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Search for "halide" in Full Text gives 359 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.

Oxetanes: formation, reactivity and total syntheses of natural products

  • Peter Gabko,
  • Martin Kalník and
  • Maroš Bella

Beilstein J. Org. Chem. 2025, 21, 1324–1373, doi:10.3762/bjoc.21.101

Graphical Abstract
  • discussed in more detail and illustrated by specific examples. 1.1 C–O bond-forming cyclisations 1.1.1 Intramolecular Williamson etherifications: Discovered by Alexander Williamson in 1850, this reaction is an SN2 substitution in which a leaving group, typically a halide or sulphonate ester, is displaced by
  • addition of the aryl halide, the disubstituted oxetane product is generated by a reductive elimination. Finally, the two catalytic cycles are closed by an oxidation/reduction process: the Fe(II) species is reoxidised by atmospheric oxygen and the Ni(I) complex is reduced by the added manganese powder. In
  • groups including esters, ketones, sulphones and heteroaryls. The mechanistic proposal, supported by DFT calculations, starts with an oxidative decarboxylation to give an aminooxetanyl radical 157. This species is in turn coupled with the aryl halide by the active Ni(0) catalyst (generated in situ by
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Published 27 Jun 2025

Recent advances in oxidative radical difunctionalization of N-arylacrylamides enabled by carbon radical reagents

  • Jiangfei Chen,
  • Yi-Lin Qu,
  • Ming Yuan,
  • Xiang-Mei Wu,
  • Heng-Pei Jiang,
  • Ying Fu and
  • Shengrong Guo

Beilstein J. Org. Chem. 2025, 21, 1207–1271, doi:10.3762/bjoc.21.98

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  • direct activation of unactivated alkyl bromides through a visible-light-induced Pd(0)/Pd(I) catalytic cycle, which circumvents the conventional requirement for external photoredox catalysts or high temperatures. This strategy expands the scope of alkyl halide functionalization and highlights the
  • Scheme 50, involves single-electron reduction of the halomethane at the cathode, generating a halomethyl radical and a corresponding halide ion. The halomethyl radical is then captured by the acrylamide, leading to intramolecular radical cyclization. Final oxidation and deprotonation steps afford the
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Published 24 Jun 2025

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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  • in situ nitro reduction using Mn powder to afford the amide intermediate 42. The acid halide once again was applied for cinnamic acid amidation. Xiao and co-workers (2021) performed a transesterification and aminolysis of the tert-butyl ester 43 simply by using PCl3 through in situ generation of the
  • scaled up to a gram scale. Uozumi and co-workers (2019) reported a carbonylation under aqueous flow conditions using alkenyl halide 240 to prepare cinnamic acid (7) catalyzed by an amphiphilic polystyrene-poly(ethylene glycol) resin-supported Pd-diphenylphosphine catalyst (cat 6) (Scheme 65A) [31]. Also
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Published 28 May 2025

On the photoluminescence in triarylmethyl-centered mono-, di-, and multiradicals

  • Daniel Straub,
  • Markus Gross,
  • Mona E. Arnold,
  • Julia Zolg and
  • Alexander J. C. Kuehne

Beilstein J. Org. Chem. 2025, 21, 964–998, doi:10.3762/bjoc.21.80

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  • the time that they remain in their enantiopure state. The glum as a measure for the strength of CPL is of order 8 × 10−4 for PTM and 5 × 10−4 for TTM. Mixed halide triarylmethyl radicals Substitution of all para-positions in PTM with iodine atoms yields the 3I-PTM radical with a red-shifted emission
  • )methyl (TTBrM) radical exhibits λem = 593 nm and ϕ of 0.8% (in dichloromethane-solution, at room temperature) [50][51]. Functionalization of TTM in the para-position has also been achieved with a pseudo-halide, namely a nitrile group. While the absorption and emission spectra are slightly
  • orange for chlorine, and to red for bromine [6][57]. This shift can be explained by the decreasing electronegativity of the halide substituents. The more electronegative fluorine will reduce the HDMO energy more strongly than the bromine, while the SOMO remains energetically almost unaffected, explaining
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Published 21 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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  • formation of intermediate Int-87 via oxidative addition. Rapid coupling with the in situ-generated acyl radical produces copper-bound intermediate Int-88. Base-mediated anionic exchange then displaces the halide ligand with amine, yielding intermediate Int-89. Final reductive elimination from this species
  • affords amide product 91 with concurrent regeneration of the catalyst Int-83. Notably, a competitive pathway emerges through alternative reactivity of Int-88 (path c). The coordinated CO ligand undergoes nucleophilic attack by the amine, bypassing halide exchange to instead generate Int-86. This
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Published 07 May 2025

Unraveling cooperative interactions between complexed ions in dual-host strategy for cesium salt separation

  • Zhihua Liu,
  • Ya-Zhi Chen,
  • Ji Wang,
  • Qingling Nie,
  • Wei Zhao and
  • Biao Wu

Beilstein J. Org. Chem. 2025, 21, 845–853, doi:10.3762/bjoc.21.68

Graphical Abstract
  • the dual-host strategy were aimed at separating alkali metal halide salts from aqueous solutions into organic phases, including KCl, CsCl, and CsNO3 [23][24][25][26][27][28][29]. In these studies, 18-crown-6 was commonly utilized, and various anion receptors were selected to achieve tailored anion
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Published 29 Apr 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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  • tendency for hydro-dehalogenation. Tetrabutylammonium halide was chosen as the electrolyte due to its lower hygroscopicity and reduced tendency for reductive homocoupling of 4-bromobenzotrifluoride. In the presence of chlorinated substituents, neither the double coupling product nor the hydro
  • carbonyl group. The halide salts did not lead to product formation, indicating that chloride and bromide anions cannot generate the corresponding radicals to accelerate the conversion of diphenylphosphine. The reaction yield decreased when the methyl group was placed in ortho-position. Moreover, the
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Published 16 Apr 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

Graphical Abstract
  • 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

Synthesis of N-acetyl diazocine derivatives via cross-coupling reaction

  • Thomas Brandt,
  • Pascal Lentes,
  • Jeremy Rudtke,
  • Michael Hösgen,
  • Christian Näther and
  • Rainer Herges

Beilstein J. Org. Chem. 2025, 21, 490–499, doi:10.3762/bjoc.21.36

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  • cross-coupling reactions were performed by an organic halide reacting with an organotin compound. A great advantage of the used organostannanes is the easy accessibility, and their high air and moisture stability, so that usually a wide range of functional groups can be introduced under mild conditions
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Published 04 Mar 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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  • groups Directing from glycosylation with glycosyl halide donors by Fischer [72] and Michael [73] and later modified by Koenigs and Knorr [74], there have been reports of the synthesis of a wide range of glycosides involving the Walden-type inversion in the anomeric position. This concept of Walden
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Published 17 Feb 2025

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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  • those that lead to α-alkyl-substituted compounds, is still challenging [27]. For example, in the SN2 reaction of alkyl halides with sulfoxonium ylides, the initially formed α-alkyl-substituted ylide reacts further with the halide to expel the sulfoxide and ultimately generate an α-halogenated product
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Published 04 Dec 2024

Hypervalent iodine-mediated intramolecular alkene halocyclisation

  • Charu Bansal,
  • Oliver Ruggles,
  • Albert C. Rowett and
  • Alastair J. J. Lennox

Beilstein J. Org. Chem. 2024, 20, 3113–3133, doi:10.3762/bjoc.20.258

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  • firstly through the coordination of an alkene by the HVI reagent, which activates it toward intramolecular attack by an internal nucleophile. Following this, substitution of the iodane(III) can occur from the nucleophilic halide in solution to reveal the halo-cyclised product (Figure 2). In this review
  • , we have collected and described the HVI-mediated halocyclisation reactions reported in the literature for each halide. We have organised the examples firstly by the halide nucleophile, and then secondly by the internal heteroatom nucleophile involved in the cyclisation. The selectivity (chemo-, regio
  • is an important approach that yields a broad variety of heterocycles under mild and efficient oxidative conditions. The internal nucleophile, length of the carbon chain and halide can be designed such that a very broad range of 5-, 6- and 7-membered heterocycles can be accessed. The identity of the
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Published 28 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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  • group from position 4, and then regioselective vicinal functionalization of the generated aryne. The method's compatibility with halide-substituted aryl compounds enhances its versatility and practicality. Moreover, the completion of reaction within a mere 40 minutes at room temperature underscores its
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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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  • 64% yield (Table 1, entry 8). Finally, CsCl was substituted by silica, which, to our surprise, blocked the product formation completely (Table 1, entry 9). Apparently, the presence of an alkali halide salt was beneficial, most likely by stabilizing the consistency of the reaction mixture leading to a
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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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Published 09 Oct 2024

Synthesis and conformational analysis of pyran inter-halide analogues of ᴅ-talose

  • Olivier Lessard,
  • Mathilde Grosset-Magagne,
  • Paul A. Johnson and
  • Denis Giguère

Beilstein J. Org. Chem. 2024, 20, 2442–2454, doi:10.3762/bjoc.20.208

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  • orbitals. Keywords: organofluorine; pyran inter-halide; solid-state conformation; solution-state conformation; Introduction Polyfluorinated pyran analogues of carbohydrates have attracted attention over the years. This class of glycomimetics has great biological potential with useful applications [1][2
  • ][3][4][5][6][7]. What about other halogens? Pyran inter-halide analogues of carbohydrates were rarely investigated as new tools in glycobiology [8]. This is surprising since the incorporation of halogens can improve cellular uptakes and enhance membrane binding and permeation [9][10][11]. In addition
  • , halogen bonding is an important interaction in biological systems [12][13][14][15][16][17] and the beneficial effect of the chloro substituent has been reviewed recently [18]. As a result, there is a lack of efficient synthetic strategies to access multivicinal inter-halide stereocenters (i.e., contiguous
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Published 27 Sep 2024

Evaluating the halogen bonding strength of a iodoloisoxazolium(III) salt

  • Dominik L. Reinhard,
  • Anna Schmidt,
  • Marc Sons,
  • Julian Wolf,
  • Elric Engelage and
  • Stefan M. Huber

Beilstein J. Org. Chem. 2024, 20, 2401–2407, doi:10.3762/bjoc.20.204

Graphical Abstract
  • donors [16][17] from our group as well as of dicationic N-heterocyclic-substituted monodentate catalysts by Nachtsheim [15]. While such compounds are necessary to activate neutral substrates in more challenging reactions, monodentate and monocationic congeners provide sufficient activation in halide
  • halide abstraction is the crucial step towards the formation of a catalytically active gold species [18][19]. Furthermore, iodonium species 1BArF–4BArF have been shown to be halide abstracting agents in the Ritter-type solvolysis of α-methylbenzyl bromide and via the crystal structures of 1Cl, 2Cl, and
  • 3Cl which resulted from crystallization of the respective cation with the abstracted chloride from the Ritter-type solvolysis of benzhydryl chloride [13]. The crystal structure of 5Br was also obtained directly from the halide-abstraction reaction (see Supporting Information File 1). These three facts
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Published 23 Sep 2024

Electrochemical allylations in a deep eutectic solvent

  • Sophia Taylor and
  • Scott T. Handy

Beilstein J. Org. Chem. 2024, 20, 2217–2224, doi:10.3762/bjoc.20.189

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  • , J = 16.5, 1H), 6.25 (dd, = 6.54, 15.78 Hz, 1H), 5.90–5.79 (m, 1H), 5.22–5.15 (m, 2H), 4.36 (q, J = 5.85, 1H), 2.41 (q, J = 8.94, 2H). Influence of electrode material. Aldehyde variations. Halide variations. Recycling for the allylation of p-anisaldehyde in TBAB/EG DES and Sn electrodes. Tin metal
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Published 02 Sep 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

Graphical Abstract
  • the blue region. This complex then accelerates the oxidative addition of the aryl halide to the metal, which is usually the rate-limiting step for palladium-catalyzed cross-couplings. Based on these results we decided to perform all Negishi reactions under blue light irradiation. With the optimized
  • conditions in hand, we proceeded with the investigation of the heteroaryl halide scope in batch (Scheme 3). Thiazoles proved to be challenging substrates typically affording the desired products in moderate yields (2b–h). While 2-chlorothiazole led to the production of 2b in 44% yield, 2-bromo-5
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Published 08 Aug 2024

Methyltransferases from RiPP pathways: shaping the landscape of natural product chemistry

  • Maria-Paula Schröder,
  • Isabel P.-M. Pfeiffer and
  • Silja Mordhorst

Beilstein J. Org. Chem. 2024, 20, 1652–1670, doi:10.3762/bjoc.20.147

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  • pathways Methyltransferases can be classified based on various factors, such as their substrates (small molecule MTs, protein MTs, or RNA/DNA MTs), the atom that accepts the methyl group (oxygen = O-MTs, nitrogen = N-MTs, carbon = C-MTs, sulphur = S-MTs, or halide = H-MTs), metal or cofactor dependence
  • atom, describing O-, N-, C-, and S-MTs; halide MTs have not (yet) been identified in RiPP pathways. The enzymes described below are either conventional SAM-dependent MTs or radical SAM (rSAM) MTs; rSAM MTs are one subfamily of the large rSAM enzyme superfamily, which encompasses enzymes catalysing a
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Published 18 Jul 2024

Tetrabutylammonium iodide-catalyzed oxidative α-azidation of β-ketocarbonyl compounds using sodium azide

  • Christopher Mairhofer,
  • David Naderer and
  • Mario Waser

Beilstein J. Org. Chem. 2024, 20, 1510–1517, doi:10.3762/bjoc.20.135

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  • catalyst/DBPO combinations next (Table 1, entries 5–10), showed that the reaction requires a quaternary ammonium halide containing an easily oxidizable counter anion, i.e., iodide or bromide (Table 1, entries 5 and 7). No product formation was observed in the absence of any catalyst (Table 1, entry 6) or
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Published 05 Jul 2024

A comparison of structure, bonding and non-covalent interactions of aryl halide and diarylhalonium halogen-bond donors

  • Nicole Javaly,
  • Theresa M. McCormick and
  • David R. Stuart

Beilstein J. Org. Chem. 2024, 20, 1428–1435, doi:10.3762/bjoc.20.125

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  • halogen-bond formation by the linear combination of the % p-orbital character on the halogen and energy of the σ-hole on the halogen-bond donor. Keywords: aryl halide; diarylhalonium; halogen; halogen bond; non-covalent interaction; Introduction Halogen bonding has emerged as an important attractive
  • pentafluorophenyl halide series with chloride anion (Scheme 4c, 49–52). A similar trend for decreasing bond length with increasing van der Waals radii has also been observed for some [38], though not all [39], series of chalcogen bonds. Generally, shorter bonds are stronger and longer bonds are weaker, and the
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Published 27 Jun 2024

Synthesis of substituted triazole–pyrazole hybrids using triazenylpyrazole precursors

  • Simone Gräßle,
  • Laura Holzhauer,
  • Nicolai Wippert,
  • Olaf Fuhr,
  • Martin Nieger,
  • Nicole Jung and
  • Stefan Bräse

Beilstein J. Org. Chem. 2024, 20, 1396–1404, doi:10.3762/bjoc.20.121

Graphical Abstract
  • the pyrazole tautomerism [28], the formation of two possible regioisomers, 17 and 18, was anticipated and could be confirmed experimentally. Depending on the employed halide 16, the distribution of the obtained products varied. A considerable excess of the dominating isomer with yields of up to 70
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Published 20 Jun 2024

Generation of alkyl and acyl radicals by visible-light photoredox catalysis: direct activation of C–O bonds in organic transformations

  • Mithu Roy,
  • Bitan Sardar,
  • Itu Mallick and
  • Dipankar Srimani

Beilstein J. Org. Chem. 2024, 20, 1348–1375, doi:10.3762/bjoc.20.119

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  • terminal arylalkynes bearing electron-donating and electron-withdrawing substituents were well compatible with this method. The procedure is limited to electron-withdrawing and electron-neutral aryl halides. The presence of a conjugated substituent in the p-position of an aryl halide is crucial for
  • metallaphotoredox catalysis (Scheme 19). Therein, alcohols were activated by the use of NHC salts. This activation facilitated the construction of C–C bonds when combined with aryl halide coupling partners. A diverse array of alcohols and various medicinally important aryl and heteroaryl halides reacted well in
  • avoid the use of various halide-based reactants but also opened up C–O bond activations in terms of alcohol and acid functionalizations, choice of reactants, etc. Consequently, in this review, we focused on the advancements in photocatalytic alkyl and acyl radial generation from alcohols and acids. It
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Published 14 Jun 2024

Rhodium-catalyzed homo-coupling reaction of aryl Grignard reagents and its application for the synthesis of an integrin inhibitor

  • Kazuyuki Sato,
  • Satoki Teranishi,
  • Atsushi Sakaue,
  • Yukiko Karuo,
  • Atsushi Tarui,
  • Kentaro Kawai,
  • Hiroyuki Takeda,
  • Tatsuo Kinashi and
  • Masaaki Omote

Beilstein J. Org. Chem. 2024, 20, 1341–1347, doi:10.3762/bjoc.20.118

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  • and Discussion Methodology development In our work towards Rh-catalyzed homo-coupling reactions of benzyl halides, we observed that a similar rhodium–bis(benzyl) complex can also be formed from benzyl halide by using a Grignard reagent instead R2Zn in the presence of RhCl(PPh3)3 to subsequently give
  • RhCl(PPh3)3 in THF as shown in Scheme 3. In addition, similar reactions using 4-fluorobenzyl bromide (1b) or 4-bromobenzyl bromide (1c) gave the desired dibenzyl products 2b (85%) or 2c (90%) along with 3a in 64% or 54% yield, respectively. Mechanistically, the benzyl halide works as an oxidizing agent
  • yields, especially 1,2-dibromoethane was the best oxidant. The reaction proceeded in good yield, even if 0.5 equiv of 1,2-dibromoethane were used in this reaction, as shown in Table 1, entries 7 and 8. However, it has been confirmed that this reaction did not proceed when no alkyl halide was added to the
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Published 12 Jun 2024
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