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Search for "deprotonation" in Full Text gives 545 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.

Recent advances in synthetic approaches for bioactive cinnamic acid derivatives

  • Betty A. Kustiana,
  • Galuh Widiyarti and
  • Teni Ernawati

Beilstein J. Org. Chem. 2025, 21, 1031–1086, doi:10.3762/bjoc.21.85

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Published 28 May 2025

Recent total synthesis of natural products leveraging a strategy of enamide cyclization

  • Chun-Yu Mi,
  • Jia-Yuan Zhai and
  • Xiao-Ming Zhang

Beilstein J. Org. Chem. 2025, 21, 999–1009, doi:10.3762/bjoc.21.81

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  • of the resulting acyliminium [30]. Unlike the monocyclization, which involves deprotonation of the acyliminium ion, the success of this polycyclization relies on the interception of the acyliminium ion by an aryl nucleophile, resulting in the formation of N-heterocyclic fused[6,6,5]tricycles
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Published 22 May 2025

Recent advances in controllable/divergent synthesis

  • Jilei Cao,
  • Leiyang Bai and
  • Xuefeng Jiang

Beilstein J. Org. Chem. 2025, 21, 890–914, doi:10.3762/bjoc.21.73

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  • follows a concerted metalation–deprotonation (CMD) mechanism to generate ruthenium intermediate Int-75. Subsequently, diazo compound 78 or 79 coordinates with intermediate Int-75, followed by deazidation to form the ruthenium carbenoid species Int-76. The ruthenium–aryl bond in this intermediate migrates
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Published 07 May 2025

Recent advances in the electrochemical synthesis of organophosphorus compounds

  • Babak Kaboudin,
  • Milad Behroozi,
  • Sepideh Sadighi and
  • Fatemeh Asgharzadeh

Beilstein J. Org. Chem. 2025, 21, 770–797, doi:10.3762/bjoc.21.61

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  • proceeded via the anodic oxidation of diarylphosphines to diarylphosphine oxides, followed by further anodic oxidation to give phosphine oxide radicals. In the subsequent step treatment of alkoxide radicals (formed via the deprotonation of alcohols with cesium carbonate and anodic oxidation), the phosphine
  • oxidation of phosphines to phosphine oxides, followed by further anodic oxidation to give a phosphine oxide radical. In the subsequent step, treatment of the thiol radical (formed via the deprotonation of thiols with cesium carbonate and anodic oxidation) with the phosphine oxide radical gave the
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Published 16 Apr 2025

Entry to 2-aminoprolines via electrochemical decarboxylative amidation of N‑acetylamino malonic acid monoesters

  • Olesja Koleda,
  • Janis Sadauskis,
  • Darja Antonenko,
  • Edvards Janis Treijs,
  • Raivis Davis Steberis and
  • Edgars Suna

Beilstein J. Org. Chem. 2025, 21, 630–638, doi:10.3762/bjoc.21.50

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  • initial deprotonation of carboxylic acid 9a by cathodically generated hydroxide is followed by anodic oxidation/decarboxylation of the formed carboxylate 9a-I to generate stabilized cation 9a-II. The latter undergoes intramolecular cyclization with the tethered N-nucleophile into cyclic aminal 6a. In a
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Published 19 Mar 2025

Formaldehyde surrogates in multicomponent reactions

  • Cecilia I. Attorresi,
  • Javier A. Ramírez and
  • Bernhard Westermann

Beilstein J. Org. Chem. 2025, 21, 564–595, doi:10.3762/bjoc.21.45

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  • be useful for metal activation of the C–H alkyne deprotonation. The use of dihalomethanes in these reactions provides a wide scope in terms of the type of alkyne and amine that can be employed (Scheme 22) [62][63][64][65][66][67][68]. In general, aromatic and aliphatic alkynes, even with electron
  • afford propargyl halide C. Finally, intermediate C reacts with the secondary amine to give the propargylamine product D. As outlined in the catalytic cycle, the presence of a base plays a dual role: co-activation of the alkynyl C–H bond through deprotonation and trapping of the HCl produced during the
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Published 13 Mar 2025

Electrochemical synthesis of cyclic biaryl λ3-bromanes from 2,2’-dibromobiphenyls

  • Andrejs Savkins and
  • Igors Sokolovs

Beilstein J. Org. Chem. 2025, 21, 451–457, doi:10.3762/bjoc.21.32

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  • Br(II) followed by subsequent deprotonation to generate radical B. A following disproportionation of radical B would lead to the formation of Br(III) species C (anodic oxidation cannot be fully excluded), which undergoes intramolecular SNAr-type substitution to form cyclic λ3-bromane 1a and
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Published 27 Feb 2025

The effect of neighbouring group participation and possible long range remote group participation in O-glycosylation

  • Rituparna Das and
  • Balaram Mukhopadhyay

Beilstein J. Org. Chem. 2025, 21, 369–406, doi:10.3762/bjoc.21.27

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Published 17 Feb 2025

Synthesis, structure, ionochromic and cytotoxic properties of new 2-(indolin-2-yl)-1,3-tropolones

  • Yurii A. Sayapin,
  • Eugeny A. Gusakov,
  • Inna O. Tupaeva,
  • Alexander D. Dubonosov,
  • Igor V. Dorogan,
  • Valery V. Tkachev,
  • Anna S. Goncharova,
  • Gennady V. Shilov,
  • Natalia S. Kuznetsova,
  • Svetlana Y. Filippova,
  • Tatyana A. Krasnikova,
  • Yanis A. Boumber,
  • Alexey Y. Maksimov,
  • Sergey M. Aldoshin and
  • Vladimir I. Minkin

Beilstein J. Org. Chem. 2025, 21, 358–368, doi:10.3762/bjoc.21.26

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  • decrease to normal values of 1800–2000 cm−1, indicating a complete inhibition of the ESIPT process. These spectral transformations are usually caused by the formation of a strong N–H(O–H)···CN− (F−) hydrogen bond up to deprotonation [28]. Using the principle of “relay recognition” [29], we investigated the
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Published 17 Feb 2025

Molecular diversity of the reactions of MBH carbonates of isatins and various nucleophiles

  • Zi-Ying Xiao,
  • Jing Sun and
  • Chao-Guo Yan

Beilstein J. Org. Chem. 2025, 21, 286–295, doi:10.3762/bjoc.21.21

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  • addition of Lewis base is needed. When triphenylphosphine or tri(n-butyl)phosphine were involved in the reaction, the similar SN2’ substitution of tri(n-butyl)phosphine with the elimination of carbon dioxide and tert-butoxide anion gives the phosphonium salt C. Then, the deprotonation of phosphonium salt C
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Published 06 Feb 2025

Visible-light-promoted radical cyclisation of unactivated alkenes in benzimidazoles: synthesis of difluoromethyl- and aryldifluoromethyl-substituted polycyclic imidazoles

  • Yujun Pang,
  • Jinglan Yan,
  • Nawaf Al-Maharik,
  • Qian Zhang,
  • Zeguo Fang and
  • Dong Li

Beilstein J. Org. Chem. 2025, 21, 234–241, doi:10.3762/bjoc.21.15

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  • intermediate D via intramolecular radical cyclization. A single-electron-transfer (SET) process then occurred between the radical B and the radical D, resulting in the generation of cationic intermediate E, difluoroacetate anion and PhI. Finally, the product 3a was obtained after the deprotonation by
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Published 30 Jan 2025

Cu(OTf)2-catalyzed multicomponent reactions

  • Sara Colombo,
  • Camilla Loro,
  • Egle M. Beccalli,
  • Gianluigi Broggini and
  • Marta Papis

Beilstein J. Org. Chem. 2025, 21, 122–145, doi:10.3762/bjoc.21.7

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  • corresponding saturated compounds. Subsequent nucleophilic addition of the cyclic vinyl ether to the iminium salt generates an intermediate XXI susceptible of intramolecular electrophilic attack to give a tricyclic structure XXII. The final deprotonation provides the desired product 24. The multicomponent
  • , results in a spiro-cyclized intermediate XLI that affords the final product by deprotonation and loss of the copper species. Four-component reactions Two different four-component procedures catalyzed by Cu(OTf)2 are reported in the literature, both to access 1,2,3-triazole derivatives. The first one is a
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Published 14 Jan 2025

Recent advances in organocatalytic atroposelective reactions

  • Henrich Szabados and
  • Radovan Šebesta

Beilstein J. Org. Chem. 2025, 21, 55–121, doi:10.3762/bjoc.21.6

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  • ) annulation of enals with ynamides 8 to afford axially chiral 7-arylindolines 9 was reported [20]. The reaction mechanism, rationalized by DFT calculations, is believed to occur through catalyst C3 activation of the substrate 8, dehydration, and deprotonation with tautomerization leading to the enamine
  • -Breslow-type intermediates with the chiral NHC-catalyst and subsequent deprotonation toward the nitrile product. Zhang, Wang, Ye, and co-workers utilized NHC-catalysis for the atroposelective synthesis of axially chiral diaryl ethers 59 and 61 [38]. This transformation was realized via desymmetrization of
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Published 09 Jan 2025

Non-covalent organocatalyzed enantioselective cyclization reactions of α,β-unsaturated imines

  • Sergio Torres-Oya and
  • Mercedes Zurro

Beilstein J. Org. Chem. 2024, 20, 3221–3255, doi:10.3762/bjoc.20.268

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  • the squaramide moiety and a nucleophile through deprotonation as Brønsted base. On the other hand, a chiral phosphoric acid provides a confined chiral environment where the reactants are approached, activating both the azadiene by interaction with the acidic hydrogen and a dienophile bearing a
  • catalysts are synthesized by joining together two fragments of cinchona alkaloids. In this manner, it is possible to obtain a symmetric catalyst, which can engage in hydrogen bonding interactions and deprotonation processes. Although they were originally used for Sharpless dihydroxylation, they have been
  • patterns and aryl R2 substituents led to the desired products. However, the presence of a cyclopropyl or isopropyl R2 substituent, led to a complex mixture of products (Scheme 15). In the mechanism proposed by the authors, (DHQ)2PHAL XIII provokes the deprotonation of the γ-nitro ketone at the α-position
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Published 10 Dec 2024

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

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  • deprotonation would complete the pathway. The alternative mechanistic proposal is an SN2 reaction [40][41][42] between 1a and the iodonium ion 2a’, which directly furnishes B without invoking halogen bonded adducts. To assess which of these mechanistic possibilities was more probable, we turned to computational
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Published 04 Dec 2024

Surprising acidity for the methylene of 1,3-indenocorannulenes?

  • Shi Liu,
  • Märt Lõkov,
  • Sofja Tshepelevitsh,
  • Ivo Leito,
  • Kim K. Baldridge and
  • Jay S. Siegel

Beilstein J. Org. Chem. 2024, 20, 3144–3150, doi:10.3762/bjoc.20.260

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  • 32.2 [4], respectively (Scheme 1) [5][6]. The reaction enthalpy for deprotonation of CpH is ca 20 kcal/mol less endothermic than DPMH and ca. 24–27 kcal/mol less endothermic than 1,4-pentadiene (PDH; pKa ≈ 35 in DMSO) [3], values strikingly similar to the resonance stabilization energy estimated for
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Published 02 Dec 2024

Advances in the use of metal-free tetrapyrrolic macrocycles as catalysts

  • Mandeep K. Chahal

Beilstein J. Org. Chem. 2024, 20, 3085–3112, doi:10.3762/bjoc.20.257

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  • [48]. Therefore, most of the work involving metal-free porphyrins is limited to investigations on N–H tautomerization and protonation–deprotonation studies [49][50][51][52]. However, there are several chemical tools to convert the planar geometry of porphyrins to nonplanar, such as functionalization
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Published 27 Nov 2024

Advances in radical peroxidation with hydroperoxides

  • Oleg V. Bityukov,
  • Pavel Yu. Serdyuchenko,
  • Andrey S. Kirillov,
  • Gennady I. Nikishin,
  • Vera A. Vil’ and
  • Alexander O. Terent’ev

Beilstein J. Org. Chem. 2024, 20, 2959–3006, doi:10.3762/bjoc.20.249

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  • -AcrClO4 as the photocatalyst has been disclosed (Scheme 24) [67]. According to the authors, the irradiation of the photocatalyst (Acr+-Mes) A with a blue LED leads to the excited state (Acr·-Mes·+) B. The aliphatic carboxylic acid 66 is converted by deprotonation to the corresponding carboxylate, which is
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Published 18 Nov 2024

gem-Difluorovinyl and trifluorovinyl Michael acceptors in the synthesis of α,β-unsaturated fluorinated and nonfluorinated amides

  • Monika Bilska-Markowska,
  • Marcin Kaźmierczak,
  • Wojciech Jankowski and
  • Marcin Hoffmann

Beilstein J. Org. Chem. 2024, 20, 2946–2953, doi:10.3762/bjoc.20.247

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  • our laboratory, we have explored the synthesis of 3,3,3-trifluoro- and 2,3,3,3-tetrafluoro-N-substituted propanamides, contributing to the field of fluorinated amides [25]. We have also investigated deprotonation at the α position of other fluorinated carbonyl derivatives as a route to new building
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Published 15 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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  • from 6 on reacting with arynophiles 14 (Scheme 5) [59]. The reaction is unique due to its ability to functionalize position 3, despite its greater steric hindrance compared to position 5. The process involves deprotonation at the 3-position of the aryl(Mes)iodonium salts, followed by exit of a leaving
  • intermediate I. Furthermore, intermediate I subsequently undergoes another SET reaction, resulting in intermediate II and the regeneration of the photocatalyst. Intermediate II undergoes deprotonation, facilitated by the presence of Cs2CO3 as base, to yield the final products 27 or 29. Additives like BQ likely
  • assist in the deprotonation of intermediate II to produce final products 27, while K2S2O8 aids in the oxidation of the photocatalyst in the case of pyridine N-oxide. In another photoinduced reaction procedure, Murarka et al. reported the formation of aryl radicals from a tetrameric electron donor
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Published 13 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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  • with the generation of difluorocarbene from TMSCF2Br and KFHF. This is followed by a nucleophilic attack of the oxygen atom of ketone 1 on the difluorocarbene. Subsequently, a protonation–deprotonation sequence occurs, which can either be intermolecular, involving a molecule of HF, or intramolecular
  • isolating the low-boiling non-polar products. Mechanistic studies suggested that in situ-generated difluorocarbene reacts with the ketone oxygen, followed by intermolecular protonation/deprotonation. Although the process has still synthetic limitations, also acyclic ketones can now be converted into
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Published 04 Nov 2024

A review of recent advances in electrochemical and photoelectrochemical late-stage functionalization classified by anodic oxidation, cathodic reduction, and paired electrolysis

  • Nian Li,
  • Ruzal Sitdikov,
  • Ajit Prabhakar Kale,
  • Joost Steverlynck,
  • Bo Li and
  • Magnus Rueping

Beilstein J. Org. Chem. 2024, 20, 2500–2566, doi:10.3762/bjoc.20.214

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  • activate alcohols presents a significant synthetic challenge. The carbazate substrates are easily prepared from ubiquitous alcohol precursors. The first stage of the transformation involves the sequential anodic oxidation of the carbazate and subsequent deprotonation to form a diazenecarboxylate. Further
  • subsequent C–H abstraction. The methylarene undergoes oxidation, deprotonation, and a second oxidation before being captured by MeOH to produce a monomethoxylated product. This intermediate then undergoes a second oxidation round to yield the final product. Additionally, the same group disclosed an aromatic
  • direct activation of C(sp3)–H bonds under mild conditions [17]. The pronounced electron-deficient W2C nanocatalysts greatly facilitate the direct deprotonation process, ensuring the longevity of the electrode by overcoming self-oxidation. The LSF of drug molecules such as ibuprofen methyl ester and
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Published 09 Oct 2024

Photoredox-catalyzed intramolecular nucleophilic amidation of alkenes with β-lactams

  • Valentina Giraldi,
  • Giandomenico Magagnano,
  • Daria Giacomini,
  • Pier Giorgio Cozzi and
  • Andrea Gualandi

Beilstein J. Org. Chem. 2024, 20, 2461–2468, doi:10.3762/bjoc.20.210

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  • ) [23][24][25]. The nucleophilic attack of the nitrogen atom on the oxidized C=C double bond results in the formation of a radical intermediate after deprotonation. This radical intermediate can proceed through various pathways (e.g., HAT, oxidation) to yield the desired final product. In the
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Published 01 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

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  • amide at both the oxygen and the nitrogen, however, the ΔG‡ value for the latter was lower by 2.5 kcal·mol−1. This demonstrates a clear kinetic preference for formation of the five-membered ring over the seven-membered one [19]. Subsequent deprotonation of 11 leads to tertiary amide 12. Upon cyclization
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Published 30 Sep 2024

Facile preparation of fluorine-containing 2,3-epoxypropanoates and their epoxy ring-opening reactions with various nucleophiles

  • Yutaro Miyashita,
  • Sae Someya,
  • Tomoko Kawasaki-Takasuka,
  • Tomohiro Agou and
  • Takashi Yamazaki

Beilstein J. Org. Chem. 2024, 20, 2421–2433, doi:10.3762/bjoc.20.206

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  • products was concluded by the observed NOESY cross peaks between H2-H4 and H3-H4, clearly demonstrating the relationship between these three hydrogen atoms as cis. Formation of syn,syn-7a and -7b by the above tertiary amines would be mechanistically elucidated by the deprotonation of the most acidic H2
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Published 25 Sep 2024
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