MW) heating at 70 ⁰C for 10 min in ACN, product 3a was formed in 74% yield (Table 1
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Published 04 Dec 2024
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  • )rotaxane framework The rotaxane framework is often deployed as a molecular device in which the positional relationship between the axle and wheel is controlled by external stimuli [14][32]. Acid–base, photoisomerization, redox, ion recognition, solvent polarity, or heating treatment is generally used for
  • visible-light irradiation or heating, CD was moved back to the azobenzene moiety, and the entire process was reversible. This system was further developed in 2005 by introducing bipyridinium moieties to implement the selective transfer of the wheel via heating or light irradiation (Figure 5B) [57]. During
  • the urea end-capping synthesis method (Figure 9) [46][47]. First, [3]rotaxane 3 synthesized using 2-bromophenyl isocyanate (yield: 73%) was confirmed to be a size-complementary rotaxane whose desilippage was observed in a DMSO solvent by heating at approximately 80 °C (Figure 9A,B). As the
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Published 19 Nov 2024

Structure and thermal stability of phosphorus-iodonium ylids

  • Andrew Greener,
  • Stephen P. Argent,
  • Coby J. Clarke and
  • Miriam L. O’Duill

Beilstein J. Org. Chem. 2024, 20, 2931–2939, doi:10.3762/bjoc.20.245

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  • heated to temperature T2 (136–205 °C, see Supporting Information File 1) until 20–40% mass loss of original weight. Based on this data, the following decomposition mechanism is proposed (Figure 4a): MS, 1H and 31P NMR analysis after heating to T1 showed the presence of (methyloxycarbonylmethyl
  • ) results in (methoxycarbonyl(iodo)methyl)triphenylphosphonium salt 5 (observed by MS). Deiodination or decarboxylation from this intermediate afford 6 and 7, respectively. After heating to T2, (methyl)triphenylphosphonium salt 8 is observed, which may be formed from 6 and 7 by decarboxylation and loss of
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Published 14 Nov 2024

Recent advances in transition-metal-free arylation reactions involving hypervalent iodine salts

  • Ritu Mamgain,
  • Kokila Sakthivel and
  • Fateh V. Singh

Beilstein J. Org. Chem. 2024, 20, 2891–2920, doi:10.3762/bjoc.20.243

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  • -pulling groups at the para and meta-position of the aryl group were compatible with the reaction leading to moderate to good yields of products. In contrast, products with substitutions at the ortho position were obtained only after heating the reaction mixture to 60 °C. These compounds were further
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Published 13 Nov 2024

Multicomponent synthesis of α-branched amines using organozinc reagents generated from alkyl bromides

  • Baptiste Leroux,
  • Alexis Beaufils,
  • Federico Banchini,
  • Olivier Jackowski,
  • Alejandro Perez-Luna,
  • Fabrice Chemla,
  • Marc Presset and
  • Erwan Le Gall

Beilstein J. Org. Chem. 2024, 20, 2834–2839, doi:10.3762/bjoc.20.239

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  • species 2 were collected using a syringe and allowed to react with an amine 3 and an aldehyde 4 under moderate heating (Scheme 2). The multicomponent couplings proceeded smoothly, with an acceptable yield of the α-branched amine being obtained after 3 h at 50 °C. A range of secondary amines as well as
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Published 07 Nov 2024

Synthesis of tricarbonylated propargylamine and conversion to 2,5-disubstituted oxazole-4-carboxylates

  • Kento Iwai,
  • Akari Hikasa,
  • Kotaro Yoshioka,
  • Shinki Tani,
  • Kazuto Umezu and
  • Nagatoshi Nishiwaki

Beilstein J. Org. Chem. 2024, 20, 2827–2833, doi:10.3762/bjoc.20.238

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  • heating, acting both as base and acid. This dual role activates the amide moiety and the ethynyl group, respectively. Using larger amounts of ammonium acetate substantially prolongs the reaction time due to its dissociation properties. Consequently, the yield of 5a increased to 92% by increasing the
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Published 06 Nov 2024

Mechanochemical difluoromethylations of ketones

  • Jinbo Ke,
  • Pit van Bonn and
  • Carsten Bolm

Beilstein J. Org. Chem. 2024, 20, 2799–2805, doi:10.3762/bjoc.20.235

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  • footprint of organic reactions [12][13]. Beyond environmental benefits and enhanced human safety, mechanochemical reactions often feature shorter reaction times, eliminate the need for external heating, and offer alternative product selectivity [3][14]. In general, such reactions are characterized by the
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Published 04 Nov 2024

C–C Coupling in sterically demanding porphyrin environments

  • Liam Cribbin,
  • Brendan Twamley,
  • Nicolae Buga,
  • John E. O’ Brien,
  • Raphael Bühler,
  • Roland A. Fischer and
  • Mathias O. Senge

Beilstein J. Org. Chem. 2024, 20, 2784–2798, doi:10.3762/bjoc.20.234

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  • . Coalescence of the β-ethyl resonances was observed when heating the sample to 70 °C and the same 1H NMR spectrum was observed after subsequent cooling of the sample as before heating. This indicates the thermodynamically favored dimeric structure to reassemble when cooling, reverting to the previous NMR trace
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Published 04 Nov 2024

Transition-metal-free decarbonylation–oxidation of 3-arylbenzofuran-2(3H)-ones: access to 2-hydroxybenzophenones

  • Bhaskar B. Dhotare,
  • Seema V. Kanojia,
  • Chahna K. Sakhiya,
  • Amey Wadawale and
  • Dibakar Goswami

Beilstein J. Org. Chem. 2024, 20, 2655–2667, doi:10.3762/bjoc.20.223

Graphical Abstract
  • standing. Also, it has been reported that the generation of the hydroperoxide may be accelerated by heating the solvent under open atmospheric conditions [19]. We envisaged that such autooxidation of THF [20] will produce THF hydroperoxide, and this will facilitate the transformation of 3-arylbenzofuran-2
  • use of a hydroperoxide generating solvent made the protocol operationally simple. To investigate the generality of the protocol, the previously synthesized 3-arylbenzofuran-2(3H)-ones 3aa–ka were treated with 1.0 equiv Cs2CO3 in THF under open atmospheric heating. As revealed in Scheme 2, the reaction
  • a bulky substitution at the 7-position of the benzofuranone also hinders the formation of 2-hydroxybenzophenone, we prepared 3,7-diphenylbenzofuran-2-one (3ma). However, on heating 3ma with Cs2CO3 in THF, the corresponding benzophenone 4ma was obtained, which confirmed that a bulky substituent in
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Published 21 Oct 2024

Deciphering the mechanism of γ-cyclodextrin’s hydrophobic cavity hydration: an integrated experimental and theoretical study

  • Stiliyana Pereva,
  • Stefan Dobrev,
  • Tsveta Sarafska,
  • Valya Nikolova,
  • Silvia Angelova,
  • Tony Spassov and
  • Todor Dudev

Beilstein J. Org. Chem. 2024, 20, 2635–2643, doi:10.3762/bjoc.20.221

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  • upon heating. Conclusion Using experimental and computational methods as well as available literature data, the present study reliably estimates the number of water molecules present in γ-CD, their preferable binding position, and thermal stability. Comparison with the other cyclodextrins revealed that
  • Differential Scanning Calorimeter. The samples were placed in aluminum pans and heated in the temperature range between 300–440 K at a constant rate of 10 °C min−1 under pure nitrogen atmosphere. Similarly, thermogravimetric measurements were conducted using DTA/TG (TA-SDT 600) at the same heating rate and
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Published 17 Oct 2024

Efficient modification of peroxydisulfate oxidation reactions of nitrogen-containing heterocycles 6-methyluracil and pyridine

  • Alfiya R. Gimadieva,
  • Yuliya Z. Khazimullina,
  • Aigiza A. Gilimkhanova and
  • Akhat G. Mustafin

Beilstein J. Org. Chem. 2024, 20, 2599–2607, doi:10.3762/bjoc.20.219

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  • determined that room temperature is inadequate for fully oxidizing substrates. The optimal oxidation temperature for uracils 1 and 4 is between 60–65 °C, whereas for pyridines 7 and 9 it is 45 °C. Heating the reaction mixture at a temperature higher than the optimum level causes the substrates to be
  • % after 10 h of heating [36]. It is essential to include 2–3 equiv of H2O2 to obtain the best result (Table 4). The analysis of the results obtained from Table 3 and Table 4 indicates that the binary oxidation system of APS/H2O2 consumes APS more slowly and therefore the substrates (MU, TMU, and Py) are
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Published 16 Oct 2024

Base-promoted cascade recyclization of allomaltol derivatives containing an amide fragment into substituted 3-(1-hydroxyethylidene)tetronic acids

  • Andrey N. Komogortsev,
  • Constantine V. Milyutin and
  • Boris V. Lichitsky

Beilstein J. Org. Chem. 2024, 20, 2585–2591, doi:10.3762/bjoc.20.217

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  • the reactions that require heating. General experimental procedure for the synthesis of tetronic acids 4 A mixture of corresponding amide 3 (1 mmol) and 1,1-carbonyldiimidazole (0.49 g, 3 mmol) was stirred in acetonitrile (7 ml) for 5 min at room temperature, then DBU (0.17 g, 1.1 mmol) was added and
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Published 14 Oct 2024

Transition-metal-free synthesis of arylboronates via thermal generation of aryl radicals from triarylbismuthines in air

  • Yuki Yamamoto,
  • Yuki Konakazawa,
  • Kohsuke Fujiwara and
  • Akiya Ogawa

Beilstein J. Org. Chem. 2024, 20, 2577–2584, doi:10.3762/bjoc.20.216

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  • under transition-metal-free and open-air conditions. Conventional methods required photoirradiation or electrolysis to generate aryl radicals from triarylbismuthines. In this study, it was found that simply heating the solution of triarylbismuthines in benzotrifluoride (BTF) in air successfully led to
  • reaction conditions were harsh, requiring heating at 260 °C for several days [50]. Thus, only two examples of the use of triarylbismuthines as aryl radical sources have been reported for the synthesis of arylboronates, which proceeds under light irradiation conditions (Scheme 1a) [47][48]. Our group has
  • investigated various transition-metal-free methods for the generation of aryl radicals from shelf-stable aryl compounds (Scheme 1b). For example, the heating of arylhydrazine hydrochlorides (ArNHNH2·HCl) in the presence of base under open-air conditions successfully led to the generation of aryl radicals and
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Published 11 Oct 2024

Hypervalent iodine-mediated cyclization of bishomoallylamides to prolinols

  • Smaher E. Butt,
  • Konrad Kepski,
  • Jean-Marc Sotiropoulos and
  • Wesley J. Moran

Beilstein J. Org. Chem. 2024, 20, 2455–2460, doi:10.3762/bjoc.20.209

Graphical Abstract
  • ]. Iodoethane was also shown to be an effective reagent furnishing the product in up to 56% upon heating to 40 °C (Table 1, entries 11 and 12). It was envisaged that oxidation of iodoethane led to formation of oxidized forms of iodide by C–I-bond cleavage, therefore tetrabutylammonium iodide was utilized to see
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Published 30 Sep 2024

Deuterated reagents in multicomponent reactions to afford deuterium-labeled products

  • Kevin Schofield,
  • Shayna Maddern,
  • Yueteng Zhang,
  • Grace E. Mastin,
  • Rachel Knight,
  • Wei Wang,
  • James Galligan and
  • Christopher Hulme

Beilstein J. Org. Chem. 2024, 20, 2270–2279, doi:10.3762/bjoc.20.195

Graphical Abstract
  • increased the overall yield of the reaction (Table 1, entry 5). In summary, minimal formamide (1–2 equiv), excess [D2]-formic acid, and heating to 170 °C in a microwave reactor for 5 minutes is expected to give excellent yields in good deuteration %. A tentative mechanism to [D3]-formamides is shown in
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Published 06 Sep 2024

Heterocycle-guided synthesis of m-hetarylanilines via three-component benzannulation

  • Andrey R. Galeev,
  • Maksim V. Dmitriev,
  • Alexander S. Novikov and
  • Andrey N. Maslivets

Beilstein J. Org. Chem. 2024, 20, 2208–2216, doi:10.3762/bjoc.20.188

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  • 0.267/0.305) substituents reacted with primary and secondary alkylamines, requiring prolonged heating and a 1.5 excess of amine (Scheme 4), to give meta-substituted arylamines in reasonable synthetic yields. In the case of 1,3-diketone 1d, the addition of molecular sieves is necessary in order to reduce
  • reaction of 1,3-diketones 1e and 1f with aliphatic amines was expected. Indeed, the reaction of 1,3-diketones 1e or 1f with benzylamine was sluggish, and a number of undefined side-products were formed (LC control). m-Isoxazole arylamine 3ea was isolated in low yield (21%) after heating for 6 days (Scheme
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Published 02 Sep 2024

O,S,Se-containing Biginelli products based on cyclic β-ketosulfone and their postfunctionalization

  • Kateryna V. Dil and
  • Vitalii A. Palchykov

Beilstein J. Org. Chem. 2024, 20, 2143–2151, doi:10.3762/bjoc.20.184

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  • using simplest heating in acetic acid (Table 1, entries 13–16). After some playing with temperature, reaction time, and ratio of starting reagents we ultimately found conditions (AcOH, 110 oC, 4 h) suitable best for our chemistry and leading to the yield of the target product 2a 74% (Table 1, entry 16
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Published 27 Aug 2024

Efficacy of radical reactions of isocyanides with heteroatom radicals in organic synthesis

  • Akiya Ogawa and
  • Yuki Yamamoto

Beilstein J. Org. Chem. 2024, 20, 2114–2128, doi:10.3762/bjoc.20.182

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  • –heteroatom bonded compound (E–E) upon heating or photoirradiation. Similarly, E• adds to 1 to form 2, which undergoes atom (or group)-transfer from E–E to give the 1,1-addition product 4 with regeneration of E• [17][18]. In method 3, the photoinduced redox reaction of a heteroatom compound takes place using
  • methods, methods 1 and 3 require the addition of a radical initiator and a photocatalyst, respectively. In contrast, method 2 does not require any additive, although, if the heating or photoirradiation is performed by electricity, the combustion of fossil fuels may cause environmental pollution. However
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Published 26 Aug 2024

From perfluoroalkyl aryl sulfoxides to ortho thioethers

  • Yang Li,
  • Guillaume Dagousset,
  • Emmanuel Magnier and
  • Bruce Pégot

Beilstein J. Org. Chem. 2024, 20, 2108–2113, doi:10.3762/bjoc.20.181

Graphical Abstract
  • their ability to be engaged in such a rearrangement [4][5]. Upon activation with trifluoromethanesulfonic anhydride and under heating, we showed their transformation to ortho thioethers with a fairly acceptable selectivity towards the pathway of sulfilimine synthesis (Scheme 1b). Following our seminal
  • Discussion We started our optimization with the reaction between acetonitrile and phenyl trifluoromethyl sulfoxide (1a, Table 1). We firstly chose the same stoichiometry as described in our previous study and tried to reduce the reaction time by the help of microwave heating (Table 1, entry 1). Under these
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Published 23 Aug 2024

Computational toolbox for the analysis of protein–glycan interactions

  • Ferran Nieto-Fabregat,
  • Maria Pia Lenza,
  • Angela Marseglia,
  • Cristina Di Carluccio,
  • Antonio Molinaro,
  • Alba Silipo and
  • Roberta Marchetti

Beilstein J. Org. Chem. 2024, 20, 2084–2107, doi:10.3762/bjoc.20.180

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Published 22 Aug 2024

Multicomponent syntheses of pyrazoles via (3 + 2)-cyclocondensation and (3 + 2)-cycloaddition key steps

  • Ignaz Betcke,
  • Alissa C. Götzinger,
  • Maryna M. Kornet and
  • Thomas J. J. Müller

Beilstein J. Org. Chem. 2024, 20, 2024–2077, doi:10.3762/bjoc.20.178

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Published 16 Aug 2024

Understanding X-ray-induced isomerisation in photoswitchable surfactant assemblies

  • Beatrice E. Jones,
  • Camille Blayo,
  • Jake L. Greenfield,
  • Matthew J. Fuchter,
  • Nathan Cowieson and
  • Rachel C. Evans

Beilstein J. Org. Chem. 2024, 20, 2005–2015, doi:10.3762/bjoc.20.176

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  • pattern to that of the native, E isomer (Figure 2). Changes occur immediately, after 1 s of X-ray exposure, and saturate after ca. 5 s. The changes are comparable to those observed on Z–E isomerisation induced using blue (460 nm) light or heating to 55 °C but occur at a much faster rate (Figure S2
  • the micelle shape of this isomer. The fast rate of the morphology change, in comparison to using blue light or heating to 55 °C, shows rapid rates of Z–E isomerisation from X-ray-induced catalysis, which may be due to the presence of multiple different catalysing species and therefore isomerisation
  • that Z–E isomerisation cannot be easily induced using gentle heating or visible light, as shown by the stability of the UV–vis absorbance spectra and SAXS patterns under these conditions (Figures S1 and S3, Supporting Information File 1). In contrast, irradiation with X-rays leads to significant
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Published 14 Aug 2024

Harnessing the versatility of hydrazones through electrosynthetic oxidative transformations

  • Aurélie Claraz

Beilstein J. Org. Chem. 2024, 20, 1988–2004, doi:10.3762/bjoc.20.175

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  • prepared prior to the electrolysis through the condensation of 2-hydrazinopyridine 13 and various aromatic, aliphatic and α,β-unsaturated aldehydes 14. The electrooxidative transformation was performed under constant current at 7 mA in a mixture of acetonitrile and water under heating. From a mechanistic
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Published 14 Aug 2024

Negishi-coupling-enabled synthesis of α-heteroaryl-α-amino acid building blocks for DNA-encoded chemical library applications

  • Matteo Gasparetto,
  • Balázs Fődi and
  • Gellért Sipos

Beilstein J. Org. Chem. 2024, 20, 1922–1932, doi:10.3762/bjoc.20.168

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  • )acetate at the bottom of the vial after a few hours of storage in the fridge. The solid can be easily re-dissolved by gentle heating, and without affecting the product concentration and integrity. After a brief screening, Pd(dba)2 and X-Phos (in a 1:2 ratio) were selected as the catalyst system for the
  • screening and rapid optimization [46][47]. Homogenous heating and mixing in flow reactors can lead to higher reaction rates and yields. In terms of photochemistry, continuous flow setups provide enhanced light irradiation as well [48][49]. These advantages make flow chemistry a powerful tool for chemical
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Published 08 Aug 2024

Access to 2-oxoazetidine-3-carboxylic acid derivatives via thermal microwave-assisted Wolff rearrangement of 3-diazotetramic acids in the presence of nucleophiles

  • Ivan Lyutin,
  • Vasilisa Krivovicheva,
  • Grigory Kantin and
  • Dmitry Dar’in

Beilstein J. Org. Chem. 2024, 20, 1894–1899, doi:10.3762/bjoc.20.164

Graphical Abstract
  • tested in a previous study [3]. The reaction requires rather severe heating under microwave irradiation (200 °C, chlorobenzene, sealed vial), ensuring complete conversion of the diazo compound in a rather short time. Initial experiments using p-anisidine as a nucleophile showed that the target β-lactam
  • derivative 3a could be obtained in high yield (83%) after simple chromatographic separation of the reaction mixture (Scheme 2). When the synthesis was carried out using conventional heating in 1,2-dichlorobenzene (200 °C, 1 h), product 3a was obtained in slightly lower yield (75%), so further experiments
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Published 05 Aug 2024
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